Vacuum pump is used to keep a siphon in the cooling water system of power generation equipment, so that the cooling water circulating pump can keep working at the designed flow rate with low power consumption. The liquid ring vacuum pump is an ideal choice for vacuum suction.
Therefore, the frequency conversion operation of vacuum system is a development direction of energy saving and consumption reduction in power plants. Vacuum system is an important auxiliary system in power plant. Vacuum system, as the main energy-consuming equipment of circulating water system, is the key link of circulating water system operation and energy saving.
The working principle of the vacuum system is to start the main vacuum pump group of the system, until the vacuum degree in the vacuum tank reaches the set upper limit, the vacuum pump stops running automatically, and the vacuum in the central vacuum system is maintained by the vacuum check valve on the pipeline automatically. If the vacuum in the vacuum tank decreases and falls below the set lower limit, the standby vacuum pump set will start automatically. As a result, the vacuum degree of the vacuum system can maintain a stable vacuum source and meet the production requirements.
Thermal power plants need a large amount of cooling water to supply continuously because of the need of providing heat engine cooling source and various kinds of cooling. A power plant with a million kilowatt condensing unit needs 30 m3/s of cooling water, so much cooling water is pressed into the condenser through a vacuum pump to exchange heat with the superheated steam after work. Therefore, the energy consumption of vacuum pumps in gas power plants is very high. How to reduce the energy consumption of vacuum pumps and reduce the cost of power generation, and how to reform and optimize the cold end of gas power plants in design becomes the key link.
Gas power plant is a kind of circulating system which is composed of gas turbine and generator, waste heat boiler and steam turbine. It converts high temperature exhaust gas discharged by gas turbine into steam through waste heat boiler, and then injects steam into steam turbine for power generation. With the development of gas turbine technology, the change of national energy structure and the improvement of environmental protection requirements, the development of gas turbine power plants will be greatly accelerated.
The advantages of vacuum pump application in vacuum suction in power industry are mainly embodied in the following aspects:
1. The overall cycle efficiency of the power plant is high.
2. Minimal environmental pollution;
3. Unit (ratio) investment is lower; under the same conditions, unit (ratio) investment is lower.
4. Good peak shaving performance; quick start-stop. From start-up to full-load operation, the gas turbine usually runs in less than 20 minutes, and the time can be shorter when it starts quickly.
5. It occupies less land. Because there is no need for coal yard, coal conveying system, ash and slag removal system, dust removal, desulfurization, system and so on, the area occupied by coal-fired power plants is much smaller than that occupied by coal-fired power plants.
6. Consumption of water is low; gas-fired power plants do not need a large amount of cooling water, which can reduce the supply of cooling water, which is particularly important for the construction of power plants in arid and water-deficient areas.
7. Short construction period, high automation and advanced vacuum system can greatly reduce the number of controllers.
8. Low power consumption.
We provide the application of vacuum system in power plant, and then increase the power generation capacity, so that the coal consumption of power supply can be effectively reduced, energy saving and emission reduction can be achieved, ensuring the economic and safe operation of the unit, and ensuring the disappearance of leak points after treatment and the improvement of tightness.