Air source heat pump high-temperature steam unit

Abstract

The utility model relates to the technical field of air source heat pump steam engines, in particular to an air source heat pump high-temperature steam engine unit which comprises a first refrigerant circulation loop, a second refrigerant circulation loop and a water circulation passage. The second refrigerant circulation loop is communicated with the water circulation passage through a steam generator; the water circulation passage comprises a water supplementing port, a water pump, the steam generator and a first gas-liquid separator which are sequentially communicated, the steam generator is provided with a first water outlet, the first gas-liquid separator is provided with a second water outlet, and the first water outlet and the second water outlet can be respectively communicated with the water pump. The non-evaporated water in the steam generator and the first gas-liquid separator and the supplemented water of the system can be input into the water pump so as to return to the water circulation path to participate in the second heat exchange, and the heat exchange efficiency can be further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air source heat pump steam engines, and particularly relates to an air source heat pump high-temperature steam unit. Background Art

[0002] 50% - 70% of industrial energy consumption in China is consumed in the form of heat energy, and most of it is the demand for high-temperature heat energy above 80°C. Traditional high-temperature heating uses coal-fired, oil-fired, gas-fired boilers or electric boilers, etc., which have problems such as low efficiency and high pollution. As an efficient and clean heating method, air source heat pumps have been widely used in the field of medium and low-temperature heating. However, limited by refrigerants and refrigeration systems, it is difficult to achieve a large temperature rise, resulting in difficulty in producing steam products above 100°C through air source heat pump technology. In the existing technical solutions, the formed two-stage refrigerant circulation loop can generate water vapor above 100°C without using the indirect method of negative pressure / micro-pressure flashing of a flash tank to generate steam; but for the water that has not evaporated after heat exchange in the water circulation path of the existing heat pump system, since it cannot return to the water circulation path to participate in heat exchange again, the heat exchange efficiency will be low. Summary of the Utility Model

[0003] The purpose of the utility model is to overcome the technical problem that the existing air source heat pump system cannot make the unevaporated water return to the water circulation path to participate in heat exchange again, which will cause low thermal efficiency, and provide an air source heat pump high-temperature steam unit.

[0004] In the first aspect, the utility model provides an air source heat pump high-temperature steam unit, which includes a first refrigerant circulation loop, a second refrigerant circulation loop and a water circulation path. The first refrigerant circulation loop and the second refrigerant circulation loop are connected through an evaporation condenser, and the second refrigerant circulation loop and the water circulation path are connected through a steam generator; the water circulation path includes a water replenishing port, a water pump, the steam generator and a first gas-liquid separator connected in sequence. The steam generator is provided with a first water outlet, and the first gas-liquid separator is provided with a second water outlet. The first water outlet and the second water outlet can be respectively connected to the water pump.

[0005] Compared with the existing air source heat pump system, which cannot return the unevaporated water to the water circulation path to participate in heat exchange again, resulting in the technical defect of low thermal efficiency, the present application can set a first water outlet on the steam generator in the water circulation path, set a second water outlet on the first gas-liquid separator, and connect the first water outlet and the second water outlet to a water pump respectively, so as to realize the input of the unevaporated water in the steam generator and the first gas-liquid separator into the water pump and then return to the water circulation path to participate in the second heat exchange, further improving the heat exchange efficiency. The unit can absorb heat from the air, release heat to the water flowing in a liquid film in the steam generator through two-stage boosting, evaporate it into steam, improve the heat exchange efficiency, reduce the condensation temperature of the second refrigerant in the steam generator, and comprehensively improve the overall energy efficiency of the unit.

[0006] Preferably, the first refrigerant circulation loop includes a first compressor, the evaporation condenser, a first throttling device, an evaporator, and a second gas-liquid separator connected in sequence.

[0007] Here, the flow direction of the low-pressure refrigerant in the first refrigerant circulation loop is the first compressor, the evaporation condenser, the first throttling device, the evaporator, the second gas-liquid separator, and the first compressor.

[0008] Preferably, a fan is provided on the evaporator.

[0009] Preferably, a defrost bypass branch is further provided in the first refrigerant circulation loop. The inlet end of the defrost bypass branch is connected to the outlet end of the first compressor, the outlet end of the defrost bypass branch is connected to the inlet end of the evaporator, and a bypass valve is provided in the defrost bypass branch.

[0010] Preferably, the second refrigerant circulation loop includes a second compressor, the steam generator, a second throttling device, the evaporation condenser, and a third gas-liquid separator connected in sequence.

