Ram Pump

And Solar Pump

Training

Fredrik Bjarnegard, Allen Chou, Sukon ”Tae” Phunpunyakorakul, Yotin Pupaolan, Salinee Tavaranan

A collaboration of BGET TOPS ZOA KNCE TBCAF GREEN EMPOWERMENT PALANG THAI

B G E TBORDER GREEN ENERGY TEAM

B G E TB G E TBORDER GREEN ENERGY TEAM

Contact Us at

Border Green Energy Team TOPS

34/53 Mae Sod – Mae Tao Rd Mae Sod, TAK 63110

055-542-068

Or

Border Green Energy Team c/o TOPS

PO Box 66 Mae Sod, TAK 63110

This manual is available at www.bget.org

List of contents Introduction............................................................................................................................................. 3

Water – the primary source of life........................................................................................................ 3 Different ways of pumping water ......................................................................................................... 3

Water Resources ..................................................................................................................................... 5 Surface water vs Groundwater.............................................................................................................. 5 Water Demand ...................................................................................................................................... 5 Water Storage ....................................................................................................................................... 6 Water Distribution ................................................................................................................................ 6

Solar pumping......................................................................................................................................... 8 The technology ..................................................................................................................................... 8 Performance........................................................................................................................................ 10 Designing a solar pumping system..................................................................................................... 11 Calculation example ........................................................................................................................... 11

Hydraulic ram pump............................................................................................................................ 13 Introduction......................................................................................................................................... 13 How a hydram works.......................................................................................................................... 13 Performance........................................................................................................................................ 15 Designing a hydraulic ram pump system............................................................................................ 16 Calculation example ........................................................................................................................... 17 Installation requirements .................................................................................................................... 18

References.............................................................................................................................................. 20 Appendix................................................................................................................................................ 21

Appendix A Formulae for Energy and Power............................................................................. 22 Appendix B Specification for Diesel Pump ................................................................................ 23 Appendix C Specification for Solar Panels................................................................................. 24 Appendix D Specification for Yeser 12 V DC water pump........................................................ 25 Appendix E Hydraulic Ram Pump Tuning................................................................................. 31 Appendix F 1” Ram Pump Test Results ..................................................................................... 33 Appendix G Steps in Installing Hydraulic Ram Pump System................................................... 40 Appendix H Problems and Solutions during Ram Pump Installation ......................................... 41

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Introduction

Water – the primary source of life Water is the primary source of life for mankind and one of the most basic necessities for rural development. Two-thirds of the world’s households use a water source outside the home1. Often it must be carried by hand, and since water is heavy it is very hard work. Therefore it is convenient to be able to pump water.

Different ways of pumping water Water pumping has a long history and many methods have been developed to pump water with a minimum of effort. These have utilized a variety of power sources, namely human energy, animal power, hydro power, wind, solar and fossil fuels for small generators. The relative merits of these are laid out in Table 1 below. Table 1 Comparison of pumping techniques

Type of pump Advantages Disadvantages Hand pumps • local manufacture is possible

• easy to maintain • low capital cost • no fuel costs

• loss of human productivity • often an inefficient use of boreholes • only low flow rates are achievable

Animal driven pumps • more powerful than humans • lower wages than human power • dung may be used for cooking

fuel

• animals require feeding all year round

• often diverted to other activities at crucial irrigation periods

Hydraulic pumps (e.g. rams)

• unattended operation • easy to maintain • low cost • long life • high reliability

• require specific site conditions • low output

Wind pumps • unattended operation • easy maintenance • long life • suited to local manufacture • no fuel requirements

• water storage is required for low wind periods

• high system design and project planning needs

• not easy to install Solar PV • unattended operation

• low maintenance • easy installation • long life

• high capital costs • water storage is required for cloudy

periods • repairs often require skilled

technicians Diesel and gasoline pumps • quick and easy to install

• low capital costs • widely used • can be portable

• fuel supplies erratic and expensive • high maintenance costs • short life expectancy • noise and fume pollution

1 Women, A World Report Debbie Taylor et al, UN/Methuen 1985.

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All pumping techniques above have one thing in common. They require energy. In this training, we will cover a few different energy sources that can be used for water pumping. These are diesel engines, solar (photovoltaic [PV]) panels and ram pump. Diesel, gasoline, and kerosene pumps (including windmills) have traditionally been used to pump water. However, reliable solar (photovoltaic [PV]) and ram pumps are becoming an attractive alternative to the traditional power sources. These technologies, powered by renewable energy sources (solar and hydro), are especially useful in remote locations where a steady fuel supply is problematic and skilled maintenance personnel are scarce.

