Frost-free air source cascade heat pump with liquid freezing

Abstract

The present invention provides a frost-free air source cascade heat pump for solution dehydration, including a cascade heating cycle and an ice dehydration cycle; the ice dehydration cycle includes a solution heat exchange pipeline, a storage liquid circulation pipeline and a solution regeneration pipeline, the solution heat exchange pipeline includes an evaporator, a heat exchange tower, a second stop valve and a first pump; the storage liquid circulation pipeline includes a dilute solution discharge pipeline and a concentrated solution circulation pipeline, the dilute solution discharge pipeline includes a second pump and a first liquid storage tank, and the concentrated solution circulation pipeline includes a second liquid storage tank and a first pump; the solution regeneration pipeline includes a first throttle valve, a dehydrator, a first liquid storage tank and a third pump. The frost-free air source cascade heat pump of the present invention can realize three operating modes such as heating + ice dehydration + deicing, ensure the continuous operation of heating and the regeneration effect of the solution, occupy a low area and investment cost, is simple to operate, saves the consumption of heat energy, and improves the energy efficiency of the frost-free air source heat pump system.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat pumps, and in particular relates to a frost-free air source cascade heat pump for solution regeneration based on ice removal. Background Art

[0002] As a highly efficient and energy-saving system, the frost-free air source cascade heat pump cycle is strongly supported by the industry. However, due to limited technology, there are still many areas for improvement in the frost-free air source cascade heat pump cycle. Among them, after the antifreeze solution is diluted in the frost-free air source cascade heat pump cycle, how to increase the concentration of the antifreeze in a more energy-efficient way is still being explored. When the frost-free air source cascade heat pump cycle is running for heating in winter, since the air contains a certain amount of moisture in winter, during the heat exchange process between the antifreeze circulation and the air, the moisture in the air is continuously dissolved in the antifreeze after being cooled, diluting the antifreeze. In order to separate and remove the moisture in the antifreeze, the existing technology is to use various forms of heating and drying methods such as electric heating, fuel boiler heating or solar heating, but the above-mentioned heating methods all lead to increased energy consumption of the system operation, increased investment and increased operating costs.

[0003] The existing patent proposes to use freezing regeneration to remove moisture from the antifreeze, which has a better regeneration effect. However, the heating operation needs to be stopped during the regeneration process, or an independent heat pump unit needs to be used to provide cold water for solution regeneration to ensure the normal operation of the user-side unit. The two sets of units not only increase the floor space and investment cost, but also bring great inconvenience to the adjustment of the system, making it difficult to apply to actual occasions. Summary of the invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a frost-free air source air supplementation and enthalpy increase heat pump for solution dehydration with high efficiency, low energy consumption and good energy-saving performance.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0006] A frost-free air source cascade heat pump with solution freezing, including a cascade heating cycle and an ice removal cycle; the cascade heating cycle includes a first compressor, a second compressor, a condenser, a first throttle valve, a second throttle valve, an evaporative condenser and an evaporator; the ice removal cycle includes a solution heat exchange pipeline, a storage liquid circulation pipeline and a solution regeneration pipeline, wherein the solution heat exchange pipeline includes an evaporator, a heat exchange tower, a second stop valve and a first pump, the solution in the heat exchange tower is sent to the evaporator through the second stop valve and the first pump, and returns to the top of the heat exchange tower after heat exchange with the refrigerant in the evaporator; the storage liquid circulation pipeline includes a dilute solution discharge pipeline and a concentrated solution circulation pipeline, the dilute solution discharge pipeline includes a second pump and a first liquid storage tank, and the bottom of the heat exchange tower The dilute solution is discharged into the first liquid storage tank through the second pump; the concentrated solution circulation pipeline includes the second liquid storage tank and the first pump, and the concentrated solution in the second liquid storage tank is transported to the evaporator through the sixth stop valve and the first pump; the solution regeneration pipeline includes the first throttle valve, the dehydrator, the first liquid storage tank and the third pump, part of the refrigerant flowing out of the first throttle valve flows to the second inlet of the dehydrator through the third stop valve, and the second outlet of the dehydrator is connected to the compressor; the dilute solution outlet of the first liquid storage tank is connected to the first inlet of the dehydrator through the seventh stop valve, and the first outlet of the dehydrator is connected to the inlet of the third pump; the outlet of the third pump is connected to the concentrated solution inlet of the first liquid storage tank through the fourth stop valve, and is connected to the concentrated solution inlet of the second liquid storage tank through the fifth stop valve.

