Fundamentals And Applications For Creatin Novel Absorption Refrigeration Cycles

With economic development and improvement of people’s life quality, the energy consumed by the refrigeration and heating makes up a growing percentage of the total energy consumed by the whole society; On the other hand, a lot of industrial waste heat has not been utilized. This leads to the researches on absorption refrigeration systems which can be driven by waste heat and are friendly to environment have attracted more and more attentions.The competitive power of absorption refrigeration systems can be improved by improving their performance. Using the novel absorption refrigeration cycles is one of the most important methods to improve their performance. Conventionally, constructing the novel absorption refrigeration cycles mainly depends on the talent of the researchers. It would take a long time and be not efficient. Considering the characteristic of the process of the cooling, this paper proposes a new method named as cooling availability and uses it to analyze the absorption refrigeration cycles and construct novel absorption refrigeration cycles.For the technical problem of that variable-temperature waste heat at medium-low temperature are not made full use, this paper finds that there are potential diffusion cooling availability which belong to the solution out from the absorber of conventional single effect cycle. The potential diffusion cooling availability can be converted to real diffusion cooling availability by decreasing the equivalent surrounding temperature of the solution. Based on the above breakthrough of research approach, a new novel absorption refrigeration cycle with simple structure is constructed in this paper. This cycle can make efficient use of the variable-temperature waste heat. Then the detail theoretical analysis on the new cycle is presented. Simulation results show that the cooling per unit mass of the heating fluid of the new cycle is always20%higher than that of conventional single effect cycle at all simulated working conditions.For the technical problem of that it is difficult to make efficient use of the waste heat at low temperature, this paper constructs two new novel0.x effect absorption refrigeration cycles based on cooling availability analysis method by making rational use of the real diffusion cooling availability of the solution or changing the real diffusion cooling availability to match different working conditions. The simulation results show that the performance of the new cycles are better than that of conventional cycles at most simulated working conditions. This is very important to make efficient use of the waste heat at low temperature.For the technical problem of that it is difficult to make efficient use of the waste heat at medium temperature, this paper constructs two novel1.x effect absorption refrigeration cycles based on cooling availability analysis method by changing the real diffusion cooling availability of the solution by changing the concentration of the solution into absorber or ideal absorption temperature of the solution out from absorber respectively. The simulation results show that the COP of the1.x effect absorption refrigeration cycles is20%higher than that of conventional single effect cycle at some simulated working conditions.To validate the performance of the proposed new cycles and theory model used in this paper, an experimental system of the ejector-absorption combined refrigeration cycle based on conventional double effect absorption refrigeration cyccle is designed and built.The ejector-absorption combined refrigeration cycle is one type of1.x effect absorption refrigeration cycle proposed in this paper. The experimental research shows that the experimental results coincide well with the simulation results. What is more, when evaporation temperature is5℃, absorption temperature and condensation temperature are40℃, if the generation temperature reaches to135.3℃, the COP of the new cycle is about0.9and24%higher than that of conventional single effect cycle, when generation temperature is127℃, absorption temperature and condensation temperature are40℃, if the evaporation temperature reaches to10℃, the COP of the ejector-absorption combined refrigeration system is about1and30%higher than that of conventional single effect cycle. Then the performance of the constructed new cycles being better than that of conventional cycle is proved by experiment.