Performance Analysis of an Evaporator for a Diesel Engine-Organic Rankine Cycle (ORC) Combined System and Influence of Pressure Drop on the Diesel Engine Operating Characteristics

被引：23

作者：

Bei, Chen ^{[1
,2
]}

Zhang, Hongguang ^{[1
,2
]}

Yang, Fubin ^{[1
,2
]}

Song, Songsong ^{[1
,2
]}

Wang, Enhua ^{[3
]}

Liu, Hao ^{[1
,2
]}

Chang, Ying ^{[1
,2
]}

Wang, Hongjin ^{[1
,2
]}

Yang, Kai ^{[1
,2
]}

机构：

[1] Beijing Univ Technol, Coll Environm & Energy Engn, Beijing 100124, Peoples R China

[2] Collaborat Innovat Ctr Elect Vehicles Beijing, Beijing 100124, Peoples R China

[3] Tsinghua Univ, State Key Lab Automot Safety & Energy, Beijing 100084, Peoples R China

来源：

ENERGIES | 2015年 / 8卷 / 06期

基金：

北京市自然科学基金; 中国国家自然科学基金;

关键词：

TUBE HEAT-EXCHANGERS; FINNED-TUBE; RECOVERY; ENERGY; GENERATION; PRINCIPLE; INDUSTRY;

D O I：

10.3390/en8065488

中图分类号：

TE [石油、天然气工业]; TK [能源与动力工程];

学科分类号：

0807 ; 0820 ;

摘要：

The main purpose of this research is to analyze the performance of an evaporator for the organic Rankine cycle (ORC) system and discuss the influence of the evaporator on the operating characteristics of diesel engine. A simulation model of fin-and-tube evaporator of the ORC system is established by using Fluent software. Then, the flow and heat transfer characteristics of the exhaust at the evaporator shell side are obtained, and then the performance of the fin-and-tube evaporator of the ORC system is analyzed based on the field synergy principle. The field synergy angle (beta) is the intersection angle between the velocity vector and the temperature gradient. When the absolute values of velocity and temperature gradient are constant and beta < 90 degrees, heat transfer enhancement can be achieved with the decrease of the beta. When the absolute values of velocity and temperature gradient are constant and beta >90 degrees, heat transfer enhancement can be achieved with the increase of the beta. Subsequently, the influence of the evaporator of the ORC system on diesel engine performance is studied. A simulation model of the diesel engine is built by using GT-Power software under various operating conditions, and the variation tendency of engine power, torque, and brake specific fuel consumption (BSFC) are obtained. The variation tendency of the power output and BSFC of diesel engine-ORC combined system are obtained when the evaporation pressure ranges from 1.0 MPa to 3.5 MPa. Results show that the field synergy effect for the areas among the tube bundles of the evaporator main body and the field synergy effect for the areas among the fins on the windward side are satisfactory. However, the field synergy effect in the areas among the fins on the leeward side is weak. As a result of the pressure drop caused by the evaporator of the ORC system, the diesel engine power and torque decreases slightly, whereas the BSFC increases slightly with the increase of exhaust back pressure. With the increase of engine speed, power loss, torque loss, and BSFC increment increase gradually, where the most significant change is less than 1%. Compared with the diesel engine itself, the maximum increase of power output of the diesel engine-ORC combined system is 6.5% and the maximum decrease of BSFC is 6.1%.

引用

页码：5488 / 5515

页数：28

共 31 条

[1] Analysis of heat-transfer performance of cross-flow fin-tube heat exchangers under dry and wet conditions [J].