Cascade type air source heat pump straight-out steam unit

Abstract

The utility model relates to the technical field of energy conservation of air source heat pumps, in particular to a cascade type air source heat pump straight-out steam unit. The unit comprises a low-temperature-stage heat pump system circulation assembly, a high-temperature-stage heat pump system circulation assembly and a steam system assembly. The low-temperature-stage heat pump system circulation assembly comprises a low-temperature gas-liquid separator, a low-temperature-stage compressor, a heat release pipe of the intermediate heat exchanger, a low-temperature liquid storage tank, a low-temperature throttling element and an air heat exchanger. The high-temperature-stage heat pump system circulation assembly comprises a high-temperature gas-liquid separator, a high-temperature-stage compressor, a high-temperature water heat exchanger, a high-temperature liquid storage tank, a high-temperature throttling element and a heat absorption pipe of an intermediate heat exchanger. The steam system assembly comprises a steam-liquid separator, a constant-pressure make-up pump, a circulating pump, an electric control valve, a steam outlet flow meter, a flow control valve and a one-way valve. By optimizing the structure of the unit, the effects of directly discharging steam and stably discharging steam can be achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of air source heat pump energy saving, and particularly relates to a cascade air source heat pump direct steam generating unit. Background Art

[0002] Most of the existing cascade air source heat pump steam generating units use a cascade system to generate high-temperature hot water, and then a flash tank is added at the end of the cascade system for pressurization to generate micro-pressure steam. The disadvantage of this type of cascade air source heat pump steam generating unit is that adding a flash tank at the end of the cascade system requires multiple units to be connected in parallel to meet the requirements of high heating capacity and large steam output. In this case, if the end demand is small, it is difficult to adapt to the corresponding flash tank. In addition, there will also be a certain amount of heat loss in this form.

[0003] Another existing cascade air source heat pump steam generating unit uses a form in which a flash tank is integrated in the unit for pressurization to generate steam, and components such as a circulating water pump and a makeup water pump are added. At the same time, timed makeup water or constant-level makeup water is carried out through the liquid level in the tank. The disadvantage of this type of cascade air source heat pump steam generating unit is that only the flash tank and the water pump are integrated in the unit, and during the operation of the unit, the circulating water temperature will decrease during the makeup water process, the steam output will decay too much, the steam output will be unstable, and the heating capacity will be insufficient.

[0004] Therefore, a new technology is urgently needed to solve the above problems. Summary of the Utility Model

[0005] To make up for the deficiencies of the prior art, the present application provides a cascade air source heat pump direct steam generating unit. By optimizing the unit structure, the unit can achieve the effects of direct steam output and stable steam output.

[0006] To achieve the above object, the utility model provides a cascade air source heat pump direct steam generating unit.

[0007] The unit includes a low-temperature stage heat pump system circulation component, a high-temperature stage heat pump system circulation component, and a steam system component.

[0008] The low-temperature stage heat pump system circulation component includes a low-temperature gas-liquid separator, a low-temperature stage compressor, the heat release pipe of an intermediate heat exchanger, a low-temperature liquid storage tank, a low-temperature throttling element, and an air heat exchanger. The low-temperature stage circulating medium flows through the low-temperature gas-liquid separator, the low-temperature stage compressor, the heat release pipe of the intermediate heat exchanger, the low-temperature liquid storage tank, the low-temperature throttling element, and the air heat exchanger in sequence and then flows back into the low-temperature gas-liquid separator to form a low-temperature stage cycle.

[0009] The high-temperature stage heat pump system circulation components include a high-temperature gas-liquid separator, a high-temperature stage compressor, a high-temperature water heat exchanger, a high-temperature liquid storage tank, a high-temperature throttling element, and the heat absorption pipe of an intermediate heat exchanger. The high-temperature circulating medium flows through the high-temperature gas-liquid separator, the high-temperature stage compressor, the high-temperature water heat exchanger, the high-temperature liquid storage tank, the high-temperature throttling element, and the heat absorption pipe of the intermediate heat exchanger in sequence, and then flows back into the high-temperature gas-liquid separator to form a high-temperature stage cycle.