[0007] As one of the preferred schemes of the present invention, it also includes a deicing cycle, which includes an eighth stop valve and a dehydrator. The eighth stop valve is connected in parallel with the first stop valve. The refrigerant outlet of the condenser is connected to the third inlet of the dehydrator through the eighth stop valve, and the third outlet of the dehydrator is connected to the inlet of the first throttle valve.

[0008] As one of the preferred solutions of the present invention, it includes a normal heating mode, a heating + ice removal mode and a heating + ice removal mode.

[0009] As one of the preferred schemes of the present invention, in the heating + ice dehydration mode, when the solution at the first outlet of the dehydrator does not meet the requirements, the solution is transported to the first liquid storage tank via the third pump and the fourth stop valve; when the solution at the first outlet of the dehydrator meets the requirements, the solution is transported to the second liquid storage tank via the third pump and the fifth stop valve, and the concentrated solution in the second liquid storage tank is transported to the evaporator via the first pump.

[0010] As one of the preferred solutions of the present invention, the heat exchange tower includes a solution tank and a heat exchange cavity located above the solution tank. The solution at the top of the heat exchange tower contacts and exchanges heat with air in the heat exchange cavity and then flows into the solution tank.

[0011] As one of the preferred schemes of the present invention, the dehydrator includes an ice-making chamber, a partition and a liquid storage chamber arranged from top to bottom. An ice-making tray and an ice-making heat exchange pipe arranged on the back of the ice-making tray are arranged in the ice-making chamber. A solution nozzle is arranged on the front side of the ice-making tray to spray the solution onto the surface of the ice-making tray. After the solution exchanges heat with the refrigerant in the ice-making heat exchange pipe, ice cubes adhere to the surface of the refrigeration tray, and unfrozen water and solution enter the liquid storage chamber through the holes on the partition.

[0012] As one of the preferred solutions of the present invention, a deicing heat exchange pipe is also provided on the back of the ice making tray, and an ice discharge port is provided on one side of the bottom of the ice making chamber. After the ice cubes are heated by the refrigerant in the deicing heat exchange pipe, they fall off the surface of the ice making tray and are discharged through the ice discharge port.

[0013] As one of the preferred solutions of the present invention, the partition is inclined downward toward the ice discharge port.

[0014] As one of the preferred solutions of the present invention, a plurality of ice-making grooves are provided on the front side of the ice-making tray.

[0015] Compared with the prior art, the present invention has the following beneficial effects: compared with the traditional frost-free air source cascade heat pump, the present invention can realize three operating modes, namely heating + ice dehydration + deicing, which can not only ensure the continuous operation of heating and the regeneration effect of the solution, but also use the waste heat of the refrigerant to maintain the dehydration effect of the dehydrator. It has a low footprint and investment cost, is easy to operate, saves thermal energy consumption, and improves the energy efficiency of the frost-free air source heat pump system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the composition of the heat pump of the present invention;

[0017] Figure 2 It is a structural schematic diagram of the water remover in the heat pump of the present invention;

[0018] Figure 3 is a schematic diagram of the process of the heat pump of the present invention in the ordinary heating mode;

[0019] Figure 4-1 is a schematic diagram of stage 1 of the heat pump of the present invention in the heating + freezing and dehydration mode;

[0020] Figure 4-2 is a schematic diagram of the second stage of the heat pump of the present invention in the heating + freezing and dehydration mode;

[0021] Figure 4-3 is a schematic diagram of stage three of the heat pump of the present invention in the heating + freezing and dehydration mode;

[0022] Figure 5 It is a schematic diagram of the flow of the heat pump in the heating + deicing mode of the present invention.

