Chemical Adsorption Refrigeration System, Numerical Simulation And Experimental Study

Adsorption refrigeration is advantageous for environmental friendliness and energy conservation, so it is a promising alternative to traditional vapor compression refrigeration, and concerned by many scientists in the world. The application of adsorption refrigeration to recovery of engine exhaust heat is attractive and significant to social economy. This dissertation presents a preliminary analysis of adsorption refrigeration for diesel exhaust heat recovery by experimental investigations and numerical simulations. The main works are summarized as following.1. The progress of researches on adsorption refrigeration is presented. Especially the studies on working pairs, cycles and the design of adsorbent beds. The working pairs and cycles suitable for diesel exhaust heat recovery are chosen. The empirical adsorption rate of CaCIa桸Ha pair is modified through experimental investigation for non-equilibrium adsorption condition.2. An experimental adsorption refrigeration system is established. In order to simulate parameters of different diesel exhaust heat, an simulative multi-heat testing flat is set up with an combustor and two fans. The performance and basic parameters of several adsorbent beds driven by different diesel exhaust heat are experimentally obtained.3. The mathematical model for heat and mass transfer in the adsorbent bed is established, the porous of adsorbent, the flow of adsorbate in adsorbent, the characteristic of non-equilibrium adsorption are combined in the model, and a more accurate model of fluid flow in porous media-Ergun model is adopted.So the model is more integral and accurate in describing the performance ofheat and mass transfer in the adsorbent bed than the traditional mathematicalmodel.4. PENS ( perturbational exponential numerical scheme) is adopted to ensure the successful solving of the mathematical model and the reliability of results. Time-dependence of the mathematical model is taken into account, and time-dependent form of PENS is deduced.5. Numerical analysis of heat and mass transfer in the adsorbent bed ispresented, transient distribution of pressure, temperature, velocity and adsorption in it is obtained.6. Through numerical simulations, effects of the adsorbent bed configuration, thermal conductivity and permeability of the adsorbent are analyzed. Some technologies of heat transfer intensification are revalued.7. The research works about engineering application of adsorption refrigeration are presented. Questions about whether the adsorbent is endurable and whether the adsorption refrigeration equipment has effect on the performance of diesel are answered with theoretical analysis and test. Numerical simulation is used in optimum design of adsorbent bed of an adsorption refrigeration prototype which is driven by exhaust heat of gas electric generator.