Operation Of Heat Pump System Research Articles

Modelling and simulation of the chemical reaction heat pump system adopting the reactive distillation process

This study dealt with the optimal design of the chemical reaction heat pump system employing the reactive distillation process through modelling and simulation. A set of 2-propanol dehydrogenation and acetone hydrogenation reactions was used as heat transfer media. The results of simulation showed that the chemical reaction heat pump system embedded with a reactive distillation process had the better performance compared to the previous ones using a conventional distillation process. This paper proposes a new design criterion for the optimal operation of the chemical heat pump system employing the reactive distillation process by mathematical modelling and numerical simulation.

Experiences with a 3.3 MW heat pump using sewage water as heat source

In the town of Sala, situated in the middle part of Sweden 100 km west of Stockholm, a 3.3 MW heat pump extracting heat from purified sewage water is used to feed the district heating system. The heat pump which is equipped with a screw compressor was put into operation in June 1981. During the first year the need for maintenance was extensive. The reliability growth was delayed mainly because of vibrations in the slide valve used for capacity control of the compressor which caused damages in pipes and valves. After this initial period the heat pump has reached expected availability and performance. For 1983 the heat production was 25.6 GWh, the mean annual coefficient of performance 2.6 and the availability 93%. The profit for 1983 was calculated to 750,000 Sek, which indicates a pay-off time of 6.5 yr. Performance and operation of heat pump systems are generally sensible to temperatures and heat demand. The experiences from Sala confirm this and show the importance of having detailed information on the actual conditions already in the design phase. The evaporator which is made of galvanized carbon steel shows no signs of corrosion damage due to the sewage water. Heavy fouling of the evaporator has been observed at two occasions, both times in connection with the use of water from the nearby river as a supplementary heat source. Fouling of the evaporator due to the sewage water seems to be a minor problem. The water distributor outlet holes are easily clogged by larger particles from the sewage water and must be cleaned several times per year.

Residential heat pump experiments — I

AS A RESULT of experience in the operation of experimental heat pump systems in Philadelphia, Pa., it has become evident that it is necessary to direct efforts toward improving substantially the annual load factor of electrical service supply to such systems, to overcome the competitive handicaps inherent in utilizing electricity for house heating. The author believes that this objective may be accomplished through the development of economically feasible media for storing heat in sufficient quantities to permit a reduction in the maximum kilowatt demand for electricity of a heat pump system.