Talking about the characteristics and main points of air compressor waste heat recovery
With the continuous improvement of the domestic economic level, the corresponding prices of various energy products continue to rise, and energy consumption is critical to the corresponding production and operation of related industrial enterprises. In recent years, problems in energy conservation and emission reduction have continued to emerge. With the implementation and deepening of the national strategic energy conservation plan, the energy costs faced by enterprises are also increasing day by day. Therefore, the improvement of corresponding facilities energy conservation is becoming more and more important.
Air is a free resource given to us by nature, but it is very expensive after being compressed. The corresponding motor drives the compressor to increase the pressure of the relevant air to convert electrical energy into aerodynamic energy. In this conversion process, the corresponding electrical energy is not 100% converted. Only about 10% of the motor input power of the air compressor can be reasonably converted into usable compressed air power, which is equivalent to using 10kW of electric energy to obtain 1kW of aerodynamic energy. For enterprises, it is necessary to effectively analyze the design plan for recycling the waste heat of the air compressor and its economic benefits, so as to find an effective plan and give full play to the corresponding function of recovering the waste heat.
1. What is waste heat recovery?
Waste heat recovery is the recovery of substances contained in gaseous (such as high-temperature flue gas), liquid (such as cooling water, high-temperature lubricating oil for air compressors), and solid (such as various high-temperature steel) discharged from the industrial production process. Some heat energy, and the process of using it. According to statistics, about 50% of industrial energy consumption in my country is not utilized, but directly wasted in various forms of waste heat, of which the recovery rate is as high as 60%. The average recovery rate of waste heat resources in my country is only about 30%, which is 10-20% behind the international advanced level.
There are many ways to recover waste heat resources. The basic method is to transfer the waste heat of a higher temperature fluid to another fluid of lower temperature through a heat transfer device. For example, the waste heat in the exhaust gas of the boiler can be used for the boiler. Feed water or supplemental water heating, so that the water enters the boiler after being preheated, or the combustion air entering the boiler is preheated, which reduces fuel consumption, improves boiler efficiency, and makes operation safer.
2. What is the waste heat recovery of air compressor? The air compressor compresses the air during work, and in the process of compression, the air gains potential energy and heat energy, and these energy are the additional energy that consumes the electric energy of the air compressor and converts it into the air. This energy will not affect the production. Favorable factors can sometimes have negative effects on the air compressor, such as reducing compression efficiency and damaging the air compressor. The air compressor will also increase the temperature of the air compressor oil during operation. The rated air production per minute m3/min given by the aerodynamicist and air compressor manufacturer is determined by the temperature measurement at 80°C. The gas production m3/min of the screw air compressor will decrease as the unit operating temperature increases. The mechanical efficiency of the air compressor will not stabilize at the 80°C calibration and the gas output will work. Its inverse degree is: every time the temperature rises by 1°C, the gas production decreases by 0.5%, and the temperature rises by 10°C, the gas production decreases by 5%. Generally, air-cooled air compressors run at 88-96°C, and the drop rate is 4-8%. Even worse in summer, the waste heat recovery equipment can reduce the temperature of the air compressor by 8-15℃, so its economic benefits are even more significant. It can be seen that when the air compressor oil reaches a higher temperature, the compressed air efficiency of the air compressor will become lower, and when the temperature of the air compressor oil is higher, it will cause the air compressor oil to accelerate aging and deterioration, and will make the air The high temperature of the compressor head reduces the operating life of the air compressor. One of the air compressor waste heat recovery is to reduce the temperature of the air compressor oil and compressed air to improve the operating efficiency of the air compressor, and the other is to recover the excess heat in the air compressor oil and compressed air. The heat is recycled and reused to meet the requirements of energy saving and environmental protection.
3. Air compressor waste heat recovery equipment
Air compressor waste heat recovery equipment is to recover and reuse the heat generated during the operation of the air compressor, so as to achieve the purpose of energy saving and environmentally friendly production.
Studies have shown that air compressors suck in air from the environment and discharge high-pressure air after compression. This process not only increases the pressure potential energy of the air, but also generates a large amount of compression heat. According to statistics from the U.S. Energy Agency, the electric energy used to increase the potential energy of the air only accounts for about 20% of the total electricity consumption, and about 80% of the electric energy is converted into heat. It should be pointed out that because the internal circulation of the compressor requires oil temperature, and the heating value of different temperatures is different, the heat exchanger> heat exchange efficiency is different. According to the actual engineering experience, the heat that can be used is converted into the shaft power of the compressor. About 65%, the double recovery efficiency of oil and gas can reach more than 88%. If this part of heat recovery is used for cold water heating, it can save a lot of energy expenditure for the factory.
Fourth, the characteristics of air compressor waste heat recovery
1. Before the energy saving plan, save the following energy waste:
