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MICROHYDRO POWER PLANT, Future energy sources
Book · September 2018
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Preface
Praise to the presence of God Almighty over the abundance of His Blessings and Grace so that the writer can finish writing with the title "Micro Hydro Power Plant".
Maluku, is a province located in the eastern part of the archipelago in the Territory of the Republic of Indonesia needs attention to research on renewable energy sources, especially hydro power that can be utilized as small-scale power plants. Alternative energy sources, especially water energy if it can be mapped, must be a contribution to the region so that in the future it can also be integrated with other plants. Writing a book is part of an international journal that has been published and the attention of one of the book publishers for writers can publish the work of writing a book.
The author of this book is the first work in writing a book that can be used as a guide in learning to realize that in this paper there are still many that need to be refined so the riter desperately needs a lot of input to complete the lack in writing this thesis.
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Contents
__________________________
1. Introduction
1.1. Overview 6
2. Hydropower Basic 8
2.1. New renewable energy potential 8
2.2. Classification of Water Power Projects 9
2.3. Micro Hydro Technology 10
2.4. Working Principle of Micro Hydro Power 10
2.5. Power House 10
2.6. Method of measuring water discharge 11
2.6.1. Direct Debit Measurement: Dams Bend Method 11
2.6.2. Bucket Method 12
2.6.3. Indirect Debit Measurement 13
2.6.4. Floating Method 13
2.6.5. Current Meter 14
3. Potential Locations of Hydropower 16
3.1. Maps and Mapping 16
3.2. Coordinate system 16
3.3. Geographic information system 17
3.4. Determination of Village Location 18
3.5. Analysis of Satellite Imagery with Digital Elevation Model 18
3.6. Usage application DEM 19
3.7. Scientific Methods 20
3.7.1. Method of Measuring Water Debit 20
3.7.2. Rain Probability Method 22
3.7.3. Watersheds 23
3.7.4. Mainstay Debit 24
4. Civil Buildings 25
4.1. DAM Intake 25
4.2. The height of the Dam 25
4.3. Intake Structure 26
4.4. Settling Tub 27
4.5. Forebay 27
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4.6. Penstock 28
5. Electrical System 30
5.1. AC Generator 30
5.2. Transformator and Distribution 32
5.3. System Control 34
6. Mechanical System 34
6.1. Hydraulic Turbine 34
6.2. Turbine Impuls 34
6.2.1. Turbine Turgo 36
6.2.2. Turbine Cross Flow 36
6.3. Turbine Reaction 36
6.3.1. Turbine Propeller 37
6.3.2. Turbine Kaplan 37
6.4. Turbine Selection Criteria 37
6.5. High Waterfall 37
6.6. Range of Discharge Through Turbine 38
6.7. Turbine Efficiency 40
6.8. Electrical Equipment 40
7. Operation and Maintanace 41
7.1. Operation 41
7.2. Maintanace 44
7.3. Recording 44
8. Microhydro Power Management 45
8.1. Management 45
8.2. Planning 45
8.3. Organization 46
8.4. Briefing 46
8.5. Supervision 47
BIBLIOGRAPHY 48
AUTHOR BIOGRAPHY 50
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Chappter 1 Introduction
__________________________
1.1. Overvieuw
In Indonesia the provision of electrical energy is carried out by the State Electricity Company sourced from various types of power sources such as power plants, steam power plants and hydropower. However, the power of source is not yet able to reach the whole community as a whole, especially people living in remote rural areas.
The geographical condition of the Indonesian state, which consists of thousands of islands and islands, abandoned and not buried the center of power, low electricity demand in some areas, the high cost of building electricity supply system, and limited financial ability is an inhibiting factor for the supply of Electrical Energy on a national scale.
Fuel energy sources such as petroleum and coal certainly still have some weaknesses, such as non-renewable and pollutant or pollute the environment. This energy will be exhausted if the use is done continuously.
Geographically in the islands have the potential of a source of water energy for microhydro plants but not yet optimally utilized. The prospect of developing water resources has a great and strategic opportunity because it is a clean, environmentally friendly, and sustainable energy source so that its development will contribute greatly to the improvement of people's welfare, which means increasing the economic growth of the area.
As an effort to fulfill the need of electric power, the policy of utilization of water resources development potential is done with the aim that the management of regional potency can be utilized optimally. In this case will be studied the potential of water energy in order to be utilized as much as possible for microhydro power plant. On the other hand it can increase people's knowledge about small-scale power generation technology.
Micro hydro is one of the power plants that utilize small-scale water energy as a medium for generating electrical energy. Micro hydro is also an environmentally friendly powerhouse and does not cause air pollution.
This writing originated from the mapping of potential water energy sources given the unavailability of complete data on the potential of river water as a micro power plant. Mapping the potential of water energy for microhydro power plant is done by
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geographic information system which is computer based information system which is used to process and store data.
In the archipelagic region with a river whose water potential has not been studied to be utilized as a power plant. In addition, there are still villages or hamlets that have not enjoyed electricity like people in urban areas. One factor is that the community lacks the knowledge to harness the potential of the river as a renewable energy source for power generation.
If electricity is available in adequate quantities and quality in the village, it is expected to accelerate the economic recovery of communities that support the pace of development in various sectors. One of the obstacles in spurring the growth of regional development especially in rural areas is the unavailability of electricity facilities.
Therefore, in this research will be mapped water potential for microhydro power plant in Maluku islands, so that data will be obtained for its development in the future.
From the results of this mapping will be able to know the potential of water energy from the river that can be utilized as a small-scale power plant. Geographic Information System (GIS) is a computer-based information system designed to be used as a vehicle for capturing, storing, modeling, retrieving, manipulating, analyzing, and displaying georeferencing spatial data with map multiplication.
GIS mapping is a simple geographical map of the real-world location, then, a number of datasets are added to the base map to form an additional map layer. Users can change the amount of information they can see on the map, and zoom in and out.
The advantages of using GIS are geospatial data stored in standard format, easier revisions, geospatial data and information more easily searched, analyzed and presented, geospatial data can be shared and exchanged freely.
Mapping in this research is more directed to mapping the potential of water energy for microhydro power plant or small-scale power plant. GIS mapping allows policymakers, utilities to determine which location is more appropriate for the development of water energy potential for micro power generation.