[0010] The steam system components include a vapor-liquid separator, which is provided with an inlet, a liquid outlet, and a vapor outlet. The liquid outlet is connected to the inlet of the first heat absorption pipe of the high-temperature water heat exchanger, and the inlet is connected to the outlet of the first heat absorption pipe of the high-temperature water heat exchanger.

[0011] Preferably, the liquid outlet is connected to the inlet of the first heat absorption pipe of the high-temperature water heat exchanger through a liquid inlet pipeline, and a circulation pump is provided on the liquid inlet pipeline.

[0012] Preferably, a vapor outlet pipeline is connected to the vapor outlet of the vapor-liquid separator, and an electric control valve and / or a vapor flowmeter are provided on the vapor outlet pipeline.

[0013] Preferably, the unit further includes a water replenishing system component. The water replenishing system component includes a water replenishing pipe. A liquid replenishing port is further provided on the vapor-liquid separator. The water replenishing pipe is connected to the inlet of the second heat absorption pipe of the high-temperature water heat exchanger, and the outlet of the second heat absorption pipe of the high-temperature water heat exchanger is connected to the liquid replenishing port of the vapor-liquid separator.

[0014] Preferably, a water replenishing pump is provided on the water replenishing pipe.

[0015] Preferably, the water replenishing pump is a constant pressure water replenishing pump.

[0016] Preferably, a flow control valve and / or a one-way valve are provided on the water replenishing pipe.

[0017] Preferably, the low-temperature stage heat pump system circulation components further include a low-temperature economizer disposed between the low-temperature liquid storage tank and the low-temperature throttling element. The low-temperature economizer includes a low-temperature main pipeline and a low-temperature auxiliary pipeline. One end of the low-temperature main pipeline is connected to the low-temperature liquid storage tank through a low-temperature main inflow pipe, and the other end of the low-temperature main pipeline is connected to the low-temperature throttling element through a low-temperature main outflow pipe. One end of the low-temperature auxiliary pipeline is connected to the low-temperature throttling element through a low-temperature auxiliary inflow pipe, and the other end of the low-temperature auxiliary pipeline is connected to the low-temperature stage compressor through a low-temperature auxiliary outflow pipe. A low-temperature auxiliary throttling element is provided on the low-temperature auxiliary inflow pipe.

[0018] Preferably, the high-temperature heat pump system circulation component further includes a high-temperature economizer arranged between the high-temperature liquid storage tank and the high-temperature throttling element, the high-temperature economizer includes a high-temperature main pipeline and a high-temperature auxiliary pipeline, one end of the high-temperature main pipeline is connected to the high-temperature liquid storage tank through a high-temperature main inlet pipe, the other end of the high-temperature main pipeline is connected to the high-temperature throttling element through a high-temperature main outlet pipe, one end of the high-temperature auxiliary pipeline is connected to the high-temperature throttling element through a high-temperature auxiliary inlet pipe, the other end of the high-temperature auxiliary pipeline is connected to the high-temperature stage compressor through a high-temperature auxiliary outlet pipe, and a high-temperature auxiliary throttling element is arranged on the high-temperature auxiliary inlet pipe.

[0019] Preferably, a four-way valve is provided on the circulation component of the low-temperature heat pump system, and the four-way valve is arranged on the pipeline between the low-temperature compressor and the intermediate heat exchanger and between the air heat exchanger and the low-temperature gas-liquid separator, wherein the D port of the four-way valve is connected to the low-temperature compressor, the C port is connected to the heat release pipe of the intermediate heat exchanger, the S port is connected to the low-temperature gas-liquid separator, and the E port is connected to the air heat exchanger.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] First, the cascade air source heat pump direct steam unit involved in this application adopts a vapor-liquid separator to meet the use scenario with small steam demand. At the same time, the unit achieves stable operation and constant steam output by optimizing the water supply system components.

