Foreword
Heat pump is essentially a heat recovery unit, which absorbs heat from the low-temperature heat source and enhances the grade, and then heat at a high temperature heat source, to save high-energy rental. Since 1989, heat pump technology in China's application and development has entered a boom. According to statistics, in 1996, the total cooling capacity of air-conditioning equipment (electric chiller-heater units, absorption chiller-heater units, room air conditioners and unit air conditioning units, but excluding imported units) is about 20 million kW, of which the heat pump The cooling capacity of the unit accounts for about 60% [1].
In the early 1980s, China adopted a water ring heat pump air conditioning system in some foreign-invested buildings [2]. Today, the water ring heat pump air conditioning system in our application has been no small popularity. Water ring heat pump air conditioning system in the 90's in China has been widely used. According to statistics, a total of 52 projects were adopted in China in 1997 [2]. Not only it has been adopted by some projects in big cities such as Beijing, Shanghai, Guangzhou, Shenzhen and Tianjin, but also small and medium-sized cities such as Foshan, Shaoxing, Huizhou and Quanzhou have begun to adopt water-ring heat pump air-conditioning systems. In addition, the research on water-ring heat pump air-conditioning system is also fruitful. From 1993 onwards, the original Harbin Institute of Construction began the water ring heat pump air conditioning system in our application of predictive analysis and evaluation. After that, many related papers were published, such as the literature [3]. In 2005, domestic water ring heat pump air conditioning system engineering monograph, namely literature [4] - "water ring heat pump air conditioning system design" published.
1 water ring heat pump air conditioning system overview
Water ring heat pump air conditioning system is a small water / air heat pump unit application, that is, the water circuit will be small water / heat pump units connected in parallel to form a closed loop to form a set of recycling waste heat inside the building as a Its low heat source heat pump heating, cooling air conditioning system. A typical water ring heat pump air conditioning system consists of three parts: (1) indoor small water / air heat pump units; (2) water cycle; (3) auxiliary equipment (such as cooling towers, heating equipment, thermal storage devices, etc.).
Water ring heat pump air conditioning system's basic working principle is: in the water / air heat pump unit heating to the water cycle loop water as a heating source; unit cooling, the water as a heat source. When the water ring heat pump air conditioning system heating operation heat absorption is less than the heating operation of the heat release, the water temperature in the loop increases, to a certain extent, the use of cooling tower release heat; the other hand, the temperature of the water loop loop Reduce, to a certain extent through the auxiliary heating equipment to absorb heat. Only when the heat capacity of the heating operation of the water / air heat pump unit is substantially equal to the heat release capacity of the cooling operation, can the water in the circulation loop be maintained within a certain temperature range and the system operates efficiently at this time.
2 water ring heat pump air conditioning system advantages
Some water ring heat pump air conditioning systems used in our country in the early 1980s showed many advantages: such as the unique function of recycling building waste heat; unlike the traditional boiler that would pollute the environment; saving or reducing the cost of conventional air conditioning system Cold and heat source equipment and room; easy to household metering and billing; easy to install, manage and so on. According to the predictions of the literature, a promising energy-saving air-conditioning system for water-ring heat pump air-conditioning systems [2]. In the following, this article analyzes the advantages of water-ring heat pump air-conditioning systems one by one from the three aspects that make up the system.
2.1 water cycle loop
First of all, according to the water ring heat pump air conditioning system in buildings, it belongs to heat recovery heat pump system. In the case of low outdoor air temperature, the building's peripheral area requires additional heat to maintain a stable and comfortable indoor temperature; at the same time, the inner area of ​​the building is cooled down by indoor heat sources (such as lighting, equipment, and human body) ), But need to reduce the indoor temperature. Water ring heat pump air-conditioning system can transfer the waste heat generated in the inner zone to the peripheral zone by connecting the water circulation loop in the peripheral zone and the inner zone of the building at the same time, and heats the peripheral zone while cooling the inner zone but does not exist or A small amount of conventional air conditioning system in the same situation of heat and energy offset by the waste of energy. Therefore, the system of building heat recovery effect, make full use of waste heat while saving energy. When the inside of the building is operated at the same time by the heating condition unit and the cooling condition unit mode, the running cost of the water ring heat pump air conditioning system can be reduced to about 50% at most.
Second, similar to the above, in order to achieve the same effect of cooling and heating, the water circulation loop of the water ring heat pump air-conditioning system is still two-pipe system, compared with the conventional air-conditioning system which needs the expensive four-pipe fan coil system. In this way, the conventional four-tube fan coil system will not exist or reduce the heat and heat offset in the room air conditioners requiring different conditions, thus avoiding the unnecessary consumption of energy and saving the piping system The initial investment costs.