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Chapter 2
Hydropower Basic
___________________________
2.1. New renewable energy potential
Indonesia's vast territory contains various energy potentials that may be utilized as a source of electrical energy. Energy potential is primary energy or fossil energy such as petroleum, gas and coal and potential renewable energy or alternative energy such as water, geothermal, mini / micro hydro, solar power, wind power and even uranium.
The potential of hydro power throughout Indonesia is estimated to reach 845.00 million BOE, (Barrels of Oil Equivalent) equal to 75.67 GW. Of this amount, it can be used for 6,851.00 GWh with an installed capacity of 4,200 MW. This potential is spread in Papua, Kalimantan, Sumatra, Sulawesi, Java, Bali, West Nusa Tenggara (NTB), East Nusa Tenggara (NTT) and Maluku. Large-scale water use only 5.55%.
(Blue-Print PEN 2005-2025. Dep. ESDM)
According to the White Paper, the State Ministry for Research and Technology (2006), the use of renewable energy has not been large, except for hydropower, as its production costs have not been competitive compared to conventional energy.
Generally, the price of electricity generated from solar power plant, wind power plant, Geothermal and other renewable energy power plants is still higher than fuel oil (subsidized) except Hydroelectric power plant. Up to 2005, new and installed renewable energy capacity is only about 3.0% of the existing potential. 54 MW Hydroelectric power plant required a long-term national policy in the energy sector that can overcome some of the main challenges facing Indonesian society in realizing sustainable energy supply. The provision of sustainable energy includes the expansion of access to adequate, reliable and affordable energy supplies with due regard to all necessary energy infrastructure and environmental impacts. Therefore, it is necessary to conduct energy planning research that can provide certainty of sustainable energy supply.
Roadmap for microhydro sector development 2005 - 2025 refers to research and development, market opportunities, policies and initiatives involving government and industry roles. For research and development, the government's role is to develop locally generated MHP systems and control systems, develop efficient MHP turbines and develop a 750 kW capacity system, update potential hydroelectric power plant data in the area and make a feasibility study of hydroelectric power plant, industry role , development of turbines, generators and control systems hydroelectric power plant.
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For market opportunities, the government's role is to build an integrated information and information center at the provincial / district level as part of promotion, in collaboration with the banking and finance industries to encourage the funding of power industry based on hydroelectric power plant, the role of industry is to create a model of electricity business based on hydroelectric power plant good grid off (stand alone) and integrated with connected grid in cooperation with banks and financial institutions to achieve the target of 150 MW grid utilization, 50 MW off-grid grid installed. For policies and initiatives, the government's role is to set a target of 0.22%
utilization of MHP from a mix of national energy and industrial roles that provide inputs to the government to encourage the release of a more conducive financial support system for power generation under hydroelectric power plant.
2.2. Classification of Water Power Projects.
Water power projects are generally categorized into two parts:
1. Small water power 2. High water power
Some other countries follow different categories in setting the upper limit of small hydro power in the power range from 5-50 MW. But worldwide there is no consensus on the definition of hydropower. Some countries such as Portugal, Spain, Ireland, Greece and Belgium consider 10 MW as the upper limit of installed capacity.
In the UK the small hydro power limit is generally 20 MW. India established a hydroelectric project with a capacity of up to 20 MW as a small hydropower project.
Although several countries have different criteria for hydroelectric classification, the general classification of hydropower is as follows.
Table. 2.1. Classification of power capacity
Type Capacity
Big power More than 100 MW
Medium power 15-100 MW
Little power 1-15 MW
Mini hydro 200 kW – 1 MW
Micro hydro 5 kW – 200 kW
Pico hydro From a few hundred watts - 5 kW
Small hydroelectric centers are grouped according to head size or high plunge on turbines. The general classification is as follows.
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Table. 2.2. Classification of head
Type Head Range
Height Head Above 100 m
Middle Head 30 - 100 m
Low Head 2 - 30 m
2.3. Micro Hydro Technology.
Hydropower is a non-polluting and environmentally friendly renewable energy source. The power of water is based on a simple concept. The water moves around the turbine, the turbine converts the generator and generates electricity generators.
Many other components are used in the system but they all come from kinetic power in water movement. The use of water that falls from a height has long been used as an energy source. Renewable energy is the oldest known to man for the conversion of mechanical power and power generation
2.4. Working Principle of Micro Hydro Power
The power plant from the water depends on the combination of head and flow height.
Both must be available to generate electricity. Water is diverted from the river to the pipe, where it descends the hill and is directed through the turbine. The vertical / head drop creates pressure on the bottom of the pipe.
Pressurized water emerging from the end of the pipe creates the force that drives the turbine. The turbine in turn rotates and drives the generator in which electricity is generated. The water pressure or high drop is created by the difference in height between the water and turbine intake. The head can be expressed as distance, or as pressure.
The net head is the pressure that is available in the turbine during running water, which will always be smaller than the pressure when the flow of water is dead (head static) due to friction between the water and the pipe. The diameter of the pipe also affects the clean head. The discharge is the amount of water available, and expressed as the volume of cubic meters per second (m3/s), or liters per minute (l/s). The design flow is the maximum flow in which the hydro system is designed.
2.5. Power House
The role of a small hydropower scheme is to protect the electromechanical equipment that converts the potential energy of water into electricity. The number, type and strength of the turbo generator, head scheme and geomorphological configuration will determine the shape and size of the building.
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As shown in Figure below this the following equipment will be displayed at powerhouse in electric house.
Figure below this Is the schematic of the power plant for the low head scheme ? The substructure is the weir section that manifests the power flow with the vertical axis from the turbine to the generator.
In the medium and high head schemes, see Figure beside, the entry of the penstock and tailrace pipes to be flown to the turbine to the next generator to generate electricity.
2.6. Method of measuring water discharge
The design of the MHP scheme requires knowledge of the amount of discharge and change the flow time of the river in the selected location. The proposed river for the installation of MPH is very rare covered by hydrometric networks and data on the amount of river discharge is very rare available.
Although the technique of estimating discharge at the site without post measurement can be done but it is a must to measure the discharge at the site planned for at least a year or dry season. This will provide at least some data for reexamination hydrological calculations and discharge estimates. That may already exist from measurement measurements that are far from MPH locations where there are different flow patterns.
