Disclosure of Invention
According to the technical problem, a wide-ring temperature type CO2 air source heat pump system for low-pressure exhaust heat recovery is provided.
The invention adopts the following technical means:
a wide loop temperature CO2 air source heat pump system for low pressure exhaust heat recovery, comprising:
the system comprises a low-pressure section CO2 compressor, an exhaust one-way valve, a low-pressure section exhaust electronic three-way valve, a high-pressure section CO2 compressor, a heat recovery plate heat exchanger, a regenerative cycle plate heat exchanger, a high-pressure electronic pressure regulating valve, an evaporator, a gas-liquid separator, a vapor-separation electronic pressure regulating valve, a low-pressure section air suction electronic three-way valve and an electric ball valve;
one end of the low-pressure section CO2 compressor is communicated with one port of the low-pressure section exhaust electronic three-way valve through a pipeline with an exhaust one-way valve, and the other end of the low-pressure section CO2 compressor is communicated with one port of the low-pressure section air suction electronic three-way valve through a pipeline;
the other pipeline of the low-pressure section exhaust electronic three-way valve is communicated with the input end of the high-pressure section CO2 compressor through a heat recovery plate heat exchanger, and the last pipeline of the low-pressure section exhaust electronic three-way valve is communicated with an inlet gas path of the gas-liquid separator through an evaporator;
the other path of the low-pressure section air suction electronic three-way valve is communicated with the input end of the high-pressure section CO2 compressor, the last path of the low-pressure section air suction electronic three-way valve is communicated with the gas-liquid separator through the regenerative circulating plate heat exchanger, and an electric ball valve is arranged on a pipeline between the gas-liquid separator and the regenerative circulating plate heat exchanger on a path pipeline;
the output end pipeline of the high-pressure section CO2 compressor is communicated with the inlet of the gas-liquid separator after sequentially passing through the heat recovery plate heat exchanger, the regenerative cycle plate heat exchanger and the evaporator, and a high-pressure electronic pressure regulating valve is arranged at the position between the regenerative cycle plate heat exchanger and the evaporator and between the regenerative cycle plate heat exchanger and the desuperheater;
the last path of the low-pressure section exhaust electronic three-way valve is converged into a pipeline between a high-pressure electronic pressure regulating valve of an output end pipe of the high-pressure section CO2 compressor and the evaporator and between the high-pressure electronic pressure regulating valve and the desuperheater;
the other output pipeline of the gas-liquid separator is provided with a vapor-separating electronic pressure regulating valve, and finally the vapor-separating electronic pressure regulating valve is converged on the connecting pipeline of the gas-liquid separator and the regenerative circulating plate heat exchanger.
During high-ring temperature heating, a CO2 refrigerant is compressed by a high-pressure section CO2 compressor, compressed into high-temperature and high-pressure refrigerant gas, the high-temperature and high-pressure refrigerant gas enters a heat recovery plate heat exchanger, water is heated in the heat recovery plate heat exchanger and simultaneously cools the CO2 refrigerant, the high-pressure transcritical refrigerant is formed after cooling, the transcritical refrigerant is further cooled in a regenerative cycle plate heat exchanger, the transcritical refrigerant enters an evaporator after being throttled by a high-pressure electronic pressure regulating valve, the low-pressure refrigerant is evaporated and absorbed in the evaporator, the low-pressure refrigerant is formed and enters the regenerative cycle plate heat exchanger after passing through an electric ball valve, the overheated CO2 refrigerant is formed after passing through the plate heat exchanger, and the overheated refrigerant returns to the high-pressure section compressor after passing through a low-pressure section air suction electronic three-way valve, so that heating cycle is completed. In the operation process of the compressor, the vapor separation electronic pressure regulating valve is opened, so that the oil in the vapor can return to the compressor along with the refrigerant.
