Design And Experimental Investigation Of Ejector Refrigeration System Utilizes Ship Waste Energy

Energy crisis is becoming a pressing issue, which leads to energy saving and emission reduction being a researching hotspot and also a focus for all sectors of society. Ship waste heat ejector refrigeration system utilizes low grade energy as a driving force, which can effectively recycle and reuse waste heat energy that generated during ship’s operation, what’s more, the environmentally friendly working medium water is used as refrigerant, integrated advantages of simple construction, reliable working, long operation life and easy to repair and maintain makes it having grate research value and wide application prospect.This paper takes the ship "COSBRIGHT LAKE" which belongs to Dalian COSCO as an example, uses the datas of "COSBRIGHT LAKE" to calculates and analyses the ship waste energy utilization, the solutions of application project on ejector refrigeration system utilizes ship waste heat energy are presented. As the lower COP of the ejector refrigeration system limits its practical application, a experimental steam ejector refrigeration system was designed and built to make experimental investigations in order to optimize the design and improve the performance of the system. This paper studies (1) the influence of working conditions on the performance of the system, including condensing pressure, generation temperature, and evaporation temperature;(2) the influence of geometry ejectors on the performance of the system, including the length of constant section in the mixing chamber, the diameter of nozzle exit, the diffuser size. Conclusions can be drawn:(1) there is a critical condensing pressure in the working process, when condensing pressure is less than the critical value, the COP of the system does not change with the increase of condensing pressure, and when condensing pressure is greater than the critical value, the COP of the system quickly reduces with the increase of condensing pressure and finally reduces to zero;(2) the COP of the system reduces with the rise of generation temperature, and increases with the rise of evaporation temperature. The critical condensing pressure of the system increases with the rise of generation temperature and evaporation temperature.(3) the geometry ejectors have a great influence on the performance of the system, and the best ejector structure geometry needs to be designed according to different refrigeration requirements and certain working conditions.This paper provides a theoretical study for the optimization design of ejector refrigeration system utilizes ship waste heat energy, and is meaningful for the practical application in the future.