Heat pump unit because of its energy-saving, environmental protection and well-being, etc., is currently widely used in the country. This collection of all kinds of newspapers and magazines throughout the country, Annual Meeting of the information collection and Proceedings related to heat pump technology and the application of a total of 207 papers in this area. Here as a seminar for all the teachers and students here for reference. The related issues are summarized as follows: Air source (air-cooled) heat pump The current products are mainly domestic heat pump air conditioners, commercial unit heat pump air-conditioning units and heat pump hot and cold water units. Heat pump air conditioner has accounted for 40 to 50% of sales of home air conditioners, the annual output of 400 million units. Since the early 90s, heat pump water chiller units have been widely used in the hot summer and cold winter regions. According to incomplete statistics, some 30% of the central air-conditioning hot and cold water chiller units in some cities in the region account for 20% to 30% , And the scope of application continues to expand and there is a tendency to move toward this. This collection of 55 papers on the air source heat pump, the main contents are: 1, air source heat pump energy consumption evaluation issues In order to evaluate and compare heat pump units and other heating and cooling equipment, about 30 papers on this issue. The theory and software of energy consumption analysis for heat pump units are introduced. Based on the parameters of air conditioning cooling load, outdoor dry bulb temperature and heat pump outlet temperature, the frequency of heat pump is used to solve the annual energy consumption of heat pump cooling. In the calculation of heat pump winter energy consumption, in addition to considering air conditioning heat load, heat pump water temperature, outdoor dry-bulb temperature, but also to the outdoor relative humidity (ie, temperature and humidity frequency) to consider the heat pump heating performance, The actual energy consumption has a good match, provides a method for energy consumption evaluation. 2, the selection of air-cooled heat pump unit At present, the design of air-cooled heat pump water heater units, often based on the calculated heat load, considering the use of both coefficient and cold (heat) loss factor, according to the unit nameplate calibration value to select the number of units . As the air-source heat pump unit of the amount of cooling (heat) with the outdoor parameters change, this method of selection may result in the unit is too large, resulting in waste; or choose too small, so that the lack of cooling (heat) Not meet the requirements. For this reason, it is suggested that the time-dependent heating and cooling load of the air conditioner and the time-varying curve of the heating and cooling capacity of the heat pump unit be compared with each other, and satisfactory results will be obtained. 3, the winter heat pump defroster air source heat pump winter heating run, one of the biggest problem is that when the outdoor temperature is low, the outdoor heat exchanger fin surface frost, (need to take defrosting measures). According to the relevant literature, after two years of field follow-up tests, the result is that the defrosting loss accounts for about 10.2% of the total energy loss of the heat pump, and about 27% of the defrosting function is caused by the defrosting function Frosting is not serious, do not need defrost into the defrost cycle. Some of the commonly used methods, more or less there are some problems, such as the occurrence of extra defrost action, or need to defrost without signaling and other ills. The best defrosting time control and maximum average heat supply control defrosting proposed in the literature are quite new in theory, but they are more difficult to achieve. Adopting the idea of ​​self-adjusting fuzzy defrosting control and the basic structure of the system to determine the indoor and outdoor atmospheric temperature, the relative humidity difference and the rate of change of the fin temperature as input universe, the fuzzy amount of input and fuzzy reasoning methods, The simulation of fuzzy defrost control is implemented on the high-level computer. Compared with the experimental data, defrost by this method is more consistent with the actual situation. Compared with the conventional defrosting method, this method not only prolongs heating working time, reduces the number of defrosting and defrosting loss, but also improves the working performance and reliability of the unit. Where outdoor air temperature is low, an auxiliary heater is required due to insufficient heat supply in winter. Common method is to set the heater outlet at the indoor unit, this method not only low heat transfer efficiency, poor safety and long defrost time, indoor temperature drop, the use of Freon heater can significantly overcome the above shortcomings, this method Is the indoor side of the heat exchanger before and after the two parts, in the middle to add a freon auxiliary heater, heat pump in the winter run, the compressor discharge of high-temperature chlorine gas into the indoor heat exchanger before the part of the gas has been part of the gas being Condensation into liquid. At this point by the Freon heater heating, so that part of the liquid is evaporated again into gas, and then re-enter the second half of the indoor heat exchanger. In this way, relying on the entire indoor heat exchanger, the heat absorbed by the heat pump outdoor heat exchanger, together with the heat generated by the Freon heater, are transmitted to the air-conditioned room to make up for the insufficient heat supply due to the low outdoor ambient temperature . Related literature introduction KFRd-70LW heat pump air conditioner test, get a good auxiliary heating effect, and defrost time reduced from 3min to 1min (outdoor temperature -1 ℃); reduced from 10min to 3min (outdoor temperature -7 ℃). 4, heat pump noise control Single or multiple heat pump noise control. The noise propagation characteristics of the air-cooled heat pump unit are analyzed. Combined with the example of noise control project of the heat pump unit, the design method, design points and control effect of the closed-type noise-damping device are introduced. As air-cooled heat pump operation, management and maintenance of more parties to make, with dual cooling and heating functions, cooling unit without the need for cooling towers, so more and more applications. However, the noise of heat pump units has a certain impact on the surrounding environment. In recent years, there has been an increase in the number of heat pump noise disturbing people in Shanghai and other places, which has become a common problem of fixed source noise pollution in cities in recent years. Therefore, it is of universal significance to understand the noise propagation characteristics of single or multiple heat pumps and to explore the methods of preventing and controlling the noise of heat pump units. From the heat pump unit noise source, noise characteristics, heat pump unit noise management examples, noise control and management of technical point of view, heat pump noise control projects have some examples of promotional value and significance of a better solution to the heat pump heat dissipation , Into the exhaust problem, to ensure the normal operation of the heat pump premise, the use of fully enclosed sound insulation muffler device, the A-level heat pump noise reduction of about 20dB, in some special occasions to reduce the heat pump noise to the extent necessary Noise control engineering provides a successful example that can be drawn on, especially when the heat pump exhaust pressure is low or does not understand the specific residual pressure, the design of the sound insulation muffler inlet ventilation system can have a Specific calculation basis.
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