Tham khảo tài liệu 'steam power by mike brown_6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Simpo PDF Merge and Split Unregistered Version - http Figure 19 Typical Automatic Extraction Cycle 750 F Í TURBINE GENERATOR BOILER 400 PSIG STEAM TO PROCESS OR HEATING LOAD ---- HIGH I PRESSURE 1 HEATER i 75 PSIG ELECTRICITY CONDENSER FEED BOILER PUMP COOL NG WATER CONDENSATE RETURN tank CONDENSATE RETURN CONDENSATE --Í RETURN CŨNDENĐATE PUMP DEAERATING HEATING Simpo PDF Merge and Split Unregistered Version - http MIL-HDBK-1003 7 Back Pressure Type. Back pressure turbines usually operate with high pressure high temperature throttle steam supply and exhaust at steam pressures in the range of 5 to 300 psig 34 to 2068 kPa gage . Un-controlled steam extraction openings can be provided depending on throttle pressure and exhaust pressures. Two methods of control are possible. One of the methods modulates the turbine steam flow to be such as to maintain the turbine exhaust pressure constant and in the process generate as much electricity as possible from the steam passing through the turbine. The amount of electricity generated therefore changes upward or downward with like changes in steam demand from the turbine exhaust. A typical back pressure cycle is shown in Figure 13. The other method of control allows the turbine steam flow to be such as to provide whatever power is required from the turbine by driven equipment. The turbine exhaust steam must then be used at the rate flowing through the turbine by other steam consuming equipment or excess steam if any must be vented to the atmosphere. Atmospheric Exhaust. Atmospheric exhaust is the term applied to mechanical drive turbines which exhaust steam at pressures near atmospheric. These turbines are used in power plants to drive equipment such as pumps and fans. Turbine Generator Sizes. See Table 9 for nominal size and other characteristic data for turbine generator units. Noncondensing and Automatic Extraction Turbines. The sizes of turbine generators and types
