A novel liquid desiccant air conditioning with batch-wise operation strategy

摘要

Building climate control including temperature and humidity control by liquid desiccant air conditioning can account for more than 50% of total building energy consumption. Considerable energy savings can be achieved by system optimal design and fully utilizing the capacities of absorbing moisture of liquid desiccant. The paper proposes a novel liquid desiccant air conditioning with batch-wise operation strategy which can make full use of solution's potential in dehumidification by adopting two solution storage tanks. Desiccant solutions in dehumidifier and regenerator are self-circulation independently and exchanging intermittently to get a fully utilization of solution dehumidification capacity. Heat and mass transfer model based on control volume method is developed to evaluate the performance of dehumidifier and regenerator under different operating parameters, especially varying desiccant concentrations. Solution transfer process is described to determine the initial concentrations both in dehumidifier and regenerator after the transfer completed. Simulation study is carried out to compare the air dehumidification rate and solution regeneration rate between conventional ongoing exchange scheme and proposed scheme with batch-wise operation strategy. Results indicate that proposed batch-wise operation strategy can improve the performance of LDAC by about 6%. Optimal lower and upper limitations should be determined to get higher improvements.