2 technical approach to energy-saving design 2. 1 reduce the refrigeration load of the refrigerator The cooling load calculated by BCD-248W refrigerator design is shown in the following table (excluding cargo heat load). We pay attention to the following measures to reduce the cooling load: 2. 1. Reasonably distribute the thickness of the foam layer of the box for the refrigerator cabinet The different parts, the temperature difference between the inside and outside of the box, and the rationality of the outer dimensions of the box to distribute the thickness of the foam layer. If there is a supply duct on the back of the refrigerator compartment, the temperature difference between the outside and the outside is large, and the foam layer is thicker than other parts, reaching 64mm. Similarly, the thickness of the foam layer is also affected by the compressor at the bottom of the freezer compartment. Designed to be thicker, reaching 74mm. 2. 1. 2Reducing the leakage of the door seal The leakage heat at the seal of the door accounts for about 18% of the heat load of the whole box. BCD-248W is designed to improve the thermal resistance of the door seal. In addition, a large door seal tail strip is specially designed to form a squeeze seal with the tank liner and the door liner to reduce the leakage of cold; in addition, the optimal gap fit between the tank liner and the door liner is also great. The air conditioner was locked in limits. 2. 1. 3 reduce the thermal load of electrical components Air-cooled refrigerators have many electric devices. In addition to directly increasing the power consumption, some components are installed in the interior, which also causes an increase in thermal load, which double affects power consumption. Therefore, the design of the refrigerator is The use of electrical devices should be minimized and the power consumption of electrical devices should be reduced. In some conventional air-cooled refrigerators, heating devices are generally installed in the air duct system and the drainage system to prevent condensed water from freezing. In the two-part design, the BCD-248W refrigerator is structurally designed to avoid possible condensate icing. The distribution of the thickness of the foam layer around the air duct of the refrigerating compartment not only considers the icing caused by the influence of the evaporator on the return air duct, but also considers the possible condensation of the heat transfer between the return air duct and the backboard. Dew and the effect of the condenser on the temperature in the return air duct when the system is working; and the design of the heating tube position also effectively prevents the icing water from forming icing, while also minimizing the occurrence of defrosting heater work. The effect of heat on the temperature of the freezer compartment. 2. 1. 4 Reduce the heat transfer of the anti-condensation tube The arrangement and direction of the anti-condensation tube is also an aspect that affects the energy consumption of the refrigerator. If the superheated steam is used to heat the casing door frame, although the anti-condensation effect is good, the heat exchange temperature difference is large due to the heat exchange between the inside and outside of the tank, thereby increasing the heat load. BCD-248W adopts split type condenser, that is, the anti-condensation tube is placed between the left and right condensers, and the condensed liquid refrigerant is used to heat the door frame, which not only has the anti-condensation effect, but also reduces the leakage inside the box. Heat, to achieve energy-saving purposes. 2. 2 The cooling speed is faster and the temperature distribution is more uniform. However, the traditional air-cooled refrigerator has a simple air passage structure, a single air supply, and the temperature inside the box is still not uniform, the gradient is large, and the compressor operating rate is increased. Lead to increased energy consumption. The design of the air duct system of BCD-248W refrigerator is more complicated. It adopts the three-dimensional layer-by-layer air supply mode. It can be seen from the design that each compartment of the refrigerator compartment and the ice greenhouse, each drawer of the freezer compartment is provided with an independent air supply port. In order to ensure uniform temperature throughout the box, the temperature difference between the coldest part and the hottest part is only 1 , and there will never be a compression due to the temperature in one of the tanks being lower and the other temperature still not falling. The phenomenon of increased machine operating rate effectively saves energy consumption and is conducive to food preservation and storage. 2. 3 Optimization of the refrigeration system In the refrigeration theory, we know that too high condensing pressure and too low evaporation pressure will cause a decrease in the unit cooling capacity and cooling coefficient, and also increase the box due to the increase in heat transfer temperature difference. Body heat load has a great impact on energy consumption. However, in actual design, it is often impossible to use excessive heat exchangers due to installation space and cost constraints. BCD-248W refrigerators are designed in the design of evaporators and condensers. The high efficiency evaporator and condenser are selected, and the combination of theoretical calculation and experimental verification is used to reasonably match the heat transfer area, avoiding too low evaporation pressure and excessive condensing pressure, and achieving energy saving purposes. 