The application of high-temperature heat pump systems in the industrial field has the following meanings: First, a large amount of industrial waste heat solves the problem of low-temperature heat sources (see Table 2), which allows the heat pump to make full use of the industrial waste heat harder to utilize by other methods Much higher than other heating efficiency (heat pump cycle efficiency is generally around 3) to provide industrial heat required. From the ASHRAE survey results of the United States and Canada, the prospect of this idea is optimistic [4]; secondly, the industrial waste heat can be discharged at a lower temperature by the heat pump, reducing the thermal pollution to the environment; Thirdly, the application of heat pump heating also has a positive effect on reducing the greenhouse effect. Compared with coal-fired boilers, carbon dioxide emissions can be reduced by 30-50% by saving fuel [5]. At present, the condensing temperature is below 50 ℃ at room temperature heat pump has been more mature, its end cooling device is mainly fan coil; condensing temperature of 50 ~ 65 ℃ intermediate temperature heat pump cycle refrigerant is mostly R22, by condensing pressure Limited, its water supply temperature should be below 55 ℃, so it is necessary to use special end cooling type (such as: fan coil or floor radiant heating); Condensation temperature of 80 ~ 100 ℃ high temperature heat pump can increase the water supply temperature to 70 ℃ Or above 80 ℃, which basically meets the design standard of northern heating. Therefore, the end cooling device of the high-temperature heat pump can be a low-cost cast iron radiator. Therefore, the heat pump can be used as a heating source for ordinary buildings and can also be used in old buildings Transformation (instead of coal-fired boiler), in fact, high-temperature heat pump can not only be used as a heating source can also be used for a variety of other industries, such as drying. As the high temperature heat pump has good application prospects, making it a recent international heat pump research a basic direction. High-temperature heat pumps are one of the key research topics in Japan's super heat pump project [6], the IEA heat pump center in the United States and the IIR heat pump development plan [7] and the European large-scale heat pump research project. In summary, high-temperature heat pump has obvious economic and social benefits, the market has great potential, therefore, to how to improve its efficiency and ensure the normal operation of various research projects for the purpose of great significance. 2 working fluid research progress Talking about the high temperature heat pump system, the first will have to face the selection of circulating fluid in the heat pump system. Only select the appropriate circulating refrigerant, heat pump system to meet the set conditions. At present, there are more than 5 million kinds of organic matter identified and more than 50,000 kinds of inorganic matter. However, there are not many suitable ones for circulating high temperature heat pump fluids. In the selection of working fluid, the main factors to be considered are as follows: (1) suitable condensing pressure should be below 2.4MPa (compressor pressure capacity is generally 2.5MPa); (2) the appropriate evaporation pressure, Should be above 0.1MPa, in order to avoid the formation of negative pressure in the system; (3) the appropriate volume of heat, should be 2.5J / cm3 above, so as not to over-size compressor, resulting in increased equipment costs; (4) Other common requirements of working fluids, such as non-toxic, small harm to the environment, chemical stability, excellent thermal properties, etc .; (5) to meet the above requirements, the pursuit of higher cycle performance coefficient. With Japan as the leader, many scholars in the world have done more researches on non-azeotropic mixed refrigerants in high-temperature heat pump systems. For example, Akio Miyara made an experimental study with R22 / R114 as the working medium in l993 (condenser inlet temperature 40 ° C, outlet temperature 60 ° C; evaporator inlet water temperature 30 ° C, outlet 10 ° C); Kazo Nakatani et al. R22 / 134a, R22 / R152a, R22 / R142b and R22 / R123 working fluid, the condensing temperature of 70 ℃ heat pump performance was tested [9]; Japan's super heat pump developed in the highly efficient heat pump, using R123 / R134a In addition, Ieon Liebenberg and others use R22 / R142b as working fluid for hot water heat pumps to provide hot water at 60 ° C [11]; Vance Payne et al. Tested the heating and cooling performance of heat pumps using R32 / R290, R32 / R152a and R290 / R600a as working fluids [12]; Sukumar Devotta [13] equaled the 1994 proposal for HFCs and HFEs Conducted a theoretical cycle analysis. Calculated condensing temperature range of 80-120 ℃, all materials are specified for the cycle conditions of no subcooling, no overheating, no pressure drop, adiabatic compression, temperature rise 40 ℃. The results show that the COP of R143 and R134 is relatively high. The above results are mainly from the thermodynamic cycle performance of non-azeotropic mixtures. Domestically, there are mainly four research institutes (Tsinghua University, Tianjin University, Shanghai Jiaotong University and Guangzhou Institute of Energy, Chinese Academy of Sciences) on the high temperature heat pump. Tsinghua University [14] has declared the patent for R124 / R142b mixed working medium. The condensing temperature of a given high-temperature water source heat pump is 90 ° C. Shanghai Jiaotong University, the use of mixed refrigerant R22 / R141b condensate from 70 ℃ to 80 ℃, and the relationship between the compressor frequency and COP conducted a preliminary study [15]. Tianjin University since the late 80s of last century for a series of high-temperature heat pump to carry out a series of research work, including a fixed temperature rise of 40 ℃, condensation temperature of 60-80 ℃, superheat of about 10 ℃, undercooling of 5 R142b, R227ea / R600, R22 / R142b and R124 / R141b were studied theoretically and experimentally on the heat pump performance [16]. By the combination of R22 / R142b / R21 and R290 / R600a / R123, Working fluid, the heat pump outlet temperature of 85 ° C, COP in 3 above the experimental results [17]; recently the condensing temperature was raised to 95 ° C, providing 90 ° C condensate [18]; the above studies have been at high temperatures Heat pump refrigerant made a positive exploration. Generally speaking, however, there are not many related literatures, and most of them are in simple thermodynamic cycle analysis and preliminary experimental verification of non-azeotropic mixed refrigerants, which is not enough to provide sufficient theoretical guarantee for the actual operation of high-temperature heat pump systems. 