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Water Resources

Surface water vs Groundwater The available water resource is an important criterion for choosing the kind of energy sources for any given water pumping application. Water can come either from surface water or groundwater. Surface water includes lakes, rivers, seawater, and rainwater; groundwater is found in underground aquifers, including springs. Groundwater can be shallow or deep depending on the ground’s hydrological formation. Surface water can dry up in the dry season depending on the kind of aquifer, the annual rainfall, and the geographical location (such as arid, semiarid, and humid climates). These factors also affect the depth of the water table. The water resource identified should be large enough to fulfill the demand. Unusual climate changes such as droughts and seasonal variation of the water table must be considered. In general, large quantities of water are required for irrigation. The amount of water required for domestic water supplies and livestock watering in rural areas generally depends on the size of the human and livestock populations.

Water Demand Water demand is another important criterion for designing rural water supply systems. The three main areas of need are:

• Village water supply • Water for livestock • Water for irrigation

Water demand for village water supplies is estimated from population size and from the daily per capita water consumption. A person needs 5 liters a day for drinking and cooking; 25 more to stay clean. Water consumption also depends on the availability of water. Table 2 shows typical daily water consumption for households with varying water access. Table 2 Typical Daily Water Consumption for Households2

Type of Household Daily Water Consumption (liters/person)

Households with dishwashers, washing machines, and sprinklers

1,000

Households with a piped supply and taps 100-350 Households using a public hydrant in the street

20-70

Households depending on a stream or handpump several miles distant

2-5

2 Water for Agriculture, Sandra Postel (Worldwatch 1989)

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Similarly, demand for livestock watering is estimated from the number of animals using the system multiplied by the per capita water consumption. Typical daily water consumption for farm animals is shown in Table 3. Table 3 Typical Daily Water Consumption for Farm Animals

Type of Animal Daily Water Consumption (liters/animal)

Dairy cows 80 Beef brood cows 50 Horses and mules 50 Calves 30 Pigs 20 Sheep and goats 10 Chickens 0.1 Unlike demands for domestic and livestock water supplies, water demand for crop irrigation is seasonal. Because some crops require a maximum water supply for a relatively short growing season, all irrigation systems need to be designed for peak water demands. Estimating the water demand for an irrigation application is complex and is beyond the scope of this training. However, local practice and experience are probably the best guides to estimating water requirements for a specific application. Table 4 shows the estimated daily water requirements for various types of crop irrigation. Table 4 Estimated Maximum Daily Water Demand for Various Types of Crop Irrigation

Crops Daily Water Requirement (m3/ha)

Rice 100 Rural village farms 60 Cereals 45 Sugar cane 65 Cotton 55

Water Storage Storage is necessary for good water management. The available power resource must be considered when determining storage size. The size of water tanks for conventional systems depends only on the peak and average daily water demand. PV systems, on the other hand, depend on daily weather conditions. Cloudy days with poor solar radiation create problems for meeting the daily water demand, so water tanks should be larger for such systems. Generally, 3 days of storage is recommended for renewable energy water pumping systems. Water tanks can be smaller if alternative water sources, such as hand pumps and rainwater, are available. In rural areas rainwater can be collected to water livestock and wash clothes, depending on the amount of annual rainfall distribution in the area. Surface water that flows year-round (such as a river) can also be used for such tasks, reducing the need for large capacity water tanks.

Water Distribution To distribute water fairly to the rural community, pumping it first to the tank and then distributing it from the tank by using gravity is recommended. This way, enough pressure can be built up at the water tank to distribute water by gravity. In addition, water will continuously flow in the tank, which helps to reduce the growth of bacteria. Finally, this helps maintain any leakage with little water loss and few interruptions to other distribution areas. However, distribution pipes must be sized carefully because

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smaller pipes create more friction than bigger pipes. Because oversized distribution pipes will raise the investment costs of the system, there are tradeoffs. The rural distribution network is relatively small, so leakage in these systems is less of a concern than in city water supplies. The water pressure in the distribution pipe is generally low in these systems and the chances of the pipe bursting are very unlikely.

