【 Weak current College 】 refrigeration system main energy-saving adjustment---Power By 【 China power house network 】

In the actual operation of the refrigeration equipment and systems engineering, we recognize that not only should the refrigeration system adjusts to a reasonable range, meet the requirements of the refrigeration technology, maintaining its security to work, but also and can be further adjusted to the refrigeration system running at optimum levels to achieve the purpose of running efficiency, improve the energy efficiency of refrigerating equipment.
1 evaporation temperature and evaporation pressure
In the design of refrigeration equipment, increasing evaporation temperature will make refrigeration system compression ratio reduction, reduction in power consumption, this energy is very favorable. The problem is evaporating temperature depends on being cool object, adjust the evaporating temperature must not be cooled refrigeration process requirements of the object. But in the refrigeration system operation regulation, should observe, promptly take appropriate measures, such as the right to increase the defrosting, suitable for fluid, carries on the evaporator put oil in addition to the dirt cleaning, effective on the compressor, so that the energy regulation the evaporation temperature stable temperature in the design, to avoid unnecessary evaporation temperature too low or very necessary.
From the energy point of view, due to increased evaporation temperature is reasonable, the calculation shows that when using the-25 ℃ temperature instead of library-30 ℃ library temperature, evaporation temperature rise will be saving energy 9.8%. Therefore, for the shorter storage life, the quality is not high to the low-temperature requirements, can be appropriately increased evaporation temperature to achieve energy-saving effect. In addition to General refrigeration appliances are designed according to the full-load and the actual run at full load time is not long, most of the time is less than the design load conditions. In part load is cooling consumption reduction, increasing evaporation temperature, can be used to reduce the evaporator temperature difference, achieve the same cooling effect. For example, when the condensation temperature of 38 ° c, the refrigeration systems of evaporation temperature-33 ℃; when the cooling consumption is reduced to 50% of the original design, the evaporator heat temperature by 10 ° c to 5 ° c, the Treasury will still use the original equipment, making libraries temperature is maintained at-23 ° c, but at this point the evaporating temperature up to-28 ° c, the calculation shows that energy-saving effect of up to 15%.
2 condensing temperature and condensing pressure
Condensing temperature is too high, causing the compressor pressure too high, the exhaust temperatures, the safe operation of the compressor is negative, it caused the accident; at the same time reducing the efficiency of refrigerating equipment, energy consumption increased. From the energy point of view, the design of the refrigeration equipment should be appropriate to select a higher condensation temperature, i.e. Configuring large condensation heat transfer area, reach the purpose of the actual energy saving operation.
From the operational point of view of regulation, control of refrigeration equipment in the condensation temperature as low as possible, to improve cooling efficiency, reduce operating costs. Condensing temperature is determined by the temperature of the cooling medium, flow, velocity, condensation area, the amount of exhaust compressor and air humidity, oil, incrustation and so affect the condenser heat transfer efficiency of various factors. To make the condensing temperature as low, mainly from two aspects: one is to keep the heat transfer area of clean, eliminate the factors that influence heat that timely fouling, fuel, excluding non condensing gases; on the other hand, is to control the flow of cooling medium, flow rate, guaranteed cooling medium evenly through the heat transfer area; also pay special attention to the cooling water in the distribution of uniformity in the condenser. In the system devices when running in partial load, should pay special attention at the corresponding control condensation system pump or fan load to avoid invalid heat power consumption. Since the total energy consumption of refrigeration equipment includes a compressor power and heat exchanger pump and fan energy consumption.
3 liquid subcooling and suction superheat
Liquid refrigerant throttle back into the two-phase wet steam zone, in which case the refrigerants of dryness, its in the evaporator thermal gasification of aspiration that the larger the refrigerant volume cycle refrigeration, the higher the coefficient also. In a certain amount of condensing temperature, evaporation temperatures, with the throttle in front of the refrigerant liquid cooling method to reduce the throttle back refrigerant dryness aims to increase the cooling capacity of the refrigerating cycle.