Third, because the water temperature in the water circuit is within the range of normal temperature and not much different from the ambient temperature, normal-temperature water consumes much less energy than a conventional air conditioning system. At the same time, the heat loss of the loop is much smaller than that of the conventional air-conditioning system because of the reduction of loss of heat and cooling in the process of transmission and distribution. Overall, the water-ring heat pump air-conditioning system compared with the conventional air-conditioning system, only the pipeline heat loss to reduce this one, energy-saving efficiency of about 8% to 15% [5]. Moreover, due to water circulation loop pipe insulation and moisture can be separated from the wet, but also reduce the insulation layer and other materials costs.
2.2 small water / air heat pump unit
In general, water ring heat pump air conditioning systems are used indoors, according to the size of the indoor load were installed in each room. Users in each room can freely adjust the heating or cooling in the room at any time of the year according to the outdoor temperature changes and their different requirements without affecting the temperature in other rooms. As easy to adjust the room will not appear too cold, overheating and so on, both to avoid the conventional air conditioning system, energy waste, but also to create a good indoor environment. At the same time, indoor small water / air heat pump units also facilitate household metering and household charges.
For the owners, if the conventional air-conditioning system is used, it is necessary to purchase the chiller units and other equipment at one time, which often causes great financial pressure. In addition, the chiller units generally need to be installed for one to two years before they can benefit. The water ring heat pump Air-conditioning system in small water / air heat pump units can be phased investment, construction in batches, or even before the user to move into the layer by layer, the return on investment of its high efficiency, quick. This feature also makes the water ring heat pump air conditioning system in the renovation of old buildings or system quite market, because the conventional air conditioning system can not avoid damage to the original structure, and not easy to find a suitable refrigeration room, the general also need to shut down the whole building Renovation project, resulting in greater economic losses.
For the designer, the system is more compact, simple and flexible because of the indoor small water / air heat pump unit and no bulky air duct, water chiller, etc., and the air conditioner room (or Reduce the engine room area), but also for the owners to increase the use of space and effective space. Water ring heat pump air conditioner. For the construction side, the installation work on the site is reduced because the small water / air heat pump unit can be assembled in the project.
2.3 Auxiliary equipment
If the water ring heat pump air conditioning system to add storage devices and other ancillary equipment, the system can improve the economy. Because the heat storage device can achieve the balance between the condensation heat released into the water circulation loop by the inner area refrigeration unit and the heat absorbed by the peripheral heating unit from the water circulation loop over a period of one day or more, And the annual energy consumption of water heaters.
3 water ring heat pump air conditioning system shortcomings
The development of water-ring heat pump air-conditioning system mainly from two aspects: First, from the system point of view, some buildings in the domestic waste heat is small or no preheating, still need to add heating equipment, resulting in it can not give full play to Some of the original advantages; the other is from the equipment point of view, the water ring heat pump air conditioning system used in small water / air heat pump there are some inherent problems also limits its wider application. At present, for the above two shortcomings, there have been many solutions to promote the water ring heat pump air conditioning system.
3.1 less than waste heat in the building
By analyzing the operating characteristics of water-ring heat pump air-conditioning system, we can see that only when there is a lot of waste heat in the inner area of ​​the building and the surrounding area needs heating, can the water heat pump air conditioning system transfer the waste heat in the building area to the peripheral area that needs heat , So as to achieve the purpose of recycling waste heat of buildings and saving energy. However, the load of various types of buildings in our country is not large and the inner area of ​​buildings is small, so the residual heat of buildings is also small. In this case, if you want to use water ring heat pump air conditioning system, it is bound to add a boiler. However, the high heat of the boiler heats the circulating water in the water cycle to a low-temperature heat source which is almost the same as room temperature, and then the water / air heat pump unit consumes electric energy and elevates it to a high level to heat the room to the interior, which in itself is uneconomical ,unreasonable. In addition, if the use of coal-fired boiler, there is still a problem of environmental pollution.
