KATHMANDU UNIVERSITYSCHOOL OF ENGINEERING

DEPARTMENT OF MECHANICAL ENGINEERING

A Proposal on“Performance Testing of Micro Hydro & Laboratory Setup”

as the Fourth Year Undergraduate Project Works

Supervisor:Mr. Biraj Singh Thapa

Submitted by:Abinash Baral (41053)

Rojan K. Katuwal (41089)

28 December 2011

ABSTRACT

This is the proposal submitted to Department of Mechanical Engineering in the project

entitled “Performance Testing of Micro Hydro & Laboratory Setup”. The primary target

of our project is to setup a laboratory for the testing of micro-hydro cross-flow turbines. The

initial phase will include the dismantling of the previous test rig placed at pico-hydro turbine

testing laboratory at Kathmandu University (KU) and re-installing it at the newly built

turbine testing laboratory at KU. After, initial performance tests the latter stages will include

modifications and improvements in the test rigs for other micro-hydro turbine testing.

This project intends to study testing procedures adopted elsewhere and every possibility of

implementation. The success of our project might ease and establish certain procedures of

turbine testing, further relieving the pressure on micro hydro-power developers. Our aim is to

study and test micro-hydro turbines and prepare hill charts of the turbine with a proper

laboratory setup.

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TABLE OF CONTENTS

Abstract ii

Chapter 1: Introduction 1

1.1 Rationale 11.2 Objectives

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Chapter 2: Literature Review 2

Chapter 3: Methodology 5

Chapter 4: Discussion 7

4.1 Laboratory test 7

Chapter 5: Gantt Chart 9

Chapter 6: Conclusion 10

References 11

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CHAPTER 1

INTRODUCTION

1.1 Rationale

The easy availability as well as the abundance of falling water sources is the main inspiration

for the project. Besides the environment friendly nature of micro-hydro powers, easy

production is equally relevant in economy stripped country like ours. If simple procedures of

turbine testing are used then optimization of the turbines will be easier. This is a good

possibility of its wide acceptance among people that may even lead to establishments of

micro-hydro systems at different parts of the country electrifying the rural and semi-urban

communities.

1.2 Objectives

The main objectives of our project include:

i. To test the efficiency of the 15 KW cross-flow turbine currently installed in the rig.

ii. To prepare hill chart of the same.

iii. To further test other micro-hydro turbines and prepare their hill charts.

The secondary objectives of our project include:

i. To study other testing laboratory setup.

ii. To apply testing procedure considering availability and accuracy.

iii. To test micro-hydro turbines.

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CHAPTER 2

LITERATURE REVIEW

Micro hydro is hydro power with electrical output of five to 20 kilowatts. Hydro power systems

of this size benefit in terms of cost and simplicity from different approaches in the design,

planning and installation than those which are applied to larger hydro power. Recent innovations

in micro hydro technology have made it an economic source of power even in some of the

world’s poorest and most inaccessible places. It is also a versatile power source. AC electricity

can be produced enabling standard electrical appliances to be used and the electricity can be

distributed to a whole village. Common examples of devices which can be powered by micro-

hydro are light bulbs, radios, televisions, refrigerators and food processors.

The purpose of a hydraulic turbine is to transform the water potential and kinetic energy to

mechanical rotational energy. Various types of turbines exist to cope with different levels of

head and flow. The two broad categories are:

Impulse turbines – notably the Pelton, Turgo or the Banki-Michell (cross-flow) - in which

water impinges or enters the runner, which is designed to change the water’s direction

and thereby extract the momentum from it with scarce change of pressure energy.

Reaction turbines – notably Francis and Kaplan – which run full of water and in effect,

generate hydrodynamic “lift” forces to propel the runner blades, extracting thus the

pressure energy of inflowing water.

Crossflow turbines are widely used on micro hydro sites with typical power outputs from 5 kW

up to 100 kW, though they can actually be up to 3 MW in size on the very largest systems,

though generally speaking there are better turbine choices for these higher power outputs. They

will work on net heads from just 1.75 metres to 200 metres, though there are more appropriate

turbine choices for sites with heads above 40 metres.  They will work on average annual flows as

low as 40 litres/second or up to 5 m3/s, though on the higher flow rates there may be better other

turbine types to consider.