[0023] In the figure, 1-condenser, 2-first compressor, 3-second compressor, 4-evaporator, 5-first throttle valve, 6-second throttle valve, 7-condenser evaporator, 8-heat exchange tower, 9-first pump, 10-second pump, 11-third pump, 12-first liquid storage tank, 13-second liquid storage tank, 14-water remover; 21-first stop valve, 22-second stop valve, 23-third stop valve; 24-fourth stop valve, 25-fifth stop valve, 26-sixth stop valve, 27-seventh stop valve, 28-eighth stop valve;

[0024] a-the first inlet of the water eliminator, b-the first outlet of the water eliminator, c-the second inlet of the water eliminator, d-the second outlet of the water eliminator, e-the third inlet of the water eliminator, f-the third outlet of the water eliminator;

[0025] A- ice discharge port, B- partition, C- liquid storage chamber, D- ice tray, E- solution nozzle, F- heat exchange tube. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be further explained below.

[0027] like Figure 1 As shown, the frost-free air source cascade heat pump with frozen solution in this embodiment includes a cascade heating cycle and an ice removal cycle; the cascade heating cycle includes a first compressor 2, a second compressor 3, a condenser, a first throttle valve 5, a second throttle valve 6, a condenser evaporator 7 and an evaporator 4; the condenser 1 provides heat to the user side, and the evaporator 4 absorbs heat from the solution.

[0028] The deicing and dewatering cycle includes a solution heat exchange pipeline, a storage liquid circulation pipeline and a solution regeneration pipeline, wherein the solution heat exchange pipeline includes an evaporator 4, a heat exchange tower 8, a second stop valve 22 and a first pump 9, the solution in the heat exchange tower 8 is sent to the evaporator 4 through the second stop valve 22 and the first pump 9, and returns to the top of the heat exchange tower 8 after heat exchange with the refrigerant in the evaporator 4; the storage liquid circulation pipeline includes a dilute solution discharge pipeline and a concentrated solution circulation pipeline, the dilute solution discharge pipeline includes a second pump 10 and a first liquid storage tank 12, the dilute solution at the bottom of the heat exchange tower 8 is discharged into the first liquid storage tank 12 through the second pump 10; the concentrated solution circulation pipeline includes a second liquid storage tank 13 and a first pump 9, the concentrated solution in the second liquid storage tank 13 is transported to the evaporator 4 through the sixth stop valve 26 and the first pump 9; the solution regeneration pipeline includes a first throttle valve 5, a dehydrator 14, a first liquid storage tank 12 and a third pump 11, Part of the refrigerant flowing out of the first throttle valve 5 flows to the second inlet c of the water eliminator 14 through the third stop valve 23, and the second outlet d of the water eliminator 14 is connected to the compressor 2; the dilute solution outlet of the first liquid storage tank 12 is connected to the first inlet a of the water eliminator 14 through the seventh stop valve 27, and the first outlet b of the water eliminator 14 is connected to the inlet of the third pump 11; the outlet of the third pump 11 is connected to the concentrated solution inlet of the first liquid storage tank 12 through the fourth stop valve 24, and is connected to the concentrated solution inlet of the second liquid storage tank 13 through the fifth stop valve 25.

[0029] The frost-free air source cascade heat pump for dehydrating the solution described in this embodiment uses part of the cooling capacity of the cascade heating cycle to freeze and dehydrate part of the solution introduced into the dehydrator. Combined with the liquid storage cycle of the liquid storage tank, it can not only ensure the continuous operation of the heating cycle, but also improve the regeneration effect and the operating efficiency of the frost-free air source heat pump.

[0030] The frost-free air source cascade heat pump described in this embodiment also includes a deicing cycle, which includes an eighth stop valve 28 and a dehumidifier 14. The eighth stop valve 28 is connected in parallel with the first stop valve 21. The refrigerant outlet of the condenser 1 is connected to the third inlet e of the dehumidifier 14 through the eighth stop valve 28, and the third outlet f of the dehumidifier 14 is connected to the inlet of the second throttle valve 6. After the dehumidifier runs for a certain period of time, the amount of ice gradually increases. In order to ensure the dehydration effect of the dehumidifier, part of the heat of the air-injection enthalpy-increasing heating cycle is used to heat the deicing, which has a faster heating speed and a simple structure.