The solution to the problem of insufficient residual heat in buildings is to introduce a low-temperature heat source from the outside of the building to replace the residual heat in the building. Solar energy, water (surface water, well water, river water, etc.), soil and air can be used as external energy sources for water ring heat pump air conditioning system [6]. For example, Dalian Power Building (high-rise unit type building) uses the thermal power plant cooling water as the external heat source of the water ring heat pump air conditioning system and receives good energy-saving effect [2]. In addition, Harbin Institute of Technology proposed an air / water heat pump and water / air heat pump coupled two-stage heat pump heating system. The system in cold regions, air-source heat pump chillers to prepare low temperature water 10 ℃ ~ 20 ℃, through the water loop to the indoor air / air heat pump units, water / air heat pump and then draw heat from the water, direct heating Indoor air, to achieve the purpose of heating [7]. All in all, the problem of insufficient residual heat in the building can be solved through cheap auxiliary heat source, and the application scope of the water ring heat pump air conditioning system is broadened.
3.2 small water / air heat pump unit
Above all, the COP of a small water / air heat pump unit is much smaller than that of a large chiller unit, and its price is also high for other types of units at the same cooling capacity. Another important issue is that small water / air heat pump units are installed indoors. Compressors and fans inside heat pump units can become a significant noise source and can not meet the noise standards for indoor environments.
How to improve the water ring heat pump air conditioning system in the economy of the issue, we can through the air conditioning system design in the form of a hybrid system to be solved. Hybrid system refers to the water / air heat pump unit with other air conditioning equipment (such as chillers, unit cabinet air conditioner, etc.) combined to become a new air conditioning system. Similarly, in order to improve the economy of system operation, a unit air-conditioning unit (water-cooled) is provided in the inner area of ​​the building to supply cooling to the inner area, and a water / air heat pump unit is provided in the peripheral area to cool or heat the peripheral area. A notable form of hybrid system [7].
In the control room of small water / air heat pump noise problems, literature [8] gives an exhaustive description. The measures to control the noise include four aspects: controlling the noise source, designing properly, installing correctly, seriously debugging and maintaining, and each has many specific implementation measures. Practice shows that if the construction of the project can correctly handle the noise problem and take reasonable measures, it can fully meet the requirements of indoor environmental noise standards.
4 Conclusion
From the above analysis we can see that as long as we design, standardize the installation, flexible management, water ring heat pump air conditioning system will be able to play its existing economy, energy saving, environmental protection and other advantages. Of course, we should also determine whether or not to adopt the water ring heat pump air conditioning system according to the characteristics of each area and each building. Especially in the northern area, the inner area is large, and the heat loss in the inner area is also large. It is most suitable for the water-ring heat pump air-conditioning system. In contrast, water-ring heat pump air-conditioning systems should not be used in some areas of the South, which require cooling for most of the year, as it does not save energy compared to fan coils or other conventional air-conditioning systems.
Under the condition that the annual growth rate of energy is about 3% ~ 5%, the national economy will continue to grow at an annual rate of 8% ~ 9%. That is, under the conditions of energy shortage, attention must be paid to the development of energy-saving technologies and energy-saving products [1]. Water ring heat pump air conditioning system itself, the recovery of building waste heat, energy conservation, if and solar, groundwater, industrial waste water and other low heat combined to further broaden the scope of its application. In the country today, increasing emphasis on building energy efficiency, water ring heat pump air conditioning system has a huge energy saving potential and broad application prospects.
references
[1] Li Xianrui, Long four-dimensional. Heat pump status and prospects [J]. "HVAC new technology" editorial board. HVAC technology 1 [C]. Beijing: Building Industry Press, 1999,1-4
[2] The best horse, Yang Ziqiang, Ma Guangyu. Review and Prospect of Development of Heat Pump Air Conditioners in China [A]. "HVAC new technology" editorial board. HVAC technology 2 [C]. Beijing: Building Industry Press, 2000,24-27
[3] Jiang Yiqiang, Yao Yang, Ma Liang Liang. Water ring heat pump air conditioning system, a number of issues analysis [J]. Fluid Machinery, 2001, 29 (11): 52-54
[4] Ma Liang, Yao Yang, Yang Ziqiang and other editors, water ring heat pump air conditioning system design [M]. Beijing: Chemical Industry Press, 2005
[5] Meyer (Shanghai) Air Conditioning Equipment Co., Ltd. "Water source / water ring heat pump air conditioning" system components, operating principles and advantages.
