车用发动机台架宽水温控制冷却系统

研制冷却系统,以进行发动机低水温台架试验.以水箱恒温水对汽油机稳定工况大循环冷却系统进行实验,得出冷却水温不变的结论.据此叙述系统主要研制技术和水温控制原理.系统采用旁通阀手动排泄适宜的进箱前冷却水量,用浮球阀自动向箱内补充等排泄量的冷水,使箱内水温稳定,并进行试验与性能分析.结果表明:汽油机在转速4000 r.min-1时各水温控制精度≤0.3℃,满足试验要求.此冷却系统运行可靠,实现在30～97℃之间任一冷却水温控制及节能减排.

Cooling System with Wide Coolant Temperatures Control on Vehicle Engine Testing Bench

The cooling system was developed to conduct engine bench tests at low coolant temperature.A conclusion was drawn that the temperature of coolant was maintained steady when large cycle cooling system of gasoline engine at stable conditions was experimented with constant temperature coolant in tank.The major technologies developed and coolant temperature control principles were stated here accordingly.Coolant temperature in tank was stabilized by draining manually moderate flow of coolant before feeding back into the tank via a bypass valve and adding automatically to the tank colder coolant equal to the drainage quantity via a float valve.The performances of the system were analyzed after gasoline engine tests.The results indicated that the coolant temperature control accuracy at different points was within 0.3 ℃ at 4000 r·min-1 engine speed and thus satis fied the required testing conditions.The system accomplished reliable operation at any controlled coolant temperature between 30 ℃ and 97 ℃,while achieved energy saving and emission reduction.