2.6.1. Direct Debit Measurement: Dams Bend Method
The dam method is used in small rivers (B <6 m) where construction the dam uses local materials (wood), because it is more economical. Once installed, dams are an easy way to record debit data over a period of months or even years without much effort, measuring stick measurements daily can be done by residents (eg teachers) or Officers at government posts and do not require expert presence.
The most commonly used dam is a sharp edge dam (Crested sharp) is square or V-shaped. The Vnotch Dam or Thomson weir is used for discharges ranging from 1 to 120 l / sec while weirs with weirs are used for discharges above 120 l / s. The water velocity approach should be low (<0.15 m / s);
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This can be obtained if the dam can create a small pond in the upstream. The basin and the channel / river side should be far enough away from the mud, So the formula for a full weir can get damaged.
The application boundaries for the Thomson weir are shortened as follows:
Fully Contarcted Thomson Weir hl / p < = 0.4
hl / B < = 0.2 0.05m< hl =0.38
P > = 0.45 m Bl > = 0.90 m
Square measurement dams (Rectangular Sharp-Crested Weir)
The weir width is chosen so that the h1 head stays within the limit shown below for all debits to be measured.
Rectangular sharp-crested Weir B – b >= 4hl
hl / p <= 0.5 hl / b <= 0.5 0.07 m <= hl <= 0.60 m
b >= 0.30 m p >= 0.30 m
The discharge through the sharp- crested rectangular weir is determined by the following formula :
5 .
2 1
3 2
e e
e gbh
C Q
Where :
Q = discharge in m³/s.
Ce = effectve discharge coefcient according to Table H4 below.
be = effectve crest width be = b + kb (with b = weir crest in m and kb = correcton factor according to Figure H5 below)
he = effectve head; he = h + 0.001 m (with h = head in m)
2.6.2. Bucket Method
This method is suitable for measuring small discharge until very small discharge (Q <5 l/s) Suitable for pico hydraulic installation; The full discharge of the river Q is
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directed inwards Bucket or bucket with known V [liter] volume and time t [second] for charging time. The formula for determining river flow is as follows :
t Q v
Calibrating the bucket is very important.
Use a bottle with a known volume and calculate the number of bottles you need to fill the container until the different marks. If there is a scale scale, weigh the bucket / bucket that contains the water and specify volume. 200 liters of oil drum can also be used for greater disposal (Q <50 l / s) but preparation (eg weir and tub) to direct Debits to the drums will take a long time.
2.6.3. Indirect Debit Measurement
Indirect debit measurement means the discharge is calculated from the flow rate The measured cross-section and river area use the formula as follows :
Vm
A Q *
Where :
Q = debit in m3 / st
A = the cross-sectional area in m2 Vm = average discharge rate in m/s
The cross-sectional area of the river can be estimated using The following methods :
select the straight cut from the river;
Stretching the transverse band of the river perpendicular to the direction of the current
(River line);
for the width of the river up to the same number of pieces;
Calculate the depth of the river at each point by using a soak tool and wading through the rod or measuring stick
Calculate the cross-sectional area using the Simpson’s Rule (integration by number)
2.6.4. Floating Method (Float Method)
This is the easiest method to determine the flow velocity. But this can only be used for deep river and the river is calm, because the error rate of fl oat method if used for shallow rivers (<30 cm) and rivers turbulence will range between +/- 100% or
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more this inaccuracy is gained from the unknown relationship between the surface discharge and the average discharge for the entire cross-sectional area. Floating objects must be partially submerged; The partially filled bottle will be is a good solution.
The following procedures should be used :
Measure the distance D is relatively straight and equal parts of the river and mark the beginning and end by stretching the rope or tape of the river (perpendicular to the stream)
Throw floating objects that are used to the river just above the starting point
Calculate time t in detk for distance D
Calculate vs surface velocity
t Vs d
Use the correction factor to change the surface discharge Vs the average river stream Vm
Surface discharge should be reduced by using the following factors:
0.85 for smooth stream, square concrete channel
0.75 for large, sluggish, clean river
0.65 for a small but regular river with a smooth river bed
0.45 for shallow turbulent river (0.5 m)
0.25 for the river is very shallow and rocky
measure the cross-sectional area at both ends of the D distance Materials needed for float method
1. Measuring tape
2. Rope (to be stretched across the river) 3. Leveling stick or rod
4. Floating objects (bottles with plugs) 5. Stop watch
6. Pocket calculator 7. Notes and pens
2.6.5. Current Meter
The current meter is an instrument that measures the speed of water Stream it by rotating elements. The rotating element is built so that the rotation speed has a relationship.
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Particular with the speed of water. By placing the current meter in on Flow and observe the number of rotation vanes over a certain time interval, The current flow rate can be determined from the meter calibration.
There are two main levels of current meters for general use; This type of propeller (Direct acting meter) which has a horizontal axis parallel to the river flow and type of bowl (in meters erental) which has a vertical shaft rotation. Both types have small scale models for small flow or laboratory applications. The propeller type is the most commonly used current meter.
The advantages of tpe propeller meter are :
1. This type is stronger and easier in shape than cup meter type.
2. This species is not polluted by floating objects.
3. Bearing meters are protected from water and mud.
4. On newer models; Bearings, shafts and propellers can be exchanged without changing the size of the meter
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Chapter 3
Potential Locations of Hydropower __________________________
Although the construction site has been identified, it is still necessary to first roughly check whether it is true that small-scale hydroelectric power plants close to the power demand area are possible and secondly, the generated power capacity can be secured and Where, then select potential locations among other candidates. In planning a fundamental work required references and information that can be used to determine the exact location for a plan.
Search location information can be done by using application program geographic information system to know the location of a village. This can happen if the location determination is not done directly in the field. On the other hand, the number of locations in a region is large enough, so the location of the village to be determined is only the part that can represent or represent all the locations in the region. Some of the obstacles encountered are geographical location or are among the islands, and have limited time and research costs.
3.1. Maps and Mapping
In general the map is a means to get a picture of scientific data contained on the surface of the earth by describing the various signs and descriptions so easy to read and understand. Thus, the map is the result of measurements and investigations conducted either directly or indirectly on matters relating to the surface of the earth and on a scientific basis.
