Measures for energy saving and emission reduction in clean workshops

Measures for energy saving and emission reduction in clean workshops

First, the source of clean room energy consumption analysis

Although the clean room is indispensable in the current technological development, the energy consumed in the process of maintaining the clean room environment is also huge. For example, in the electronics industry, the general clean space needs 24 hours a day to operate normally. To ensure the cleanliness of the production space, the air purification system has a frequency of less than 15 times, and the zui has reached several hundred times. The energy consumption of the clean room is mainly used for the electricity and heat of the production equipment, and the power consumption of the air conditioning system is purified. , heat and cold load, the better of the refrigeration unit, the power consumption and heat consumption of the exhaust unit, the preparation and transportation of ultra-pure water and gas, and the use of fire protection.

Generally, the 10,000-class clean room, the power consumption of the entire clean room factory equipment accounts for about 60% of the total, while the consuming water in the standing equipment accounts for 64% of the chillers, followed by the MAU energy consumption of the new wind turbines. Secondly, in the cooling capacity of the chiller, it is mainly used for MAU. In most of the plants in the US where the clean room is used, the energy consumption of the clean room system accounts for more than 50% of the energy consumption of the entire plant. In the clean room system, the energy consumption of air conditioning is several times to several times that of ordinary building air conditioning. It can be seen that the energy consumption of the clean room system is still very large. In the era of intense energy and fierce competition in the world, how can we effectively use energy, save energy, reduce the sustainable development of society and reduce costs and improve competitiveness? All have important meanings.

Second, the energy-saving design of the clean room

Reasonable planning of the clean room should be to meet the demand, use it enough, do not seek high and clean room space, it will cause a lot of energy waste in the operation. The following principles can be considered when designing a clean room:

(1) It can meet the environmental needs of the process;

(2) Safety and reliability of the operation of the clean system;

(3) Improve the cost efficiency of the clean room system and try to ensure the reduction of operating costs.

Under the above principles, we must consider the high cost of long-term operation in the later period, how to improve the efficiency of energy use, and save energy. It also directly affects the operating cost of the enterprise, and the cross-section wind speed of the high-end filter is 0.3. -0.5m / s to calculate, a square area ventilation is 1080-1800m3 / h, in the industry like thousands of tens of thousands of square meters of clean workshop area. If you run 24 hours a day, the cost of maintaining clean room operation is still quite high, in order to improve the energy cost efficiency in the later operation of the clean room. In the clean room design, clean considerations are made.

1. Under the premise of meeting the production needs of the process, reasonably reduce the space or area of ​​the clean room to the appropriate size, improve the efficiency of the clean room, such as the ISO 6 to 9 requirements of the positive pressure turbulent clean room, the air supply The quantity and the number of air exchanges required by the clean room are proportional to the size of the space. The ISO0-5 positive pressure one-way flow clean room has the air supply volume and cross-section wind speed, and the cross-sectional area of ​​the air supply. In proportion, the designer's calculation of the air supply volume of the clean room is often based on the reference empirical formula, and such empirical formulas are generally relatively conservative, the selected parameters are relatively large, and there are data showing that for the turbulent clean room, Reduce the clean volume by 30% and save energy by 25%. It can be seen that the rational layout planning of the clean room will bring about obvious energy saving effects.

2. Under the premise of meeting the heat-dissipation load generated by the operation of industrial production equipment and personnel operation activities, the cross-section wind speed is reduced to a low zui, and for a clean room that is running in real time for a long time, a clean room of 3,000 square meters is used. 60%, the wind speed is reduced by 0.1m / s, the effect is to reduce the air volume by 6480m3. At the same time, the cooling capacity of the process air is significantly reduced.

3. For workshops with large demand for clean area, consider sub-regions, and disperse the fresh air to facilitate the reduction of unit operation if there is production stoppage and maintenance in each area, which can save energy and not affect the normal operation of other areas.

4. Do a detailed investigation of the thermal load of the industrial equipment, calculate and verify to determine the appropriate small air-conditioning refrigeration equipment, and do not save the map simply to take a large factor. Causes waste of later operation.

5, for the process of the exhaust heat is large, you can pass the energy-saving quiet benefit analysis to consider whether the heat recovery method can be used.

6. For the process flow with different cleanliness requirements, the micro-environment, clean shed, clean workbench, etc. can be used to design the control of local high clean environment, and the area with high energy consumption and high cleanliness can be reduced. With space.

7. The air conditioner system fan is operated by frequency conversion control mode. Because the flow rate Q is proportional to the one-time of the click speed V, the wind pressure H is proportional to the square of the click speed V, and the motor shaft power P and the motor speed V are in the cube. In direct proportion.

When a small air volume is required, the inverter speed is reduced by the inverter control device, and the input power of the motor is also reduced accordingly. If the air volume is reduced to 80%, the click speed (V) is also reduced to 80%, and the axis public (P) is decreased. Up to 51% of the rated power; if the air volume drops to 60%, the shaft power will drop to 22% of the rated power, and its energy saving potential is very large.

Third, refrigeration equipment

As long as the energy consumption of the clean room is in the refrigeration load and the fan operating load, it can be seen from the clean room load index that the refrigeration and ventilation equipment basically accounts for 50% of the energy consumption in the vicinity of the clean clean room, and the appropriate refrigeration equipment can be selected. Electric energy, natural gas, waste heat absorption, steam, geothermal and other energy sources supply all or part of the clean room to the clean room, through regional resources, comprehensive planning, in order to find the cooling combination of Zuijia, when selecting the refrigeration unit Try to combine the actual demand and select the unit with higher coefficient of performance (COP) under the same working conditions.

Fourth, distributed gas cold heat and power triple supply system

The distributed gas cooling and heating triple supply system is mainly composed of gas turbine equipment and waste heat utilization equipment. The gas turbine equipment is the core of the system, including gas turbine, internal combustion engine, etc. The waste heat utilization equipment includes waste heat boiler, absorption chiller and heat exchange device. , electric refrigerator, gas boiler, etc., its working principle is that after the gas turbine generates electricity by burning natural gas, the high-temperature flue gas is sent to the waste heat utilization equipment, which can be used for heating in winter, cold water in summer, and domestic hot water. The insufficient heat driving portion can be supplied by the supplemental gas.

When the clean room's plant area has a large demand for electric energy and cold water hot water, when the natural gas resources around the surrounding city are adequate, comprehensive consideration of natural gas prices and clean project policies can be used after the economic accounting, using the hot and cold electricity triple For the system, if colleagues can also use ice storage devices, heat storage devices, heat pumps and other equipment configurations, the energy system can be considered in various ways to improve the energy saving effect of the entire system.