[0011] Here, the flow direction of the high-pressure refrigerant in the second refrigerant circulation loop is the second compressor, the steam generator, the second throttling device, the evaporation condenser, the third gas-liquid separator, and the second compressor.

[0012] Preferably, a liquid level monitor is provided in both the steam generator and the first gas-liquid separator.

[0013] Preferably, a first valve is provided between the water replenishment port and the water pump, a second valve is provided between the first water outlet and the water pump, a third valve is provided between the second water outlet and the water pump, and a fourth valve is provided above the first gas-liquid separator.

[0014] Preferably, a first valve is provided between the water supply end and the inlet end of the water pump, a second valve is provided between the water outlet end of the steam generator and the inlet end of the water pump, a third valve is provided between the water outlet end of the third gas-liquid separator and the inlet end of the water pump, and a fourth valve is provided at the steam outlet end of the third gas-liquid separator.

[0015] Preferably, the first valve, the second valve, the third valve and the fourth valve are all solenoid valves.

[0016] Preferably, a plurality of heat exchange tubes are provided in the steam generator.

[0017] Preferably, a flow equalizing plate is further provided in the steam generator, and the flow equalizing plate is located above the heat exchange tubes.

[0018] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0019] The present utility model provides an air source heat pump high-temperature steam unit. A first water outlet can be set on the steam generator in the water circulation path, a second water outlet can be set on the first gas-liquid separator, and the first water outlet and the second water outlet are respectively connected to the water pump, so that the unevaporated water in the steam generator and the first gas-liquid separator can be input into the water pump and then return to the water circulation path to participate in the second heat exchange, which can further improve the heat exchange efficiency; the unit can absorb heat from the air, release heat to the water flowing in a liquid film in the steam generator through two-stage boosting, evaporate it into steam, improve the heat exchange efficiency, reduce the condensation temperature of the second refrigerant in the steam generator, and comprehensively improve the overall energy efficiency of the unit. Description of the Drawings

[0020] Figure 1 is a schematic diagram of the air source heat pump high-temperature steam unit of the present utility model.

[0021] Figure 2 is a schematic diagram of the steam generator of the air source heat pump high-temperature steam unit of the present utility model.

[0022] Figure 3 is Figure 2 the cross-sectional view of "B-B" in

[0023] Markings in the figure:

[0024] 1 - First compressor, 2 - Evaporative condenser, 3 - First throttling device, 4 - Evaporator, 5 - Fan, 6 - Second gas-liquid separator, 7 - Bypass valve, 8 - Second compressor, 9 - Steam generator, 10 - Second throttling device, 11 - Third gas-liquid separator, 12 - First gas-liquid separator, 13 - Second liquid level monitor, 14 - Fourth valve, 15 - Water pump, 16 - Second valve, 17 - Third valve, 18 - First valve, 91 - First water outlet, 92 - First liquid level monitor, 93 - Steam outlet, 94 - Refrigerant outlet, 95 - Heat exchange tube, 96 - Flow equalizing plate, 97 - Circulating water inlet, 98 - Refrigerant inlet. Detailed implementation mode

[0025] The following further describes the present utility model in detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present utility model to the following embodiments. Any technology implemented based on the content of the present utility model belongs to the scope of the present utility model.

[0026] In the description of the specific embodiments of the present utility model, without special explanation, the expression terms of orientation or positional relationship such as "upper", "lower", "left", "right", "center", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product / device / equipment of the utility model is commonly used and placed. These terms of orientation or positional relationship are only for facilitating the description of the solution of the present utility model or simplifying the description in the specific embodiments, so as to enable technicians to quickly understand the solution, rather than indicating or implying that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, it should not be construed as a limitation to the present utility model.

[0027] In addition, for terms such as "horizontal", "vertical", "hanging", "parallel", etc., it does not mean that the corresponding device / component / element is required to be absolutely horizontal or vertical or hanging or parallel, but can be slightly inclined or have a deviation. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined. Or, it can be simply understood that the corresponding device / component / element is arranged in the directions of "horizontal", "vertical", "hanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present utility model.

[0028] In addition, the expressions such as "first", "second", "third", etc. in the terms are only used to distinguish the descriptions of the same or similar components, and should not be understood as emphasizing or implying the relative importance of specific components.

[0029] In addition, in the description of the embodiments of the present utility model, "several", "multiple", and "a number of" represent at least 2. It can be any situation such as 2, 3, 4, 5, 6, 7, 8, 9, etc., or even more than 9.

