Air source cascade heat pump unit with supercooling and heat recovery functions

Abstract

The utility model relates to the technical field of air conditioner heat pumps, in particular to an air source cascade heat pump unit with supercooling and heat recovery, which comprises a cascade heat pump circulation system consisting of a low-temperature-stage refrigeration cycle unit and a high-temperature-stage refrigeration cycle unit, the low-temperature-stage refrigeration cycle unit comprises an air cooling evaporator, a low-temperature-stage compressor, a condensation evaporator and an economizer which are sequentially connected through pipelines and form a first refrigerant circulation loop. The low-temperature-stage refrigeration cycle unit and the high-temperature-stage refrigeration cycle unit are adopted to form the cascade heat pump cycle system with regenerative heat recovery and supercooling, so that the cascade heat pump cycle system is environment-friendly and energy-saving, and meets the existing policy requirements of energy conservation and environmental protection. The whole unit operation process is novel, the low-temperature use range of the air source heat pump unit is widened, the outlet temperature of a heat source of the air source heat pump unit is increased, and meanwhile the comprehensive operation efficiency of the unit is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air-conditioning heat pumps, in particular to an air source cascade heat pump unit with supercooling and heat recovery. Background Art

[0002] Heat pump is a device that transfers heat energy from low-temperature heat source to high-temperature heat source. It is also a new energy technology that has attracted worldwide attention. Heat pump usually obtains low-grade heat energy from natural air, water or soil, and then provides people with usable high-grade heat energy through electricity.

[0003] The low-temperature heat source of the heat pump is the medium around us - air, river water, sea water, urban sewage, surface water, groundwater, grey water, fire water pool, geothermal heat or heat from waste gas, waste water and waste oil discharged during the production process.

[0004] Conventional air source heat pumps can usually only produce 50-80℃ hot water, the output heat source temperature is not high, air source heat pumps cannot operate below -15℃, or cannot produce high-temperature hot water, and the overall energy efficiency of the unit is low. Utility Model Content

[0005] The utility model aims at the technical problems existing in the prior art and provides an air source cascade heat pump unit with supercooling and heat recovery to solve the problem of low heating efficiency of the conventional air source heat pump.

[0006] The utility model solves the above technical problems with the following technical solutions: an air source cascade heat pump unit with supercooling and heat recovery, comprising a cascade heat pump circulation system consisting of a low-temperature refrigeration cycle unit and a high-temperature refrigeration cycle unit;

[0007] The low-temperature refrigeration cycle unit comprises an air-cooled evaporator, a low-temperature compressor, a condenser evaporator and an economizer which are connected in sequence through pipelines to form a refrigerant circulation loop; the refrigerant in the refrigerant circulation loop absorbs heat from the air in the air-cooled evaporator, is compressed and heated by the low-temperature compressor, and is sequentially heat-exchanged by the condenser evaporator and the economizer and transported to the air-cooled evaporator to complete the low-temperature refrigeration cycle;

[0008] The high-temperature refrigeration cycle unit comprises a condenser evaporator, a high-temperature compressor, a high-temperature condenser and a subcooler which are sequentially connected through pipelines to form a refrigerant secondary circulation loop; the refrigerant 2 in the refrigerant secondary circulation loop absorbs the heat of the refrigerant 1 in the condenser evaporator, is compressed and heated by the high-pressure compressor, and is sequentially heat-exchanged by the high-temperature condenser and the subcooler and transported to the condenser evaporator to complete the high-temperature refrigeration cycle;

[0009] The cascade heat pump circulation system also includes a hot water delivery pipeline that sequentially connects a subcooler and a high-temperature condenser in series, and is used to perform step-by-step heating of the hot water.

[0010] On the basis of the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, a low-temperature electronic expansion valve is provided on the pipeline between the economizer and the air-cooling evaporator; and a high-temperature electronic expansion valve is provided on the pipeline between the subcooler and the condensing evaporator.

[0012] Furthermore, it also includes an oil-cooled heat recovery device; one heat exchange channel of the oil-cooled heat recovery device is connected to the oil circuit system of the low-temperature compressor through a pipeline, and the other heat exchange channel is connected in series with the hot water delivery pipeline through a pipeline.