3 system research advances In order to promote the application of high temperature heat pump, the researchers are optimizing the cycle itself. The advantages and disadvantages of the system cycle are mainly attributed to three aspects: (1) the thermal properties of the working fluid on the circulatory system; (2) the system's own matching performance; (3) the system's control strategy. In heat pump systems, the issue of heat transfer enhancement in evaporators is as important as the problem of intensification in condensers. The difference is that in the evaporator working fluid boiling heat exchanger. The commonly used method is based on reductionism. Mathematical methods are linear. Boiling systems are non-equilibrium, non-linear, random, complex and non-reductive. They must be based on holistic system theory Linear mathematical tools to study. For this reason, the Department of Mechanics of Tsinghua University introduced the theory of bifurcation and catastrophe in chaotic mathematics into the boiling system in order to make a breakthrough in the boiling mechanism [19]. In view of the phase change heat transfer of working fluid in the evaporator, Kedzierski and Bryant carefully studied the influence of the heat transfer surface angle on the heat transfer in the evaporator [20]. Bivens studied the evaporation process of the mixed refrigerant R32 / R125 / R134a in the evaporator [21]. Taking G. Venkatarathnam [22,23,24] as the main research object, the phase change heat transfer characteristics of non-azeotropic mixtures were studied in detail. The conditions for the existence of heat exchange narrow spots in evaporator and condenser and The possibility and how to avoid the occurrence of heat exchange narrow spots, which laid the necessary theoretical foundation for the application of non-azeotropic mixed working fluids in practical engineering. In addition, the Institute of Engineering Thermophysics of the Chinese Academy of Sciences has carried out theoretical and experimental studies on the evaporation heat transfer in capillary tubes in refrigeration systems [25]. Shanghai Jiaotong University has also made corresponding theoretical studies on the universal integral model of capillary tubes [26] ]. Tianjin University also made a number of interesting attempts at the frequency conversion characteristics of high temperature heat pump compressors [27], the effect of working fluid leakage on system circulation [28], and the intelligent regulation of heat pump system load [29]. Pure refrigerant multistage compression heat pump systems and installations are mainly two-stage or three-stage compressors, which use multistage centrifugal or screw refrigeration compressors [30] for district heating or industrial process heating. The working process of this kind of heat pump is similar to that of the two-stage compression refrigeration system, but generally uses multiple condensers with the same number of stages of compression to stepwise heat-up the heat-transfer medium, and its working temperature range and working fluid used and refrigeration Different systems, technology is mature, has been in practical application of heating engineering. Absorption-compression combined heat pump systems and devices combine absorption and compression systems that employ fluids that differ greatly in boiling point as working fluid pairs and utilize their solution's absorption of lower-boiling fluids to improve circulation of certain However, studies have shown that such cycles can greatly improve the performance of absorption or vapor compression heat pumps, with great potential for development [31]. Intelligent control method applied to refrigeration, heat pump unit is only a matter of recent years, Japan is stepping up the development of small variable capacity steam compression heat pump air conditioning system control technology, and the composition of the key components of air conditioning system: inverter compressor, electronic expansion valve, Heat exchanger fan and related technologies were analyzed and commented [32]. Many domestic scholars have carried out more intelligent control research on air conditioners, Xi'an Jiaotong University conducted research on fuzzy control theory for small air conditioners [33]; Southeast University used computer simulation technology to conduct heat transfer characteristics of air conditioning heat exchangers The study [34], Shanghai Jiao Tong University also conducted a large number of basic research on intelligent control technology [35], mainly focused on artificial neural network system components of refrigeration equipment identification, has been very good conclusions, but the practical application of more less. From the above analysis, it can be predicted that the intelligent control method applied to heat pump units is a trend. Its application will make the system run more smoothly, reduce energy consumption and improve human comfort. Reason to believe that the use of intelligent control technology, high-temperature heat pump units, will be more market competitiveness. 4 Domestic Application Introduction After more than ten years of research and development, several high-temperature heat pump systems have been put into practical use in Hebei, Shandong and Tianjin. The following will briefly introduce the characteristics of each system and operating parameters. (1) A company in Hebei newly built an office building (1800m2) and a production workshop (800m2), and a bungalow building such as a guard and heating area of ​​about 2,700m2. Different requirements for office buildings and workshops, the supply of water temperature is also different. The original conditions and requirements: a. There are two shallow wells (1 eye production, 1 eye irrigation), water temperature 15 ℃, as a low temperature heat source (cold source); b. Office system fan coil terminals, hot air heating in winter and summer Air-conditioning cooling; c. Production workshop terminal radiator with cast iron, hot water in winter heating, does not require cooling in summer. Design: Two independent systems, one room temperature heat pump heating air heating, cooling air conditioning in summer, another with high temperature heat pump system for the workshop hot water heating. Among them, the high-temperature heat pump system compressor electric power of 30 hits to 15 ℃ low temperature heat source for the production