[0031] The heat exchange tower 8 used in this embodiment includes a solution tank and a heat exchange cavity located above the solution tank. The solution at the top of the heat exchange tower contacts and exchanges heat with the air in the heat exchange cavity and then flows into the solution tank. Preferably, the solution at the top of the heat exchange tower is directly contacted with the air after being sprayed by a spray device to increase the contact area. Since the temperature of the solution after heat exchange is lower than the temperature of the air, the moisture in the air is continuously dissolved in the solution after being cooled, so that the concentration of the solution gradually decreases. Therefore, after the solution in the solution tank circulates for a period of time, the solution must be regenerated to maintain a continuous heating effect.

[0032] like Figure 2 As shown, the dehydrator 14 used in this embodiment includes an ice-making chamber, a partition B and a liquid storage chamber C arranged from top to bottom. An ice-making tray D and a heat exchange tube F close to the back of the ice-making tray are provided in the ice-making chamber. The heat exchange tube F includes an ice-making heat exchange tube and a deicing heat exchange tube arranged in parallel. Both ends of the ice-making heat exchange tube are respectively connected to the second inlet c and the second outlet d of the dehydrator, and both ends of the deicing heat exchange tube are respectively connected to the third inlet e and the third outlet f of the dehydrator.

[0033] The solution nozzle E is arranged on the front side of the ice making tray D, and the inlet of the solution nozzle E is connected to the first inlet a of the dehydrator, that is, the solution enters the ice making chamber from the inlet a, and is sprayed to the surface of the ice making tray D through the solution nozzle E; after the solution exchanges heat with the refrigerant in the ice making heat exchange tube, the ice cubes adhere to the grooves on the surface of the refrigeration tray D, and the unfrozen water and solution enter the liquid storage chamber C through the holes on the partition B. The bottom of the liquid storage chamber C is provided with a first outlet b, and the regenerated solution flows out to the solution tank of the heat exchange tower 8 through the first outlet b.

[0034] In this embodiment, an ice discharge port A is provided at one side of the bottom of the ice-making chamber. When the amount of ice in the dehydrator is large, the ice cubes are heated by the refrigerant in the deicing heat exchange pipe, fall off the surface of the ice tray and are discharged through the ice discharge port A. The ice discharge port A can be opened or closed manually or automatically to prevent the unfrozen solution from flowing out of the ice discharge port. At the same time, in order to better discharge the ice cubes, the partition B is tilted downward toward the ice discharge port A to increase the time efficiency of ice cube discharge.

[0035] The frost-free air source cascade heat pump for solution dehydration of the present invention can realize three operation modes, namely, ordinary heating mode, heating + deicing mode, and heating + deicing mode. The specific process is as follows:

[0036] like Figure 3As shown, in the common heating mode, the first stop valve 21, the first throttle valve 5, the second throttle valve 6, the second stop valve 22 and the first pump 9 are opened. After being discharged from the first compressor 2, the refrigerant returns to the first compressor through the condenser 1, the first stop valve 21, the second throttle valve 6, the condenser evaporator 7 in sequence; after being discharged from the second compressor 3, the refrigerant returns to the second compressor 3 through the condenser evaporator 7, the first throttle valve 5, the evaporator 4 in sequence; the solution is transported to the evaporator 4 through the bottom of the heat exchange tower 8 by the first pump 9, and returns to the top of the heat exchange tower 8 after heat exchange. In this mode, the condenser 1 provides heat to the user side, and the refrigerant in the evaporator 4 continuously absorbs the heat of the solution to maintain the heating load.