7

Solar pumping PV technology converts the sun’s energy into electricity (DC) when the PV module (array) is exposed to sunlight. The PV module can also be used for AC applications using an inverter. PV is especially suitable for water pumping because energy need not be stored for night pumping. Instead, water can be stored to supply water at night.

The technology Solar pump systems are broadly configured into 5 types as described below:

Submerged multistage centrifugal motor pumpset (Figure 1) This type is probably the most common type of solar pump used for village water supply. The advantages of this configuration are that it is easy to install, often with lay-flat flexible pipework and the motor pumpset is submerged away from potential damage. Either ac or dc motors can be incorporated into the pumpset although an inverter would be needed for ac systems. If a brushed dc motor is used then the equipment will need to be pulled up from the well (approximately every 2 years) to replace brushes. If brushless dc motors are incorporated then electronic commutation will be required. The most commonly employed system consists of an ac pump and inverter with a photovoltaic array of less than 1500Wp. Figure 1 Submerged multistage centrifugal motor pumpset

Submerged pump with surface mounted motor (Figure 2) This configuration was widely installed with turbine pumps in the Sahelian West Africa during the 1970s. It gives easy access to the motor for brush changing and other maintenance. The low efficiency from power losses in the shaft bearings and the high cost of installation has been disadvantages. In general this configuration is largely being replaced by the submersible motor and pumpset.

Figure 2 Submerged pump with surface mounted motor

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Reciprocating positive displacement pump (Figure 3) The reciprocating positive displacement pump (often known as the jack or nodding donkey) is very suitable for high head, low flow applications. The output is proportional to the speed of the pump. At high heads the frictional forces are low compared to the hydrostatic forces often making positive displacement pumps more efficient than centrifugal pumps for this situation. Reciprocating positive displacement pumps create a cyclic load on the motor which, for efficient operation, needs to be balanced. Hence, the above ground components of the solar pump are often heavy and robust, and power controllers for impedance matching often used. Figure 3 Reciprocating positive displacement pump

Floating motor pump sets (Figure 4) The versatility of the floating unit set, makes it ideal for irrigation pumping for canals and open wells. The pumpset is easily portable and there is a negligible chance of the pump running dry. Most of these types use a single stage submersed centrifugal pump. The most common type utilises a brushless (electronically commutated) dc motor. Often the solar array support incorporates a handle or 'wheel barrow' type trolley to enable transportation.

Figure 4 Floating motor pump sets

Surface suction pumpsets (Figure 5)

This type of pumpset is not recommended except where an operator will always be in attendance. Although the use of primary chambers and non-return valves can prevent loss of prime, in practice self-start and priming problems are experienced. It is impractical to have suction heads of more than 8 meters. Figure 5 Surface suction pumpsets

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Performance The performance of some commercially available products is shown in Figure 6. It can be seen that solar pumps are available to pump from anywhere in the range of up to 200m head and with outputs of up to 250m3/day. The product of head and output is defined as m4. DC pumps normally have m4 value below 1500-2000. Many systems pump water using solar energy with m4 above 2000, but here they use AC pumps and inverters and are getting into much larger systems. The m4 diagram of the 50W DC pump that we will use for demonstration purposes during this training can be found in Appendix D.

Figure 6 Performance of solar pumps

Solar pumping technology continues to improve. In the early 1980s the typical solar energy to hydraulic (pumped water) energy efficiency was around 2% with the photovoltaic array being 6-8% efficient and the motor pumpset typically 25% efficient. Today, an efficient solar pump has an average daily solar energy to hydraulic efficiency of more than 4%. Photovoltaic modules of the

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monocrystalline type now have efficiencies in excess of 12% and more efficient motor and pumpsets are available. A good sub-system (that is the motor, pump and any power conditioning) should have an average daily energy throughput efficiency of 30-40%.

Designing a solar pumping system The first steps in doing a solar pumping project are:

1. Determine the demand in water How many liters or m3 (1000 liters) per day?

2. Determine the characteristics of the available water supply Is the source from surface water or groundwater?

3. Determine the head How many meters does the water need to be pumped from the available water source to the storage tank?

4. Figure out the m4 product to see if this is a do-able project Multiply the required output (m3/day) and the head (m) to determine what type of pump is needed.

