微型燃气轮机涡轮背盘冲击冷却特性研究

受可靠性和成本制约,微型燃气轮机冷却技术的发展和应用一直较为缓慢,已成为其进一步提升热效率的主要瓶颈。针对此问题,提出了一种简单可靠的径流涡轮新型冷却技术-背盘冲击冷却,使用气热耦合的方法对该冷却技术的冷却特性进行了仿真研究。结果表明:背盘冲击冷却可以大幅降低径流涡轮背盘的温度。当冷却气体流量为主流的2%时,冷却流体温度从473.0降到323.0 K,背盘平均温度降低了143.0～202.0 K;当冷却温度为323.0 K时,冷却气体消耗量从主流质量流量的1%增加到4%时,背盘平均温度降低150.0～252.0 K。冷却流体流入主流后会对其产生一定的影响,每增加1%的冷却流量,涡轮机效率下降约1%。

Back-disk impingement cooling performance of a micro gas turbine

Restricted by reliability and cost, the development and application of cooling technology for micro gas turbines have been relatively slow, which has become the main bottleneck for further improving its thermal efficiency. To solve this problem, a simple and reliable new cooling technology for radical turbines, back-disk impingement cooling is proposed. A conjugated heat transfer (CHT) simulation was carried out on a radial turbine with a full back-disc. The results show that the impingement cooling can greatly reduce the temperature on the back-disk surface of the radical turbine. If the mass flow rate of cooling air is fixed at 2% of the mainstream and the cooalnt temperature decreases from 473K to 323K, and the averaged temperature of the surface of back-disk can be reduced by 143K-202K. When the coolant temperature is a constant of 323K, the consumption of the cooling air increases 1% to 4% of the mass flow rate of the mainstream, the averaged temperature of surface of the back-disk can be reduced by 150K-252K . When the coolant flows into the mainstream, it will have a certain impact on it. The turbine efficiency will be decreased by about 1% with every increasing the cooalnt consumption by 1%