Four-pipe cold and hot water heat pump unit

Abstract

The utility model relates to a four-pipe cold and hot water heat pump unit. An exhaust port of a compressor unit communicates with M D ports in parallel, M C ports communicate with M first ends in a one-to-one correspondence mode, M second ends communicate with M first branches in a one-to-one correspondence mode, the M second ends communicate with M second branches in a one-to-one correspondence mode, and each second end communicates with a first branch and a second branch in parallel; the M first branches and the M second branches are respectively communicated with the third branch, the third branch is connected with the port P and the port R, the port O is communicated with the M fourth branches in parallel, the M fourth branches are communicated with the M ports E in one-to-one correspondence, the port T is connected with the port B, the ports AB are connected with an air suction port of a compressor unit, and the port A is communicated with the M ports S in parallel; wherein M is larger than or equal to 2, a first throttling element is arranged on each second branch, and a second throttling element is arranged on each third branch. According to the four-pipe cold and hot water heat pump unit, the working modes can be conveniently switched, and water temperature fluctuation can be easily reduced.

Description

Technical Field

[0001] The present application relates to the technical field of refrigeration equipment, and in particular to a four-pipe refrigeration and hot water heat pump unit. Background Art

[0002] The four-pipe refrigeration and hot water heat pump unit can provide cold water and hot water at the same time, and is particularly suitable for occasions that require both cold and hot sources. It is increasingly used in hospitals, archives, high-end hotels, and constant temperature and humidity workshops.

[0003] When the water temperature on the hot water or cold water side meets the requirements, traditional medium and large four-pipe heat pump units need to switch between the three modes of cooling water, cooling water + hot water, and hot water by switching the four-way reversing valve. However, the switching of the above working modes requires the switching of the entire compressor unit system, which can easily cause large fluctuations in water temperature. Utility Model Content

[0004] A four-tube refrigeration and hot water heat pump unit, the four-tube refrigeration and hot water heat pump unit comprising a compressor unit, a hot water heat exchanger, a cold water heat exchanger, M first branches, M second branches, a third branch, M fourth branches, a three-way assembly, M four-way reversing valves and M balanced heat exchangers, the hot water heat exchanger has an O port and a P port, the cold water heat exchanger has an R port and a T port, the three-way assembly has an A port, a B port and an AB port, each balanced heat exchanger has a first end and a second end, each four-way reversing valve has a D port, an E port, an S port and a C port; the exhaust port of the compressor unit is connected in parallel with the M D ports, and the M C ports correspond one to one with the M first ends. The M second ends are connected with the M first branches in a one-to-one correspondence, the M second ends are connected with the M second branches in a one-to-one correspondence, each second end is connected with a first branch and a second branch in parallel, the M first branches and the M second branches are connected with the third branch respectively, the third branch connects the P port and the R port, the O port is connected with the M fourth branches in parallel, the M fourth branches are connected with the M E ports in a one-to-one correspondence, the T port is connected with the B port, the AB port is connected with the suction port of the compressor unit, and the A port is connected with the M S ports in parallel; wherein, M≥2, each second branch is provided with a first throttling element, and the third branch is provided with a second throttling element.

[0005] In one embodiment, the third branch includes a second pipe section, a first pipe section and a third pipe section which are connected in sequence from the P port to the R port, a second one-way valve which is unidirectionally connected from the P port to the first pipe section is provided on the second pipe section, and a second throttling element is provided on the third pipe section; M first branches are respectively connected to the connection between the second pipe section and the first pipe section, and each first branch is provided with a first one-way valve which is unidirectionally connected from the second end to the first pipe section; M second branches are respectively connected to the connection between the first pipe section and the third pipe section; each fourth branch is provided with a third one-way valve which is unidirectionally connected from the E port to the O port.

