An Analytical Model for Predicting the Performance of an Exhaust Gas Cooling System

摘要

A typical system for removing exhaust gases from an altitude test cell consists of cooling the exhaust gases in water spray coolers and removing the saturated exhaust stream by means of mechanical pumping machinery. The spray cooling system may consist of a cooling chamber immediately downstream of the test cell where atomized water is mixed with hot exhaust gases to cool by saturation and dehumidification and a second cooling chamber of similar construction immediately upstream of the exhaust pumping machinery for additional cooling by dehumidification. An analytical model of such a system is presented that develops the mathematical relationship between the two spray cooling chambers and the required pumping machinery parameters and the required engine conditions. Then by varying the cooling water flow rate, velocity, and temperature at separate coolers in the model and specifying the maximum desired duct temperature, it is possible to predict those conditions that will give a minimum cooler inlet pressure. Several typical conditions are investigated using the analytical model to show the influence of cooling water parameters on the test cell pressure. (Author)