[0037] like Figure 4-1 to Figure 4-3 As shown in the figure, in the heating + deicing mode, ordinary heating operates normally. After a period of circulation, the concentration of the solution flowing out of the second outlet of the evaporator slowly decreases. This mode goes through three stages:

[0038] Stage 1 Figure 4-1 As shown, the storage liquid in the second liquid storage tank circulates: the second pump 10 is turned on, and the dilute solution in the heat exchange tower 8 enters the first liquid storage tank 12. When the dilute solution in the heat exchange tower 8 is about to flow out, the sixth stop valve 26 is opened, and the second stop valve 22 and the second pump 10 are closed. The concentrated solution in the second liquid storage tank 13 enters the first evaporator 4 through the sixth stop valve 26 and the first pump 9 to exchange heat with the refrigerant and enters the heat exchange tower 8. After the concentrated solution in the second liquid storage tank 13 is exhausted, the sixth stop valve 26 is closed, and the second stop valve 22 is opened to maintain the normal circulation of the solution.

[0039] Stage 2 Figure 4-2 As shown, it is a solution regeneration cycle: the third stop valve 23, the seventh stop valve 27, the third pump 11 and the fourth stop valve 24 are opened. The dilute solution in the first liquid storage tank 12 enters the dehumidifier 15 through the seventh stop valve 27. Part of the refrigerant flowing out of the first throttle valve 5 enters the second inlet of the dehumidifier 15, and the solution flowing into the dehumidifier 15 is sprayed by the solution nozzle E onto the ice tray D with a groove in the dehumidifier. Due to the difference in the concentration of the refrigerant flowing into the dehumidifier and the evaporator, the water in the solution sprayed on the ice tray freezes (while the solution in the evaporator does not freeze). At the same time, the second throttle valve 6 can be adjusted to change the temperature and pressure of the refrigerant passing through the dehumidifier 18, so that the freezing process can be carried out better, and the unfrozen water and antifreeze in the dehumidifier 15 become concentrated solutions, which flow into the liquid storage chamber C through the holes on the partition B in the dehumidifier, flow out along the first outlet b of the dehumidifier 14, and return to the first liquid storage tank 12 through the third pump 11 and the fourth stop valve 24. As the solution circulates in this way, the concentration gradually increases and the water continues to freeze into ice.

[0040] Stage 3 Figure 4-3As shown, when the solution flowing out of the first outlet b of the water remover 14 reaches the concentration requirement, the fourth stop valve 24 is closed, and the fifth stop valve 25 is opened. The solution enters the second liquid storage tank 13 through the third pump 11 and the fifth stop valve 25. When the second liquid storage tank 13 is filled with concentrated solution, the sixth stop valve 26 is opened to allow the concentrated solution to enter the solution circulation pipeline. When the solution concentration meets the requirements, the solution regeneration circulation pipeline and the sixth stop valve can be closed to maintain the solution circulation in the normal heating mode.

[0041] like Figure 5 As shown, in the heating + deicing mode, ordinary heating operates normally, the first stop valve 21, the third stop valve 23 to the seventh stop valve 27, the second pump 10 and the third pump 11 are closed; the eighth stop valve 28 is opened. The hot refrigerant from the condenser 1 flows into the third inlet c of the dehydrator 14 through the eighth stop valve 28, and exchanges heat with the ice tray in the dehydrator. As the refrigeration tray is heated, the ice attached to its surface will fall off, and the fallen ice will flow out along the ice discharge port A.

[0042] Compared with the traditional frost-free air source cascade heat pump, the present invention can realize three operating modes including heating + deicing + ice removal. It can not only ensure the continuous operation of heating and the regeneration effect of the solution, but also use the waste heat of the refrigerant to maintain the dehydration effect of the dehydrator. It has a low footprint and investment cost, is easy to operate, saves heat energy consumption, and improves the energy efficiency of the frost-free air source heat pump system.

[0043] It should be noted that the above embodiments can be freely combined as needed. The above description is only a detailed description of the preferred embodiments and principles of the present invention. For ordinary technicians in this field, according to the ideas provided by the present invention, there will be changes in the specific implementation methods, and these changes should also be regarded as the protection scope of the present invention.