[0006] In one of the embodiments, the four-pipe refrigeration and hot water heat pump unit also includes a liquid reservoir and an auxiliary branch, the liquid reservoir is located on the second pipe section and is connected in series between the P port and the second one-way valve, one end of the auxiliary branch is connected to the liquid reservoir, and the other end is connected between the second throttling element and the R port, and a switch valve is provided on the auxiliary branch; when the four-pipe refrigeration and hot water heat pump unit is in a single cooling mode, the D port is connected to the C port, and the E port is connected to the S port; the first throttling element is closed; the second throttling element is opened, and the opening size is adjusted according to the superheat near the R port; the switch valve is opened; the B port is connected to the AB port, and the A port is isolated from the AB port.

[0007] In one of the embodiments, when the four-pipe refrigeration and hot water heat pump unit is in the single heating mode, port D is connected to port E, and port C is connected to port S; the first throttling element is opened, and the opening size is adjusted according to the superheat near the corresponding second end position; the second throttling element is closed; port A is connected to port AB, and port B is isolated from port AB.

[0008] In one of the embodiments, when the four-pipe refrigeration and hot water heat pump unit is in full heat recovery mode, port D is connected to port E, port C is connected to port S; the first throttling element is closed; the second throttling element is opened, and the opening size is adjusted according to the superheat near port R; port B is connected to port AB, and port A is isolated from port AB.

[0009] In one of the embodiments, when the four-pipe refrigeration and hot water heat pump unit is in a partial heat recovery mode, the D ports of the N four-way reversing valves are connected to the C port, the E port is connected to the S port, and the first throttling elements on the corresponding N second branches are closed; the D ports of the remaining MN four-way reversing valves are connected to the E port, the C port is connected to the S port, and the first throttling elements on the corresponding MN second branches are closed; the second throttling element is opened, and the opening size is adjusted according to the superheat near the R port; the B port is connected to the AB port, and the A port is isolated from the AB port; wherein, 1≤N<M.

[0010] In one of the embodiments, when the four-pipe refrigeration and hot water heat pump unit is in partial cold recovery mode, port D is connected to port E, port C is connected to port S, the first throttling elements on the N second branches are opened, and the opening size is adjusted according to the superheat near the corresponding second end position; the first throttling elements on the remaining MN second branches are closed; the second throttling elements are opened; port B is connected to port AB, and port A is connected to port AB; wherein, 1≤N<M.

[0011] In one embodiment, the balancing heat exchanger is configured as an air-refrigerant heat exchanger, and when the four-pipe refrigeration and hot water heat pump unit is defrosted in the single heating mode, the D port of N four-way reversing valves is connected to the C port, the E port is connected to the S port, and the first throttling elements on the corresponding N second branches are closed; the D port of the remaining MN four-way reversing valves is connected to the E port, the C port is connected to the S port, and the first throttling elements on the corresponding MN second branches are opened, and the opening size is adjusted according to the superheat near the corresponding second end position; the second throttling element is closed; the B port is isolated from the AB port, and the A port is connected to the AB port; wherein, 1≤N<M.

[0012] In one embodiment, the balancing heat exchanger is configured as an air-refrigerant heat exchanger, and when the four-pipe refrigeration and hot water heat pump unit is defrosted in a partial cold recovery mode, the D ports of the N four-way reversing valves are connected to the C port, the E port is connected to the S port, and the first throttling elements on the corresponding N second branches are closed; the D ports of the remaining MN four-way reversing valves are connected to the E port, the C port is connected to the S port, and the first throttling elements on the corresponding MN second branches are opened, and the opening size is adjusted according to the superheat near the corresponding second end position; the second throttling element is opened, and the opening size is adjusted according to the superheat near the R port; the B port is connected to the AB port, and the A port is connected to the AB port; wherein, 1≤N<M.

[0013] In one embodiment, the flow area between port A and port AB is defined as S1, the flow area between port B and port AB is defined as S2, S1+S2=K, and both S1 and S2 are adjustable in size; wherein K is the inlet flow area of ​​the three-way assembly and is a fixed value.