[0030] In addition, in the description of the technical solution of the present utility model, unless otherwise clearly specified / defined / restricted, when the terms "set", "installed", "connected", "linked", "provided with", "laid", "arranged" appear, they 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 connection means commonly used in the art such as welding, riveting, bolting, and threaded connection. Such a connection can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components.

[0031] Embodiment

[0032] This embodiment provides an air source heat pump high-temperature steam unit.

[0033] Figure 1 is a schematic diagram of the air source heat pump high-temperature steam unit of the present utility model; Figure 2 is a schematic diagram of the steam generator of the air source heat pump high-temperature steam unit of the present utility model; Figure 3 is Figure 2 the cross-sectional view of "B-B" in

[0034] As Figures 1 to 3 shown in, the air source heat pump high-temperature steam unit described in the present utility model may include a first refrigerant circulation circuit, a second refrigerant circulation circuit, and a water circulation path. An evaporation condenser 2 may be connected between the first refrigerant circulation circuit and the second refrigerant circulation circuit, and a steam generator 9 may be connected between the second refrigerant circulation circuit and the water circulation path; the water circulation path may include a water replenishing port, a water pump 15, a steam generator 9, and a first gas-liquid separator 12 that are connected in communication. The steam generator 9 may be provided with a first water outlet 91, and the first gas-liquid separator 12 may be provided with a second water outlet. The first water outlet 91 and the second water outlet can be respectively communicated with the water pump 15.

[0035] Compared with the existing air source heat pump system that cannot return the unevaporated water to the water circulation path to participate in heat exchange again, which will cause the technical defect of low thermal efficiency, the present application can set a first water outlet 91 on the steam generator 9 in the water circulation path, set a second water outlet on the first gas-liquid separator 12, and connect the first water outlet 91 and the second water outlet to the water pump 15 respectively, so as to realize that the unevaporated water in the steam generator 9 and the first gas-liquid separator 12 is input into the water pump 15 and then returns to the water circulation path to participate in the second heat exchange, which can further improve the heat exchange efficiency. The unit can absorb heat from the air, release heat to the water flowing in a liquid film in the steam generator through two-stage lifting, evaporate it into steam, improve the heat exchange efficiency, reduce the condensation temperature of the second refrigerant in the steam generator, and comprehensively improve the overall energy efficiency of the unit.

[0036] The low-pressure refrigerant in the first refrigerant circulation loop can transfer heat to the high-pressure refrigerant in the second refrigerant circulation loop in the evaporation condenser 2, so as to perform the first-stage heating on the high-pressure refrigerant. After the first-stage heating, the high-pressure refrigerant can be secondarily pressurized and heated in the second refrigerant circulation loop through the second compressor 8, reaching a high enough temperature, and then directly heating the water in the steam generator 9 to generate steam for heating.

[0037] In this embodiment, the first refrigerant circulation loop may include a first compressor 1, an evaporation condenser 2, a first throttling device 3, an evaporator 4, and a second gas-liquid separator 6 that are connected in series. The flow path of the low-pressure refrigerant in the first refrigerant circulation loop is also in the above order, that is, the low-pressure refrigerant exchanges heat in the evaporation condenser 2, undergoes a cooling and condensation heat release process, then passes through the first throttling device 3 and enters the evaporator 4, absorbs heat and vaporizes in the evaporator 4, then passes through the second gas-liquid separator 6 and enters the first compressor 1 to be heated up again, and then enters the evaporation condenser 2 for heat exchange.

[0038] Optionally, a blower 5 may be provided on the evaporator 4, and the blower 5 can accelerate the evaporation of the low-pressure refrigerant.

[0039] In this embodiment, a defrost bypass branch may also be provided in the first refrigerant circulation loop. The two ends of the defrost bypass branch may be respectively connected to the inlet end of the evaporator 4 and the outlet end of the second compressor 8, and a bypass valve 7 may be provided in the defrost bypass branch.

[0040] In this embodiment, the second refrigerant circulation loop may include a second compressor 8, a steam generator 9, a second throttling device 10, an evaporation condenser 2, and a third gas-liquid separator 11 that are connected in series.

[0041] In this embodiment, a first valve 18 may be provided between the water replenishing port and the water pump 15, a second valve 16 may be provided between the first water outlet 91 and the water pump 15, a third valve 17 may be provided between the second water outlet and the water pump 15, and a fourth valve 14 may be provided above the first gas-liquid separator 12.

