A Design Of Compact Solar Li-Br Absorption Chiller Driven By Low-temperature Heat Source

As people demand higher on the thermal environment of buildings, a series of problemsaccompanied by building energy consumption and environmental pollution has received moreand more attention. Solar thermal driven cooling system, which has no pollution, low energyconsumption and good season match, are a promising alternative to electric compressionchillers. In the previous research in our lab, the effects of ultrasonic waves on the masstransfer enhancement in absorption chiller were carefully studied. This paper proposed acompact solar Li-Br absorption chiller driven by low-temperature heat source base on theformal study. This paper focuses on the design of the internal heat transfer unit structural ofthe absorption chiller including heat-transfer area, heat-transfer coefficient, and structuredimensions etc. A simulation model is built by solar transient simulation software–TRNSYS.The influence of main components of solar chiller on the performance is analyzed. A microcontroller is designed for control system of absorption chiller. Finally, the performancesoptimization of the controlling system is preliminary designed. Specific research contents andconclusions are as follows:(1) In this paper, cooling load of room101, No.19thbuilding of South China Universityof Technology is chosen as research object. Computing software of solar Li-br absorptionchiller which is developed previous used to determine the parameters of state points ofabsorption chiller and completed the heat balance calculation. Based on the result of thedesign state point parameters, the paper calculates the heat transfer load of internal componentof chiller and then designs its structure parameters. In view of the different workingenvironment and features of heat transfer equipment, different surface of structure aredesigned to strengthen heat and mass transfer. Finally, the cooling tower of absorption chillerand solar heating/storage system is designed.(2) In order to evaluate the performance of solar thermal driven cooling system, asimulation model is built by solar transient simulation software TRNSYS. The influences ofsolar collectors, heat storage water tank and absorption chiller on solar fraction, the averageefficiency of the solar heating system and the performance of solar thermal cooling system areresearched. According to typical meteorological year data of Guangzhou area, theperformance curve of solar thermal cooling system in July is analyzed.（3）Automatic control system is developed according to the continuously changingcharacteristics of load and operating parameter of absorption chiller. A micro controller, which including analog acquisition, data input/output, serial port communication and digital displayet al, is designed based on the requirements. Finally, the preliminary design and optimize theautomatic control program of solar thermal driven cooling system is completed.