Economic Analysis And Experimental Study On Heating Rebuilding Of Condensing Turbine

With the development of the society and improvement in living conditions,The heat requirement of users is increasing, but heat supply form the existing cogeneration unit can't meet the heat requirement. Meanwhile, the running hours of power generating units goes down because the low increasing rates of social power consumption and the development of clean energy, so this leads to a contradiction between the heat output and power supply. To solve the problem, an effective way is to reform the heat-supply on the condensing power units, this way can meet the heat requirement and increase the running hours.The heating reformation of condensing turbine can be solved in several ways. for instance, remaking to a back extraction pressure turbine, holing extraction on turbine, low vacuum circulating water heating. This paper briefly introduces and analyzes the technological features of these ways. By comparing the thermal efficiency indices among different plans, the best plan was decided. the safety and economics of the new units are analyzed through the field test and the theory calculation.Through the practice, the position of the extraction hole has great influence on the economy of the turbine which is holed. This paper takes a 350 MW condensing turbine as an example, using the theory of equivalent enthalpy drop and the map of heat balance provided by the design institute under nominal working condition, the increased standard coal consumption rates are calculated when the steam is extracted from 1# extraction hole to 6# respectively, the result shows that the lower the extraction position pressure, the less the increased standard coal consumption rates.The thermal efficiency indices under different working condition of the heating reformation turbine are calculated when the extraction position is on pressure pipe between intermediate pressure cylinder and low pressure cylinder. the result shows that the lower main steam flow, the less the coal consumption rates.To verify the rationality and accuracy of the theoretical calculation, thermal performance test is done. The thermal parameters' value are measured under different working condition based on national standard(GB8117-2008), and the thermal economical indices under different working condition are calculated after collecting and organizing data. The result shows that the test results are the same as the theoretical analysis on the whole.Finally, the running chart under different working condition are drawn based on the calculated results, this provides theory basis for safety and economical operation of co-generation unit.