Typically, it is assumed that the condenser outlet temperature lower than the condensing temperature 3 ~ 5K, cooling water temperature rise of the condenser is 3 ~ 8K, thereby cooling water inlet temperature lower than the condensing temperature 5 ~ 13K, this is enough to make the refrigerant outlet temperature reaches a certain number of undercooling. In horizontal shell and tube condenser, if condensation does not immediately after the liquid from the bottom of the condenser discharged, but accumulate in the condenser, the liquid will continue to bring heat to the cooling water canal and the ambient medium when the discharge will be entitled to certain undercooling.
Undercooling of access have not produced an increase in power consumption of the compressor, which means Super-cooling would cause the device to increase the refrigeration system, improve the coefficients of the refrigeration equipment operating economics. Study on calculation showed that condensation temperature 40 ° c evaporation temperature 5 ° c, working conditions, the undercooling 5K makes R22 refrigerant equipment cooling capacity increase 4.27%, input power no change, COP value increase 4.27%. At the same time, certain undercooling also effectively preventing the liquid refrigerant at choke valve from the condenser to the pipeline occurrence partial gasification caused cooling capacity and expansion valve failure.
Compared to R22 refrigerant equipment, suction superheat impact is even more complicated, because the suction superheat in effectively improve volumetric efficiency enhancing compressor and the system of quality cooling capacity, also inevitably increases the compressor suction of capacitance, exhaust temperature, power consumption and condenser heat load. Despite its integrated impact or would make the cooling capacity with the superheat increase increased equipment systems of refrigerating factor is reduced accordingly. This is like running with energy-saving equipment has the barges with, but in the refrigeration equipment, especially in low-temperature refrigeration equipment, suction temperature too low will cause the compressor to have serious Frost, lubrication conditions deteriorate. In wet-stroke, the compressor running volume efficiency to reduce significantly, indicating the efficiency, effectiveness and efficiency of machinery will be reduced, allowing the compressor of the COP value will greatly decrease. Inexplicably, wet-stroke very easy to produce liquid hammer on compressors have fatal mechanical damage.
Visible, the compressor suction temperature is both an efficiency and energy consumption level of signs, safety equipment system up and running. Therefore, the actual run operation should closely monitor the timely adjustment, keep it within reasonable bounds. Maintain adequateWhen reasonable suction superheat, to ensure a more secure and reliable refrigeration equipment, high efficiency and energy saving and economical operation.
Of course,the above mentioned suction superheat, refers to occur in the evaporator itself, or the installation to be cooling compartment of the suction pipes, heat absorbed by the heat from the cooling of the space in the media, that is, suction superheat yielded effective cooling effect. Those who have not been cooling space media produces refrigerating effect of invalid overheating, only unilateral increase energy consumption of the compressor, as unwanted heat insulation measures taken should be strictly avoided, otherwise it will effectively make the economy of the refrigeration equipment. In addition, the full use and temperature of the heat load reduction by night, condensing temperature decreasing and evening trough power grid as possible in the refrigeration equipment operating at night; in the optimization of refrigeration environments even air distribution; the use of multi-level segmentation refrigeration technology make refrigeration equipment in various periods in different operating parameters, lower heat temperature, continuous variable temperature regulation principles of refrigeration factor to increase the investment actually saving energy in refrigeration freezing process also has a more obvious economic benefits.
In summary, as energy issues have become increasingly prominent, on saving energy place high demands on all the Nations of the world has developed a new energy economy policy measures, our Government has also been in Government work report drawn up in units of energy control less energy. Thus, overall, in refrigeration equipment design and construction, appropriately increase the initial one-time investments, to reduce the energy consumption of refrigerating equipment operation, the purpose of achieving efficient, lower cost of operation of equipment, is the design idea should be used. As energy prices resulted in a rise in the cost of the equipment is put into operation, because the initial energy increase gradually shorter payback period, youcan get higher overall economic efficiency.
In addition, we adjust the refrigeration system operation is insufficient understanding of the importance of refrigeration equipment operation and maintenance management in General is poor. The technical weakness on the economic operation of the refrigeration equipment technology management ideas weak consciousness. The more we need to all aspects of the industry work together to strengthen the system of reasonable design and run the importance of carefully control regulation, and refrigeration equipment safety high efficiency energy-saving purposes, publicity and follow-up work.