[0013] Furthermore, one heat exchange channel input and output port of the economizer is connected to the condenser evaporator and the low-temperature compressor in sequence through pipelines, and another heat exchange channel input and output port is connected to the condenser evaporator and the air-cooled evaporator in sequence through pipelines.

[0014] Furthermore, an economizer electronic expansion valve located between the economizer and the condenser evaporator is also provided on the pipeline connecting the economizer, the condenser evaporator and the low-temperature compressor.

[0015] Furthermore, the high temperature stage condenser is a shell and tube type or a plate type condenser.

[0016] Furthermore, the high temperature stage condenser outputs hot water and / or steam at 80° C. to 120° C. through a hot water delivery pipeline.

[0017] Furthermore, the operating environment temperature of the air-cooled evaporator is -30°C to 40°C.

[0018] Moreover, the air source cascade heat pump unit with supercooling and heat recovery provided by the utility model has at least the following beneficial effects compared with the prior art:

[0019] The low-temperature refrigeration cycle unit and the high-temperature refrigeration cycle unit are used to form a cascade heat pump circulation system with heat recovery and supercooling. It is environmentally friendly and energy-saving, and meets the existing energy-saving and environmental protection policy requirements.

[0020] The entire unit operation process is novel, which broadens the low-temperature use range of the air source heat pump unit, increases the outlet temperature of the heat source of the air source heat pump unit, and greatly improves the overall operation efficiency of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the system principle of the utility model.

[0022] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0023] 1. Air-cooled evaporator, 2. Low-temperature compressor, 3. Oil-cooled heat recovery device, 4. Subcooler, 5. High-temperature condenser, 6. High-temperature compressor, 7. High-temperature electronic expansion valve, 8. Condenser evaporator, 9. Economizer electronic expansion valve, 10. Economizer, 11. Low-temperature electronic expansion valve. DETAILED DESCRIPTION

[0024] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0025] It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integrally formed structure. For ordinary technicians in this field, the specific meanings of such terms in this patent can be understood according to specific circumstances.

[0026] like Figure 1 As shown, the air source cascade heat pump unit with supercooling and heat recovery designed in this utility model includes a cascade heat pump circulation system composed of a low-temperature refrigeration cycle unit and a high-temperature refrigeration cycle unit.

[0027] In this embodiment, the low-temperature refrigeration cycle unit includes an air-cooled evaporator 1, a low-temperature compressor 2, a condensing evaporator 8 and an economizer 10 which are connected in sequence through pipelines to form a refrigerant circulation loop; the refrigerant in the refrigerant circulation loop absorbs heat from the air in the air-cooled evaporator 1, is compressed and heated by the low-temperature compressor 2, and is heat-exchanged in turn by the condensing evaporator 8 and the economizer 10 and transported to the air-cooled evaporator 1 to complete the low-temperature refrigeration cycle.

[0028] Specifically, a low-temperature electronic expansion valve 11 is further provided on the pipeline between the economizer 10 and the air-cooling evaporator 1 .

[0029] During the low-temperature refrigeration cycle, the refrigerant in the air-cooled evaporator 1 absorbs heat from the air to evaporate through heat exchange. The evaporated low-temperature and low-pressure refrigerant vapor is sucked into the low-temperature compressor 2, and the low-temperature and low-pressure refrigerant vapor is compressed into high-temperature and high-pressure refrigerant vapor and discharged into the condenser evaporator 8; in the condenser evaporator 8, the high-temperature and high-pressure refrigerant vapor exchanges heat with the low-temperature and low-pressure refrigerant liquid and is cooled into a medium-temperature and high-pressure refrigerant liquid; then the medium-temperature and high-pressure refrigerant liquid passes through the economizer 10 and is throttled by the low-temperature electronic expansion valve 11 before entering the air-cooled evaporator 1 to absorb heat from the air to evaporate through heat exchange. The evaporated low-temperature and low-pressure refrigerant gas is sucked into the low-temperature compressor 2, and finally the low-temperature cycle is completed.