[6] Lu Yajun, Ma Liang, edited by Zou Pinghua. HVAC [M]. Beijing: Building Industry Press, 2002
[7] Yao Yang, Ma Liang Liang. Water ring heat pump air conditioning system in our application should pay attention to several issues [J]. Fluid Machinery, 2002,30 (9): 59-61
[8] Zou Huiming. Noise in water ring heat pump system [J]. HVAC, 2005,35 (7): 131-132
Heat pump is essentially a heat recovery unit, which absorbs heat from the low-temperature heat source and enhances the grade, and then heat at a high temperature heat source, to save high-energy rental. Since 1989, heat pump technology in China's application and development has entered a boom. According to statistics, in 1996, the total cooling capacity of air-conditioning equipment (electric chiller-heater units, absorption chiller-heater units, room air conditioners and unit air conditioning units, but excluding imported units) is about 20 million kW, of which the heat pump The cooling capacity of the unit accounts for about 60% [1].
In the early 1980s, China adopted a water ring heat pump air conditioning system in some foreign-invested buildings [2]. Today, the water ring heat pump air conditioning system in our application has been no small popularity. Water ring heat pump air conditioning system in the 90's in China has been widely used. According to statistics, a total of 52 projects were adopted in China in 1997 [2]. Not only it has been adopted by some projects in big cities such as Beijing, Shanghai, Guangzhou, Shenzhen and Tianjin, but also small and medium-sized cities such as Foshan, Shaoxing, Huizhou and Quanzhou have begun to adopt water-ring heat pump air-conditioning systems. In addition, the research on water-ring heat pump air-conditioning system is also fruitful. From 1993 onwards, the original Harbin Institute of Construction began the water ring heat pump air conditioning system in our application of predictive analysis and evaluation. After that, many related papers were published, such as the literature [3]. In 2005, domestic water ring heat pump air conditioning system engineering monograph, namely literature [4] - "water ring heat pump air conditioning system design" published.
1 water ring heat pump air conditioning system overview
Water ring heat pump air conditioning system is a small water / air heat pump unit application, that is, the water circuit will be small water / heat pump units connected in parallel to form a closed loop to form a set of recycling waste heat inside the building as a Its low heat source heat pump heating, cooling air conditioning system. A typical water ring heat pump air conditioning system consists of three parts: (1) indoor small water / air heat pump units; (2) water cycle; (3) auxiliary equipment (such as cooling towers, heating equipment, thermal storage devices, etc.).
Water ring heat pump air conditioning system's basic working principle is: in the water / air heat pump unit heating to the water cycle loop water as a heating source; unit cooling, the water as a heat source. When the water ring heat pump air conditioning system heating operation heat absorption is less than the heating operation of the heat release, the water temperature in the loop increases, to a certain extent, the use of cooling tower release heat; the other hand, the temperature of the water loop loop Reduce, to a certain extent through the auxiliary heating equipment to absorb heat. Only when the heat capacity of the heating operation of the water / air heat pump unit is substantially equal to the heat release capacity of the cooling operation, can the water in the circulation loop be maintained within a certain temperature range and the system operates efficiently at this time.
2 water ring heat pump air conditioning system advantages
Some water ring heat pump air conditioning systems used in our country in the early 1980s showed many advantages: such as the unique function of recycling building waste heat; unlike the traditional boiler that would pollute the environment; saving or reducing the cost of conventional air conditioning system Cold and heat source equipment and room; easy to household metering and billing; easy to install, manage and so on. According to the predictions of the literature, a promising energy-saving air-conditioning system for water-ring heat pump air-conditioning systems [2]. In the following, this article analyzes the advantages of water-ring heat pump air-conditioning systems one by one from the three aspects that make up the system.
2.1 water cycle loop
First of all, according to the water ring heat pump air conditioning system in buildings, it belongs to heat recovery heat pump system. In the case of low outdoor air temperature, the building's peripheral area requires additional heat to maintain a stable and comfortable indoor temperature; at the same time, the inner area of ​​the building is cooled down by indoor heat sources (such as lighting, equipment, and human body) ), But need to reduce the indoor temperature. Water ring heat pump air-conditioning system can transfer the waste heat generated in the inner zone to the peripheral zone by connecting the water circulation loop in the peripheral zone and the inner zone of the building at the same time, and heats the peripheral zone while cooling the inner zone but does not exist or A small amount of conventional air conditioning system in the same situation of heat and energy offset by the waste of energy. Therefore, the system of building heat recovery effect, make full use of waste heat while saving energy. When the inside of the building is operated at the same time by the heating condition unit and the cooling condition unit mode, the running cost of the water ring heat pump air conditioning system can be reduced to about 50% at most.
Second, similar to the above, in order to achieve the same effect of cooling and heating, the water circulation loop of the water ring heat pump air-conditioning system is still two-pipe system, compared with the conventional air-conditioning system which needs the expensive four-pipe fan coil system. In this way, the conventional four-tube fan coil system will not exist or reduce the heat and heat offset in the room air conditioners requiring different conditions, thus avoiding the unnecessary consumption of energy and saving the piping system The initial investment costs.
