Application Study of Newly Developed Turbo Heat Pump for 130 Degrees Celsius Water for an Industrial Process

This paper reports application study of newly developed turbo heat pump for 130 degrees Celsius (°C) water for an industrial process in an actual factory. The heat pump is characterized by high efficiency and large heat output, by using a state-of-the-art turbo compressor. The heat pump requires a low temperature heat source in order to achieve high efficiency. The heat demand is for several drying furnaces in the factory, which requires producing hot air of 120 °C. The heat exchanger was designed to produce the hot air. Experiments were conducted to confirm the performance of the heat exchanger under a reduced size of the heat exchanger. Low temperature heat sources are from both exhaust gas of the drying furnaces and that of an annealing furnace. The heat exchangers were also designed to recover heat of the exhaust gas from the two types of furnace. A thermal storage tank was prepared for the low temperature heat source, and for adjusting the time difference between the heat demand and the low temperature heat source. The size of the tank was determined by considering the schedule of furnaces operations. As a result of the present study, it was confirmed that the heat pump was able to satisfy the present heat demand while retaining high efficiency. Primary energy consumption and CO₂ emission of the heat pump were calculated on the basis of the present results in order to compare them with those of the boilers.