[0030] In this embodiment, the high-temperature refrigeration cycle unit includes a condenser evaporator 8, a high-temperature compressor 6, a high-temperature condenser 5 and a subcooler 4 which are connected in sequence through management to form a refrigerant secondary circulation loop; the refrigerant 2 in the refrigerant secondary circulation loop absorbs the heat of the refrigerant 1 in the condenser evaporator 8, is compressed and heated by the high-pressure compressor 6, and is heat-exchanged by the high-temperature condenser 5 and the subcooler 4 in sequence and transported to the condenser evaporator 8 to complete the high-temperature refrigeration cycle.

[0031] Specifically, a high-temperature electronic expansion valve 7 is further provided in the pipeline between the subcooler 4 and the condenser evaporator 8 .

[0032] Specifically, the high temperature stage condenser 5 is a shell and tube type or a plate type condenser.

[0033] During the high-temperature refrigeration cycle, the high-temperature compressor 6 inhales low-temperature and low-pressure refrigerant 2 vapor from the condenser evaporator 8, compresses it into high-temperature and high-pressure refrigerant 2 vapor, and then discharges it into the high-temperature condenser 5; in the high-temperature condenser 5, the high-temperature and high-pressure refrigerant 2 vapor exchanges heat with hot water and is cooled into medium-temperature and high-pressure refrigerant 2 liquid; then the medium-temperature and high-pressure refrigerant 2 liquid passes through the subcooler 4 and is throttled by the high-temperature electronic expansion valve 7 before entering the condenser evaporator 8, where it absorbs the heat of refrigerant 1 for heat exchange and evaporation, and the evaporated low-temperature and low-pressure refrigerant 2 gas is inhaled by the high-temperature compressor 6, thereby completing a high-temperature refrigeration cycle.

[0034] In this embodiment, the cascade heat pump circulation system further includes a hot water delivery pipeline which sequentially connects the subcooler 4 and the high-temperature stage condenser 5 in series, so as to perform step-by-step heating of the hot water.

[0035] Specifically, it also includes an oil-cooled heat recovery device 3; one heat exchange channel of the oil-cooled heat recovery device 3 is connected to the oil circuit system of the low-temperature compressor 2 through a pipeline, and the other heat exchange channel is connected in series with the hot water delivery pipeline through a pipeline. The oil-cooled heat recovery device 3 can cool the lubricating oil in the oil circuit system of the low-temperature compressor 2 and transfer the heat to the water for use.

[0036] The hot water is heated in stages through the heat recovery oil cooler 3, the subcooler 4 and the high temperature condenser 5, and the hot water output temperature can reach 80°C-120°C.

[0037] During the whole process, the low-temperature refrigeration cycle and the high-temperature refrigeration cycle form a cascade heat pump system cycle, using environmentally friendly refrigerants and a cascade refrigeration cycle with heat recovery and supercooling, which greatly improves the application range, water outlet temperature and comprehensive energy efficiency of the heat pump unit.

[0038] As an embodiment, one heat exchange channel input and output port of the economizer 10 is connected to the condenser evaporator 8 and the low-temperature compressor 2 in sequence through a pipeline, and another heat exchange channel input and output port is connected to the condenser evaporator 8 and the air-cooled evaporator 1 in sequence through a pipeline.

[0039] The pipeline connecting the economizer 10 with the condenser evaporator 8 and the low-temperature compressor 2 is also provided with an economizer electronic expansion valve 9 located between the economizer 10 and the condenser evaporator 8 .

[0040] The economizer 10 acts as a heat exchanger, absorbing heat through the throttling evaporation of the refrigerant itself, so that the other part of the refrigerant is supercooled. A part of the refrigerant is throttled through the economizer electronic expansion valve 9 to reduce the temperature of the other part of the refrigerant, thereby achieving a supercooling effect. The supercooled refrigerant directly enters the air-cooled evaporator 1 through the low-temperature electronic expansion valve 11 for refrigeration, while the uncooled gaseous refrigerant re-enters the low-temperature compressor 2 through the connecting pipe between the economizer 10 and the low-temperature compressor 2 to continue circulating, which can effectively control the energy flow, adjust the energy load and recycle energy, thereby achieving energy saving effects.

