Tandem type water source heat pump

Abstract

The utility model relates to the technical field of heat pumps, in particular to a tandem type water source heat pump which comprises evaporators, compressors, condensers and expansion valves which are sequentially connected to form a closed pipeline, the number of the compressors and the number of the expansion valves are equal, the evaporators and the condensers are divided into multiple sections, and each section corresponds to one compressor and one expansion valve. The single-section evaporator is connected with a single water source side pipeline, and the whole-section condenser is located in a single use side water pipe. A first condensation pipe, a second condensation pipe... an Nth condensation pipe are sequentially distributed on the condenser from the water inlet end to the water outlet end of the use side water pipe, N is not smaller than 3, and an (N-1) th condensation pipe, an (N-2) th condensation pipe... the first condensation pipe further penetrate through the circulating pipeline corresponding to the Nth condensation pipe. According to the water source heat pump, a multi-stage gradient heating mode is adopted, water in the water pipe on the using side can be fully heated, the heating efficiency of the water source heat pump is improved, and the heating requirement of large-flow water is met.

Description

Technical Field

[0001] The present application relates to the technical field of heat pumps, and in particular to a series water source heat pump. Background Art

[0002] Water source heat pump units have been increasingly widely used in my country in recent years due to their high efficiency and energy saving, and their ability to meet both cooling and heating requirements. Water source heat pump units have excellent working conditions and efficient heat exchange, making their operating efficiency far higher than that of ordinary water cooling units, air source heat pumps or other cooling and heating methods.

[0003] Chinese patent CN102706038A discloses an industrial waste heat water source heat pump heating unit, including an evaporator, a compressor, a condenser and an expansion valve connected in sequence to form a closed circulation pipeline, wherein the compressor and the expansion valve are provided in plurality, and the evaporator and the condenser are respectively divided into multiple sections, the water circuits between the multiple sections of the condensers are connected in series, and the water circuits between the multiple sections of the evaporators are connected in parallel, and each section of the condenser is connected to form a refrigerant circulation pipeline with one section of the evaporator through one of the compressors and one of the expansion valves, and the refrigerant circulation pipelines are connected in parallel with each other. The water source heat pump heating unit can make full use of the principle that lowering the condensing temperature can reduce the power consumption of the compressor when the evaporation temperature is the same, effectively improve the energy efficiency ratio of the water source heat pump, and has good practicality.

[0004] However, when the prior art uses a multi-stage condenser to perform step-by-step heating on the side water pipes, the temperature inside the side water pipes at the end is relatively high, and the refrigerant in the corresponding condenser cannot be completely liquefied or cannot be liquefied at all. At this time, the evaporator cannot be supplied with liquid, causing the overheating temperature to rise rapidly, resulting in the compressor exhaust temperature being too high. At this time, the viscosity of the lubricating oil drops rapidly and loses its lubricating effect, causing damage to the compressor or even burning the compressor. Utility Model Content

[0005] In order to overcome the problems existing in the prior art, the present application provides a series water source heat pump.

[0006] The present application provides a series water source heat pump adopting the following technical solution:

[0007] A series water source heat pump comprises an evaporator, a compressor, a condenser and an expansion valve which are connected in sequence to form a closed pipeline. The compressor and the expansion valve are provided in multiple and equal numbers. The evaporator and the condenser are respectively divided into multiple sections and each section corresponds to a single compressor and an expansion valve. A single water source side pipeline is connected to the single section evaporator, and the whole section condenser is located in a single user side water pipe. The condenser is sequentially provided with a first condenser tube, a second condenser tube ... an Nth condenser tube from the water inlet end to the water outlet end of the user side water pipe, wherein N is not less than 3, and a circulation pipeline corresponding to the Nth condenser tube is also penetrated by an N-1th condenser tube, an N-2th condenser tube ... the first condenser tube.