[0042] Optionally, the first valve 18, the second valve 16, the third valve 17 and the fourth valve 14 may all be solenoid valves.

[0043] Optionally, a liquid level monitor may be provided in both the steam generator 9 and the first gas-liquid separator 12. Specifically, a first liquid level monitor 92 is provided in the steam generator 9, and a second liquid level monitor 13 is provided in the first gas-liquid separator 12. The first liquid level monitor 92 and the second liquid level monitor 13 may respectively monitor in real time the liquid level changes of the unevaporated water in the steam generator 9 and the first gas-liquid separator 12, and may control the opening or closing of the second valve 16 and the third valve 17 according to the amount of water in the steam generator 9 and the first gas-liquid separator 12, so as to timely discharge the water and return it to the water circulation path for re-evaporation.

[0044] Optionally, a plurality of heat exchange tubes 95 are provided in the steam generator 9; a flow equalizing plate 96 is also provided in the steam generator 9, and the flow equalizing plate 96 may be located above the heat exchange tubes 95. The steam generator 9 may be a falling film type steam generator, and water may flow uniformly downward along the outer side of the heat exchange tubes 95 through the flow equalizing plate 96 and exchange heat with the high-pressure refrigerant in the heat exchange tubes 95, so as to evaporate the water to form water vapor for heating.

[0045] Normal heating principle of the system:

[0046] Refrigerant circulation process: In the normal heating mode, the bypass valve 7 is closed and the fan 5 is turned on. The heat pump circulation loop is divided into two stages. The first-stage circulation is the low-pressure stage circulation, and the second-stage circulation is the high-pressure stage circulation. The first refrigerant circulation loop and the second refrigerant circulation loop are connected by the evaporation condenser 2 for heat exchange. In the first refrigerant circulation loop, the low-temperature and low-pressure refrigerant gas is compressed by the first compressor 1 into a medium-temperature and medium-pressure refrigerant gas, enters the evaporation condenser 2 for cooling and condensation, and releases heat to the high-pressure refrigerant in the second refrigerant circulation loop. The cooled low-pressure refrigerant enters the first throttling device 3 for throttling and pressure reduction, and then enters the evaporator 4 to absorb heat from the air and evaporate. After that, it returns to the first compressor 1 through the second gas-liquid separator 6; in the second refrigerant circulation loop, the high-pressure refrigerant absorbs heat from the low-pressure refrigerant in the evaporation condenser 2 and evaporates. After passing through the third gas-liquid separator 11, it is sucked by the second compressor 8 and compressed into a high-temperature and high-pressure refrigerant gas. It enters the steam generator 9 through the refrigerant inlet 98 and releases heat to the water flowing down in a liquid film on the inner wall surface by the outer wall surface of the heat exchange tube 95 to vaporize it. The condensed refrigerant liquid flows out from the refrigerant outlet 94, enters the second throttling device 10 for throttling and pressure reduction, and then enters the evaporation condenser 2 again to absorb heat.

[0047] Water circulation process: The low-temperature water passes through the first valve 18 and is mixed successively with the water flowing out from the bottom of the first gas-liquid separator 12 through the third valve 17 and the water flowing out from the bottom of the steam generator 9 through the first water outlet 91 and the second valve 16. Then it is pumped by the water pump 15 to the top of the steam generator 9 at the circulating water inlet 97. Then, after being evenly distributed by the flow equalizing plate 96, it falls to the outside of the heat exchange tube 95 and forms a liquid film flowing down on the outer wall of the heat exchange tube 95. Part of the water is heated and evaporated into water vapor and flows out through the steam outlet 93. The unevaporated water falls to the bottom and participates in the water circulation again. After the water vapor flows out from the steam outlet 93 of the steam generator 3, it enters the first gas-liquid separator 12 for gas-liquid separation. The liquid remains at the bottom, and the steam is transported through the pipeline from the fourth valve 14 to the user's heat consumption place.

[0048] Principle of system defrosting:

[0049] When the unit reaches the defrosting condition during operation in the heating mode, the fan 5 of the low-pressure stage circulation is turned off and the bypass valve 7 is opened. Part of the medium-temperature refrigerant vapor heated by the first compressor 1 still enters the evaporation condenser 2 to release heat, and the other part passes through the bypass valve 7 and is mixed with the refrigerant after throttling and pressure reduction by the first throttling device 3, enters the evaporator 4 to release heat and melt the frost layer on the fin, and then returns to the first compressor 1 through the second gas-liquid separator 6 for compression and temperature rise again. Turning off the fan 5 during defrosting can reduce the heat exchange with the surrounding ambient air, mainly use the heat for defrosting, and improve the defrosting efficiency.