Mapping is the activity of processing survey data to present it to geo-information. To create a mapping can be done in the laboratory / studio or in the field or by using software
3.2. Coordinate system
Coordinates are statements of geometric numbers that determine the position of a point by measuring the magnitude of a vector of a single item Coordinate is a geometric quantity statement that determines the position of a point by measuring the vector size to a predetermined reference position.
The introduction of coordinate system is very important in order to be able to use GPS optimally. There are at least two classifications about the coordinate system used by the GPS as well as in the mapping :
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1. The global coordinate system commonly referred to as geographic coordinates 2. Coordinate the system within the Projection field.
Some of the commonly used projection systems in Indonesia are: Marcator Projection, Mercer Tranverse, Mercer Tranverse Universal (UTM) and Conical cone.
Each of these systems has advantages and disadvantages, and projection selection is generally based on the purpose of the map to be made. The production map of the Hydraulic Oceanographic Service (dishidros) generally uses Tranverse Mercator projection with Geographic or UTM coordinate system. While the Bakosurtanal production map generally uses UTM projection.
The coordinate system in the projection field can not be separated from the datum used. There are two types of datum commonly used in horizontal datum mapping and vertical datum. Horizontal datum is used to determine the map coordinates (X.Y), while the vertical datum for the determination of elevation (topographic map) or depth (bathymetry map). The calculations are performed with a certain transformation, so that the transformation between the datum, between the projection system, and between the coordinate system can be performed.
3.3. Geographic information system
Geographic Information System (GIS) hereinafter referred to as GIS is a computer-based information system used to process and store data or geographic information. In general the notion is a component consisting of hardware, software, geographic data and human resources that work together effectively to incorporate, store, repair, update, manage, manipulate, integrate, analyze and display data in geographic-based information.
GIS has the ability to connect various data at a certain point on earth, combine it, analyze it and finally map out the results. Data to be processed in the GIS is spatial data which is geographically oriented data and is a location that has a certain coordinate system, as a reference base. GIS applications can answer some questions such as;
Locations, conditions, trends, patterns and modeling.
The advantages of Geographic Information System application are geospatial data stored in standard format, easier revision, the result has added value (graphic, depth of information), geospatial data and information more easily searched, analyzed and presented, increased and more efficient productivity, Geospatial data can be used together and exchanged freely, can be made better decisions. This ability differentiates GIS from other information systems.
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3.4. Determination of Village Location
The purpose of microhydro location identification is to know the location generating and supplying areas to evaluate eligibility project and get information for electrical plan. One from The most important activity in location identification is measuring Water and head release can be used for microhydro power plants.
The process of determining the village location is done by using a particular area map formatted on a graphical map, such as JPG or PNG.
The maps are then converted to spatial coordinate data through a digital / trace process, to obtain map data coordinated with earth (X, Y). After going through data transformation process, from coordinate data which not yet coordinate to data with georeference, then the data will be formatted in the form of file with shp extension (shapefile), which looks as shown in Figure, Then map file is inserted into screen GIS.
Once map data is entered, the Maluku map will appear on the GIS screen, as shown In the image as shown in the tool bar which is the identity of the tool, that's the tool part of the GIS used to identify the object or locale.
The identity tool, as shown in the picture is enabled to display the required object or village location. As an example of the above process, the village shown is Waesala village, West Seram regency, Central Maluku district, Indonesia.
The process of identifying the village location can be done for each region according to the required village location. Village location data is recorded in the table provided.
Each designated village location is made into the table. The village location will also be equipped with coordinate data for further processing.
3.5. Analysis of Satellite Imagery with Digital Elevation Model
The digital elevation model is a digital display of the surface of the earth. Viewed from the distribution of dots representing the shape of the earth's surface can be distinguished in the form of regular, semi-regular and random. While in terms of data collection can be distinguished in the measurement directly on the object (terestris), the measurement on the object model (photogrametris) and from analog map data source (digitasi). The point of demik of terestris, fotogrametris and digitization is by measuring on the object model, can be done if from the existing image can be reconstructed in the form of stereo model.
There are several definitions of DEM
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1. DEM is a data storage point about terrain topography. DEM represents the coordinate representation (X, Y, H) from digital points
2. DEM is a continuous representation of basic level statistics of known X, Y and Z coordinate points under certain conditions
3. DEM is a database with coordinates X, Y and Z, which are used to present the ground surface digitally.
3.6. Usage application DEM
DEM is used in a variety of applications both in the form of visualization of the ground surface model and with processed first into other products. The basic information provided by DEM and used in processing is the coordinate point on the ground surface.
Other information that can be derived from DEM are:
1. Distance on the relief or the shape of the ground surface 2. Surface area of an area
3.Volume excavations and heaps 4. Slope and aspect
5. Contours 6. Profile
Examples of applications that use DEM 1. Civil engineering
2. Hydrographic mapping 3. Topographic mapping
4. Geological and geophysical mapping 5. Mining engineering
6. Ground surface simulation and visualization
Digital elevation model analysis is used to obtain slope gradient data or to determine the height of falling water.
The color gradations in this image illustrate the high differences in each region. The difference in altitude between places and other places forms a slope or slope. Assessment of MPH development potential in Seram island and hunting can also be assessed to the slope of the soil or the slope of a region.
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The location of the microhydro potential is determined by the permanently flowing river and the slope of the stream suitable enough to produce the energy indicated by the MPH power calculation.
In the figure above, the incision is performed on one of the stream streams to determine the vertical profile known as the elevation gradient. The elevation gradient shown by the figure is 6.7 meters with a slope of 14.59 ° used as an effective water level elevation.
3.7. Scientific Methods
Scientific method is the step taken to obtain scientific results. The scientific method used in this research is as follows.
3.7.1. Method of Measuring Water Debit
Stream or discharge: Q (m3 / sec) is another important part in determining the power output of the MHP scheme. The amount of discharge in the MHP scheme is not the same as the total debit or maximum discharge that is in the river.
The debit is required to know the highest current limit at the lowest current occurring in the current. Variations in the number of discharges throughout the year and changes during the dry and dry seasons need to be known and analyzed carefully to determine the design debits to be applied in the system. Design discharge is usually set slightly above the minimum limit to maintain the performance and efficiency of generating equipment.