And during low-ring-temperature heating, a CO2 refrigerant is compressed by a low-pressure stage CO2 compressor, refrigerant gas compressed into high temperature and medium pressure enters a heat recovery plate heat exchanger after passing through a low-pressure stage exhaust electronic three-way valve, water is heated in the heat recovery plate heat exchanger and CO2 refrigerant is cooled at the same time, medium pressure refrigerant is formed after cooling, the medium pressure refrigerant enters a high-pressure stage CO2 compressor for continuous compression, the refrigerant gas compressed into high temperature and high pressure enters the heat recovery plate heat exchanger again, water is heated in the heat recovery plate heat exchanger and simultaneously cools the CO2 refrigerant, the high pressure transcritical state refrigerant is formed after cooling, the transcritical refrigerant is further cooled in a backheating circulation plate heat exchanger, the high pressure electronic pressure regulating valve throttles and then enters an evaporator, the low pressure refrigerant is evaporated and absorbed in the evaporator, the low pressure gas refrigerant enters the backheating circulation plate heat exchanger after passing through an electric ball valve, the over-heating state CO2 refrigerant is formed after passing through the plate heat exchanger, and the over-heating state refrigerant returns to the low-pressure stage electronic three-way valve after cooling, and the backheating circulation plate heat exchanger is completed. In the operation process of the compressor, the vapor separation electronic pressure regulating valve is opened, so that the oil in the vapor can return to the compressor along with the refrigerant.
During defrosting, a CO2 refrigerant is compressed by a low-pressure section CO2 compressor, refrigerant gas compressed into high temperature and medium pressure enters an evaporator through a low-pressure section exhaust electronic three-way valve, the high temperature gas is used for defrosting the evaporator, the medium pressure refrigerant after defrosting enters a regenerative cycle plate heat exchanger after being throttled and depressurized by a vapor separation electronic pressure regulating valve, and part of heat is absorbed and then returns to the low-pressure section compressor through a low-pressure section air suction electronic three-way valve, so that defrosting cycle is completed.
The invention has the advantages that: the heating process of high-temperature and low-temperature can be realized, and the winter application in northern areas of China can be well satisfied. The hot water prepared by the heat pump system can be used for various aspects such as household hot water, heating and the like. The electronic three-way valve is controlled by the controller, so that intelligent conversion can be realized, and good matching performance is realized between system operation and environmental working conditions. The system has strong practicability and universality, accords with the current energy-saving and environment-friendly design concept, and provides a good system design for future heat pump system application.
Detailed Description
It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present invention. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.
The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. Meanwhile, it should be clear that the dimensions of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.
In the description of the present invention, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present invention: the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.
Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present invention.
As shown in fig. 1, the present invention provides a wide-loop temperature type CO2 air source heat pump system for low-pressure exhaust heat recovery, comprising:
the low-pressure section CO2 compressor 1, the exhaust one-way valve 2, the low-pressure section exhaust electronic three-way valve 3, the high-pressure section CO2 compressor 4, the heat recovery plate heat exchanger 5, the regenerative cycle plate heat exchanger 6, the high-pressure electronic pressure regulating valve 7, the evaporator 8, the gas-liquid separator 9, the vapor-separation electronic pressure regulating valve 10, the low-pressure section air suction electronic three-way valve 11 and the electric ball valve 12;
one end of the low-pressure section CO2 compressor 1 is communicated with one port of the low-pressure section exhaust electronic three-way valve 3 through a pipeline with an exhaust one-way valve 2, and the other end of the low-pressure section CO2 compressor is communicated with one port of the low-pressure section air suction electronic three-way valve 11 through a pipeline;
the other pipeline of the low-pressure section exhaust electronic three-way valve 3 is communicated with the input end of the high-pressure section CO2 compressor 4 through the heat recovery plate heat exchanger 5, and the last pipeline of the low-pressure section exhaust electronic three-way valve 3 is communicated with an inlet gas circuit of the gas-liquid separator 9 through the evaporator 8;
the other path of the low-pressure section air suction electronic three-way valve 11 is communicated with the input end of the high-pressure section CO2 compressor 4, the last path of the low-pressure section air suction electronic three-way valve 11 is communicated with the gas-liquid separator 9 through the regenerative cycle plate heat exchanger 6, and an electric ball valve 12 is arranged on a pipeline positioned between the gas-liquid separator 9 and the regenerative cycle plate heat exchanger 6 on the path pipeline;
the output end pipeline of the high-pressure section CO2 compressor 4 sequentially passes through the heat recovery plate heat exchanger 5, the regenerative cycle plate heat exchanger 6 and the evaporator 8 and is finally communicated with the inlet of the gas-liquid separator 9, and a high-pressure electronic pressure regulating valve 7 is arranged at the position, between the regenerative cycle plate heat exchanger 6 and the evaporator and between the high-pressure section CO2 compressor 4 and the desuperheater 8;
the last path of the low-pressure section exhaust electronic three-way valve 3 is converged into a pipeline between a high-pressure electronic pressure regulating valve 7 of an output end pipe of the high-pressure section CO2 compressor 4 and the evaporator and the desuperheater 8;
the other output pipeline of the gas-liquid separator 9 is provided with a vapor-separating electronic pressure regulating valve 10, and finally the vapor-separating electronic pressure regulating valve is converged into the connecting pipeline of the gas-liquid separator 9 and the regenerative cycle plate heat exchanger 6.