Claims

1. A frost-free air source cascade heat pump with solution freezing, characterized in that: It includes a cascade heating cycle and an ice removal cycle; the cascade heating cycle includes a first compressor, a second compressor, a condenser, a first throttle valve, a second throttle valve, an evaporative condenser and an evaporator; The deicing cycle includes a solution heat exchange pipeline, a storage liquid circulation pipeline and a solution regeneration pipeline, among which: The solution heat exchange pipeline includes an evaporator, a heat exchange tower, a second stop valve and a first pump. The solution in the heat exchange tower is sent to the evaporator through the second stop valve and the first pump, and returns to the top of the heat exchange tower after heat exchange with the refrigerant in the evaporator; The storage liquid circulation pipeline includes a dilute solution discharge pipeline and a concentrated solution circulation pipeline. The dilute solution discharge pipeline includes a second pump and a first liquid storage tank. The dilute solution at the bottom of the heat exchange tower is discharged into the first liquid storage tank through the second pump. The concentrated solution circulation pipeline includes a second liquid storage tank and a first pump. The concentrated solution in the second liquid storage tank is transported to the evaporator through the sixth stop valve and the first pump. The solution regeneration pipeline includes a first throttle valve, a water remover, a first liquid storage tank and a third pump. Part of the refrigerant flowing out of the first throttle valve flows to the second inlet of the water remover through the third stop valve, and the second outlet of the water remover is connected to the compressor; the dilute solution outlet of the first liquid storage tank is connected to the first inlet of the water remover through the seventh stop valve, and the first outlet of the water remover is connected to the inlet of the third pump; the outlet of the third pump is connected to the concentrated solution inlet of the first liquid storage tank through the fourth stop valve and the concentrated solution inlet of the second liquid storage tank through the fifth stop valve; The heat exchange tower includes a solution tank and a heat exchange cavity located above the solution tank. The solution at the top of the heat exchange tower contacts and exchanges heat with air in the heat exchange cavity and then flows into the solution tank. The solution at the top of the heat exchange tower is sprayed by the spray device and then comes into direct contact with the air.

2. The frost-free air source cascade heat pump with solution freezing according to claim 1, characterized in that: It also includes a deicing cycle, which includes an eighth stop valve and a dehydrator. The eighth stop valve is connected in parallel with the first stop valve. The refrigerant outlet of the condenser is connected to the third inlet of the dehydrator through the eighth stop valve, and the third outlet of the dehydrator is connected to the inlet of the second throttle valve.

3. The frost-free air source cascade heat pump with solution freezing according to claim 2, characterized in that: It includes normal heating mode, heating + ice removal mode and heating + ice removal mode.

4. The frost-free air source cascade heat pump with solution freezing according to claim 3, characterized in that: In the heating + ice removal mode, when the solution at the first outlet of the dehydrator does not meet the requirement, the solution is transported to the first liquid storage tank via the third pump and the fourth stop valve; when the solution at the first outlet of the dehydrator meets the requirement, the solution is transported to the second liquid storage tank via the third pump and the fifth stop valve, and the concentrated solution in the second liquid storage tank is transported to the evaporator via the first pump.

5. The frost-free air source cascade heat pump with solution freezing according to claim 4, characterized in that: The dehydrator includes an ice-making chamber, a partition and a liquid storage chamber arranged from top to bottom. An ice-making tray and an ice-making heat exchange pipe arranged on the back of the ice-making tray are arranged in the ice-making chamber. A solution nozzle is arranged on the front side of the ice-making tray to spray the solution onto the surface of the ice-making tray. After the solution exchanges heat with the refrigerant in the ice-making heat exchange pipe, ice cubes adhere to the surface of the refrigeration tray, and unfrozen water and solution enter the liquid storage chamber through the holes on the partition.

6. The frost-free air source cascade heat pump with solution freezing according to claim 5, characterized in that: There is also an ice-removing heat exchange pipe on the back of the ice tray, and an ice discharge port is provided on one side of the bottom of the ice chamber. After the ice cubes are heated by the refrigerant in the ice-removing heat exchange pipe, they fall off the surface of the ice tray and are discharged through the ice discharge port.

7. The frost-free air source cascade heat pump with solution freezing according to claim 6, characterized in that: The partition is inclined downward toward the ice discharge port.

8. The frost-free air source cascade heat pump with solution freezing according to claim 7, characterized in that: A plurality of ice-making grooves are arranged on the front of the ice-making tray.

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