[0014] Compared with the prior art, the four-tube refrigeration and hot water heat pump unit provided in the present application uses a compressor unit and a four-way reversing valve to form multiple parallel and independent refrigerant circuits. For example, the compressor unit, a balanced heat exchanger, a first branch, a third branch, a second throttling element, and a cold water heat exchanger can be connected to form a refrigerant circuit, at which time the balanced heat exchanger is used as a condenser and the cold water heat exchanger provides cold water; the compressor unit, the fourth branch, the hot water heat exchanger, a second branch and the first throttling element thereon, and a balanced heat exchanger can be connected to form a refrigerant circuit, at which time the balanced heat exchanger is used as an evaporator and the hot water heat exchanger provides hot water; the compressor unit, the fourth branch, the hot water heat exchanger, the third branch, the second throttling element and the cold water heat exchanger can be connected to form a refrigerant circuit, at which time the hot water heat exchanger provides hot water and the cold water heat exchanger provides cold water. In this way, multiple parallel and independent refrigerant circuits are formed by the cooperation of the compressor unit and the four-way reversing valve, so that when the four-pipe refrigeration and hot water heat pump unit switches the working mode, part of the refrigerant circuit can be switched without switching the entire compressor system, which is beneficial to reduce water temperature fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A schematic diagram of the connection of various components of the four-pipe refrigeration and hot water heat pump unit provided in this application;

[0017] Figure 2 A schematic diagram of the four-pipe refrigeration and hot water heat pump unit provided in this application in a single cooling mode;

[0018] Figure 3 A schematic diagram of a four-pipe refrigeration and hot water heat pump unit provided in this application in a heating-only mode;

[0019] Figure 4 A schematic diagram of a four-pipe refrigeration and hot water heat pump unit provided for this application in full heat recovery mode;

[0020] Figure 5 A schematic diagram of a four-pipe refrigeration and hot water heat pump unit provided for this application in a partial heat recovery mode;

[0021] Figure 6 A schematic diagram of a four-pipe refrigeration and hot water heat pump unit provided for this application in a partial cold recovery mode;

[0022] Figure 7 A schematic diagram of a four-pipe refrigeration and hot water heat pump unit provided in the present application during defrosting in heating-only mode;

[0023] Figure 8 This is a schematic diagram of the four-pipe refrigeration and hot water heat pump unit provided in this application when defrosting in partial cold recovery mode.

[0024] Figure numerals: 10, compressor unit; 11, exhaust port; 12, air intake port; 20, hot water heat exchanger; 30, cold water heat exchanger; 41, first branch; 412, first one-way valve; 42, second branch; 413, first throttling element; 43, third branch; 401, first pipe section; 411, drying filter; 404, second pipe section; 414, second one-way valve; 405, third pipe section; 415, second throttling element; 44, fourth branch; 441, third one-way valve; 45, auxiliary branch; 451, switch valve; 50, three-way assembly; 60, four-way reversing valve; 70, balanced heat exchanger; 71, first end; 72, second end; 80, liquid reservoir. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0026] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0028] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0029] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0030] Please refer to Figure 1The present application provides a four-tube refrigeration and hot water heat pump unit, which includes a compressor unit 10, a hot water heat exchanger 20, a cold water heat exchanger 30, M first branches 41, M second branches 42, a third branch 43, M fourth branches 44, a three-way assembly 50, M four-way reversing valves 60 and M balancing heat exchangers 70, the hot water heat exchanger 20 has an O port and a P port, the cold water heat exchanger 30 has an R port and a T port, the three-way assembly 50 has an A port, a B port and an AB port, each balancing heat exchanger 70 has a first end 71 and a second end 72, and each four-way reversing valve 60 has a D port, an E port, a S port and a C port. The exhaust port 11 of the compressor unit 10 is connected in parallel with M D ports, M C ports are connected in one-to-one correspondence with M first ends 71, M second ends 72 are connected in one-to-one correspondence with M first branches 41, M second ends 72 are connected in one-to-one correspondence with M second branches 42, each second end 72 is connected in parallel with a first branch 41 and a second branch 42, the M first branches 41 and the M second branches 42 are respectively connected with the third branch 43, the third branch 43 connects the P port and the R port, the O port is connected in parallel with M fourth branches 44, the M fourth branches 44 are connected in one-to-one correspondence with the M E ports, the T port is connected to the B port, the AB port is connected to the suction port 12 of the compressor unit 10, and the A port is connected in parallel with the M S ports; wherein, M≥2, a first throttling element 413 is provided on each second branch 42, and a second throttling element 415 is provided on the third branch.

