Thermodynamic pump testing
Encyclopedia
Thermodynamic pump testing is a form of pump testing
where only the temperature rise and power consumed need to be measured to find the efficiency of a pump. This is measured by means of temperature and pressure probes fitted to tapping points on the pump’s inlet and outlet. Flow rate is derived from the pump efficiency measurement and electrical power supplied to the pump.
The thermodynamic method was developed in the 1960s at the University of Glasgow
and the University of Strathclyde
in Scotland, and the National Engineering Laboratory in France (Electricite de France) and Austin Whillier (Chamber of Mines, Johannesburg, South Africa) and his paper titled "pump efficiency determination from temperature measurements" as published in the October 1967 edition of The South African Mechanical Engineer.
This method is capable to undertake a calibration check on the flow meter on each pump and provides a precise flow measurement to enhance leakage detection and allows for accurate calculation of performance, especially for non-revenue water
.
When calculating pump efficiency, highly accurate measuring equipment should be used to get the most accurate reading, resulting in maximum efficiency. For example, the temperature rise is very small (only hundredths of a kelvin
), so very sensitive, stable thermocouple
s must be used to accurately measure the rise. Properly installed and maintained pumps for water can be around 70–90% efficient, while less-cared for pumps can be less efficient due to wear on the impeller and general back leakage through over large clearances.
The alternative to the thermodynamic method or, conventional method, is to install a flow meter and pressure sensors. However, this takes much longer and is on the whole less accurate, but nevertheless suitable for some installations.
Thermodynamic pump testing can be incorporated with Integrated Geographical Information System for better predictive maintenance system. A few companies provide such products including Riventa Ltd UK, SAJ Holdings Sendirian Berhad, a subsidiary of Ranhill Berhad
, Malaysia and collaborated with Thames Water, UK. With these tools, the maintenance teams can monitor closely the pumping systems and avoid break-downs or down-times.
Pump testing
To minimise energy use, and to ensure that pumps are correctly matched to the duty expected pumps, and pumping stations should be regularly tested.In water supply application, which are usually fitted with centrifugal pumps, individual large pumps should be 70 - 80% efficient...
where only the temperature rise and power consumed need to be measured to find the efficiency of a pump. This is measured by means of temperature and pressure probes fitted to tapping points on the pump’s inlet and outlet. Flow rate is derived from the pump efficiency measurement and electrical power supplied to the pump.
The thermodynamic method was developed in the 1960s at the University of Glasgow
University of Glasgow
The University of Glasgow is the fourth-oldest university in the English-speaking world and one of Scotland's four ancient universities. Located in Glasgow, the university was founded in 1451 and is presently one of seventeen British higher education institutions ranked amongst the top 100 of the...
and the University of Strathclyde
University of Strathclyde
The University of Strathclyde , Glasgow, Scotland, is Glasgow's second university by age, founded in 1796, and receiving its Royal Charter in 1964 as the UK's first technological university...
in Scotland, and the National Engineering Laboratory in France (Electricite de France) and Austin Whillier (Chamber of Mines, Johannesburg, South Africa) and his paper titled "pump efficiency determination from temperature measurements" as published in the October 1967 edition of The South African Mechanical Engineer.
This method is capable to undertake a calibration check on the flow meter on each pump and provides a precise flow measurement to enhance leakage detection and allows for accurate calculation of performance, especially for non-revenue water
Non-revenue water
Non revenue water is water that has been produced and is “lost” before it reaches the customer. Losses can be real losses or apparent losses . High levels of NRW are detrimental to the financial viability of water utilities, as well to the quality of water itself...
.
When calculating pump efficiency, highly accurate measuring equipment should be used to get the most accurate reading, resulting in maximum efficiency. For example, the temperature rise is very small (only hundredths of a kelvin
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
), so very sensitive, stable thermocouple
Thermocouple
A thermocouple is a device consisting of two different conductors that produce a voltage proportional to a temperature difference between either end of the pair of conductors. Thermocouples are a widely used type of temperature sensor for measurement and control and can also be used to convert a...
s must be used to accurately measure the rise. Properly installed and maintained pumps for water can be around 70–90% efficient, while less-cared for pumps can be less efficient due to wear on the impeller and general back leakage through over large clearances.
The alternative to the thermodynamic method or, conventional method, is to install a flow meter and pressure sensors. However, this takes much longer and is on the whole less accurate, but nevertheless suitable for some installations.
Thermodynamic pump testing can be incorporated with Integrated Geographical Information System for better predictive maintenance system. A few companies provide such products including Riventa Ltd UK, SAJ Holdings Sendirian Berhad, a subsidiary of Ranhill Berhad
Ranhill Berhad
Ranhill Berhad is one of Malaysia's largest companies. Having started out in 1973 as engineering consultants, it expanded first into engineering, procurement and project management, then into turnkey construction, facility management, development and ownership of projects...
, Malaysia and collaborated with Thames Water, UK. With these tools, the maintenance teams can monitor closely the pumping systems and avoid break-downs or down-times.