In practice there are various methods that can be used to determine the flow of water on an open channel, one method is the floating method (float method).
The float method is the easiest method to know the flow velocity. But this should be used only for deep streams and rivers with a calm flow, because the float error rate if used for shallow (<30 cm) and turbulent rivers will range between +/- 100% or more.
This inaccuracy is obtained from an unknown relationship between surface discharge and the average discharge for all cross sectional areas. Floating objects must drown some partially filled bottles would be a good solution
With this floating method some steps that must be done is :
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a. Determine the water flow velocity (V).
Average time is the result of the division between the total measurement time and the number of repeat measurements.
n Taverage
timeWhere :
Average T = Average time (seconds) Σ Time = Total Measurement Time N = Measurement Repeat
b. Flow Rate Calculation (V)
Calculate the velocity (V) by using the mean cross-sectional area variable (A) and the mean time (T) according to the formula.
Speed (V) is the result of the division between channel length / current (P) divided by the mean time (Taverage )
s T m
V P
average
/
c. Determining the cross-sectional area of the river (A).
To calculate cross section area (A) can use the following equation
) (m d x l A
Where :
A = cross-sectional area of river (m2) I = width river (meters)
D = average water depth (meters) d. Calculation of water discharge (Q)
The water debit (Q) is the result of multiplication between the cross-sectional area (A) of the stream and the flow rate of water (V).
s m A V
Q * 3 /
Where :
Q = Debit flow (m3 / sec)
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A = Area of cross section (m2) V = Water flow rate (m / sec)
3.7.2. Rain Probability Method
After rainfall for certain areas or areas, security factors are still needed to achieve better design results. The need for this security factor is due to consideration of what might happen in the future, which can not be ascertained when it will happen.
This security factor is known in statistical terms because of the possibility of recurring events or return periods. The return period is a hypothetical time where rain / debit of a certain amount will be the same or exceeded within that time period. (There is no understanding that the event will be repeated regularly for each return period).
In essence, the greater the repeated period, the security of designing the system to be better, although often requires a higher cost. The steps in the frequency analysis can be explained through the following figure.
There is one method for estimating rainfall with repeating periods in a given year, the Normal Distribution
S K X
X
T
T.
Where :
XT = approximate value occurring with T year return period X = Average value of rainfall data
S = standard deviation
KT = frequency factor, is an opportunity function or return period and a mathematical model type of opportunity distribution used for opportunity analysis.
The intensity of the rain plan is the amount of rainfall that occurs over a period of time.
While the intensity curve is the indentation of the relationship between drying time and rainfall intensity.
The synthetic rain intensity curve used when rainfall data is available is the maximum daily rainfall data. An equation that can be used to form an intensity curve is the following equation.
3 2 24
t 24 24 I R
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The intensity of rain indicates the amount of rain that falls in the watershed over time. To observe the intensity of rainfall that occurs in three watersheds, the calculation of intensity in each watershed. The calculations are performed according to the preceding rainfall plan, then the calculation results are entered into the IDF (Intensity Duration Function) curve.
Duration is the duration of a rain event. The high intensity of rain generally takes place with a short duration and covers an area that is not too wide. Rain that covers a large area, rarely with very high intensities but can last for a long duration.
To calculate or estimate the amount of water discharge that will occur in various recurring periods with good results can be done by analyzing the current data from the river in question. To calculate the water discharge can use the equation:
A I C Q 0 , 002778 . . .
Where :
Q = Water Debit (m3 / s)
C = run off coefficient = 0.15 (steep slope sand type) I = Rainfall Intensity (mm)
A = Watershed Area (km2)
The runoff coefficient (C) is the presentation of the amount of water that can melt through the soil surface of all falling rainwater in an area. The soil surface is more impermeable, the higher the current coefficient. The factors that influence the runoff coefficient value are soil conditions, infilation rate, land slope, plant cover and rain intensity.
The effect of land use on the surface stream is expressed in the surface flow coefficient (C), which is the number that shows the ratio between the surface flow and the amount of rainfall. Level of surface flow coefficient is one indicator to know the physical condition of a watershed. The value of C ranges from 0 to 1. The value of C
= 0 indicates that all rainwater is tapped and infiltrated into soil, whereas for C = 1 values indicates that rainwater flows as runoff
3.7.3. Watersheds
Watershed area (DAS) is a limited area of the topographical area of hill mountains where if the rain falls then the water flows into the river.
Factors determining the formation of a watershed are:
- Climate
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- Topography - Soil
- Geology - Land use
3.7.4. Mainstay Debit
Hydrological planning is always associated with the characteristics of the watershed. Rainfall and watershed characteristics greatly affect the flow conditions.
The fact of getting river flow data in many watershed areas is often incomplete. The availability of long-term river flow data at the site of the taking building is necessary for planning purposes of MHP. This is because the water building function depends heavily on water requirements throughout the season, so to get continuity of water supply according to the calculation planning required for reliable debit.
The expected release of the mainstay debit is always available throughout the year with the risk of failure being calculated as small as possible. Mainstay debit data is generally required for hydro-power plant development planning, namely to determine the calculation of water supply in building intake (intake).
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Chapter 4 Civil Buildings
__________________________
The main obstacle to the development of small-scale power generation is the high cost of development. In this chapter, technological elements are explained with the assumptions required to reduce the cost of civil construction (no explanation provided for the same use for designing a typical hydro power plant)
4.1. DAM Intake
There are several types of basic types and intakes as mentioned below : 1. Gravity concrete dam
2. Concrete floats dam 3. Land dam
4. Urugan stone dam 5. Wet rock masonry 6. Rock bronjong dam
7. Reinforced concrete bronjong stone dam 8. Twigs of wood dam
9. Wooden dam
10. Wood frame with kinky dam
From the above type, basically weirs and flexible stones and dam bronjong, etc..
It is well known in Southeast Asian countries because some of the advantages such as (i) are less affected by ground conditions basically and (ii) relatively easily repaired if damaged.
However, they can be penetrated by floods so that their structure and use should be preceded by careful testing of important constructions such as civil structures and undercurrent conditions.
