Process design and analysis of a flexibly adjusted zonal absorption heat exchanger for high-rise building heating systems

Abstract

• A flexibly adjusted zonal absorption heat exchanger is proposed. • It can realize the function of independent heat supply in each zone. • The heat exchange efficiency under the design condition reaches 1.268. • The system has symmetry for the heat supply of each zone. • The zonal absorption heat exchanger has excellent flexible adjustment ability. In terms of the high-rise buildings with large areas, the heating system of the vertical zone is generally considered to solve the problems of hydraulic imbalance and bearing pressure. On the basis of the conventional plate heat exchanger, a flexibly adjusted zonal absorption heat exchanger utilized in the heating station for high-rise buildings is proposed in this paper. This system can realize the function of the zonal plate heat exchanger and the absorption heat exchanger at the same time. Under the conventional design condition, this system can reduce the outlet water temperature of the primary network to 17.4 K lower than the inlet water temperature of the secondary network. The heat exchange efficiency of the AHE reaches 1.268. The low water outlet water temperature of the primary network contributes to the waste heat recovery and improves the heating capacity. Moreover, the system has excellent heat load adaptability and adjustment ability under the partial load. The heat load rate of different zones decreases in the same proportion at the partial load condition. When the flow rate of the primary network decreases to 25% of the design value, the difference of the heat load rate in different zones is only 1.7%. The results contribute to the energy conservation in zonal heating systems.