[0022] In addition, the unit has added the function of replenishing air and increasing enthalpy by adopting low-temperature economizer and high-temperature economizer, which can enable the unit to operate normally and stably with steam output in a more severe low-temperature environment.

[0023] In addition, the unit has optimized the water replenishment control method by adopting steam cycle technology. By using the steam outlet flow rate as the water replenishment target flow rate, the flow regulating valve in the water replenishment system is controlled to achieve a balance between the water replenishment volume and the steam outlet volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present application may be better understood by describing the embodiments of the present application in conjunction with the accompanying drawings, in which:

[0025] Figure 1 A schematic structural diagram of a cascade air source heat pump direct steam unit of the present application; and

[0026] Figure 2 For Figure 1 A schematic diagram of the local structure of the embodiment shown.

[0027] Description of Figure Numbers:

[0028] 1. Low-temperature gas-liquid separator; 2. Low-temperature stage compressor; 3. Four-way valve; 4. Intermediate heat exchanger; 5. High-temperature gas-liquid separator; 6. High-temperature stage compressor; 7. High-temperature water heat exchanger; 8. Circulation pump; 9. Vapor-liquid separator; 10. Electric control valve; 11. Steam flowmeter; 12. Make-up port; 13. Make-up water pump; 14. Flow control valve; 15. Check valve; 16. High-temperature liquid storage tank; 17. High-temperature economizer; 18. High-temperature bypass throttling element; 19. High-temperature throttling element; 20. Low-temperature liquid storage tank; 21. Low-temperature economizer; 22. Low-temperature bypass throttling element; 23. Low-temperature throttling element; 24. Air heat exchanger. Detailed implementation manners

[0029] Unless otherwise defined, the technical terms or scientific terms used in this specification and claims shall have the ordinary meanings as understood by those of ordinary skill in the technical field to which the present invention belongs.

[0030] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the 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 thus should not be construed as a limitation to the present invention.

[0031] In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "plurality" is two or more.

[0032] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0033] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] This embodiment relates to a Figure 1 and Figure 2 The cascade air source heat pump direct steam unit shown.

[0035] The unit includes a low-temperature heat pump system circulation component, a high-temperature heat pump system circulation component and a steam system component.

[0036] The low-temperature heat pump system circulation components include a low-temperature gas-liquid separator 1, a low-temperature compressor 2, a heat release pipe of an intermediate heat exchanger 4, a low-temperature liquid storage tank 20, a low-temperature throttling element 23 and an air heat exchanger 25. The low-temperature circulation medium flows through the low-temperature gas-liquid separator 1, the low-temperature compressor 2, the heat release pipe of an intermediate heat exchanger 4, the low-temperature liquid storage tank 20, the low-temperature throttling element 23 and the air heat exchanger 25 in sequence and then flows into the low-temperature gas-liquid separator 1 again to form a low-temperature circulation.

[0037] In some embodiments, the low-temperature heat pump system circulation component further includes a low-temperature economizer 21 disposed between the low-temperature liquid storage tank 20 and the low-temperature throttling element 23, and the low-temperature economizer 21 includes a low-temperature main pipeline and a low-temperature auxiliary pipeline, one end of the low-temperature main pipeline is connected to the low-temperature liquid storage tank 20 through a low-temperature main inlet pipe, the other end of the low-temperature main pipeline is connected to the low-temperature throttling element 23 through a low-temperature main outlet pipe, one end of the low-temperature auxiliary pipeline is connected to the low-temperature throttling element 23 through a low-temperature auxiliary inlet pipe, the other end of the low-temperature auxiliary pipeline is connected to the low-temperature compressor 2 through a low-temperature auxiliary outlet pipe, and a low-temperature auxiliary throttling element 22 is provided on the low-temperature auxiliary inlet pipe. By adding the low-temperature economizer 21, the function of supplementing air and increasing enthalpy can be achieved, so that the unit can still operate normally and stably in a more severe low-temperature environment.

