Vacuum pump can be used in two processes of vacuum pumping and vacuum maintenance of steam turbine condenser. Vacuum pumping is an indispensable and important process before refrigerant filling in refrigeration equipment during production or repair. The application of vacuum pump in steam turbine condenser has the effect of vacuum pumping. Vacuum pump refers to the device or equipment that uses mechanical, physical, chemical or physical chemical methods to extract air from the pumped container to obtain vacuum. Simply speaking, vacuum pump is a device that improves, produces and maintains vacuum in a closed space by various means. It is widely used in pharmaceutical, metallurgical, chemical, food, electronic coating and other occupations.
After the exhaust steam of the steam turbine leaves the low pressure cylinder, it enters the shell side of the condenser. The circulating water supplied by the circulating water pump is flowed into the condenser tube as the refrigerant to condense the exhaust steam into water. Then the condensate pump is pumped into the condensate system and recycled. This is the function of the condenser.
As steam condenses into water, its volume shrinks abruptly, which forms a high vacuum in the condenser.
Generally speaking, the condenser vacuum, that is, the exhaust pressure, can be determined by the corresponding saturated steam temperature. The higher the vacuum is, the lower the exhaust temperature is, the higher the thermal cycle efficiency of the steam turbine is.
Steam Turbine Condenser Working Principle：
The high temperature and high pressure refrigeration steam from the compressor enters the condenser through the high pressure hose; because the temperature outside the vehicle is lower than that of the refrigerant entering the condenser, most of the heat of the refrigerant flowing in the condenser is taken away by the air outside the vehicle with the help of the condensing fan, thus the high temperature and high pressure gas is condensed into high temperature and high pressure. The liquid. When the high temperature and high pressure liquid flows through the throttle expansion valve, the volume suddenly becomes larger and the pressure is lowered due to the throttling effect. It becomes a low pressure and low temperature mist liquid which enters the evaporator and vaporizes under constant pressure. Because the temperature of the refrigerant vaporizes in the tube is lower than the circulating air outside the evaporator tube, it can absorb the heat in the air outside the tube. As a result, the air temperature flowing through the evaporator decreases, resulting in cooling effect. The vaporized refrigeration steam is sucked and compressed by the compressor, and becomes high temperature and high pressure gas, thus completing a refrigeration system cycle.
In the vacuum pumping stage, the air and other non-condensable gases in the condenser are extracted by the initial vacuum pumping when the steam has not been introduced into the condenser; in the vacuum maintenance stage, the vacuum pump continues to work to extract the leaking dry air during the operation of the condenser to maintain the condenser back pressure at the optimum working point to ensure the efficient operation of the steam turbine. OK, improve the thermal efficiency of the power plant. The optimized vacuum pump can satisfy the reliable operation of users under various complex working conditions.
With the widening application of refrigeration equipment, vacuum pump equipment will also receive great attention. The market prospect of vacuum pump is broad. Only by eliminating the shortcomings of the profession at that time and improving them, can the market demand be satisfied. In the future, automata and intellectualization trend are remarkable. Intelligent vacuum pump may become one of the keys to skill breaking.
At present, problems such as cavitation and impeller cracks are common in condensers, and the power consumption of vacuum pumps can be reduced by 70-80% under the same working conditions. Roots vacuum pump can reduce the pressure fluctuation amplitude at the moment of exhaust, reduce the aerodynamic noise and temperature rise from the source, and speed up the vacuum extraction speed of condenser because of its fast pumping speed and unaffected by ambient temperature. Therefore, vacuum pumps are very popular in the steam turbine condenser industry.