Third, because the water temperature in the water circuit is within the range of normal temperature and not much different from the ambient temperature, normal-temperature water consumes much less energy than a conventional air conditioning system. At the same time, the heat loss of the loop is much smaller than that of the conventional air-conditioning system because of the reduction of loss of heat and cooling in the process of transmission and distribution. Overall, the water-ring heat pump air-conditioning system compared with the conventional air-conditioning system, only the pipeline heat loss to reduce this one, energy-saving efficiency of about 8% to 15% [5]. Moreover, due to water circulation loop pipe insulation and moisture can be separated from the wet, but also reduce the insulation layer and other materials costs.
2.2 small water / air heat pump unit
In general, water ring heat pump air conditioning systems are used indoors, according to the size of the indoor load were installed in each room. Users in each room can freely adjust the heating or cooling in the room at any time of the year according to the outdoor temperature changes and their different requirements without affecting the temperature in other rooms. As easy to adjust the room will not appear too cold, overheating and so on, both to avoid the conventional air conditioning system, energy waste, but also to create a good indoor environment. At the same time, indoor small water / air heat pump units also facilitate household metering and household charges.
For the owners, if the conventional air-conditioning system is used, it is necessary to purchase the chiller units and other equipment at one time, which often causes great financial pressure. In addition, the chiller units generally need to be installed for one to two years before they can benefit. The water ring heat pump Air-conditioning system in small water / air heat pump units can be phased investment, construction in batches, or even before the user to move into the layer by layer, the return on investment of its high efficiency, quick. This feature also makes the water ring heat pump air conditioning system in the renovation of old buildings or system quite market, because the conventional air conditioning system can not avoid damage to the original structure, and not easy to find a suitable refrigeration room, the general also need to shut down the whole building Renovation project, resulting in greater economic losses.
For the designer, the system is more compact, simple and flexible because of the indoor small water / air heat pump unit and no bulky air duct, water chiller, etc., and the air conditioner room (or Reduce the engine room area), but also for the owners to increase the use of space and effective space. Water ring heat pump air conditioner. For the construction side, the installation work on the site is reduced because the small water / air heat pump unit can be assembled in the project.
2.3 Auxiliary equipment
If the water ring heat pump air conditioning system to add storage devices and other ancillary equipment, the system can improve the economy. Because the heat storage device can achieve the balance between the condensation heat released into the water circulation loop by the inner area refrigeration unit and the heat absorbed by the peripheral heating unit from the water circulation loop over a period of one day or more, And the annual energy consumption of water heaters.
3 water ring heat pump air conditioning system shortcomings
The development of water-ring heat pump air-conditioning system mainly from two aspects: First, from the system point of view, some buildings in the domestic waste heat is small or no preheating, still need to add heating equipment, resulting in it can not give full play to Some of the original advantages; the other is from the equipment point of view, the water ring heat pump air conditioning system used in small water / air heat pump there are some inherent problems also limits its wider application. At present, for the above two shortcomings, there have been many solutions to promote the water ring heat pump air conditioning system.
3.1 less than waste heat in the building
By analyzing the operating characteristics of water-ring heat pump air-conditioning system, we can see that only when there is a lot of waste heat in the inner area of ​​the building and the surrounding area needs heating, can the water heat pump air conditioning system transfer the waste heat in the building area to the peripheral area that needs heat , So as to achieve the purpose of recycling waste heat of buildings and saving energy. However, the load of various types of buildings in our country is not large and the inner area of ​​buildings is small, so the residual heat of buildings is also small. In this case, if you want to use water ring heat pump air conditioning system, it is bound to add a boiler. However, the high heat of the boiler heats the circulating water in the water cycle to a low-temperature heat source which is almost the same as room temperature, and then the water / air heat pump unit consumes electric energy and elevates it to a high level to heat the room to the interior, which in itself is uneconomical ,unreasonable. In addition, if the use of coal-fired boiler, there is still a problem of environmental pollution.
