摘要
针对椭圆公式在汽轮机有限级适用的问题,通过改变等熵指数计算最佳椭圆指数,并对有限级两种达临界状态进行推导建模,建立了音速压比模型和质量流量压比模型。结果表明:改进椭圆公式比传统椭圆近似公式的计算结果更趋近彭台门系数;在实际有损失流动时,若要级质量流量达最大,以质量流量压比模型公式计算,若要级出口达音速,以音速压比模型公式计算;两种压比模型均满足工程应用的精度要求。
To solve the problem existing in application of ellipse formula to turbines with a finite number of stages,the optimal index of elliptic operator was calculated by changing the isentropic index,and with the establishment of mass flow pressure ratio model and sonic pressure ratio model,the formula derivation and modeling were conducted for the turbine with a finite number of stages under two critical conditions respectively.Results show that the result calculated based on the improved ellipse formula is more close to the Pengtemen coefficient than that based on traditional ellipse approximation formula.When energy loss exists in actual flows,to maximize the stage flow,the mass flow pressure ratio model is to be adopted,whereas,to make the stage outlet achieve the sonic speed,the sonic pressure ratio model would be preferred.Both the models can meet the precision requirements in engineering applications.
作者
陈晓欣
胥建群
毛宝雪
Chen Xiaoxin;Xu Jianqun;Mao Baoxue(Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,Southeast University, Nanjing 210096, China)
出处
《发电设备》
2020年第2期92-95,共4页
Power Equipment
关键词
汽轮机
椭圆公式
椭圆指数
质量流量压比模型
音速压比模型
精度
steam turbine
ellipse formula
index of elliptic operator
mass flow pressure ratio model
sonic pressure ratio model
precision
