Research Of Absorption Heat Transformer With Falling Film Inside Tubes

Absorption heat transformers ( AHTs ) for upgrading of heat are useful for heat recovery of low-level thermal energy. In industrial applications, AHTs take thermal energy from a low-temperature process stream and deliver it to a higher-temperature point in the process. The recycled thermal energy will therefore reduce the prime energy need in the process.For the purpose of developing more efficient and compact AHTs on different conditions, more abroad and elaborate work about AHTs needed to be done in these area:A) the research of thermodynamic and absorption mechanism;B) the research of the heat and mass transfer enhancement;C) the development of new working fluids;D) the research of the optimization and simulation.A new designed AHT with falling films of absorbent inside vertical tubes is proposed, and then experiments are conducted on the AHT newly set. The main work is as follows:A) To set up a set of AHT with falling films of absorbent inside vertical tubes, investigations of AHT performance provide some theoretical bases for the optimal operation and design of industrial scale AHT systems.B) The result proves the new design of heat pump more convenient in maintenance, excellent in performance, and the COP of the AHT is about 0.38~0.42, Eth is about 0.62.C) We apply spirally corrugated tubes in the absorber, generator, evaporator of the AHT, and analyze its heat and mass transfer performance.D) The result proves spirally corrugated tubes are excellent in heat and mass transfer performance, and more stable in practice.E) Absorption SIMulation (ABSIM) is employed to simulate the newly designed AHT system. The computer code ABSIM developed by Gershon Grossman is used for simulation and design optimization of absorption systems in a flexible and modular form.F) The simulation result proves that experimental data and calculated data show fairly good agreement. So it may serve well for investigation of various cycle configuration with different working fluids, and calculation of the heat and mass transfer coefficients and performance coefficients.