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The present paper analyzes the feasibility of an exhaust gas driven jet-ejector cooling system for charge air cooling of turbocharged gasoline engines in addition to the conventional charge air cooler to increase the engine efficiency. Thereto, steady-state experiments of a jet-ejector cooling system and an exhaust gas heat exchanger prototype working with the refrigerant R134a are used to analyze the operation and control of the compound system and determine feasible cooling capacities, charge air temperatures, thermal COP th and hydraulic COP h . Moreover, the cooling system is rated regarding its power densities and engine backpressure. The exhaust gas waste heat recovery, system power densities, and engine backpressure are acceptable. However, the hydraulic COP h and the amount of reject heat need to be improved, necessitating for instance a multi-staging of the jet-ejection. [ABSTRACT FROM AUTHOR]

Abstract: An important drawback of solid sorption systems which are operated in batch mode against liquid sorption systems is the imperfect heat exchange between loaded and unloaded adsorbent, as compared to the almost perfect counter-flow solution heat exchanger. We will discuss a simple hardware solution for a significant improvement. We divide the batch reactors into several compartments, not with respect to the refrigerant side, but with respect to the heat transfer medium (heat exchanger loop). If these compartments have individual and arbitrary heat exchange possibilities with each other the efficiency of heat recovery can be improved from a co-flow characteristic to a cross-flow characteristic. We want to stress that this is different from a multi-bed or multistage arrangement. The method is explained, and an algorithm for deriving the exchange efficiency is given. Although this paper is only meant for outlining the basic mechanism, a proposition for realisation of the external hydronic circuit is given in addition. [Copyright &y& Elsevier]