2. 3. 2 Air distribution in the freezing and refrigerating rooms In addition to the thermal load of each room, the factors such as the resistance loss caused by the air duct system and the heat transfer temperature difference must be considered. Therefore, the air volume is reasonably selected and distributed. The reduction in energy consumption of air-cooled refrigerators is particularly important. BCD-248W is the lower freezing structure. To send the cold air up to the refrigerating room, it is necessary to overcome the natural cooling of the cold air and the resistance along the air passage. We have obtained the optimized air volume through the combination of computer dynamic simulation and experiment. Further, the energy consumption is further reduced, and the total air volume is 0.74 m 3 /min, wherein the refrigerator compartment needs to allocate 16% of the air volume. 2. 3. 3 Optimization of control parameters The control parameters of the refrigerator mainly refer to the boot time, downtime and operating rate of the refrigerator, and these parameters are closely related to the refrigeration capacity, COP and insulation performance of the compressor. . For a certain heat load box, a compressor with a small cooling capacity can be used to reduce the input power, but since the operating rate is increased, the energy consumption of the refrigerator may not be reduced; and when the operating rate is constant, if the booting time is too long The evaporation temperature will be too low, which is not conducive to energy saving, and the storage temperature fluctuation is increased, which is not conducive to food storage. If the startup time is too short, due to the large starting power of the compressor, frequent startup will bring about an increase in energy consumption. . Therefore, in the design of the refrigerator, we must comprehensively consider the heat load of the cabinet, the cooling capacity and efficiency of the compressor, the working cycle of the refrigerator and the operating rate to achieve the best matching state. 2. 3. 4 Energy-saving design of the gas return heat exchanger R134a refrigerant has similar working characteristics as R12, and the regenerative cycle can improve the refrigeration coefficient and the cooling capacity per unit volume. Therefore, the gas return heat exchanger is generally installed in the refrigerator. The BCD-248W refrigerator mainly strengthens the heat exchange efficiency from the following three aspects; the refrigerant in the capillary and the return pipe adopts countercurrent heat exchange; the capillary and the back The trachea adopts the method of parallel soldering; increasing the length of soldering of the capillary tube and the return pipe makes the final heat exchange efficiency reach 98%. 2. 3. 5 The energy-saving matching of the refrigeration system is also related to many other aspects such as the flow rate of the capillary, the charge of the refrigerant, etc. The theoretical calculation of these parameters is often only instructive, and the accurate flow and charge must be relied on. The experiment continued to explore. In addition, the design of the refrigerator should not blindly pursue some unnecessary functions, such as wide gas zone, cryogenic quick freezing, large freezing, etc., because the realization of these functions will inevitably reduce the cycle efficiency of the refrigeration system, which is not conducive to the energy saving of the refrigerator. . The BCD-248W refrigerator has passed the above-mentioned comprehensive energy-saving design. After testing, the power consumption is 1. 04KW. h / 24h, that is, the power consumption per liter is only 0. 42W. h / 24h, in the full air cooling The COP is 1. 35. The average foam layer thickness is 53 mm for the refrigerating chamber, 72 mm for the freezer, and the compressor COP is 1.35. Analysis of energy-saving approaches From the above analysis, we can see that the energy-saving design of refrigerators is a comprehensive technology. There are many ways to reduce energy consumption. In the specific implementation, its comprehensive benefits must be considered. Whether energy-saving technology will cause an increase in production equipment, adjustment of production processes, increase in product cost, and deterioration of other products (such as noise indicators). Richard, the original author of the refrigerator analysis software ERA! Dr. Marion proposed a method called Multiple Pathways Analysis, which is to analyze the benefit and cost of each energy-saving approach and derive its benefit cost ratio (BCR). Find the best solution for the production and sales of the company. Trolling Motor Wiring, Wire Control Trolling Motor Ningbo Haibo Group Co.,Ltd. , https://www.hbtrollingmotors.com
Environmental preset for air-conditioned refrigerator facilities
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