5. Calculate the array size to determine if this is going to fit in a budget The energy required to pump water is calculated by the following formula:

hgmW ××= where W is the energy in Joule (J), m is the mass of the water in kilograms (kg), g is the constant of gravity (~10 m/s2), and h is the head in meters (m). Power is the amount of energy per time and is expressed in Watts (W).

tWP =

where P is the power in Watts (W), W is the energy in Joule (J), and t is the time in seconds (s). Because of inefficiencies in both the pump and the solar panel, the required input is larger than the power output. This is described by the following formula.

fPP o

i =

where Pi is the required input power (from the solar panel), Po is the power output (the water pumped to a higher altitude), and f is the efficiency (eg. 1 is 100% efficiency and 0.5 is 50% efficiency).

Calculation example

1. Determine the demand in water A village needs domestic water supply for 500 people. The average consumption per person would be 40 liters. Total water demand: 500 x 40 liters/day = 20,000 liters/day = 20 m3/day

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2. Determine the characteristics of the available water supply The village has a well with a depth of 3 meters, and a storage tank elevated on a hill, with the top of the tank 15 meters above the ground where the well is.

3. Determine the head The head would be the 3 meters that the water has to be pumped up to ground level, plus 15 meters to the top of the tank, plus an allowance of about 10% for friction loss in the pipe, (which you would really calculate instead of assume), for about 20 meters of head.

4. Figure out the m4 product to see if this is a do-able project The m4 product would be 20 m x 20 m3/day = 400m4/day. Figure 6 shows that this is the region for a DC MSC (multistage centrifugal) pump with a solar array of between 600 W and 1400 W.

5. Calculate the array size to determine if this is going to fit in a budget

The required energy per day would be: MJJhgmW 4000,000,42010000,20 ==××=××=

Assuming we can get an average of 3 hours of sunlight per day, this is:

sh 800,10606033 =××= The required power output would be:

Wt

WPo 370800,10

000,000,4===

With a total system efficiency of 30% this would require a solar array of:

WPi 12353,0

370== , which is between 600 W and 1400 W as indicated in Figure 6.

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Hydraulic ram pump

Introduction The hydraulic ram pump, or hydram, concept was first developed by the Mongolfier brothers in France in 1796 (they are better remembered for their pioneering work with hot-air balloons). Essentially, a hydram is an automatic pumping device which utilizes a small fall of water to lift a fraction of the supply flow to a much greater height; i.e. it uses a larger flow of water falling through a small head to lift a small flow of water through a higher head. The main virtue of the hydram is that its only moving parts are two valves, and it is therefore mechanically very simple. This gives it very high reliability, minimal maintenance requirements and a long operation life.

How a hydram works Its mode of operation depends on the use of the phenomenon called water hammer and the overall efficiency can be quite good under favorable circumstances. More than 50% of the energy of the driving flow can be transferred to the delivery flow. Figures 7-10 illustrates the principle; initially (Figure 7) the impulse valve (or waste valve since it is

the non-pumped water exit) will be open under gravity (or in some designs it is held open by a light spring) and water will therefore flow down the drive pipe (through a strainer) from the water source. As the flow accelerates, the hydraulic pressure under the impulse valve and the static pressure in the body of the hydram will increase until the resulting forces overcome the weight of the impulse valve and start to close it. As soon as the valve aperture decreases, the water pressure in the hydram body builds up rapidly and slams the impulse valve shut.

The moving column of water in the drive pipe is no longer able to exit via the impulse valve so its velocity must suddenly decrease; this continues to cause a considerable rise of pressure which forces open the delivery valve to the air-chamber. Once the pressure exceeds the static delivery head, water will be forced up the delivery pipe (Figure 8).

Figure 8

Figure 7

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Air trapped in the air chamber is simultaneously compressed to a pressure exceeding the delivery pressure. Even-tually the column of water in the drive pipe comes to a halt and the static pressure in the casing then falls to near the supply head pressure. The delivery valve will then close, when the pressure in the air chamber exceeds that in the casing. Water will continue to be delivered after the delivery valve has closed until the compressed air in the air chamber has expanded to a pressure equal to the delivery head (Figure 9). The air chamber is a vital component, as apart from improving the efficiency of the process by allowing delivery to continue after the delivery valve has closed, it is also essentialthe incompressible nature of water.

This is because if the waste valve stays openpumped, so the efficiency is reduced, but if itlong enough in the hydram body, so again lesthat limits the opening of the valve to a predeoptimize its performance. A skilled installer optimum performance. Please refer to Appepump tuning. A storage tank is usually includrawn in variable amounts as needed.