4.2. The height of the Dam
Since the volume of the dam is proportional to the square of its height, it is important for that determine the height of the dam in terms of minimizing the following conditions into consideration.
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1. Conditions that limit channel height
To determine the height of the DAM, consider the condition topography and geology of channel pathways for additional materials consideration at the dam construction site. A careful examination is needed In locations where the calculation of the cost of waterway construction has a proportion of the total construction cost.
High dams at locations where waterways are built under existing roads, often determined by reference to the altitudes of the road in question.
2. The possibility of rising bottom of the river bottom
The height of dams for small-scale power plants is generally low, there is Attention to normal function can be disrupted by the upstream river flows. Therefore, the rise of the river floor in the future must be estimated determine the height of the dam if the planned location is in this case the following case.
a. The slope of the river is not too steep with the rate of change / Sediment movement is quite high
b. Presence of filled check dam, etc. Lower intake of dam Planned.
c. The existence of a damaged site downstream that is likely to continue suffered damage later on.
d. There is a narrow section in the downstream area that will block the current sediment and / or wood waste.
3. Influence on power generation
In locations where the use of small altitudes or where it is designed secure altitude with dam, high dam significantly affects the level of electrical energy generation. Based on this, it is necessary to determine the height of the dam at the site by comparing the expected changes in both construction and power generation costs due to the difference in the height of the dam.
4.3. Intake Structure
Generally there are three categories of intake structures :
1. Intake with free water level (Free water level)
The flow of water in the river is not dammed due to diversion (no weirs Transverse);
This category includes free consumption (also called edge intake) And the basic intake (also called the basic intake of the river or Tyrolean weir.
27 2. Intake with dense dam
The height of the water in the river is raised with dense crossed land There is a steady stream of intake throughout the year especially at this time low river flow.
3. Intake with a weir that can move
The face of the weir can be adjusted with a water gate or with a membrane that can be inflated so that the weir can be lowered during a flood. The dam pumps are expensive and needed only in flat areas where high river waterfalls will have extensive consequences (requires Long flood ditch to prevent water from flooding the upstream area). Dams like these are not relevant to the development of the MHP scheme.
4.4. Settling Tub
Many rivers and moats carry numerous sand and fine particles in the sediment, especially during floods. The sediment load can not be removed in the intake.
Tranquilizers are needed to reduce the sediment load to an acceptable level, operation of the problem-free MHP possible if the following conditions are met.
- There should be no sediment deposition on the carrier or any other place In the existing system
- Damage to turbine runners and valves due to abrasion must be maintained at that level low
4.5. Forebay
The upright shower is used to remove deep sand particles water. Complementary basin function is very important to protect MHP components due to sand / dirt / garbage impact. The tranquilizer function is to adjust the difference in the volume of the water output between the penstock and the headrace to be stable (balanced input and output) at a position with a certain height difference from the turbine position. And for the final separation of impurities in water such as sand, leaves and trees by pepohanan by using filtered water filters. The tranquilizer is the connecting medium between open channels connected to the dam with the penstock connected to the turbine
The overall depth of the forebay is determined by the minimum sinking (s) of the penstock inlet preventing air from entering the vortex.
The required sinking distance or water seal can be calculated using the given formula. The filter must be slightly tilted (between 60 ° to 75 ° with horizontal line) to facilitate cleaning with rake. The drain dump for floating debris and plator should be built right downstream of the filter so operators have easy access to clean the filter.
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Upholstery also protects the penstock channel so that no objects can fall into the penstock by children who play with rocks or marbles. The approximate speed of the trashrack should be less than 0.5 m / s.
The functions of a tranquilizer are as follows
Controls the difference of discharge in penstock and a carrier channel Due to load fluctuations
Last waste removal (soil and sand, floating wood, etc.) In flowing water
Keep penstock inlet still immersed in water (water seal) Important things to design a tranquilizer :
Detailed designs for a small hydroelectric tank on Essentially the same as a medium scale hydro power plant is
1. Includes water depth and mounting height of the penstock inlet
At small-scale hydroelectric diameter pipe is generally small (Usually 1.0 m or less), the penstock must be sufficient to secure the whole The water depth is equal to or greater than the diameter of the pipe. However, in the case of channels where the diameter of the pipe is rapid and the slope of the large Pipe as illustrated below, the occurrence of turbulence flow. Already explained before. While the entire water depth was decided Use the reference illustration below where the diameter inside the penstock added 1.0 m
2. Filter chamber suitable for turbine type,
The filter space (the effective size of filter filter) is approximately determined by the diameter of the valve but must still consider the type and dimensions of the turbine And the quantity because the quality of dirt / garbage can pass. The reference value of the effective size of the filter distance is described below.
3. Installing the vent pipe as a complement to the tranquilizer door
If installation of a tranquilizer door is made to a power plant, it is necessary Installation of a vent pipe behind the door of a sedative to prevent damage penstock channel.
4.6. Penstock
At present, the main material of fast pipe is steel pipe, ductile pipe and pipe FRPM (fiber reinforced plastic multi unit). While small-scale hydroelectric power plants use vinyl chloride pipes, coating pipes or spiral welding pipes can be considered because of their small internal diameter and pressure relatively low.
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Determining the Penstock Diameter
In general the pipe diameter is determined by comparison with the cost of fast pipe and the cost of losing the pipe head quickly. The penstock diameter can be determined by penstock average angle (see here's the picture) and design debit (Q).
Briefly, in the case of debit design (Qd) = 0.50m3 / s, penstock length (Lp) = 60m, Elevation of sedative to ower house (Hp) = 15m, average angle (Ap) = 15/60 = 0.25, the optimum velocity (Vopt) is determined around 2.32 at Reference 5-2. Thus the diameter of the penstock pipe (d) is :
d = 1.273 × (Qd／ Vopt)0.5 =1.273 × (0.5／ 2.32)0.5 = 0.59 m
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Chapter 5
Electrical System
__________________________
Almost all PLTMHs are built to generate energy Electricity, although there are some cases where PLTMH turbines are used directly to move the machine, such as a illing machine, or a water pump (waterSystem supply). Therefore, planning aspects of electricity play a very important role in the MHPP project. In addition, field surveys of the population (consumers) need to be done accurately, especially regarding the use of electricity. For the purposes produktf where will be used electric motor (load inductf) for example, it takes a generator with the ability to hold the startng current big.