The solution to the problem of insufficient residual heat in buildings is to introduce a low-temperature heat source from the outside of the building to replace the residual heat in the building. Solar energy, water (surface water, well water, river water, etc.), soil and air can be used as external energy sources for water ring heat pump air conditioning system [6]. For example, Dalian Power Building (high-rise unit type building) uses the thermal power plant cooling water as the external heat source of the water ring heat pump air conditioning system and receives good energy-saving effect [2]. In addition, Harbin Institute of Technology proposed an air / water heat pump and water / air heat pump coupled two-stage heat pump heating system. The system in cold regions, air-source heat pump chillers to prepare low temperature water 10 ℃ ~ 20 ℃, through the water loop to the indoor air / air heat pump units, water / air heat pump and then draw heat from the water, direct heating Indoor air, to achieve the purpose of heating [7]. All in all, the problem of insufficient residual heat in the building can be solved through cheap auxiliary heat source, and the application scope of the water ring heat pump air conditioning system is broadened.
3.2 small water / air heat pump unit
Above all, the COP of a small water / air heat pump unit is much smaller than that of a large chiller unit, and its price is also high for other types of units at the same cooling capacity. Another important issue is that small water / air heat pump units are installed indoors. Compressors and fans inside heat pump units can become a significant noise source and can not meet the noise standards for indoor environments.
How to improve the water ring heat pump air conditioning system in the economy of the issue, we can through the air conditioning system design in the form of a hybrid system to be solved. Hybrid system refers to the water / air heat pump unit with other air conditioning equipment (such as chillers, unit cabinet air conditioner, etc.) combined to become a new air conditioning system. Similarly, in order to improve the economy of system operation, a unit air-conditioning unit (water-cooled) is provided in the inner area of ​​the building to supply cooling to the inner area, and a water / air heat pump unit is provided in the peripheral area to cool or heat the peripheral area. A notable form of hybrid system [7].
In the control room of small water / air heat pump noise problems, literature [8] gives an exhaustive description. The measures to control the noise include four aspects: controlling the noise source, designing properly, installing correctly, seriously debugging and maintaining, and each has many specific implementation measures. Practice shows that if the construction of the project can correctly handle the noise problem and take reasonable measures, it can fully meet the requirements of indoor environmental noise standards.
4 Conclusion
From the above analysis we can see that as long as we design, standardize the installation, flexible management, water ring heat pump air conditioning system will be able to play its existing economy, energy saving, environmental protection and other advantages. Of course, we should also determine whether or not to adopt the water ring heat pump air conditioning system according to the characteristics of each area and each building. Especially in the northern area, the inner area is large, and the heat loss in the inner area is also large. It is most suitable for the water-ring heat pump air-conditioning system. In contrast, water-ring heat pump air-conditioning systems should not be used in some areas of the South, which require cooling for most of the year, as it does not save energy compared to fan coils or other conventional air-conditioning systems.
Under the condition that the annual growth rate of energy is about 3% ~ 5%, the national economy will continue to grow at an annual rate of 8% ~ 9%. That is, under the conditions of energy shortage, attention must be paid to the development of energy-saving technologies and energy-saving products [1]. Water ring heat pump air conditioning system itself, the recovery of building waste heat, energy conservation, if and solar, groundwater, industrial waste water and other low heat combined to further broaden the scope of its application. In the country today, increasing emphasis on building energy efficiency, water ring heat pump air conditioning system has a huge energy saving potential and broad application prospects.
references
[1] Li Xianrui, Long four-dimensional. Heat pump status and prospects [J]. "HVAC new technology" editorial board. HVAC technology 1 [C]. Beijing: Building Industry Press, 1999,1-4
[2] The best horse, Yang Ziqiang, Ma Guangyu. Review and Prospect of Development of Heat Pump Air Conditioners in China [A]. "HVAC new technology" editorial board. HVAC technology 2 [C]. Beijing: Building Industry Press, 2000,24-27
[3] Jiang Yiqiang, Yao Yang, Ma Liang Liang. Water ring heat pump air conditioning system, a number of issues analysis [J]. Fluid Machinery, 2001, 29 (11): 52-54
[4] Ma Liang, Yao Yang, Yang Ziqiang and other editors, water ring heat pump air conditioning system design [M]. Beijing: Chemical Industry Press, 2005
[5] Meyer (Shanghai) Air Conditioning Equipment Co., Ltd. "Water source / water ring heat pump air conditioning" system components, operating principles and advantages.
[6] Lu Yajun, Ma Liang, edited by Zou Pinghua. HVAC [M]. Beijing: Building Industry Press, 2002
[7] Yao Yang, Ma Liang Liang. Water ring heat pump air conditioning system in our application should pay attention to several issues [J]. Fluid Machinery, 2002,30 (9): 59-61
[8] Zou Huiming. Noise in water ring heat pump system [J]. HVAC, 2005,35 (7): 131-132