[0031] It can be understood that the four-tube refrigeration and hot water heat pump unit provided in the present application uses the compressor unit 10 and the four-way reversing valve 60 to form multiple parallel and independent refrigerant circuits. For example, the compressor unit 10, a balanced heat exchanger 70, a first branch 41, a third branch 43, a second throttling element 415, and a cold water heat exchanger 30 can be connected to form a refrigerant circuit. At this time, the balanced heat exchanger 70 is used as a condenser, and the cold water heat exchanger 30 provides cold water; the compressor unit 10, the fourth branch 44, the hot water The heat exchanger 20, a second branch 42 and the first throttling element 413 thereon, and a balanced heat exchanger 70 can be connected to form a refrigerant circuit. At this time, the balanced heat exchanger 70 is used as an evaporator, and the hot water heat exchanger 20 provides hot water; the compressor unit 10, the fourth branch 44, the hot water heat exchanger 20, the third branch 43, the second throttling element 415 and the cold water heat exchanger 30 can be connected to form a refrigerant circuit. At this time, the hot water heat exchanger 20 provides hot water, and the cold water heat exchanger 30 provides cold water. In this way, the compressor unit 10 and the four-way reversing valve 60 cooperate to form multiple parallel and independent refrigerant circuits, so that when the four-tube refrigeration and hot water heat pump unit switches the working mode, it can switch part of the refrigerant circuit without switching the entire compressor system, which is conducive to reducing water temperature fluctuations.

[0032] Optionally, 2≤M≤10, for example, the value of M can be 2, 3, 4, 5, 6, 7, 8, 9 or 10, etc.

[0033] Optionally, the compressor unit 10 is configured as a variable speed compressor unit or a variable displacement compressor unit. The balanced heat exchanger 70 is configured as an air-refrigerant heat exchanger assembly, or the balanced heat exchanger 70 is configured as a water-refrigerant heat exchanger assembly. A gas-liquid separator (not shown) may also be provided between the port B of the three-way assembly 50 and the air intake port 12 of the compressor unit 10.

[0034] For further information, please refer to Figure 1 The third branch 43 includes a second pipe section 404, a first pipe section 401 and a third pipe section 405 which are connected in sequence from the P port to the R port, a second one-way valve 414 which is unidirectionally connected from the P port to the first pipe section 401 is provided on the second pipe section 404, and a second throttling element 415 is provided on the third pipe section 405; the M first branches 41 are respectively connected to the connection between the second pipe section 404 and the first pipe section 401, and each first branch 41 is provided with a first one-way valve 412 which is unidirectionally connected from the second end 72 to the first pipe section 401; the M second branches 42 are respectively connected to the connection between the first pipe section 401 and the third pipe section 405; each fourth branch 44 is provided with a third one-way valve 441 which is unidirectionally connected from the E port to the O port.

[0035] The first pipe section 401 is provided with a filter dryer 411. Optionally, an economizer subcooling device (not shown) is provided at the outlet of the filter dryer 411. The first throttling element 413 and the second throttling element 415 are used to throttle the refrigerant and can be switched on and off. Optionally, the first throttling element 413 and the second throttling element 415 can be configured as an electronic expansion valve; or a combination of a solenoid valve and an electronic expansion valve; or a combination of a solenoid valve and a thermal expansion valve.

[0036] The four-pipe cooling and hot water heat pump unit further includes a liquid reservoir 80 and an auxiliary branch 45. The liquid reservoir 80 is located on the second pipe section 404 and is connected in series between the P port and the second one-way valve 414. One end of the auxiliary branch 45 is connected to the liquid reservoir 80, and the other end is connected between the second throttling element 415 and the R port. A switch valve 451 is provided on the auxiliary branch 45. The switch valve 451 may be a solenoid valve.