Topography and population distribution play a key role in determining transmission network length. Mastery of the basic rules of electricity, installation and safety is The essentials of a planner and a technician should be involved Implementation of microhydro projects.
The components and electrical systems of MHP are the most sensitive components. Basically the components in the electrical system of microhydro generators can be grouped into the following :
5.1. AC Generator
The alternating current generator (AC) is often called a synchronous generator (Simultaneously) because the rotation speed of the magnetic field is equal to rotation speed of the rotor generator. A typical AC generator is also called an alternator Is an electric machine that serves to change the mechanical energy (motion) to alternating current of electrical energy (AC) with induction magnetic field.
This energy change occurs because of the relative movement between magnetic fields with a generator roll. Relative movement is the occurrence of field changes.
Magnets on the anchor coil (stator coil) which is the place. The voltage generated on the generator due to the movement of the magnetic field against. Stator coil or vice versa. This AC generator produces alternating electrical energy behind (AC) and usually produced to produce 1 phase or 3 phase AC power.
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Viewed from the position of the magnetic pole and the coil of the place the formation of GGL induction can be distinguished above the outer pole generator and the generator poles inside.
It is called an outside pole generator because its magnetic poles are deep stationary conditions (in the stator), whereas the GGL formation coil Induction in spinning conditions. And it is called internal pole generator because its magnetic pole is in rotating condition, whereas GGL Induction coil formation is in silent condition (in stator).
Judging from the number of turns, AC power plants can be distinguished above High rotary generator, medium rotary generator, and low rotary generator.
Called a high rotator generator because it reaches its own frequency determined (for Indonesia at 50 Hz), a large number of generator rotations are required in the case of 3000 rotations per minute (RPM) and the number of poles of 2 pieces.
Called a moderate rotary generator because to reach a predetermined frequency (50 Hz) required the number of generator turns in this case between 600 s / d 1500 RPM and the number of poles of 4 to 10 pieces.
The water turbine converts the water pressure into a shaft mechanical power, which can be used to rotate electric generators, or other machines. Available power is proportional to the result of high fall and flow rate.
This is indicated by the term efficiency, which uses the ratio between output power and input power (to produce a machine). Thus, the electrical output of the MHP scheme can be shown as follows.
] [
*
*
*
* H Q kW
g
Pe t g net Where :
Pe = power generator G = gravity = 9.81 ɳt = turbine efficiency
ɳg = efficiency of the generator H = high plunge (m)
Q = water discharge (m3 / sec)
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In addition there are several factors generator ratings, such as temperature, height, electronic controler correction factor, and load factor power. The coefficients for these factors are given in the following table.
Table 2.7. Rating Factor Generator Max. ambient
temperature in oC 20 25 30 35 40 45 50 55
Altitude 1000 1500 2000 2500 300
0
3500 4000 4500 A Temperatur Factor 1.10 1.08 1.06 1.03 1.00 0.96 0.92 0.88 B Altitude Factor 1.00 0.96 0.93 0.90 0.86 0.83 0.80 0.77
C ELC Correction Factor 0.88
D Power Factor When load is light bulbs only 1.0
When load includes tube light and other
inductive loads 0.8
The calculation to determine the generator size is based on the following formula :
] [kVA D
x C x B x A
Output Power
P Generator
Daya G
Where :
A (Temperatur Factor Altitude) B (Altitude Factor)
C (ELC Correction Factor) D (Power Factor)
Parameters A, B, C, D are predetermined nominal values that may affect the size of the generator capacity at the time of calculation using equation 2.9. Parameters A, B, C and D are determined with altitude in the study area 4000 m with a space temperature of 50o, so that the value of A has a temperature factor of 0.92, the value of B has a factor of height of 0.80, value C has an ELC correction factor of 0.88 and the D value has a 0.8 power factor.
5.2. Transformator and Distribution
Electric energy is generally generated by a powerhouse far from the urban center where customers are generally located. The problem now is how to distribute electric power economically at a considerable distance. In general it can be said that the power supply system consists of three elements, namely:
1. Power Plant 2. Transmission 3. Distribution
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In general, the location of the MHP is located quite far from the center of charge (consumer). Therefore the need for transmission and distribution systems in this case will be required. The transmission system needs to be well planned to meet the technical, safety and economic criteria. There are several things to note in the distribution system planning as follows.
Maximum allowable voltage variation of the no-load and full-load voltage
Maximum loss of permitted power
Protection from lightning and other damage
Stability of the structure in the state of strong winds (or in temperatures extreme;
hot, rain)
Security for human and work close to the network
One of the goals of transmission system planning is to know its size suitable conductors, to obtain power loss and cost estimates Needed.
Underground or overhead
More overhead networks are used, because by using air as cable insulation, cable is cheaper and installation costs are simpler easy. In many developing countries cables without insulation are more available than underground cables (underground).
Cables without insulation are more at risk of lightning and fallen trees. Area along the path the cable should be free of plants and should be checked periodically.
Electrical poles may have a limited lifespan and should be replaced perhaps around 15 years. In addition the overhead network is less efficient than underground for the specified conductor size, this is because the wide inter-conductor spacing increases the loss of inductif. Underground cables must be isolated and protected from ground motion, excavation of land, new buildings, etc. Once installed, the network should work without maintenance until the insulation material is damaged, usually longer than 50 years. Calculations for overhead and underground networks are basically the same. But the cost and maintenance implications should be considered.
Based on experience and some technical and economic aspects, for Indonesia better the overhead network used.
For high voltage transmission where the transformer is used to raise the voltage (step up) and transformer to lower the voltage (step-down). With a larger voltage the current flowing in the conductor is smaller so that smaller conductors can be used where the price will be cheaper. The cheaper price for a conductor is opposite to the price of two transformers required, one at the beginning of the transmission line and one at the end of the transmission line. Cost with high voltage system not only transformer but also transformer maintenance (isolation check and oil picker). In addition, more expensive insulation is required for placement of cables on the support poles. Conversely, low-voltage transmission without transformers is easier to manage
34
and manage by the local community. Generally it is found that low voltage transmission network more economical on high voltage for transmission lines less than 2 km. In general because the system is much simpler, low voltage system (LV) is preferred even for distances greater than 2 km. The danger with long distances is the low voltage at the end of the conductor (drop volt) to avoid this usually using a larger cable
5.3. System Control
The control system serves to balance the energy input and output energy by adjusting the input (flow) or adjust the output (electricity), so that the system will be balanced. With timely load changes, the role of the control system is critical to maintaining system stability, especially the quality of electricity generated by the generator (voltage and frequency).
