以压缩空气及水蒸气为工质的单螺杆膨胀机动力特性实验  

Experimental study of dynamic characteristics of single screw expander with compressed air and water steam as working fluid

作　　者：王景甫[1,2] 张勇[1,2] 张新欣[1,2] 薛艳青[1,2] 吴玉庭[1,2] 马重芳[1,2] 

机构地区：[1]北京工业大学传热强化与过程节能教育部重点实验室,北京100124 [2]北京工业大学传热与能源利用北京市重点实验室,北京100124

出　　处：《科学通报》2016年第17期1931-1939,共9页Chinese Science Bulletin

基　　金：国家重点基础研究发展计划(2013CB228306)资助

摘　　要：单螺杆膨胀机作为一种新型膨胀机,具有变工况性能好、低转速、高压比的特点,适用于分散型、小规模工业余热的高效热功转换.目前,国内外对单螺杆膨胀机的技术研发尚在起步发展阶段.本文以自主研发的螺杆直径117 cm的单螺杆膨胀机用于中低温热源发电系统为背景,设计和搭建了单螺杆膨胀机性能实验装置系统,分别以压缩空气和水蒸气为工质对单螺杆膨胀机的动力特性进行了实验研究.研究表明,以空气为工质时,单螺杆膨胀机在转速为2700 r/min时功率达到最高值4.4 kW,进口流量最大为32.9 m^3/h,进口和出口最大温差达到45℃,气耗率最低达55.2 kg/(kWh),总效率最高达到58.8%;以水蒸气为工质时,单螺杆膨胀机的功率最高达到3.9 kW,汽耗率最低达22.5 kg/(kWh),膨胀机总效率最高达到66%.The research and development of novel high-efficient devices used for thermal energy conversion of low-temperature heat source（blow 230°C） is of great significance for energy saving. Single screw expander is a novel expander with a lot of advantages, such as a good axial and redial force balance, a long working life which is twice of double screw, a high pressure ratio which is up to 15 for single stage, a highest volumetric efficiency which can reach 92%, 4% higher than that of double screw, a relatively high efficiency under part load condition, a simple structure, a lowest noise which is 10 d B lower than the double screw, and an oil free lubrication. In this paper, an experimental system used for testing the performance of a single screw expander whose diameter is 117 mm was designed and established. The number of screw head is 6 and the number of star wheel teeth is 11. The compressed air and the water steam were used as the working fluid to experimentally study the dynamic characteristics of single screw expander. In the experiment, the inlet temperature, the outlet temperature, the inlet pressure, the outlet pressure, the flow rate of the working fluid, the torque, the speed, and the power of the single screw expander were measured. When compressed air was used as the working fluid, the valve is fully open and the outlet pressure of the air compressor is set to be 0.75–0.85 MPa. From the experimental results, it can be seen that the single screw expander has an optimal power output working condition when the speed is about 2500–3500 r/min, and an optimal temperature drop working condition when the speed is about 2180–2700 r/min. The maximum torque was 4.4 kW when the speed of expander reached 2700 r/min. The maximum inlet flow rate was 32.9 m3/h. The initial inlet temperature of the expander was 22.7°C, and the final inlet temperature is 28.7°C. The variation of the inlet temperature is due to the inadequate heat dissipation caused by the long-time running of the air compressor. The lowest out

关 键 词：单螺杆膨胀机 压缩空气 水蒸气 动力特性 总效率 

分 类 号：TK115[动力工程及工程热物理—热能工程] TK05