The P22 Thermodynamic Pump Efficiency Monitor, which uses the direct thermodynamic method, is suitable for pumping system investigations and condition monitoring.
The thermodynamic technique is well established with ISO standards and a code of practice. The method uses accurate and stable measurement of the differential temperature and pressure across the pump to provide efficiency measurement. The measurements provided are derived as shown in the box.
In a conventional pump test, efficiency is calculated from an equation requiring measurement of flow, head, the electrical input power to the pump and the motor efficiency. Flow is quite difficult to determine accurately and many pumps do not have accurate flowmeters. Motor efficiency may also have to be estimated.
This means that pump efficiency measurement by the thermodynamic technique is usually significantly more accurate than that obtained by conventional means.
The thermodynamic pump efficiency technique can be applied to: mine de-watering pumps, water and wastewater pumps, cooling pumps, boiler feed pumps, water turbines and irrigation pumps.
The method has also been applied to solutions and slurries.
Portable units are available for monitoring large numbers of pumps regularly.
Fixed units are installed on pumps whose performance is critical to the overall plant performance where continuous predictive monitoring is cost effective.
Tapping points are necessary to measure the differential temperature and pressure across the pump.
Benefits from using the thermodynamic technique include:
Improved energy efficiency allowing overall pumping control system optimisation and pump modifications to better match the pump with the application, for example impeller modifications.
Continuous monitoring by fixed units provides early warning of pumping problems and reduced risk of plant failure.
Timely identification of maintenance requirement without dismantling the pump.