With the improvement of air conditioner technical conditions and energy-saving and high-efficiency requirements, the energy-saving and high-efficiency work of air-conditioner compressors is particularly important and urgent. China's relevant standards also impose restrictions on energy efficiency, and regulate and guide the development of the industry. Played a very good role. But at the same time, we need to make corresponding improvements. This article will focus on the cooling performance of air conditioning compressors. 2 The main performance requirements of the current standard GB/T15765-2006 standard for refrigerants R22, R407C, R410A, nominal cooling capacity of not more than 18000W for room air conditioners with fully enclosed compressors (including rotor compressors, scroll compressors and Restrictive requirements are imposed on the performance of various aspects of piston compressors. The standard determines the rated working condition of the compressor cooling test as shown in Table 1 (condition 2 is optional for scroll compressor), and the measured cooling capacity is not less than 95% of the nominal value, and the measured performance coefficient of each type of compressor ( COP) has been limited to require that the measured value be no less than 95% of the limit. 3 air conditioning conditions according to GB/T7725-2004 "room air conditioner" standard, T1 air conditioner rated cooling conditions are: indoor dry bulb temperature 27 ° C, wet bulb temperature 19 ° C; outdoor dry bulb temperature 35 ° C, wet bulb temperature 24 ° C. According to the air conditioning matching data of Shanghai Hitachi Chamber for many years, the actual operating range of the air conditioner that meets the requirements of China's air conditioning energy efficiency level 1 to 5 is: condensation temperature 43.5 ~ 55.1 ° C, evaporation temperature 1.3 ~ 7.4 ° C. Under normal circumstances, room air conditioners are required to adjust the indoor temperature to the most comfortable temperature of the human body at different outdoor temperatures. According to the research conclusions of the United States and Japan: during the cooling season, the indoor temperature is about 27 °C; during the heating season, the room temperature is The body is most comfortable around 20 °C. As for the cold load design temperature point, since the Yangtze River basin is located in the north and south of China, and the air conditioner is widely used, the summer selection of 35 °C is more representative. Therefore, it is reasonable to use the conditions in Table 1 for cold load assessment. In terms of energy efficiency, it is analyzed that the rated cooling test conditions of Table 1 are basically in the marginal zone of the actual operating range of air conditioners that meet the current air conditioning energy efficiency standards in China, and the energy efficiency assessment is obviously lacking in representativeness. And because of the low condensation temperature and high evaporation temperature of high-efficiency air conditioners, if the entry level of air-conditioning energy efficiency is raised to the current level in 2009, the energy efficiency assessment using Table 1 will lose its practical significance. 4 Air conditioning energy efficiency evaluation trend In order to analyze the compressor energy efficiency evaluation criteria, we must first understand the actual application of air conditioners and the development trend of world air conditioning energy efficiency evaluation standards. 4.1 US situation As the outdoor temperature changes during the entire cooling season, the corresponding air conditioning operating conditions are also constantly changing. Therefore, the performance under a certain fixed condition cannot objectively and comprehensively reflect the overall performance of the air conditioner. Based on the characteristics of the operating conditions of air conditioners in the cooling season, such as the change of outdoor temperature and the energy loss caused by the start-stop, since 1983, the United States has developed the energy-saving technical indicators of room air conditioners from the energy efficiency ratio of a single standard working condition. For a more scientific seasonal energy efficiency ratio (SEER), SEER is able to fully and objectively reflect the energy efficiency of the air conditioner's annual cooling season. (When heating, it is the heating seasonal energy coefficient, referred to as HSPF in English). The US SEER test consists of four working conditions: A working condition to determine the rated cooling capacity; B working condition to determine the energy efficiency (EERb); C and D test conditions are exactly the same, but in the D test condition, the air conditioner enters a cyclic working state. Each cycle consists of 6 minutes and 24 minutes off (referring to the compressor and indoor fan, manual or automatic operation), a total of 3 cycles, taking the last set of data. According to C, D E working condition test results of EER, cooling capacity, power consumption and other data, calculate Cd (in general, you can also omit C, D working condition test, take the default value Cd = 0.25), get SEER = (1-0.5 * Cd ) *EERb. According to the ARI210/240-2006 standard, 18.3 ° C ≤ outdoor temperature ≤ 27.8 ° C accounted for 75% of the entire cooling season, therefore, the US seasonal energy efficiency ratio is based on the single assessment B operating conditions, increased the start and stop for partial load conditions For the loss consideration, the basis of the SEER calculation method is: single point energy efficiency + start-stop loss, which has certain limitations for energy efficiency evaluation in a wide temperature range. 4.2 Japanese situation Japanese air conditioner seasonal energy coefficient / annual performance coefficient test / calculation is to test the air conditioner rated cooling / heating conditions and intermediate cooling / heating conditions performance, and then calculate the cooling / heating season total Cooling/heating, total power consumption and coefficient of performance, and finally calculate the annual performance coefficient APF. The annual performance coefficient APF is represented by the performance of the air conditioner under the four conditions of rated cooling/heating and intermediate cooling/heating. It is also related to the ambient temperature distribution during the cooling/heating season. For example, the APF in Tokyo, Japan can be approximated as shown in Table 4. 