Water source heat pump unit adopting deep supercooling technology

Abstract

The invention belongs to the technical field of refrigeration air conditioners and heat pumps, and particularly relates to a water source heat pump unit adopting a deep supercooling technology, which comprises a compressor, a condenser, a supercooler, an expansion valve, an evaporator, a control valve, a user side and a water source side, the first output end of the condenser is connected with the first input end of the subcooler through a first pipeline, and the first output end of the condenser is connected with the first input end of the subcooler through a second pipeline. Underground or surface water from a water source serves as a heat source of a heat pump and also serves as a cold source for supercooling of the heat pump, and due to the fact that the temperature of low-temperature drainage water behind an evaporator is often greatly lower than the condensation temperature of a system, condensed high-temperature and high-pressure refrigerant liquid can be deeply supercooled, and the system does not need to apply extra energy consumption for the high-temperature and high-pressure refrigerant liquid. Therefore, the efficiency of the refrigerating system can be obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration, air conditioning and heat pumps, and in particular to a water source heat pump unit using a deep supercooling technology. Background Art

[0002] The supercooling cycle is an important mode of the refrigeration cycle. The supercooling cycle refers to the state in which the condensed liquid refrigerant is cooled to a temperature below its saturation temperature in the refrigeration cycle. Since the refrigerant in this state has a lower temperature before entering the throttling mechanism (such as the expansion valve), it can reduce the loss caused by flash during the throttling process, and can absorb heat more effectively in the subsequent evaporation process. In the refrigeration system, the greater the supercooling degree of the supercooling cycle, the stronger the refrigeration capacity of the unit mass of the refrigerant, and the higher the efficiency of the compressor, which can improve the efficiency of the system.

[0003] Based on the principles of thermodynamics, a heat pump is a reverse refrigeration cycle, so the above-mentioned supercooling technology is also applied to the heat pump cycle.

[0004] Water source heat pump is a form of heat pump. In a broad sense, water source heat pump is a refrigeration system that uses low-grade thermal energy resources such as surface water, shallow groundwater and some industrial and domestic sewage as heat sources, with the purpose of heating or domestic hot water and some industrial hot water supply, and converts energy through the heat pump principle. Water source heat pump systems are divided into closed systems and open systems. The so-called open system is a system that uses low-grade thermal energy resources such as underground or surface water to complete heat exchange and cooling in the evaporator and then directly discharges it back to its water source. Compared with the air conditioning refrigeration system, the heat pump system has a larger temperature difference between the evaporation temperature and the condensation temperature, so the necessity of supercooling the high-temperature and high-pressure liquid after condensation becomes more prominent, especially for high-temperature heat pump units.

[0005] At present, the supercooling of heat pump units used in the field of refrigeration and air conditioning often relies solely on further cooling in the condenser. However, due to the limitation of the temperature of the condensing cooling medium, the degree of supercooling obtained by further cooling in the condenser is very limited. In addition, although there is also a method of using the gaseous refrigerant with a lower temperature coming out of the evaporator to cool the liquid refrigerant again to achieve deep supercooling, it lacks universality because, on the one hand, the overheating of part of the refrigerant has a negative impact on its refrigeration efficiency, and on the other hand, it causes the refrigerant to not absorb heat to the maximum extent in the evaporator, thereby reducing the overall performance of the refrigeration system and often making it more costly than gain, so its application is also greatly limited. In addition, because the return temperature after supercooling is too high, it will not only increase the exhaust temperature of the compressed refrigerant, but also affect the safety of the unit operation, which also greatly limits this supercooling method.

[0006] In summary, although deep supercooling technology has significant advantages in the field of refrigeration and air conditioning, its application is still severely restricted by some restrictions. The most important of these is that deep supercooling requires a low-temperature cold source with a certain temperature difference from the high-temperature and high-pressure liquid after condensation, and the acquisition of such a cold source will neither affect the original efficiency of the system nor increase the system's additional energy consumption. In an open water source heat pump system, since underground or surface water will be directly discharged back to its water source after completing its heat exchange and cooling, and its temperature is close to the evaporation temperature of the system, this drainage is undoubtedly the ideal cold source required for the supercooling cycle of the heat pump system without additional energy consumption.

