Micro Hydro Turbine Generator Measurement of Water Head and Water Flow

Measurement of water head H

Gross head H: The vertical height difference between the upstream and downstream of water sources. 

Main measurement methods: 

1. It can be measured by a pressure meter installed at the end of the pipeline. The gross head is indicated by pressure meter when closing the adjusting valve.

2. 2.The water level difference between upstream and downstream can be measured by a level gauge;

3. 3.It can be measured by GPS and other technical means. Net head H: The net head is the pressure turbine could be effectively used. Measurement: the pressure value indicated by pressure gauge when opening adjusting valve or when turbine is at work.

Measurement of water flow Q:

1.   Area method

Cross section area A

Through the measurement of the width (W ) and height ( H ) of flow within river, we can easily calculate the cross section area of flow ( A=W ´ H ). If the river is irregular, we can divide the cross section into several small areas and sum each piece (åA = A1 + A2 + A3 +……).

Flow velocity v

The flow velocity can be calculated through the distance ( L ) of floating objects travel with water within certain seconds (t ), v = L / t .

   2. Volume method

One can measure the time (t ) required for waterfalls to fill an already known volume (V ) tank, then the flow (Q) can be calculated through the equation Q =V / t .

It is suggested that when measuring flow rate an averaged value of three or four times is required. Besides, the seasonal variations should also be considered.