The original design of heating boiler feed pump adopts motor with maximum power of 450kW. Due to excess steam at 0145MPa (gauge pressure), a steam turbine is added instead of a motor-driven feed pump by adopting a combined heat / Boiler feed water needs, but also save energy and improve economic efficiency. First, the steam turbine-driven feed pump work system Heating system boiler in normal operation, its water supply must be oxygen scavenged oxygen are taken from the steam turbine exhaust steam or steam balance pipe network, which will make a lot of high-pressure steam through Throttling device into low-pressure steam, resulting in a tremendous waste, reducing the overall thermal efficiency "According to the principle of thermal power co-generation energy-saving technology, the use of low-power single-stage back pressure turbine to replace the pump motor, reducing the refinery electricity , Reduce overall energy consumption. " Heating boiler 1 #! 2 # deaerator has been using 0145MPa steam decompression desalination water heating and deoxygenation, steam consumption of about 11tPh "0145MPa steam mainly from catalytic pressure machine back pressure steam pipe network" pressure of 0145MPa! Temperature 210e Of the superheated steam down to 0105MPa! 150e, and then sent to the deaerator from the water treatment section demineralized water heated deoxygenated coagulation into 104e deaerated water, the steam consumption is only more than the original 017tPh, but with the 0145MPa Steam heat "This energy conversion in the low-pressure steam turbine to complete its thermal cycle system shown in Figure 1. Second, the application of steam turbine feed water heating system Three boilers using DG85 medium pressure feed pump and two low pressure Feed pump, DG85 Feed pump flow 85m3Ph, lift 598m, run 2, reserve 1 "In 1997 the boiler added a 10 # feed water pump, flow 150m3Ph, lift 598m, supporting motor power 440kW" under normal circumstances, Running 10 # Feed Pumps, 3 Pumps Standby "One 85m3Ph Feedwater Pump Operates on Shutdown" In order to meet the deaerator requirements of the boiler, the design flow of the steam driven feed pump is 200m3Ph and the lift is 600m The pump material 1Cr13Ni stainless steel, to overcome the cavitation of the feed pump; The pump uses mechanical seals to overcome the frequent leakage of packing seal to ensure long-term operation "Low-pressure steam turbine selection Hangzhou Steam Turbine Power Group B72L Series B0.5 -5.5P1.5 single-stage back pressure steam turbine "Rated power 500kW, speed 3000rPmin, speed range 2400 ~ 3180rPmin, into the steam pressure of 0155MPa (absolutely), the exhaust pressure of 0115MPa, into the steam temperature 180 ~ 200e, exhaust temperature 160e , Steam consumption of 28177kgP (kW # h) .Through the single-layer layout, and feed pump share a base, to reduce the installation space; Turbine and feed water pumps are used rejection oil lubrication; Support; pump and turbine connection using metal laminated flexible coupling; speed control system using the United States WOODWardTG13 governor, mechanical flying hammer speeding protection. Third, the application effect of the pump driven steam turbine after installation and commissioning , Pump flow control 160m3Ph, pressure 610MPa, steam consumption 915tPh "due to the 0145MPa steam pressure and temperature fluctuations, a direct impact on steam turbine speed, resulting in pump flow and pressure waves Move "speed control range of 2800 ~ 2920rPmin, the pump can be run smoothly" By the same water load comparison, the use of steam turbine-driven pumps to meet the production needs, electricity price of 015 yuan P (kW # h) dollars, if the Safe operation of the pump 8000h, a total of 1.6 million energy-saving fee, a year to recover the investment, significant energy-saving and efficiency. Fourth, the conclusion 1, the use of single-stage low-pressure steam turbine-driven boiler feed pump / cogeneration 0 mode, can increase the economic benefits of thermal power enterprises. 2, the boiler feed pump motor drive and turbine drive each other, can improve the reliability of the boiler safe operation. 3, Low-pressure steam turbine driven feed pump, easy installation, adaptability, energy-saving effect is remarkable.