[0008] By adopting the above technical solution, on the basis of the traditional water source heat pump, the condenser tubes in multiple groups of structures are connected in series through the side water pipe to realize the multi-stage heating function, wherein the condenser tubes in the water source heat pump are provided with multiple ones. In this case, the liquid refrigerant releasing heat will pass through these condenser tubes in sequence, and the condenser tubes in each stage can heat the water in the side water pipe step by step to realize the step-by-step heating. And the circulation pipe near the water outlet end of the side water pipe is extended to the water inlet end of the side water pipe in sequence, so that the refrigerant that is not completely liquefied in the circulation pipe can be completely liquefied and then returned to the compressor, avoiding the subsequent damage to the compressor.

[0009] Preferably, a first branch pipeline connected to the evaporator is also installed at the outlet of the circulation pipeline corresponding to the Nth condenser, wherein the circulation pipeline and the first branch pipeline are both connected to the evaporator through the same expansion valve.

[0010] Preferably, a first valve and a second valve are respectively installed at two connection points between the circulation pipeline and the first branch pipeline.

[0011] Preferably, the first valve is located at one end of the condenser, the second valve is located at one end of the evaporator, and both the first valve and the second valve are three-way valves, both including a gas monitor and a control valve.

[0012] By adopting the above technical solution, the first branch pipeline is connected to the circulation pipeline between the condenser and the expansion valve. When the refrigerant in the circulation pipeline derived from the condenser has been completely liquefied, the valve leading to the water inlet end of the water pipe near the use side can be closed by adjusting the first valve and the second valve, and the refrigerant liquid is directly transported to the expansion valve through the first branch pipe wheel. If the refrigerant in the circulation pipeline derived from the condenser is not completely liquefied, the valves on both sides of the first branch pipe wheel are closed, and it continues to enter the next group of condensers for liquefaction and heat release.

[0013] Preferably, the circulation pipeline on the Nth condenser passes through the N-1th condenser and a second branch pipeline is connected between the N-1th condenser and the N-2th condenser, wherein a first valve and a second valve are provided between the circulation pipeline and the second branch pipeline.

[0014] By adopting the above technical solution, the working principle of the second branch pipeline is the same as that of the above first branch pipeline. Setting multiple branch pipelines can reduce the distance that the coolant flows in the circulation pipeline, thereby improving the working efficiency of the entire water source heat pump.

[0015] Preferably, a first circulation pump is installed on the water source side pipeline, and a second circulation pump is installed on the use side water pipe.

[0016] By adopting the above technical solution, the first circulation pump and the second circulation pump act on the transmission of water flow in the water source side pipeline and the use side water pipe.

[0017] Preferably, the circulation pipelines located in the evaporator and the condenser both adopt a spiral structure.

[0018] By adopting the above technical solution, the design of the spiral structure increases the time that the refrigerant stays in the water pipe on the use side, thereby improving the heat exchange efficiency.

[0019] Preferably, N groups of temperature monitoring points are provided on the user-side water pipe, and the temperature monitoring points correspond one-to-one to the condensers.

[0020] By adopting the above technical solution, the temperature monitoring point can reflect the temperature of the water flow in each corresponding user-side water pipe in real time, and grasp the heating situation in the user-side water pipe in real time.

[0021] In summary, the present application includes at least one of the following beneficial technical effects:

[0022] 1. The present application avoids subsequent damage to the compressor by completely liquefying the refrigerant that is not completely liquefied in the circulation pipeline and then returning it to the compressor;

[0023] 2. The present application connects condensers in multiple groups of structures in series through side water pipes, wherein there are multiple condensers in the water source heat pump. In this case, the liquid refrigerant that releases heat will pass through these condensers in sequence, and the condenser at each stage can heat the water in the side water pipe step by step to achieve step-by-step heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall connection structure of a series water source heat pump.

[0025] Explanation of the accompanying drawings: 1. Evaporator; 2. Compressor; 3. Condenser; 31. First condenser; 32. Second condenser; 4. Expansion valve; 5. Pipeline on the water source side; 51. First circulation pump; 6. Water pipe on the user side; 61. Second circulation pump; 7. Circulation pipeline; 71. First branch pipeline; 711. First valve; 712. Second valve; 72. Second branch pipeline; 8. Temperature monitoring point. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1 This application is described in further detail.