As shown in fig. 1, during high-temperature heating, a high-pressure section CO2 compressor compresses a CO2 refrigerant, the compressed high-temperature high-pressure refrigerant gas enters a heat recovery plate heat exchanger, water is heated in the heat recovery plate heat exchanger and simultaneously cools the CO2 refrigerant, the high-pressure transcritical refrigerant is formed after cooling, the transcritical refrigerant is further cooled in a regenerative cycle plate heat exchanger, the high-pressure electronic pressure regulating valve throttles the transcritical refrigerant and enters an evaporator, the low-pressure refrigerant evaporates and absorbs heat in the evaporator, the low-pressure gas refrigerant is formed and enters the regenerative cycle plate heat exchanger after passing through an electric ball valve, the overheated CO2 refrigerant is formed after passing through the plate heat exchanger, and the overheated refrigerant returns to the high-pressure section compressor after passing through the low-pressure section air suction electronic three-way valve, so that heating cycle is completed. In the operation process of the compressor, the vapor separation electronic pressure regulating valve is opened, so that the oil in the vapor can return to the compressor along with the refrigerant.
As shown in fig. 2, during low-ring temperature heating, the CO2 refrigerant is compressed by the low-pressure stage CO2 compressor, the refrigerant gas compressed into high-temperature medium-pressure is sent into the heat recovery plate heat exchanger after passing through the low-pressure stage exhaust electronic three-way valve, the heat recovery plate heat exchanger is heated with water and simultaneously cools the CO2 refrigerant, the medium-pressure refrigerant is sent into the high-pressure stage CO2 compressor for continuous compression, the refrigerant gas compressed into high-temperature high-pressure is sent into the heat recovery plate heat exchanger again, the heat recovery plate heat exchanger heats water and simultaneously cools the CO2 refrigerant, the high-pressure trans-critical state refrigerant is formed after cooling, the trans-critical refrigerant is further cooled in the heat recovery plate heat exchanger, the low-pressure refrigerant is sent into the evaporator after being throttled by the high-pressure electronic pressure regulating valve, the low-pressure refrigerant is evaporated and absorbed in the evaporator, the low-pressure refrigerant is sent into the heat recovery plate heat exchanger after being formed into the electric ball valve, the super-heated state CO2 refrigerant is formed after passing through the plate heat exchanger, and the super-heated state refrigerant is sent back into the heat recovery plate heat exchanger after passing through the low-pressure stage electronic three-way valve, and the low-pressure heat recovery plate heat exchanger is completed. In the operation process of the compressor, the vapor separation electronic pressure regulating valve is opened, so that the oil in the vapor can return to the compressor along with the refrigerant.
As shown in fig. 3, during defrosting, the low-pressure stage CO2 compressor compresses the CO2 refrigerant, refrigerant gas compressed into high temperature and medium pressure enters the evaporator through the low-pressure stage exhaust electronic three-way valve, the high temperature gas is used for defrosting the evaporator, the medium pressure refrigerant after defrosting enters the regenerative cycle plate heat exchanger after being throttled and depressurized by the vapor separation electronic pressure regulating valve, and part of heat is absorbed and then returns to the low-pressure stage compressor through the low-pressure stage suction electronic three-way valve, so that defrosting cycle is completed.
As shown in fig. 1, the heat recovery plate heat exchanger 5 adopts a six-port form, and recovers the exhaust heat of the low-pressure section and the exhaust heat of the high-pressure section at the same time, thereby realizing the maximum recovery and utilization of the heat source.
As shown in fig. 1 and 2, the outdoor temperature change process is performed through the controller, the controller program can control the electronic three-way valve to realize the switching of the heating cycle, the two-stage compression process is ensured to be realized by the system under the condition of low ring temperature, the one-stage compression process is ensured to be realized under the condition of high ring temperature, the safe and reliable operation of the system can be ensured, and meanwhile, the high efficiency of the operation of the system is ensured.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.