Based On Organic Rankine Cycle Research In Waste Heat Recovery Of Marine Diesel Engine

Currently, the marine diesel engine thermal efficiency has been up to 50%, is the highest in all power machinery. But nearly half of the heat is lost by the way of exhaust and cooling,etc, which not only causes a waste of energy,but also pollutes the environment. If this part of the heat loss can be recycled,it will be win-win initiatives in increasing thermal efficiency and reducing environmental pollution. But the temperature of marine diesel engine heat loss is relatively low, conventional methods are difficulty to be used effectively. The Organic Rankine Cycle wasted heat recovery technology has some technical advantages in the field of low-temperature wasted heat recovery, which has been widely used in industrial wasted heat,solar and other relatively low-grade heat recycling. Therefore, the paper chooses high-power two-stroke low-speed marine diesel engine as research subject and researches on the use of Organic Rankine Cycle marine wasted heat recovery.Firstly, starting from the thermodynamic principles of Organic Rankine Cycle, the paper analyses the various stage thermodynamic models of the Organic Rankine Cycle in details and summarizes the selection principles and standards of organic working fluid. The most common of the eight organic working fluids are selected as alternative refrigerants of the following studies based on this. Bring up the thermodynamic parameters.Secondly, the paper selects main marine diesel engine 6S50ME-C8.2 type produced by the MAN Company as research object. Based on the test data of the propulsion characteristics,calculate Organic Rankine Cycle system recyclable power of exhausted heat and ORC systems recyclable power of cooling wasted heat under different main engine loads. By comparison, the effect of the Organic Rankine Cycle cooling wasted heat recovery system is better. And the solutions of cooling wasted heat recovery makes small changes in the main engine structure, which particularly applies to the wasted heat recovery projects of old ship alterations.Once again, almost no domestic companies use the ORC technology to recovery wasted heat of marine diesel engine, so that the paper gives structural designs of Organic Rankine Cycle wasted heat recovery system main thermal equipments in details and makes optimization calculations of related parameters. Provide the basis for subsequent numerical simulations and designs. At the same time, by estimating structure sizes of the 9S50ME main engine Organic Rankine Cycle wasted heat recovery system main thermal equipments, learn that space size is one of the factors restricting Organic Rankine Cycle wasted heat recovery system from applying to higher powerful marines.Finally, establish diesel main engine numerical simulation models by the GT-SUITE software. Validate the simulation models combined with the experimental data. Then install Organic Rankine Cycle wasted heat recovery models to recover the main engine cooling wasted heat. Make comparative analysis of the main parameters change under different main engine loads. Draw out that the effects of Organic Rankine Cycle system under main engine high-load operation is better. Make further analysis of the wasted heat system main parameters effects. Give out the best running program of wasted heat recovery system under the main engine high load operation.