Impact of Water Mass Flow Rate and Refrigerant Inlet Temperature on LMTD and Heat Transfer in Shell-and-Tube Heat Exchangers for Heat Pumps Using R407C

This paper presents an experimental investigation into the heat transfer performance of a shelland-tube heat exchanger using refrigerant R407C. The study focuses on the Log Mean Temperature Difference (LMTD) and heat transfer rate at varying mass flow rates and refrigerant temperatures. The results show that the rate of heat transfer increases as the mass flow rate increases, with a range of 8.78 kW to 10.72 kW as the mass flow rate changes from 0.08 kg/s to 0.1 kg/s. The increase in heat transfer rate is between 13.6% to 17.8%, with the highest observed at 82°C. The LMTD also increases with rising refrigerant temperature, ranging from 22.98°C to 26.87°C, with the highest value recorded at 84°C. These findings highlight the relationship between mass flow rate, refrigerant temperature, and heat transfer efficiency, offering valuable insights for optimizing heat pump system performance.