[0027] The embodiment of the present application discloses a series water source heat pump.

[0028] Reference Figure 1 A series water source heat pump comprises an evaporator 1, a compressor 2, a condenser 3 and an expansion valve 4 which are connected in sequence to form a closed pipeline. The compressor 2 and the expansion valve 4 are provided with multiple and equal numbers. The evaporator 1 and the condenser 3 are respectively divided into multiple sections and a single section corresponds to a single compressor 2 and an expansion valve 4. A single water source side pipeline 5 is connected to the single-section evaporator 1, and the entire condenser 3 is located in a single user side water pipe 6; the condenser 3 is sequentially distributed with a first condenser tube 31, a second condenser tube 32 and a third condenser tube from the water inlet end to the water outlet end of the user side water pipe 6, and the circulation pipeline 7 corresponding to the third condenser tube also penetrates the third condenser tube, the second condenser tube and the first condenser tube 31. On the basis of the traditional water source heat pump, the multi-stage heating function is realized by connecting the condensing tubes in multiple groups of structures in series through the use side water pipe 6, wherein the water source heat pump is provided with multiple condensing tubes. In this case, the liquid refrigerant releasing heat will pass through these condensing tubes in sequence, and the condensing tubes in each stage can heat the water in the use side water pipe 6 step by step to realize step-by-step heating. And the circulation pipe 7 near the water outlet end of the use side water pipe 6 is extended to the water inlet end near the use side water pipe 6 in sequence, so that the refrigerant in the circulation pipe 7 that is not completely liquefied can be completely liquefied and then returned to the compressor 2, avoiding subsequent damage to the compressor 2.

[0029] Reference Figure 1 , a first branch pipe 71 connected to the evaporator 1 is also installed at the outlet of the circulation pipe 7 corresponding to the third condenser, wherein the circulation pipe 7 and the first branch pipe 71 are both connected to the evaporator 1 through the same expansion valve 4. The two connections between the circulation pipe 7 and the first branch pipe 71 are respectively installed with a first valve 711 and a second valve 712. The first valve 711 is located at one end of the condenser 3, and the second valve 712 is located at one end of the evaporator 1, and the first valve 711 and the second valve 712 are both three-way valves, both of which include a gas monitor and a control valve. The first branch pipe 71 is connected to the circulation pipe near the condenser and the expansion valve 4. When the refrigerant in the circulation pipe derived from the condenser has been completely liquefied, the valve leading to the water inlet end of the water pipe 6 near the use side can be closed by adjusting the first valve 711 and the second valve 712, and the refrigerant can be directly transported to the expansion valve 4 through the first branch pipe wheel. If the refrigerant in the circulation pipeline led out from the condenser is not completely liquefied, the valves on both sides of the first branch wheel will be closed and the refrigerant will continue to enter the next group of condenser tubes for liquefaction and heat release.

[0030] Reference Figure 1 The circulation pipe 7 on the third condenser runs through the third condenser and a second branch pipe 72 is connected between the third condenser and the second condenser, wherein a first valve 711 and a second valve 712 are provided between the circulation pipe 7 and the second branch pipe 72. The working principle of the second branch pipe 72 is the same as that of the first branch pipe 71. The provision of multiple branch pipes can reduce the distance that the coolant flows in the circulation pipe 7, thereby improving the working efficiency of the entire water source heat pump.

[0031] Reference Figure 1 A first circulation pump 51 is installed on the water source side pipeline 5, and a second circulation pump 61 is installed on the user side water pipe 6. The first circulation pump 51 and the second circulation pump 61 act on the transmission of water flow in the water source side pipeline 5 and the user side water pipe 6.

[0032] Reference Figure 1 The circulation pipe 7 is located in the evaporator 1 and the condenser 3 and adopts a spiral structure. The design of the spiral structure increases the time the refrigerant stays in the use side water pipe 6 and improves the heat exchange efficiency.