Figure 9

to cushion the shocks that would otherwise occur due to

A check valve is included in the delivery pipe to prevent return flow. When the delivery valve closes, the reduced pressure in the hydram body will allow the impulse valve to drop under its own weight, thereby letting the cycle start all over again (Figure 10). Most hydrams operate at 30-100 cycles a minute. This cycling of the hydram is timed by the characteristic of the waste valve. Normally it can be weighted or pre-tensioned by an adjustable spring, and an adjustable screwed stop is generally provided which will allow the maximum opening to be varied. The efficiency, which dictates how much water will be delivered from a given drive flow, is critically influenced by the valve setting.

Figure 10

too long, a smaller proportion of the throughput water is closes too readily, then the pressure will not build up for s water will be delivered. There is often an adjustable bolt termined amount, which allows the device to be turned to should be able to adjust the waste valve on site to obtain ndix E for further information regarding hydraulic ram ded at the top of the delivery pipe to allow water to be

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Performance The flow of water that a hydraulic ram pump can deliver depends on the head (H) and flow (Q) of the water from the drive pipe, as well as the delivery head (h), i.e. the height difference between the ram pump and the storage tank where the water should be pumped. The delivery flow (q) can be calculated using the following formula:

hQHfq ×

×=

where f is the efficiency factor, H is the supply head, Q is the supply flow, and h is the delivery head. A typical efficiency factor for commercial ram pumps is 60%, but up to 80% is possible. For home made ram pumps this is usually lower.

H

D h

d

Catchment tank

q

l

L

Q

Drive pipe

Delivery pipe

Storage tank

Ram pump

Figure 11 Schematic of ram pump installation

The size and length of the drive pipe must be in proportion to the working head from which the ram operates. Also, the drive pipe carries severe internal shock loads due to water hammer, and therefore normally should be constructed from good quality steel water pipe. Normally the length (L) of the drive pipe should be around three to seven times the supply head (H). Ideally the drive pipe should have a length of at least 100 but not more than 1,000 times its own diameter (D). The drive pipe must generally be straight; any bends will not only cause losses of efficiency, but will result in strong fluctuating sideways forces on the pipe, which can cause it to break loose.

Technical Parameters for Hydraulic Ram Pump System

, where L = length of drive pipe H = supply head D = diameter of drive pipe

000,1100) −=DLb73) −=

HLa

Hydrams are mostly intended for water supply duties, in hilly or mountainous areas, requiring small flow rates delivered to high heads. They are less commonly used for irrigation purposes, where the higher flow rates required will usually demand the use of larger sizes of hydram having 6-inch or 4-inch drive pipes. Manufacturers usually describe the size of a hydram by the supply and delivery pipe diameters (generally given in inches even in metric countries because of the common use of inch sizes

15

for pipe diameters); e.g. a 6 x 3 hydram has a 6-inch diameter drive pipe and a 3-inch diameter delivery pipe. Table 5 indicates estimated performance for typical 4-inch x 2-inch and 6-inch x 3-inch commercial hydrams. Table 5 Typical ram pump performance data

Hydram size in inches 4” x 2” 6” x 3” Head ratio (h/H) 5 10 15 20 5 10 15 20 Drive flow Q (litres/s) 9.0 9.7 10.0 9.0 20.2 17.2 17.1 19.3 Delivery flow q (m3/day) 94 51 35 23 216 101 69 50 Efficiency f 61% 61% 61% 59% 62% 68% 70% 60% The ram pump that will be used for demonstration purposes during this training is manufactured by the AID foundation in the Philippines. It has a 1” drive pipe and a ½” delivery pipe. The performance data for this ram pump can be found in Appendix F.

Designing a hydraulic ram pump system The following are the steps in designing a hydraulic ram pump system:

1. Identify the necessary design factors: 1. What is the available supply head, H (the height difference between the water source and the pump

site)? 2. What is the required delivery head, h (the difference in height between the pump site and the point

of storage or use)? 3. What is the available drive flow, Q (the quantity of flow from the water source)? 4. What is the required delivery flow, q (the quantity of water for consumption)? 5. What is the length of the drive pipe, L (the distance from the source to the pump site)? 6. What is the length of the delivery pipe, l (the distance from the pump to the storage site)?

