Development Of An Industrial High Temperature Heat Pump With Twin Screw Compressor

In industrial applications, 90-150°C hot water needed during production processes is traditionally provided by fuelfired boilers. The use of fuel-fired boiler has a low efficiency of energy usage and potential danger of explosion. Byproduced 30-60°Cwaste water with large amount of energy is rejected to environment directly, which causes a great energy loss and thermal pollution. Seeking for a high efficiency and safe heating equipment is essential to replace boilers used for now. High temperature heat pump (HTHP) is an ideal solution to reuse the energy in waste water and produces hot water needed. It has a higher efficiency than boilers through the use of energy contained in waste water. Water temperature provided by high temperature heat pump could reach up to 90-120°C. In this paper, an industrial high temperature heat pump with twin screw compressor was developed. For operating at high condensation and evaporation temperature safely, the twin screw compressor used in high temperature heat pump was modified, like the built-in ratio and motor capacity. Moreover, extensive experimental tests were carried out under several working scenarios. In this paper, High temperature heat pump could provide up to 95°C hot water with coefficient of performance (COP) changed from 3.5-4.3. The 1700kW heating capacity fully met the requirement in industrial heating field. Motor temperature of compressor was lower than 85 during the test period °C and the modified compressor kept work stability of the high temperature heat pump.