[0033] Reference Figure 1 , three groups of temperature monitoring points 8 are arranged on the user side water pipe 6, and the temperature monitoring points 8 correspond to the condensers 3 one by one. The temperature monitoring points 8 can reflect the temperature of the water flow in each corresponding user side water pipe 6 in real time, and grasp the heating situation in the user side water pipe 6 in real time.

[0034] Working principle: The water source heat pump absorbs heat from the water source side pipe 5, and absorbs the heat of the water source in the evaporator 1, transforming from liquid to gas, realizing the evaporation process of the refrigerant to achieve heat exchange, and transferring the heat in the water to the refrigerant. The low-temperature and low-pressure gas in the evaporator 1 is introduced into the compressor 2, and the compressor 2 compresses the refrigerant gas into a high-temperature and high-pressure gas, increasing its temperature and pressure. The high-temperature and high-pressure refrigerant gas generated by the compressor 2 exchanges heat with the user side water pipe 6 through the condenser 3, cools and condenses into liquid, releases heat, and when the gas in the condenser near the end of the user side water pipe 6 cannot be completely or completely liquefied, it can enter the condenser toward the water inlet end of the user side water pipe 6 through the circulation pipe 7 in turn for heat exchange, and after being completely liquefied, it passes through the circulation pipe 7, the first branch pipe 71 or the second branch pipe 72 through the expansion valve 4, and the liquid refrigerant enters the evaporator 1 through the expansion valve 4, reduces the temperature and pressure, and is ready to reabsorb heat to complete a cycle.

[0035] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A series water source heat pump, comprising an evaporator (1), a compressor (2), a condenser (3) and an expansion valve (4) connected in sequence to form a closed pipeline, characterized in that: The compressor (2) and the expansion valve (4) are provided in multiple and equal numbers, the evaporator (1) and the condenser (3) are respectively divided into multiple sections and each section corresponds to a single compressor (2) and an expansion valve (4), the single section of the evaporator (1) is connected to a single water source side pipeline (5), and the entire section of the condenser (3) is located in a single user side water pipe (6); the condenser (3) is sequentially distributed with a first condenser tube (31), a second condenser tube (32) ... an Nth condenser tube from the water inlet end to the water outlet end of the user side water pipe (6), wherein N is not less than 3, and the circulation pipeline (7) corresponding to the Nth condenser tube is also penetrated by an N-1th condenser tube, an N-2th condenser tube ... the first condenser tube (31).

2. A series water source heat pump according to claim 1, characterized in that: A first branch pipe (71) connected to the evaporator (1) is also installed at the outlet of the circulation pipe (7) corresponding to the Nth condenser, wherein the circulation pipe (7) and the first branch pipe (71) are both connected to the evaporator (1) through the same expansion valve (4).

3. A series water source heat pump according to claim 2, characterized in that: A first valve (711) and a second valve (712) are respectively installed at two connection points between the circulation pipeline (7) and the first branch pipeline (71).

4. A series water source heat pump according to claim 3, characterized in that: The first valve (711) is located at one end of the condenser (3), and the second valve (712) is located at one end of the evaporator (1), and both the first valve (711) and the second valve (712) are three-way valves, and both include a gas monitor and a control valve.

5. A series water source heat pump according to claim 1, characterized in that: The circulation pipeline (7) on the Nth condenser passes through the N-1th condenser and a second branch pipeline (72) is connected between the N-1th condenser and the N-2th condenser, wherein a first valve (711) and a second valve (712) are provided between the circulation pipeline (7) and the second branch pipeline (72).

6. A series water source heat pump according to claim 1, characterized in that: A first circulation pump (51) is installed on the water source side pipeline (5), and a second circulation pump (61) is installed on the user side water pipe (6).

7. A series water source heat pump according to claim 1, characterized in that: The circulation pipeline (7) is located in the evaporator (1) and the condenser (3) and has a spiral structure.

8. A series water source heat pump according to claim 1, characterized in that: N groups of temperature monitoring points (8) are provided on the user-side water pipe (6), and the temperature monitoring points (8) correspond one-to-one to the condensers (3).

Images