[0037] The following introduces the different working modes of the four-pipe cooling and hot water heat pump unit.

[0038] Mode 1: Cooling mode only

[0039] See also Figure 2, port D is connected to port C, port E is connected to port S; the first throttling element 413 is closed; the second throttling element 415 is opened, and the opening size is adjusted according to the superheat near port R; the switch valve 451 is opened; port B is connected to port AB, and port A is isolated from port AB.

[0040] It can be understood that the refrigerant in the four-tube cooling and hot water heat pump unit is divided into two paths. One of the refrigerant circulation loops is: the exhaust port 11 of the compressor unit 10 - the D port of each four-way reversing valve 60 - the C port - the first end 71 of the balancing heat exchanger 70 - the first check valve 412 - the drying filter 411 - the second throttling element 415 - the cold water heat exchanger 30 - the B port of the three-way component 50 - the AB port of the three-way component 50 - the air intake port 12 of the compressor unit 10. The other refrigerant flows from the liquid storage tank 80 to the cold water heat exchanger 30 through the switch valve 451. That is to say, when operating in the single cooling mode, all the balancing heat exchangers 70 are used as condensers, and the cold water heat exchanger 30 is used as an evaporator and provides cold water.

[0041] Optionally, a pressure sensor may be provided near the R port of the third pipe section 405 to detect the pressure value, obtain the superheat according to the pressure value, and then adjust the opening of the second throttling element 415 according to the superheat; or a temperature sensor may be provided near the R port of the third pipe section 405 to detect the temperature value, obtain the superheat according to the temperature value, and then adjust the opening of the second throttling element 415 according to the superheat. In addition, since the refrigerant in the refrigerant circulation loop will not flow through the liquid reservoir 80 on the second pipe section 404, by adding an auxiliary branch 45 and a switch valve 451, the refrigerant stored in the liquid reservoir 80 can be introduced into the cold water heat exchanger 30 by opening the switch valve 451, and then participate in the refrigerant circulation loop as a refrigerant supplement, so as to prevent the lack of refrigerant when the single cooling mode is running, and facilitate the establishment of high and low pressure differences in the four-pipe cooling and hot water heat pump unit.

[0042] Mode 2: Heating only mode

[0043] See also Figure 3 , port D is connected to port E, port C is connected to port S; the first throttling element 413 is opened, and the opening size is adjusted according to the superheat at the position close to the corresponding second end 72; the second throttling element 415 is closed; the switch valve 451 is closed; port A is connected to port AB, and port B is isolated from port AB.

[0044] It can be understood that the circulation loop of the refrigerant in the four-pipe refrigeration and hot water heat pump unit is: the exhaust port 11 of the compressor unit 10—the D port of each four-way reversing valve 60—the E port—the third one-way valve 441—the hot water heat exchanger 20—the liquid storage tank 80—the second one-way valve 414—the drying filter 411—the first throttling element 413—the balanced heat exchanger 70—the C port—the S port of each four-way reversing valve 60—the A port of the three-way assembly 50—the AB port—the air intake port 12 of the compressor unit 10. That is, when operating in the heating mode only, the hot water heat exchanger 20 is used as a condenser, and all the balanced heat exchangers 70 are used as evaporators.

[0045] Similarly, a pressure sensor may be provided near the corresponding second end 72 of each second branch 42 to detect a pressure value, obtain superheat according to the pressure value, and then adjust the opening of the first throttling element 413 according to the superheat; or a temperature sensor may be provided near the corresponding second end 72 of each second branch 42 to detect a temperature value, obtain superheat according to the temperature value, and then adjust the opening of the first throttling element 413 according to the superheat. In addition, the B port is separated from the AB port, which can prevent the unevaporated refrigerant in the cold water heat exchanger 30 from continuing to evaporate and causing the cold water temperature to be too low, and can prevent the refrigerant in the balance heat exchanger 70 from entering the AB port through the A port and then migrating into the cold water heat exchanger 30 along the B port, resulting in a large amount of liquid refrigerant remaining in the cold water heat exchanger 30 entering the compressor unit 10 and causing liquid hammer when the four-tube refrigeration and hot water heat pump unit is started in the single cooling mode next time.

