Steam turbines have relatively good part-load performance, but . Any pressure, temperature and flow rates changing at the inlet and/or outlet conditions will affect the both turbine isentropic efficiency and thermal efficiency. Part-load . The ’80s were a period of uncertainty. Parsons actually built a number of these machines (ca. 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. produce low pressure steam while extraction turbines deliver both low . 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. Back-pressure steam turbines can have many different back pressures, further increasing the variability of the power-to-heat ratio. LP Turbine – Low-pressure Steam Turbine. 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. 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. This table is for classic steam/boiler CHP system with the capacities of 500kW, 3MW, and 15MW. pump(s) and isentropic efficiencies of steam turbine(s) and pump(s). efficiency does decline as power output is reduced. Fuel Boilers are commonly used to generate steam required for steam . After steam reaches a turbine it expands, losing pressure and temperature. can then be calculated from the ratio of actual to isentropic enthalpy drop. operation. The measurements required to determine the HP and IP turbine section efficiencies are shown in Figure 3. 1900), with blading based upon improved propeller sections. Backpressure steam turbines . The case power plant is located in Marmara region as two units. It produces 160 MW per unit with 37% efficiency. An extraction turbine has one or more openings in its casing for extraction of a portion of the steam at some intermediate pressure. 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. pressure which was utilized in the late ’60s and early ’70s. A third steam turbine type is extraction steam turbines. The extracted steam may be used for process purposes. Extraction. pressure and medium pressure steam. 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. The turbine expan-sion line in Figure 2illustrates this relationship. As a result, the solubility of the silica decreases.