The flow control can be defined as setting the amount of hydraulic power (discharge water) that goes into the turbine with the set turbine valve opening (guiding blades).
There are several things to note in the use of flow control for the system microhydro.
Because flow control is quite complicated and expensive for microhydro applications with a small strength of <100 kW, therefore the use of flow control is generally used in large plants> 100 kW.
Changes in consumer burden relatve small (stable). The flow control reaction to the load changes are relatively slow so there will be a surprise on the generator when large loads suddenly connected, resulting in reduced generator rotation so the voltage and frequency also decreases for some time (<1 minute) until the control flow reacts and the guiding blade opens according to the magnitude load installed.
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Chapter 6
Mechanical System
__________________________
6.1. Hydraulic Turbine
The purpose of a hydraulic turbine is to convert water energy into mechanical potential rotational energy. Although this book does not define guidelines for turbine design but can provide some criteria for choosing the right turbine with a variety of specific applications and can even provide the right formula for determining the primary dimension. All formulas use SI units and refer to IEC standards (IEC 60193 and 60041).
The potential energy of water is converted into mechanical energy in a turbine, with one of two basic mechanisms essentially different.
The water pressure can flow to the runner in the turbine. Turbines operating in this way are called reaction turbines. Turbine casing, with waterlogged runners should be strong enough to withstand surgical pressure. The Francis and Kaplan turbines fall into this category.
The water pressure is converted into kinetic energy before entering the runner.
Kinetic energy of high speed mounted on the edge of the runner. Turbines operating in this way are called impulse turbines. The most common impulse turbine is Pelton.
The hydraulic turbine power is given by the equation:
] [
*
*
* 81 ,
9 n H Q kW
Pt t net net Where:
Pt = Turbine Output [kW]
9.8 = Gravity
ɳt = turbine efficiency Hnet = High waterfall [m]
Qnet = water discharge [m3 / s]
6.2. Turbine Impuls
The impulse turbine is a water turbine that works by converting all water energy consisting of potential energy, pressure and available velocity into kinetic energy to rotate the turbine, generating torque energy.
36
6.2.1. Turbine Turgo
The Turgo turbine can operate on a head with a range of 50-250 m. Like Pelton, the water through the runner is at an angle of 20 °. In the picture below the runner can operate between 20% and 100% of the maximum design.
The efficiency of the turgo turbine is lower than that of Pelton and Francis (ESHA 2004). Compared to Pelton, the Turgo turbine has a higher rotational speed for flow and the same head. Turgo could be an alternative for Francis when the flow varies greatly
6.2.2. Turbine Cross Flow
The crossover turbine is also known as Banki-Michell which is used for various heads and can operate with heads between 5-200 m. The simple design of the turbine makes it cheap and easy to repair in case of runner problems due to mechanical pressure. Cross flow turbines have lower efficiency than other turbines. The distance between the runner and the head should be considered when there is a low or moderate head. In addition, on runners with high heads while using crosslink turbines may have some problems with reliability due to high mechanical stresses. Turbine turbine turbine operating range and other turbine types can be seen from the graph of water discharge charts Head vs Heading Operation Turbine Net air as follows.
From graphic images it is clear that cross flow turbines can operate at various discharges, compared to other turbine types such as Pelton and Turgo which operate only on the high head, or propellers and Kaplan at low head.
Similarly with the Francis turbine, the turbine cross flow operation area is wider.
6.3. Turbine Reaction
Turbine Reaction is a water turbine that works by converting all water energy into torque energy.
37
6.3.1. Turbine Propeller
Basically a propeller turbine consists of a propeller that resembles a ship's propeller, mounted in a tube after a fast pipe. The turbine shaft is connected out of the tube. The propeller turbine
typically has three to six blades, usually three blades for turbines with very low heads and a water flow arranged by a static blade or a goal gate mounted right upstream of the blades. This vane turbine is known as a fixed blade axial flow turbine because the angle of the rotor blade can not be changed. The efficiency of turbine operation on part-flow for this type of turbine is very low and is used for heads from 2 to 40 meters
6.3.2. Turbine Kaplan
For larger hydroelectric power plants use more sophisticated turbine turbines. In this turbine the propeller blades and the goal gates can be adjusted so that their efficiency when operating on low-load (part- flow) remains good. This variable turbine turbine is known as the Kaplan turbine
6.4. Turbine Selection Criteria
The type, geometry and dimensions of the turbine are essentially conditioned by the following criteria :
Height of the plunge (net head)
Range of discharge through turbine (discharge)
Rotation speed (rotation speed)
Problem of cavitation (cavitation problem)
Cost (cost)
6.5. High Waterfall
The first criterion to take into account the selection of turbines is a clean head. The table below determines the range of head operation for each type of turbine that can be used.
38
Table 6.1. Head Range.
Type Turbine Range Haed in meter
Kaplan and Propeller 2 < Hn < 40
Francis 25 < Hn < 350
Pelton 50 < Hn < 1300
Cros flow 5 < Hn < 200
Turgo 50 < Hn < 250
To obtain a clean head (Hn), the measurement data at the site is a dirty head where the vertical distance is between the water surface in the intake and in the turbine. While the head loss is the total loss of altitude caused by open channels, garbage racks, penstock length pipe, intake. The disadvantage is approximately or equal to 6% of the gross head (Hg). (Javed, 2010).
To calculate the net head (Hn) we can use the equation : ) (m H
H
Hn g losses
6.6. Range of discharge through turbine
Each turbine has an application with its own specific limit. It is possible that different types of turbines are feasible for the factory. Offers from different manufacturers should be compared first.
In many cases, economic onsiderations are very important in the selection of turbines. The etermination is not always clear and easy, and requires knowledge of the specific characteristics of the turbine.