[0007] To this end, a water source heat pump unit using deep supercooling technology is proposed to solve the above-mentioned problems. Summary of the invention

[0008] The object of the present invention is to provide a water source heat pump unit using deep supercooling technology to solve the problems raised in the above background technology.

[0009] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a water source heat pump unit adopting deep subcooling technology, comprising a compressor, a condenser, a subcooler, an expansion valve, an evaporator, a control valve, and a user side and a water source side, the output end of the compressor is connected to the first input end of the condenser through a first pipe, the first output end of the condenser is connected to the first input end of the subcooler through a second pipe, the second input and output ends of the condenser are respectively connected to the user side, the first output end of the subcooler is connected to the first input end of the evaporator through a third pipe, and the first output end of the evaporator is connected to the input end of the compressor through a fourth pipe; the second output end of the evaporator is connected to the second input end of the subcooler and the return water end of the water source side through a fifth pipe and a sixth pipe respectively, and the second output end of the subcooler is connected to the return water end of the water source side through a seventh pipe.

[0010] Preferably, the second input end of the subcooler is connected to the second output end of the evaporator, and the second output end of the subcooler is connected to the return water end of the water source side.

[0011] Preferably, a control valve is provided on the sixth pipeline connecting the second output end of the evaporator and the return water end of the water source side.

[0012] Preferably, an expansion valve is provided on the third pipeline at the first output end of the subcooler.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention adds a subcooler to the unit, allowing the low-temperature drainage after the evaporator and the high-temperature and high-pressure refrigerant liquid after condensation to exchange heat in the subcooler, so that the underground or surface water from the water source serves as both the heat source of the heat pump and the cold source for its subcooling. Since the temperature of the low-temperature drainage after the evaporator is often much lower than the condensation temperature of the system, the high-temperature and high-pressure refrigerant liquid after condensation can be deeply subcooled without the system having to incur additional energy consumption, thereby significantly improving the efficiency of the refrigeration system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the present invention.

[0015] In the figure: 1 compressor, 2 condenser, 3 subcooler, 4 expansion valve, 5 evaporator, 6 control valve. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0018] Example: See also Figure 1 , the present invention provides a technical solution: A water source heat pump unit adopting deep subcooling technology comprises a compressor 1, a condenser 2, a subcooler 3, an expansion valve 4, an evaporator 5, a control valve 6, a user side and a water source side, wherein the output end of the compressor 1 is connected to the first input end of the condenser 2 through a first pipe, the first output end of the condenser 2 is connected to the first input end of the subcooler 3 through a second pipe, the first output end of the subcooler 3 is connected to the first input end of the evaporator 5 through a third pipe, and the first output end of the evaporator 5 is connected to the input end of the compressor 1 through a fourth pipe; the second output end of the evaporator 5 is respectively connected to the second input end of the subcooler 3 and the return water end of the water source side through a fifth pipe and a sixth pipe, the second output end of the subcooler 3 is connected to the return water end of the water source side through a seventh pipe, the second input end and the second output end of the condenser 2 are respectively connected to the user side through an eighth pipe and a ninth pipe, one way of the second input end of the evaporator 5 and the second output end of the subcooler 3 is respectively connected to the water supply end of the water source side through a sixth pipe and a seventh pipe, and the other way of the second output end of the evaporator 5 is connected to the second input end of the subcooler 3.

[0019] The second input end of the subcooler 3 is connected to the second output end of the evaporator 5, and the second output end of the subcooler 3 is connected to the return water end of the water source side.