[0038] In some embodiments, a four-way valve 3 is provided on the circulation component of the low-temperature heat pump system, and the four-way valve 3 is provided on the pipeline between the low-temperature compressor 2 and the intermediate heat exchanger 4 and between the air heat exchanger 25 and the low-temperature gas-liquid separator 1, wherein the D port of the four-way valve 3 is connected to the low-temperature compressor 2, the C port is connected to the heat release pipe of the intermediate heat exchanger 4, the S port is connected to the low-temperature gas-liquid separator 1, and the E port is connected to the air heat exchanger 25.

[0039] The high-temperature heat pump system circulation components include a high-temperature gas-liquid separator 5, a high-temperature compressor 6, a high-temperature water heat exchanger 7, a high-temperature liquid storage tank 16, a high-temperature throttling element 19 and a heat absorption pipe of an intermediate heat exchanger 4. The high-temperature circulating medium flows through the high-temperature gas-liquid separator 5, the high-temperature compressor 6, the high-temperature water heat exchanger 7, the high-temperature liquid storage tank 16, the high-temperature throttling element 19 and the heat absorption pipe of the intermediate heat exchanger 4 in sequence and then flows into the high-temperature gas-liquid separator 5 again to form a high-temperature circulation.

[0040] In some embodiments, the high-temperature heat pump system circulation component further includes a high-temperature economizer 17 disposed between the high-temperature liquid storage tank 16 and the high-temperature throttling element 19, and the high-temperature economizer 17 includes a high-temperature main pipeline and a high-temperature auxiliary pipeline, one end of the high-temperature main pipeline is connected to the high-temperature liquid storage tank 16 through a high-temperature main inlet pipe, the other end of the high-temperature main pipeline is connected to the high-temperature throttling element 19 through a high-temperature main outlet pipe, one end of the high-temperature auxiliary pipeline is connected to the high-temperature throttling element 19 through a high-temperature auxiliary inlet pipe, the other end of the high-temperature auxiliary pipeline is connected to the high-temperature compressor 6 through a high-temperature auxiliary outlet pipe, and a high-temperature auxiliary throttling element 18 is provided on the high-temperature auxiliary inlet pipe. By adding the high-temperature economizer 17, the function of supplementing air and increasing enthalpy can be achieved, so that the unit can still operate normally and stably in a more severe low-temperature environment.

[0041] The steam system component includes a vapor-liquid separator 9, which is provided with an inlet, a liquid outlet and a steam outlet. The liquid outlet is connected to the inlet of the first heat absorption tube of the high-temperature water heat exchanger 7, and the inlet is connected to the outlet of the first heat absorption tube of the high-temperature water heat exchanger 7. The liquid outlet and the inlet of the first heat absorption tube of the high-temperature water heat exchanger 7 can be connected through a liquid inlet pipe, and a circulating pump 8 can be provided on the liquid inlet pipe. In some embodiments, the steam outlet of the vapor-liquid separator 9 is connected to a steam outlet pipe, and an electric regulating valve 10 and / or a steam outlet flow meter 11 are provided on the steam outlet pipe. By providing the steam outlet flow meter 11, the real-time flow of the steam outlet pipe can be detected. And further, the flow regulating valve 14 is controlled by the real-time flow obtained by the detection, so that the water replenishment amount and the steam outlet amount are balanced.

