Optimal procedure of heat exchanger design and its application on dual-stage-circle high temperature heat pump

An optimal procedure for heat exchanger design in high temperature heat pump (HTHP) involving heat exchanger type and heat transfer area optimization is presented. A typical dual-stage-circle HTHP system and original design of its heat exchangers are firstly introduced, integrated effects of heat transfer area on key parameters are discussed under nine heat exchanger types by means of the developed simulation tool. Within definite heat-exchanging area range, optimized heat exchanger types are obtained and then employed in further optimization involving total area optimization of evaporator and condenser (E-C plant), area ratio optimization of the E-C plant and area allocation optimization of E-C plant and regenerater. Case study show that the applied procedure is an effective way to sovle the mismatching of single components operating in HTHP. With constant heating capacity, optimal design using this precedure indicates an obvious effect with a 13% decrease on total area of exchangers and a 35.5% decrease on total number of evaporating heat exchange tubes.