2. Determine if this is a do-able project

Calculate the required efficiency factor using the formula

QHqhf

××

=

to see if it is possible to use a ram pump to meet the supply demand. The angle of the drive pipe should not be too steep. Normally the length (L) of the drive pipe should be around three to seven times the supply head (H).

3. Determine the ram pump size The table below shows the capacities for different ram pump sizes from a certain manufacturer, as well as the recommended size of the drive pipe. Table 6 Capacities for different ram pump sizes3

Hydram size 1 2 3 3.5 4 5X 6X Drive flow needed (liters/min)

7-16 12-25 27-55 45-96 68-137 136-270 180-410

Maximum lift (meters) 150 150 120 120 120 105 105 Drive pipe size (inches) 1¼” 1½” 2” 2½” 3” 4” 5”

3 US AID, 1982

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4. Determine the drive and delivery pipe size The drive pipe diameter is usually chosen based on the size of the ram and the manufacturer's recommendations as shown in Table 6. But there are also other factors to consider. The diameter of both the drive pipe and the delivery pipe should not be smaller than their respective length divided by 1,000. If the diameter is too small the capacity will be reduced due to friction losses. The diameter should also be large enough to handle the flow of water that should go through it. The table below can be used for finding the right pipe size for the available flow. Table 7 Possible flows for different pipe sizes4

Pipe diameter (inches) 1” 1.5” 2” 3” 4” Flow (liters/min) 6-36 37-60 61-90 91-234 235-360

Calculation example A small community consists of 10 homes with a total of 60 people. There is a spring l0m lower than the village, which drains to a wash 15m below the spring. The spring produces 30,000 liters of water per day. There is a location for a ram on the bank of the wash. This site is 5m higher than the wash and 35m from the spring. A public standpost is planned for the village 200m from the ram site. The lift required to the top of the storage tank is 23m.

1. Identify the necessary design factors: 1. The available supply head, H, is 10m. 2. The required delivery head, h, is 23m to the top of the storage tank. 3. The quantity of flow available, Q, equals 30,000 liters per day divided by 1,440 minutes per day

(30,000/1,440) = 20.8 liters per minute. 4. The quantity of water required, q, assuming 40 liters per day per person as maximum use is 60

people x 40 liters per day = 2,400 liters per day. 2,400/1,440 = 1.66 liters per minute (use 2 liters per minute)

5. The length of the drive pipe, L, is 35m. 6. The length of the delivery pipe, l, is 200m.

2. Determine if this is a do-able project Calculate the required efficiency factor using the formula

22.08.2010

223=

××

=××

=QHqhf

22% efficiency is VERY do-able for a hydraulic ram pump installation. Calculate the ratio between the length of the drive pipe (L) and the supply head (H).

5.31035

==HL

The length of the drive pipe should be at least three times the supply head, so this condition is also met.

3. Determine the ram pump size Table 6 can now be used to select a ram size. The volume of driving water or supply needed is 20.8 liters per minute. From Table 6, a No. 2 Hydram requires from 12 to 25 liters per minute. A No. 2

4 US AID, 1982

17

Hydram can lift water to a maximum height of 150m according to Table 6. This will be adequate since the delivery head to the top of the storage tank is 23m. Thus, a No. 2 Hydram would be selected.

4. Determine the drive and delivery pipe size Table 6 shows that for a No. 2 Hydram, the minimum drive pipe diameter is 1½ inch. The length of the drive pipe is 35 meters, so the diameter should not be less that 35 mm. Thus a 1½” (38 mm) pipe would be sufficient. Table 7 shows that a 1½” pipe is sufficient for the drive flow (20.8 liters/min). For the delivery flow (2 liters/min), Table 7 shows that a 1” pipe is sufficient

Installation requirements Figure 12 illustrates a typical hydram installation, pumping water to a small storage tank on a plateau. It can be seen that the supply head is created in this case by creating a weir. In some cases a small stream is diverted to provide the water supply.

Figure 12 Typical ram pump installation

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Where greater capacity is needed, it is common practice to install several hydrams in parallel. This allows a choice of how many to operate at any one time so it can cater for variable supply flows or variable demand. Figure 13 shows an installation with parallel ram pumps.