4.3 China's situation In China's air conditioning energy efficiency standards, the current COP assessment under rated conditions is still the main, but with the gradual deepening of energy conservation and environmental protection concepts, not only air conditioning energy efficiency standards are constantly improving, but also the need to introduce seasonal energy efficiency ratio for assessment To achieve a more reasonable and more scientific assessment of the comprehensive energy efficiency of air conditioning. Table 5 shows the cooling operation time of China in GB/T 7725-2004. Table 6 shows the cooling operation time in the approval report of the energy efficiency standard for inverter air conditioners, which is greatly improved compared with Table 5. This is not only reflected in the total cooling time from 2399 hours to 1136 hours, and from the distribution of temperature samples, the weight of the low temperature section running time is reduced, and the weight of the high temperature section is increased, which is closer to the actual use of air conditioners in China. 5Compressor energy efficiency standards discussion 5.1 Current problems Compared with the improvement of seasonal energy efficiency evaluation of air conditioners, the compressor energy efficiency evaluation standards appear to be lagging behind, mainly in the following aspects: 1 rated point condensation temperature 54.4 °C. The temperature was determined based on an outdoor ambient temperature of 35 ° C and a condenser heat transfer temperature difference of 19.4 ° C. According to the refrigeration operation schedule of China in Table 6, the operation time of the outdoor temperature ≥ 35 °C is 7.9%, and the temperature point is obviously biased. Moreover, with the improvement of the energy efficiency rating of the air conditioner, the heat exchange efficiency of the evaporator and the condenser is greatly improved. Compared with the current secondary air conditioner (entry level of 2009), the heat exchange temperature difference of the condenser is only about 12 ° C (the heat transfer temperature difference is 19.4 ° C close to In the current five-level air conditioning); 2 single point energy efficiency assessment. In China, the cooling operation time mainly occurs at 24-35 °C, and the ratio is relatively close. The energy efficiency performance is evaluated by a single rated point, so that the compressor manufacturer only focuses on the performance of the temperature point, ignoring the compressor in a wide temperature range. Good performance, which in turn affects the seasonal energy efficiency of air conditioners. It is inconsistent with the trend of seasonal energy efficiency evaluation of air conditioners and the development direction of building energy-saving society; 3 inhalation temperature. According to Shanghai Hitachi's many years of air conditioning evaluation; in line with this trend, the evaluation of product performance over a wide temperature range should also be enhanced on the compressor. It is suggested that in the revision of China's compressor energy efficiency evaluation criteria, combined with the development trend of air conditioner seasonal energy efficiency evaluation and the application of air conditioner time in China, the following discussion opinions are proposed for the current secondary energy efficiency in 2009: 1 load assessment temperature point. In order to ensure sufficient cooling capacity under high temperature conditions, the ambient temperature during cold load assessment can be maintained at 35 ° C, but considering the improvement of heat transfer efficiency of high efficiency air conditioning heat exchanger, the condenser heat transfer temperature difference can be reduced to two corresponding 12 °C, so the cold load assessment condition is the working condition 3 of Table 7; 2 inhalation temperature. According to the actual operating conditions of the air conditioner compressor, it is necessary to unify the suction temperature of the compressor evaluation condition to 18.3 °C; 3 change the single point assessment for multi-point assessment. In the outdoor temperature range of 24-35 °C in the cooling season, it is divided into low temperature section 24 ~ 28 °C, high temperature section 29 ~ 35 °C two sections (35 °C or more weight is small, ignoring energy efficiency assessment), taking the average temperature of 26 ° C, 32 °C is used as the outdoor temperature point, and the weight is determined according to the proportion of the cooling operation time. The condenser heat exchange temperature difference is determined with reference to the current secondary air conditioner. The evaluation condition is the working condition 1 and the working condition of Table 7. If further synthesis Considering the energy efficiency of the compressor under heating conditions, the outdoor temperature point of the two heating conditions can be similarly increased, and the comprehensive energy efficiency evaluation of the compressor can be carried out to guide the compressor manufacturers to pursue good product performance in a wide temperature range and promote the product. Energy saving progress.
PVC Paint Protect Film is a revolutionary product that has gained immense popularity in the automotive industry. It is a transparent, self-adhesive film that is applied to the exterior surfaces of vehicles to protect the paintwork from scratches, chips, and other forms of damage. This film is made from polyvinyl chloride (PVC), a durable and flexible material that provides excellent protection against the elements and everyday wear and tear. PVC Paint Protect Film is a cost-effective alternative to traditional paint protection methods, such as waxing or clear coat applications. It is easy to install and remove, making it a convenient choice for car owners who want to maintain the pristine appearance of their vehicles. In this article, we will explore the various benefits and applications of PVC Paint Protect Film, as well as its potential drawbacks.
PVC Paint Protect Film is a transparent, adhesive film that is applied to the surface of a vehicle's paintwork to protect it from scratches, chips, and other damages. It is made from polyvinyl chloride (PVC), a durable and flexible material. PVC Clear Film,Paint Protection Film,PVC Car Wrap,Car Paint Protection Guangzhou Fuyulai Technology Co.,Ltd , https://www.fuyulaifilm.com
The film is typically applied to high-impact areas of the vehicle, such as the hood, fenders, mirrors, and bumpers. It provides a protective barrier against road debris, UV rays, and environmental pollutants. The film is designed to be self-healing, meaning that minor scratches and swirl marks will disappear over time due to the heat of the sun or the warmth of hot water.
PVC Paint Protect Film is easy to install and can be removed without leaving any residue or damaging the paintwork. It is available in various thicknesses and finishes, including glossy and matte, to suit different preferences and needs.
Overall, PVC Paint Protect Film is a popular choice among car enthusiasts and owners who want to maintain the appearance and value of their vehicles. It provides a cost-effective and convenient way to protect the paintwork from everyday wear and tear, ensuring that the vehicle looks its best for years to come.