A cross-flow turbine gets its name from the way the water flows through, or more correctly

‘across’ the rotor as shown in figure below.  The water flows over and under the inlet guide-vane

which directs flow to ensure that the water hits the rotor at the correct angle for maximum

efficiency.  The water then flows over the upper rotor blades, producing a torque on the rotor,

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then through the centre of the rotor and back across the low rotor blades producing more torque

on the rotor.  Most of the power is extracted by the upper blades (roughly 75%) and the

remaining 25% by the lower blades.  Obviously the rotor is rotating, so what are the upper blades

one moment will be the lower blades the next.

Figure – Crossflow turbine in cross-section.

One of the advantages of a crossflow turbine is debris tolerance; leaves etc. that could get pushed

into and stuck on the upper blades are washed off by the exiting water on the lower blades, hence

the rotor is self cleaning.  Also the centrifugal force tends to throw trapped debris outwards,

further increasing the self-cleaning capabilities.

Crossflow turbines are an impulse turbine, which means that the rotor is spinning in air and is not

fully-flooded like in a reaction turbine.  The water exits the rotor and falls into the draft tube,

which can be many metres long (though not normally more than 1/3 of the total net head across

the system).  The exiting water fills the draft tube from just below the rotor to the discharge

water level.  A negative pressure inside the turbine cavity i.e. ‘suction head’ is created with the

air inlet valve on the front turbine casing.  The positive water pressure from the upstream side of

the rotor is called the ‘pressure head’ and the sum of the pressure and suction heads equals the

net head across the hydro system.

The advantage of using a draft tube to maximise the suction head is that the long draft tube

moves the main body of the crossflow turbine upwards, away from the discharge water level and

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(hopefully) above the floodwater levels during high flow events.  If the main body of the turbine

was still likely to get flooded during high flow events it would have to be built into a ‘tanked’

enclosure. Another major advantage of a crossflow turbine is there wide operating flow range

with a high efficiency across the whole range. 

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CHAPTER 3

METHODOLOGY

Fig: Methodology

Firstly, we will survey the present situation and test facilities at the Laboratory at KU. .

After that we will study the prevailing testing procedures and laboratory setup.

Then, the laboratory will be redesigned.

After that, tests will be carried out on the laboratory followed by series of modifications

and corresponding tests.

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LABORATORY SETUP STUDY

LAB OPTIMIZATION

TESTING

PROJECT SELECTION

LITERATURE SURVEY

MICRO-HYDRO STUDY

From Source

To other test rigs

Pressure Tank

Reservoir tank Pump

Turbine Re-collection

Tank

Pressure Regulating

Tank

CHAPTER 4

DISCUSSION

4.1 Laboratory

Fig: Diagrammatic representation of the current testing lab

The testing lab is as shown above. Water from source is collected in the reservoir tank which is

connected to the pressure tank with a valve. The pressure tank is connected to the water

transmission pipes and pressure regulating tank. The pressure regulating tank has a valve for

controlling the water flow to the tank itself which helps to maintain the desired pressure/head

and is connected to the reservoir tank. The turbine setup is connected to the transmission pipes

and the water outflow from the turbine is collected in the re-collection tank which is connected to

the reservoir tank. Thus, once the water in the reservoir tank reaches to the desired level tests are

performed without the loss of water unless there are leakages.

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The turbines in the field should be supplied with natural flow of water (Q) under some head (H).

However, in the laboratory the flow and head is obtained by a suitable pumping unit which

supplies water under a specified pressure. First, the pump is started and the inlet and other valves

are opened to ensure supply of water to the turbine. After the setup, the rpm of the propeller shaft

and the output of the alternator are measured using tachometer, multimeter and loads of varying

power ratings. These data are then used to calculate the efficiency and power output of the

turbine.

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CHAPTER 5

GANTT CHART

S. No.

Activities Sept Oct Nov Dec Jan Feb Mar Apr May Jun Jul

1Project Selection

2Literature Review

3Laboratory Setup Study

4Optimization of Laboratory

5Actual Testing of Turbines

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CHAPTER 6

CONCLUSION

Mirco-hydro systems are of great significance in rural Nepal because of its difficult topography

and absence of transmission lines. They can be solutions to electrifying rural households. Small

communities can be greatly served in the current times where urban areas are facing large-

spanned loadshedding. After the completion of the project we intend to obtain a fully equipped

laboratory with testing facilities for cross-flow turbines of varying range giving reliable, accurate

and simple to obtain results. We also hope for developing the skills and knowledge of various

engineering procedure for the successful accomplishment of the given job.

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REFERENCES

Khurmi R.S. (1970). The textbook of hydraulics, fluid mechanics and hydraulic machines. S. Chand & Company Ltd.: New Delhi, India.

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