Figure 13

Multiple hydrams with common delivery pipe

The hydram body requires to be firmly bolted to a concrete foundation, as the beats of its action apply a significant shock load. The hydram should be located so that the waste valve is always located above flood water level, as the device will cease to function if the waste valve becomes submerged. The delivery pipe can be made from any material capable of carrying the pressure of water leading to the delivery tank. In all except very high head applications, plastic pipe can be considered; with high heads, the lower end of the delivery line might be better as steel pipe. The diameter of the delivery line needs to allow for avoiding excessive pipe friction in relation to the flow rates envisaged and the distance the water is to be conveyed. It is recommended that a hand-valve or check-valve (non-return valve) should be fitted in the delivery line near the outlet from the hydram, so that the delivery line does not have to be drained if the hydram is stopped for adjustment or any other reason. This will also minimize any back flow past the delivery valve in the air chamber and improve efficiency. For steps in installing hydraulic ram pump systems, please refer to Appendix G. For problems that may occur during installation of ram pump systems, please refer to Appendix H.

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References The material for this training manual has been taken from the following sources: N. Argaw, R. Foster and A. Ellis, New Mexico State University, Las Cruces, New Mexico, USA, “Renewable Energy for Water Pumping Applications in Rural Villages”, NREL/SR-500-30361 Available electronically at http://www.osti.gov/bridge Technical Information Service Practical Action (formerly: Intermediate Technology Development Group) The Schumacher Centre for Technology and Development Bourton-on-Dunsmore Rugby, CV23 9QZ United Kingdom Tel: (+44) 1926 634400 Fax: (+44) 1926 634401 e-mail: infoserv@practicalaction.org.uk web: http://www.itdg.org http://www.itdg.org/docs/technical_information_service/solar_pv_waterpumps.pdf http://www.itdg.org/docs/technical_information_service/hydraulic_ram_pumps.pdf AID Foundation Alternative Indigenous Development Foundation Inc. PO Box 297 Lot 30, Blk. 12, Puentebella Subd., Brgy. Taculing, Bacolod City, Philippines Tel: (+63) 34 446 3629 Fax: (+63) 34 446 2336 e-mail: aidfi@hotmail.com web: www.aidfi.org Other websites http://www.newint.org/issue207/facts.htm http://www.thefarm.org/charities/i4at/lib2/hydrpump.htm http://www.dekpower-fj.com/diesel-water.htm http://www.solartron.co.th/Newer/product.aspx

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Appendix Appendix A Formulae for Energy and Power (1 page)

Appendix B Specification for Diesel Pump (1 page)

Appendix C Specification for Solar Panels (1 page)

Appendix D Specification for Yeser 12 V DC water pump (6 pages)

Appendix E Hydraulic Ram Pump Tuning (2 pages)

Appendix F 1” Ram Pump Test Results (7 pages)

Appendix G Steps in Installing Hydraulic Ram Pump System (1 page)

Appendix H Problems and Solutions during Ram Pump Installation (2 pages)

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Appendix A Formulae for Energy and Power Energy can be in many different forms. It can never be destroyed, only transformed from one form of energy to another. Potential energy, e.g. water stored in a reservoir

hgmW ××= where W is the energy in Joule (J), m is the mass of the water in kilograms (kg), g is the constant of gravity (~10 m/s2), and h is the head in meters (m). Electrical energy, e.g. stored in a battery

QUW ×= where W is the energy in Joule (J), U is the voltage in Volts (V), and Q is the electric charge in Coulomb (C). Power is the amount of energy per time and is expressed in Watts (W).

tWP =

where P is the power in Watts (W), W is the energy in Joule (J), and t is the time in seconds (s). Water power, e.g. water flowing in a waterfall

hgqP ×××= ρ where P is the power in Watts (W), ρ is the water density in kg/m3, q is the flow in m3/s, g is the constant of gravity (~10 m/s2), and h is the head in meters (m). Electrical power, e.g. produced in a solar panel

IUP ×= where P is the electrical power in Watts (W), U is the voltage in Volts (V), and I is the current in Amperes (A).

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Appendix B Specification for Diesel Pump

23

Appendix C Specification for Solar Panels

24

Appendix D Specification for Yeser 12 V DC water pump

25

26

27

28

29

30

Appendix E Hydraulic Ram Pump Tuning

31

32

Appendix F 1” Ram Pump Test Results

33

34

35

36

37

38

39

Appendix G Steps in Installing Hydraulic Ram Pump System

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Appendix H Problems and Solutions during Ram Pump Installation

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