[0042] In some embodiments, the unit further includes a water replenishment system component, the water replenishment system component includes a water replenishment pipe, and a liquid replenishment port 12 is further provided on the vapor-liquid separator 9. The water replenishment pipe is connected to the inlet of the second heat absorption pipe of the high-temperature water heat exchanger 7, and the outlet of the second heat absorption pipe of the high-temperature water heat exchanger 7 is connected to the liquid replenishment port 12 of the vapor-liquid separator 9. A water replenishment pump 13 may be provided on the water replenishment pipe. Specifically, the water replenishment pump 13 may be a constant pressure water replenishment pump 13. The constant pressure water replenishment pump 13 can maintain a constant water supply pressure in the water replenishment system component by adjusting the speed of the water pump, thereby ensuring the normal operation of the steam system component and avoiding pressure fluctuations that may damage the water pump or steam system component.

[0043] In some embodiments, a flow regulating valve 14 and / or a check valve 15 are provided on the water replenishing pipe.

[0044] Next, in combination with Figure 1 and Figure 2 , the working principle of the cascade air source heat pump direct steam unit involved in this embodiment will be briefly described.

[0045] When the cascade air source heat pump direct steam unit is working, first, the water replenishing system assembly is turned on. The constant pressure water replenishing pump 13 and the flow regulating valve 14 are opened. After the water level in the vapor-liquid separator 9 is replenished to the set liquid level, the water replenishing system assembly is closed. At the same time, the electric heating assembly in the water replenishing system assembly is turned on to heat the water in the water replenishing system assembly to the starting water temperature.

[0046] When the water temperature in the vapor-liquid separator 9 reaches the starting water temperature, the circulation pump 8, the low-temperature stage heat pump system circulation assembly, the high-temperature stage heat pump system circulation assembly, and the electric control valve 10 are turned on in sequence to achieve the effect of directly discharging steam.

[0047] When the unit needs to be replenished with water, the water replenishing system assembly can be turned on again. The external water enters the high-temperature water heat exchanger 7 through the constant pressure water replenishing pump 13 for preheating. The preheated warm water enters the vapor-liquid separator 9 and mixes with the hot water in the vapor-liquid separator 9 to replenish the water level in the vapor-liquid separator 9. The water replenishing system assembly preheats the external water through the high-temperature water heat exchanger 7. On the one hand, it can increase the water temperature of the water entering the vapor-liquid separator 9, prevent the problem that the water temperature in the steam system assembly is too low due to the too low replenishing water temperature, which affects the steam output. On the other hand, it can increase the subcooling degree of the high-temperature stage heat pump system and effectively improve the energy efficiency of the unit.

[0048] In the above specific embodiments, the purpose, technical solution, and beneficial effects of the present invention have been further described in detail. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cascade air source heat pump direct steam unit, characterized in that: The unit includes a low-temperature heat pump system circulation component, a high-temperature heat pump system circulation component and a steam system component; The low-temperature heat pump system circulation component includes a low-temperature gas-liquid separator, a low-temperature compressor, a heat release pipe of an intermediate heat exchanger, a low-temperature liquid storage tank, a low-temperature throttling element and an air heat exchanger. The low-temperature circulation medium flows through the low-temperature gas-liquid separator, the low-temperature compressor, the heat release pipe of the intermediate heat exchanger, the low-temperature liquid storage tank, the low-temperature throttling element and the air heat exchanger in sequence and then flows into the low-temperature gas-liquid separator again to form a low-temperature circulation; The high-temperature heat pump system circulation component includes a high-temperature gas-liquid separator, a high-temperature compressor, a high-temperature water heat exchanger, a high-temperature liquid storage tank, a high-temperature throttling element and a heat absorption pipe of an intermediate heat exchanger. The high-temperature circulating medium flows through the high-temperature gas-liquid separator, the high-temperature compressor, the high-temperature water heat exchanger, the high-temperature liquid storage tank, the high-temperature throttling element and the heat absorption pipe of the intermediate heat exchanger in sequence and then flows into the high-temperature gas-liquid separator again to form a high-temperature cycle; The steam system component includes a vapor-liquid separator, which is provided with an inlet, a liquid outlet and a vapor outlet. The liquid outlet is connected to the inlet of the first heat absorption tube of the high-temperature water heat exchanger, and the inlet is connected to the outlet of the first heat absorption tube of the high-temperature water heat exchanger.

