HYDRAULIC MACHINE

project on

Water distribution system

INTRODUCTION

WATER DISTRIBUTION SYSTEM

• The basic function of a water distribution system is to transport the water from the Main reservoir to the customer

• Methods of water distribution :

- Gravity distribution- Pumping system - combined gravity and pumping system

GRAVITY DISTRIBUTION• Suitable when source of supply is at sufficient

height.

• Most reliable and economical distribution system.

• The water head available at the consumer is just minimum required.

• The remaining head is consumed in the frictional and other losses.

PUMPING SYSTEM• water is directly pumped in to the distribution main

with out storing.

• called pumping without storage system.

• High lifts pumps are required.

• If power supply fails, complete stoppage of water supply.

• This method is not generally used.

COMBINED GRAVITY AND PUMPING SYSTEM

• Most common system.

• Treated water is pumped and stored in an elevated distribution reservoir.

• Then supplies to consumer by action of gravity.

• The excess water during low demand periods get stored in reservoir and get supplied during high demand period.

• Economical, efficient and reliable system.

PUMPS• The pump is mechanical device which carry

liquid from one place to another place. It can be defined as a hydraulic machines which converts the mechanical energy into hydraulic energy.• The pump is power absorbing machines.• Pumping means addition of energy to a liquid to

move it from one place to the another.

CLASSIFICATION OF PUMPS• The pump can be classified according to

principle by which the energy added to the fluid and their design as follows:

SELECTING BETWEEN CENTRIFUGAL PUMPS AND POSITIVE

DISPLACEMENT PUMPS • Centrifugal Pumps (Rotor-dynamic pumps) The

centrifugal or rotor-dynamic pump produce a head and a flow by increasing the velocity of the liquid through the machine with the help of a rotating vane impeller. Centrifugal pumps include radial, axial and mixed flow units. • Positive Displacement Pumps The positive

displacement pump operates by alternating of filling a cavity and then displacing a given volume of liquid. The positive displacement pump delivers a constant volume of liquid for each cycle against varying discharge pressure or head

FLOW RATE AND PRESSURE HEAD

• The two types of pumps behave very differently regarding pressure head and flow rate :

- The Centrifugal Pump has varying flow depending on the system pressure or head

- The Positive Displacement Pump has more or less a constant flow regardless of the system pressure or head. Positive Displacement pumps generally gives more pressure than Centrifugal Pump's.

CAPACITY AND VISCOSITY

• Another major difference between the pump types is the effect of viscosity on the capacity:

- In the Centrifugal Pump the flow is reduced when the viscosity is increased

- In the Positive Displacement Pump the flow is increased when viscosity is increased

MECHANICAL EFFICIENCY• The pumps behaves different considering

mechanical efficiency as well :

- changing the system pressure or head has little or no effect on the flow rate in the Positive Displacement Pump

- Changing the system pressure or head has a dramatic effect on the flow rate in the Centrifugal Pump

CENTRIFUGAL PUMPS IN SERIES AND PARALLEL

• Putting your centrifugal pumps in series will let you add the head from each together and meet your high head, low flow system requirements

CENTRIFUGAL PUMPS IN SERIES AND PARALLEL

• Putting your pumps in parallel will help you reach a low head, high flow operating point that a single pump cannot supply .

BERNOULLI EQUATION  

• In the above equation, P is pressure, which can be either absolute or gage, but should be in the same basis on both sides, ρ represents the density of the fluid, assumed constant, V is the velocity of the fluid at the inlet/outlet, and h is the elevation about a datum that is specified.

CONTINUITY EQUATION

• apply the principle of mass conservation. Since there is no flow through the side walls of the duct, what mass comes in over A1 goes out of A2, (the flow is steady so that there is no mass accumulation). Over a short time interval t,

HEAD LOSS

• Pipe loss • In the analysis of piping systems, pressure

losses are commonly expressed in terms of the equivalent fluid column height called head loss hL. • It also represents the additional height that the

fluid needs to be raised by a pump in order to overcome the frictional losses in the pipe

HEAD LOSS

• fittings lossFittings such as elbows, tees, valves and reducers

represent a significant component of the pressure loss in most pipe systems. This is the calculation of pressure losses through pipe fittings and some minor equipment using the K-value method, also known as the Resistance Coefficient, Velocity Head, Excess Head or Crane method

Formula for Calculating Head Loss from K Values

DATE

PROJECT

• The main object of the project , is to make a theoretical study of delivering the water , from a river to a small village using pump , and then store this water into a reservoir and after that make a distribution system of water for the village• In order to make a distribution for water , we should

consider the high of the village from the river , how many houses are in the village and how long it's far from the main reservoir to each house to determine the pipes length required to deliver the water.

And so find the related calculation of hydraulic machines .

DATE

• Find out the height of the village as 200 m.

• water pumping to the reservoir will be by using centrifugal pump .

• water filter will be install on the top of the suction pipe. • for water distribution inside the village we will use a

simple centrifugal pump .

• the results of the hydraulic values will obtain by using water cad program .

THE GENERAL SITUATION OF THE VILLAGE

• The village consist of 6 houses and its above the river by 200 m , all the required information are shown in the figure

WATER DEMAND

• The daily water demand per capita is 60 lit/day ; every house contain 5 persons so the demand for single house will be 60 x 5 = 300 lit/day ; so the village contains 6 houses and the overall demand will be 1800 lit/day ; and by taking the water demand factor as ( 10 ) the final water demand will be 18,000 lit/day .

FIRST STAGE

• First stage is to pump the water from the river to the tank ; the tank elevation from the river level 200 m .• The required length of the pipe is 285 m .

• By using water cad program with these input : • Total Length of the pipe L = 285 m • Pipe diameter D = 10.16 cm • Discharge Q = 5 L/s • Pipe material PVC with design coefficient C =

150

USING MULTI STAGE PUMP

FILTERS• Eaton suction filters protect hydraulic pumps

and control systems from solid contaminants. They should be used as immersion suction filters on pump inlet lines. These units have various application possibilities: as in-tank filters mounted directly to the reservoir, in the intake lines of hydraulic pumps to afford a degree of protection from contaminants to the pump and other components in the hydraulic system.

DATE

SECOND STAGE

• Second stage is to pump the water from the tank and distribute it to the houses

BY USING WATER CAD PROGRAM WE OBTAIN THESE RESULTS :

REFERENCES

1. F.M. White, Fluid Mechanics, Seventh Edition, McGraw-Hill, New York (2011).

2. M.M. Den, Process Fluid Mechanics, Prentice-Hall, Englewood Cliffs (1980).

3. Grundfos Product Center ,Available at: http://product-selection.grundfos.com (Accessed: 21th March 2016)

4. Fluid Mechanics & Fluid Power Engineering, (8th edition) by Kumar, D.S., Katarina & Sons, 2013

5. Lenz Hydraulics, Available at: http://lenzinc.com/ , (Accessed: 03th April 2016)

6. Hydraulic Power System Analysis, A. Akers, M. Gasman, & R. Smith, Taylor & Francis, New York,

2006

hank ou!