[0050] Other instructions:

[0051] In the present utility model, the function of the first liquid level monitor 92 is to monitor the water level at the bottom of the falling film steam generator 9 to ensure that the liquid level fluctuates within a required range. The function of the second liquid level monitor 13 is to monitor the water level at the bottom of the first gas-liquid separator 12. When the highest liquid level is reached, the third valve 17 opens and closes when the water at the bottom is emptied. The function of the fourth valve 14 is to maintain the pressure stability in the first gas-liquid separator 12 and opens when the saturated steam pressure required by the user is reached.

[0052] In the present utility model, no specific types of low-pressure refrigerant and high-pressure refrigerant are restricted. Specifically, in the implementation, R410a can be used as the low-pressure refrigerant, and R245fa or R1233zd(E) can be used as the high-pressure refrigerant.

[0053] In the present utility model, the form of the bypass valve 7 is not limited to one type, and its specific structure is not restricted either, as long as it can control the on-off of the refrigerant pipeline and regulate the pipeline flow rate.

[0054] In the present utility model, no specific types and structural forms of the first throttling device 3, the second throttling device 10, the first compressor 1, the second compressor 8, the evaporative condenser 2, the evaporator 4, the second gas-liquid separator 6, the third gas-liquid separator 11 and the water pump 15 are restricted.

[0055] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An air source heat pump high temperature steam unit, characterized in that: comprising a first refrigerant circulation circuit, a second refrigerant circulation circuit and a water circulation passage, The first refrigerant circulation circuit and the second refrigerant circulation circuit are connected via an evaporative condenser (2), and the second refrigerant circulation circuit and the water circulation passage are connected via a steam generator (9); The water circulation passage comprises a water replenishment port, a water pump (15), the steam generator (9) and a first gas-liquid separator (12) which are connected in sequence, the steam generator (9) being provided with a first water outlet (91), the first gas-liquid separator (12) being provided with a second water outlet, and the first water outlet (91) and the second water outlet being capable of being connected to the water pump (15) respectively.

2. The air source heat pump high temperature steam unit according to claim 1, characterized in that: The first refrigerant circulation circuit comprises a first compressor (1), the evaporative condenser (2), a first throttling device (3), an evaporator (4) and a second gas-liquid separator (6) which are connected in sequence.

3. The air source heat pump high temperature steam unit according to claim 2, characterized in that: The evaporator (4) is provided with a fan (5).

4. The air source heat pump high temperature steam unit according to claim 3, characterized in that: A defrost bypass branch is also provided in the first refrigerant circulation circuit, the inlet end of the defrost bypass branch is connected to the outlet end of the first compressor (1), the outlet end of the defrost bypass branch is connected to the inlet end of the evaporator (4), and a bypass valve (7) is provided in the defrost bypass branch.

5. The air source heat pump high temperature steam unit according to claim 1, characterized in that: The second refrigerant circulation circuit comprises a second compressor (8), the steam generator (9), a second throttling device (10), the evaporative condenser (2) and a third gas-liquid separator (11) which are connected in sequence.

6. The air source heat pump high temperature steam unit according to claim 1, characterized in that: The steam generator (9) and the first gas-liquid separator (12) are both provided with liquid level monitors.

7. The air source heat pump high temperature steam unit according to claim 1, characterized in that: A first valve (18) is provided between the water replenishment port and the water pump (15), a second valve (16) is provided between the first water outlet (91) and the water pump (15), a third valve (17) is provided between the second water outlet and the water pump (15), and a fourth valve (14) is provided above the first gas-liquid separator (12).

8. The air source heat pump high temperature steam unit according to claim 7, characterized in that: The first valve (18), the second valve (16), the third valve (17) and the fourth valve (14) are all solenoid valves.

9. The air source heat pump high temperature steam unit according to any one of claims 1 to 8, characterized in that: The steam generator (9) is provided with a plurality of heat exchange tubes (95).

10. The air source heat pump high temperature steam unit according to claim 9, characterized in that: The steam generator (9) is also provided with a flow equalizing plate (96), and the flow equalizing plate (96) is located above the heat exchange tube (95).

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