2. The cascade air source heat pump direct steam unit according to claim 1, characterized in that: The liquid outlet and the inlet of the first heat absorption tube of the high-temperature water heat exchanger are connected through a liquid inlet pipe, and a circulating pump is arranged on the liquid inlet pipe.

3. The cascade air source heat pump direct steam unit according to claim 1, characterized in that: The steam outlet of the steam-liquid separator is connected to a steam outlet pipeline, and the steam outlet pipeline is provided with an electric regulating valve and / or a steam outlet flow meter.

4. The cascade air source heat pump direct steam unit according to claim 1, characterized in that: The unit further includes a water replenishment system component, which includes a water replenishment pipe. The vapor-liquid separator is further provided with a liquid replenishment port. The water replenishment pipe is connected to the inlet of the second heat absorption pipe of the high-temperature water heat exchanger, and the outlet of the second heat absorption pipe of the high-temperature water heat exchanger is connected to the liquid replenishment port of the vapor-liquid separator.

5. The cascade air source heat pump direct steam unit according to claim 4, characterized in that: The water replenishment pipe is provided with a water replenishment pump.

6. The cascade air source heat pump direct steam unit according to claim 5, characterized in that: The water supply pump is a constant pressure water supply pump.

7. The cascade air source heat pump direct steam unit according to claim 4, characterized in that: The water supply pipe is provided with a flow regulating valve and / or a one-way valve.

8. The cascade air source heat pump direct steam unit according to claim 1, characterized in that: The low-temperature heat pump system circulation component further includes a low-temperature economizer arranged between the low-temperature liquid storage tank and the low-temperature throttling element, and the low-temperature economizer includes a low-temperature main pipeline and a low-temperature auxiliary pipeline. One end of the low-temperature main pipeline is connected to the low-temperature liquid storage tank through a low-temperature main inlet pipe, and the other end of the low-temperature main pipeline is connected to the low-temperature throttling element through a low-temperature main outlet pipe. One end of the low-temperature auxiliary pipeline is connected to the low-temperature throttling element through a low-temperature auxiliary inlet pipe, and the other end of the low-temperature auxiliary pipeline is connected to the low-temperature stage compressor through a low-temperature auxiliary outlet pipe. A low-temperature auxiliary throttling element is arranged on the low-temperature auxiliary inlet pipe.

9. The cascade air source heat pump direct steam unit according to claim 1, characterized in that: The high-temperature heat pump system circulation component further includes a high-temperature economizer arranged between the high-temperature liquid storage tank and the high-temperature throttling element, and the high-temperature economizer includes a high-temperature main pipeline and a high-temperature auxiliary pipeline. One end of the high-temperature main pipeline is connected to the high-temperature liquid storage tank through a high-temperature main inlet pipe, and the other end of the high-temperature main pipeline is connected to the high-temperature throttling element through a high-temperature main outlet pipe. One end of the high-temperature auxiliary pipeline is connected to the high-temperature throttling element through a high-temperature auxiliary inlet pipe, and the other end of the high-temperature auxiliary pipeline is connected to the high-temperature stage compressor through a high-temperature auxiliary outlet pipe. A high-temperature auxiliary throttling element is arranged on the high-temperature auxiliary inlet pipe.

10. The cascade air source heat pump direct steam unit according to claim 1, characterized in that: A four-way valve is provided on the low-temperature heat pump system circulation component, and the four-way valve is provided on the pipeline between the low-temperature compressor and the intermediate heat exchanger and between the air heat exchanger and the low-temperature gas-liquid separator, wherein the D port of the four-way valve is connected to the low-temperature compressor, the C port is connected to the heat release pipe of the intermediate heat exchanger, the S port is connected to the low-temperature gas-liquid separator, and the E port is connected to the air heat exchanger.

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