[0020] A control valve is provided on the sixth pipe connecting the second output end of the evaporator 5 with the return end of the water source side to adjust and control the bypass water volume directly returned to the return end of the water source side. Then, the low-temperature drainage discharged to the return end of the water source side is connected to the subcooler 3 and completes the heat exchange with the medium-temperature high-pressure liquid from the condenser 2 before being discharged to the return end of the water source side.

[0021] An expansion valve 4 is provided on the third pipeline at the first output end of the subcooler 3 .

[0022] The high-temperature and high-pressure refrigerant gas discharged after being compressed by the compressor 1 is first condensed into a medium-temperature and high-pressure liquid in the condenser 2, and then deeply cooled by the specially set subcooler 3 to become a low-temperature and high-pressure liquid, and then throttled by the expansion valve 4 to become a low-temperature and low-pressure liquid, and finally sent to the evaporator 5 to evaporate into gas and then be sucked into the compressor 1, thus completing a deep subcooling heat pump cycle. The evaporator 5 then completes the heat exchange of the low-temperature drainage discharged back to the water source with the medium-temperature and high-pressure liquid from the condenser 2 in the subcooler 3, and finally discharges it to its water source. This technology can be applied to both water source heat pump units and water source chillers.

[0023] (1) Refrigerant circuit The high-temperature and high-pressure refrigerant gas discharged after being compressed by the compressor 1 is first condensed into a medium-temperature and high-pressure liquid in the condenser 2, and then further cooled into a low-temperature and high-pressure liquid by a specially arranged subcooler 3, and then throttled by the expansion valve 4 to become a low-temperature and low-pressure liquid, and finally sent to the evaporator 5 to evaporate into a low-temperature and low-pressure gas, which is then sucked into the compressor 1 and compressed into a high-temperature and high-pressure refrigerant gas and then discharged, thereby completing a deep subcooling heat pump cycle.

[0024] (2) Water source and water circuit The source side water from underground or surface as the heat source of the system is first sent to the evaporator 5, where it exchanges heat with the low-temperature and low-pressure liquid after throttling by the expansion valve 4, and then sent to the subcooler 3, where it exchanges heat with the medium-temperature and high-pressure liquid from the condenser 2 and then discharged back to the water source; one way is directly discharged back to the water source through the bypass. The amount of water in the bypass is adjusted and controlled by the control valve set therein.

[0025] (3) User-side hot water circuit The hot water return from the user side is sent to the condenser 2, where it exchanges heat with the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 and is heated before being sent to the user side, thus completing its heating cycle.

[0026] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure marks in the claims should not be regarded as limiting the claims involved.

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A water source heat pump unit using deep subcooling technology, comprising a compressor (1), a condenser (2), a subcooler (3), an expansion valve (4), an evaporator (5), a control valve (6), a user side and a water source side, characterized in that: The output end of the compressor (1) is connected to the first input end of the condenser (2) through a first pipe, the first output end of the condenser (2) is connected to the first input end of the subcooler (3) through a second pipe, the second input and output ends of the condenser (2) are respectively connected to the user side, the first output end of the subcooler (3) is connected to the first input end of the evaporator (5) through a third pipe, the first output end of the evaporator (5) is connected to the input end of the compressor (1) through a fourth pipe; the second output end of the evaporator (5) is respectively connected to the second input end of the subcooler (3) and the return water end of the water source side through a fifth pipe and a sixth pipe, and the second output end of the subcooler (3) is connected to the return water end of the water source side through a seventh pipe.

2. A water source heat pump unit using deep subcooling technology according to claim 1, characterized in that: The second input end of the subcooler (3) is connected to the second output end of the evaporator (5), and the second output end of the subcooler (3) is connected to the return water end on the water source side.

3. The water source heat pump unit using deep subcooling technology according to claim 1, characterized in that: A control valve (6) is provided on a sixth pipeline connecting the second output end of the evaporator (5) and the return water end on the water source side.

4. The water source heat pump unit using deep subcooling technology according to claim 1, characterized in that: An expansion valve (4) is provided on the third pipeline at the first output end of the subcooler (3).

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