CAJ | 학술논문

针对发动机排气、冷却水余热、汽轮机中膨胀后的工质乏气以及经过单级换热后的排气处于不同品位，提出了一种梯级回收发动机余热的新型双朗肯联合循环．此系统中两级循环均采用亚临界饱和循环．在第1级循环中，以水作为工质，没有预热循环，直接利用排气与其换热；在第2级循环中，以 R123作为工质，用发动机冷却水和第1级循环中汽轮机出口的工质乏气对 R123进行串联预热，预热后的工质与经过第1级换热后的排气再进行换热．结果表明：系统发出的净膨胀功和循环热效率随两级循环蒸发压力均是先增大后趋于平坦；当第1级循环蒸发压力大于12,MPa、第2级循环蒸发压力大于1.5,MPa时，净膨胀功和循环热效率增长不大．
침대발동궤배기、냉각수여열、기륜궤중팽창후적공질핍기이급경과단급환열후적배기처우불동품위，제출료일충제급회수발동궤여열적신형쌍랑긍연합순배．차계통중량급순배균채용아림계포화순배．재제1급순배중，이수작위공질，몰유예열순배，직접이용배기여기환열；재제2급순배중，이 R123작위공질，용발동궤냉각수화제1급순배중기륜궤출구적공질핍기대 R123진행천련예열，예열후적공질여경과제1급환열후적배기재진행환열．결과표명：계통발출적정팽창공화순배열효솔수량급순배증발압력균시선증대후추우평탄；당제1급순배증발압력대우12,MPa、제2급순배증발압력대우1.5,MPa시，정팽창공화순배열효솔증장불대．
Based on the different grades of engine exhaust, coolant waste heat, the refrigerant after expansion, and the exhaust after one-stage heat exchange, a new two-stage ORC combined cycle for cascade recovery of the above waste heat is proposed. Both of the cycles in this system use sub-critical saturated cycles. In the first cycle, there is no pre-heating cycle and heat is exchanged directly between exhaust and water, which is used as the refrigerant. In the second cycle, R123, which is used as the refrigerant, is first preheated by engine coolant and the superheated refrigerant after expansion in the first cycle in series, and then heat is transferred to R123 from the exhaust after heat exchange in the first cycle. Results show that both the net output power and the cycle efficiency increase sharply first and then plainly with the increase of the first cycle and the second cycle evaporating pressure. When the first cycle and the second cy-cle evaporating pressure is over 12 MPa and 1.5 MPa, respectively, there is little change in the net output power and the cycle efficiency.