[0041] The air source cascade heat pump unit with supercooling and heat recovery involved in the utility model adopts a cascade heat pump circulation system with heat recovery and supercooling, which is environmentally friendly and energy-saving, and meets the existing energy-saving and environmental protection policy requirements.

[0042] The process design is novel, which broadens the low-temperature use range of air source heat pump units, increases the outlet temperature of the heat source of air source heat pump units, and greatly improves the overall efficiency of heat pump units. It uses air energy to produce 80℃~120℃ hot water / steam, which is suitable for ambient temperatures of -30℃~45℃. It can still operate efficiently at low ambient temperatures. It adopts a cascade heat recovery and subcooling circulation system, and the whole machine has a wide operating range. Under the same working conditions, the heating energy efficiency is more than 15% higher than that of conventional heat pump units.

[0043] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.

[0044] Although the preferred embodiments of the utility model have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the utility model.

[0045] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An air source cascade heat pump unit with subcooling and heat recovery, characterized in that: It includes a cascade heat pump circulation system consisting of a low-temperature refrigeration circulation unit and a high-temperature refrigeration circulation unit; The low-temperature refrigeration cycle unit comprises an air-cooled evaporator, a low-temperature compressor, a condenser evaporator and an economizer which are connected in sequence through pipelines to form a refrigerant circulation loop; the refrigerant in the refrigerant circulation loop absorbs heat from the air in the air-cooled evaporator, is compressed and heated by the low-temperature compressor, and is sequentially heat-exchanged by the condenser evaporator and the economizer and transported to the air-cooled evaporator to complete the low-temperature refrigeration cycle; The high-temperature refrigeration cycle unit comprises a condenser evaporator, a high-temperature compressor, a high-temperature condenser and a subcooler which are sequentially connected through pipelines to form a refrigerant secondary circulation loop; the refrigerant 2 in the refrigerant secondary circulation loop absorbs the heat of the refrigerant 1 in the condenser evaporator, is compressed and heated by the high-pressure compressor, and is sequentially heat-exchanged by the high-temperature condenser and the subcooler and transported to the condenser evaporator to complete the high-temperature refrigeration cycle; The cascade heat pump circulation system also includes a hot water delivery pipeline that sequentially connects a subcooler and a high-temperature condenser in series, and is used to perform step-by-step heating of the hot water.

2. The air source cascade heat pump unit with subcooling and heat recovery according to claim 1, characterized in that: A low-temperature electronic expansion valve is also provided on the pipeline between the economizer and the air-cooling evaporator; and a high-temperature electronic expansion valve is also provided on the pipeline between the subcooler and the condensing evaporator.

3. The air source cascade heat pump unit with subcooling and heat recovery according to claim 1, characterized in that: It also includes an oil-cooled heat recovery device; one heat exchange channel of the oil-cooled heat recovery device is connected to the oil circuit system of the low-temperature compressor through a pipeline, and the other heat exchange channel is connected in series with the hot water delivery pipeline through a pipeline.

4. The air source cascade heat pump unit with subcooling and heat recovery according to claim 1, characterized in that: The input and output ports of one heat exchange channel of the economizer are connected to the condenser evaporator (8) and the low-temperature compressor in sequence through pipelines, and the input and output ports of another heat exchange channel of the economizer are connected to the condenser evaporator and the air-cooling evaporator in sequence through pipelines.

5. The air source cascade heat pump unit with subcooling and heat recovery according to claim 4, characterized in that: The pipeline connecting the economizer, the condenser evaporator and the low-temperature compressor is also provided with an economizer electronic expansion valve located between the economizer and the condenser evaporator.

6. The air source cascade heat pump unit with subcooling and heat recovery according to claim 1, characterized in that: The high temperature stage condenser is a shell and tube type or a plate type condenser.

7. The air source cascade heat pump unit with subcooling and heat recovery according to any one of claims 1 to 6, characterized in that: The high temperature stage condenser outputs hot water and / or steam at 80° C. to 120° C. through a hot water delivery pipeline.

8. The air source cascade heat pump unit with subcooling and heat recovery according to any one of claims 1 to 6, characterized in that: The operating environment temperature of the air-cooled evaporator is -30°C to 40°C.

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