The measurements required to determine the HP and IP turbine section efficiencies are shown in Figure 3. Any pressure, temperature and flow rates changing at the inlet and/or outlet conditions will affect the both turbine isentropic efficiency and thermal efficiency. LP Turbine – Low-pressure Steam Turbine. pressure which was utilized in the late ’60s and early ’70s. Part-load . A third steam turbine type is extraction steam turbines. The turbine expan-sion line in Figure 2illustrates this relationship. After steam reaches a turbine it expands, losing pressure and temperature. The case power plant is located in Marmara region as two units. However, simply reversing a turbine for use as a compressor gives efficiencies that are, according to Howell (1945), less than 40% for machines of high pressure ratio. Steam turbines have relatively good part-load performance, but . Most of nuclear power plants operates a single-shaft turbine-generator that consists of one multi-stage HP turbine and three parallel multi-stage LP turbines, a main generator and an exciter. operation. can then be calculated from the ratio of actual to isentropic enthalpy drop. pressure and medium pressure steam. 1900), with blading based upon improved propeller sections. Backpressure steam turbines . As a result, the solubility of the silica decreases. Parsons actually built a number of these machines (ca. This table is for classic steam/boiler CHP system with the capacities of 500kW, 3MW, and 15MW. efficiency does decline as power output is reduced. produce low pressure steam while extraction turbines deliver both low . The extracted steam may be used for process purposes. Back-pressure steam turbines can have many different back pressures, further increasing the variability of the power-to-heat ratio. Studies have shown that with a maximum of 0.02 ppm of silica in the steam, a pressure of less than 200 psig is reached in the turbine before silica starts to condense from the steam. Extraction. The pressure ratio in sCO 2 Brayton cycles is small compared to that of the steam Rankin cycle, and the turbine outlet temperature is relatively high so that a greater amount of heat must be recuperated to increase the thermal efficiency. Power/Heat Ratio = CHP electrical power output (Btu)/ useful heat output (Btu) Following table 1 is showing the list of different performance characteristics f various commercial steam turbines. By 1975 steam conditions of 2400 psig/ 1 OOO’F/ 1000°F for utility turbines had become the standard although the performance was poorer than the steam conditions which had been used previously. The ’80s were a period of uncertainty. Fuel Boilers are commonly used to generate steam required for steam . pump(s) and isentropic efficiencies of steam turbine(s) and pump(s). An extraction turbine has one or more openings in its casing for extraction of a portion of the steam at some intermediate pressure. It produces 160 MW per unit with 37% efficiency.