An Air-Cooled Jet-Refrigeration Cycle Design with a Two-Stage Ejector Applied in Vehicles

摘要

A jet-refrigeration cycle which contains a two-stage ejector and an air-cooler is presented to discuss whether this refrigeration cycle is suitable for vehicles.There's huge energy from gas emitted by vehicles yet to be used,but the exhaust gas temperature is high so there's limit in choosing appropriate refrigerant.Pure water is utilized as refrigerant in this system,as the boiling temperature of water is relatively high.Waste heat from vehicles could be used effectively to heat the water up to 473K.Thusly,a two-stage ejector could be used combined with a higher condensing temperature of 318K and evaporating temperature of 278K.In order to reduce vibrating from the system,an additional valve system is presented to replace pump.Through certain adjustment strategy with valves,this system uses a small part of pressure from generator outlet as initial force for recycling water back to generator.In addition,valid mathematic model is presented for design and simulation.The COPs of the cycle in several different operating conditions are calculated to predict the experiment outcomes.A conclusion is reached that ejection cycles is suitable for vehicles with huge energy consumption.However,further investigation should be done to make the system more compact and stable.