1 Introduction In a conventional condensing steam power plant, the turbine exhaust is cooled and condensed into water in the condenser, while the cooling water is heated, and the heat is dissipated in the atmosphere or in the river, resulting in the loss of the cold source of the steam turbine. . This loss of cold source is a major cause of low thermal efficiency in thermal power plants. In order to reduce the loss of the cold source of the steam turbine, the steam turbine undergoes the following stages during the development of the steam turbine: the use of regenerative extraction steam is to use a portion of steam that has been used to perform work to heat the condensate or feed water of the steam turbine to increase the boiler feed water temperature. Reduce steam turbine exhaust steam, which is to reduce the loss of cold source. Using a back-pressure turbine or adjusting a turbine with a back-pressure turbine, a back-pressure turbine can be used to provide heat to the outside of the steam turbine exhaust, so that the cold source losses of the turbine can be utilized by the hot users to improve the operating economy of the entire system. In the same way, the steam extraction turbine is used to extract heat from a portion of the work steam for external heating, thereby reducing the loss of steam turbine cold source and improving the system economy. The so-called low-vacuum heating means artificially reducing the vacuum of the steam turbine condenser, increasing the exhaust temperature of the steam turbine, using steam turbine exhaust to heat the cooling water, increasing the outlet temperature of the cooling water, and using its external heating operation mode. . Condensing steam turbine low-vacuum heating is of great significance for improving the economic efficiency of small-scale power plants, reducing the water consumption of power plants, and reducing environmental pollution. However, due to the low-vacuum heating of steam turbines, it is a widely used operating condition. Therefore, this paper combines the low-vacuum heating reconstruction of CC12 steam turbine in Yingkou No. 1 Thermal Power Plant, the changes in the thermal process, turbine power, relative internal efficiency of steam turbine, condenser vacuum, etc., and the economic benefits of the transformation after steam turbine low-vacuum heating. Calculated and analyzed for the same type of steam turbine low-vacuum heating. 2 Comparison of Operation Modes for Low-vacuum Heat Supply of Steam Turbine The original design conditions of CC12 steam turbine at Yingkou No. 1 Thermal Power Plant were: cooling water flow Dw = 2000t/h; condenser cooling water inlet temperature = 20C; outlet temperature tW2 = 28% condensation The pressure of the unit is equal to 0.052MPa because the steam turbine only performs the low vacuum heating during the heating period in winter, and it still needs to be restored to the normal operation mode at other times. Therefore, the steam turbine body was not modified when the steam turbine was low-temperature heat-reforming. After the low-vacuum heating of the steam turbine, the cooling water flow Dw=1100t/h; the condenser inlet cooling water is also the heat user outlet water temperature twl=45C; the condenser outlet cooling water is also the hot user inlet water temperature tW2=65C, heating The area of ​​200,000 sq.m. Considering that the flow rate of the cooling water is reduced, the flow rate of the cooling water in the condenser is reduced, and the condenser is liable to cause fouling or clogging of the condenser. Therefore, the condenser is operated with a half surface. 3 Economical calculation method of low-vacuum heat supply for steam turbine Steam turbine heat flow calculation is due to turbine low-vacuum heating is a variable operating mode, in order to obtain the low-vacuum heating turbine flow through the various levels of thermal parameters, using The calculation method of the steam turbine was changed to thermal calculation under different working conditions to obtain parameters of steam turbine power, relative internal efficiency, and exhaust steam exhaust gas status point. 3. The thermal calculation of the condenser The relationship between the condensation temperature ts of the condenser and the cooling water temperature twl, the temperature rise At of the cooling water in the condenser and the terminal difference of the condenser is c), using the former Soviet Union The SuPM Thermal Research Institute's BePMaH formula. Steam Turbine Technology, 199840 (6): 332 Cao Lihua Li Yong. Improvement of Thermodynamic Calculation Method for Steam Turbine in Supercritical Stage. 化 AUTOMATION IN PETRO-CHEMICAL INDUSTRY. Steam Turbine Technology, 2001, 43(6): 341-343. Qi Fudong, et al. Power station condensing equipment and cooling system. Beijing: Water Conservancy and Electric Power Press, 1990. About thread rods is a bar that is threaded on both ends,and the thread may extend along the complete. normally it is long rod, Thread Rods, Aluminum Threaded Rod, Acme Threaded Rods Ningbo Brightfast Machinery Industry Trade Co.,Ltd , https://www.brightfastener.com
Like DIN975 own length with 1M.2M,3M,The standard is DIN975,DIN976 AND Us standards.but we also can produce non-standard ,it is according to drawings and Samples.
The grade in Germany standard:CL4.8,CL8.8
And in US standard/ASME B18.2.1 :CL2,CL5
We have ability to control the quality during production before sending to customers. We wish to do your best supplier of thread rods in China.
Thread Rods Purpose:
We are manufacture to supply our Bolts to our customers,We Have responsibility to give our best goods with good quality . So we will track all step to customers at all times. such as: products requirement,Technology and property ,package,shipment ,and files ,and sales serve,
Welcome all of you to contact with us,we promise to give our the best We are improving as your supporting.
Economic Analysis of Low Vacuum Heat Supply for Steam Turbines
Core Tips: 1 Introduction In conventional condensing steam power plants, steam turbine exhaust is cooled and condensed into water in the condenser, while the cooling water is heated and its heat is dissipated in the atmosphere or in the river, thus generating steam turbines. Loss of cold source. This loss of cold source is a major cause of low thermal efficiency in thermal power plants.