[0046] Mode 3: Full heat recovery mode

[0047] See also Figure 4 , port D is connected to port E, port C is connected to port S; the first throttling element 413 is closed; the second throttling element 415 is opened, and the opening size is adjusted according to the superheat near port R; the switch valve 451 is closed; port B is connected to port AB, and port A is isolated from port AB.

[0048] It can be understood that the circulation loop of the refrigerant in the four-pipe refrigeration and hot water heat pump unit is: the exhaust port of the compressor unit 10 - the D port of each four-way reversing valve 60 - the E port - the third one-way valve 441 - the cold water heat exchanger - the liquid storage tank 80 - the second one-way valve 414 - the drying filter 411 - the second throttling element 415 - the cold water heat exchanger 30 - the B port of the three-way component 50 - the AB port - the air intake port 12 of the compressor unit 10. That is to say, when operating in the full heat recovery mode, the hot water heat exchanger 20 is used as a condenser, the cold water heat exchanger 30 is used as an evaporator, and the balancing heat exchanger 70 does not work.

[0049] The opening adjustment method of the second throttling element 415 is referred to in Mode 1 and will not be described in detail here. In addition, the A port is isolated from the AB port, which can prevent the refrigerant in the cold water heat exchanger 30 from entering the AB port through the B port and then migrating along the A port-S port-C port into the balancing heat exchanger 70, thereby reducing the refrigerant in the refrigerant circulation loop, thereby reducing the unit output and energy efficiency.

[0050] Mode 4: Partial heat recovery mode

[0051] See also Figure 5 , the D ports of N four-way reversing valves 60 are connected to the C port, the E port is connected to the S port, and the corresponding first throttling elements 413 on the N second branches 42 are closed; the D ports of the remaining MN four-way reversing valves 60 are connected to the E port, the C port is connected to the S port, and the corresponding first throttling elements 413 on the MN second branches 42 are closed; the second throttling element 415 is opened, and the opening size is adjusted according to the superheat near the R port; the switch valve 451 is closed; the B port is connected to the AB port, and the A port is isolated from the AB port; wherein, 1≤N<M.

[0052] It can be understood that the flow direction of the refrigerant in the four-tube refrigeration and hot water heat pump unit is as follows: the refrigerant coming out of the exhaust port 11 of the compressor unit 10 is divided into two paths, one of which enters the D port-C port of N four-way reversing valves 60-the corresponding N balancing heat exchangers 70-the corresponding N first one-way valves 412; the other refrigerant enters the D port-E port of the remaining MN four-way reversing valves 60-the corresponding MN third one-way valves 441-the hot water heat exchanger 20-the liquid storage tank 80-the second one-way valve 414; the above two refrigerant paths are combined and enter the drying filter 411-the second throttling element 415-the cold water heat exchanger 30-the B port of the three-way component 50-the AB port-the suction port 12 of the compressor unit 10.

[0053] That is, when operating in the partial heat recovery mode, MN balancing heat exchangers 70 are used as condensers, the hot water heat exchanger 20 is used as a condenser, and the cold water heat exchanger 30 is used as an evaporator. In this way, part of the condensation heat is recovered to the hot water heat exchanger 20, and the remaining condensation heat is dissipated through the MN balancing heat exchangers 70.

[0054] For example, in one embodiment, Figure 5 As shown, M=4, N=2, and the number of the balancing heat exchangers 70 is 4, of which 2 balancing heat exchangers 70 are used as condensers. Of course, when M=4, N can also be 1 or 3.

[0055] Mode 5: Partial cold recovery mode

[0056] See also Figure 6, port D is connected to port E, port C is connected to port S, the first throttling elements 413 on the N second branches 42 are opened, and the opening size is adjusted according to the superheat near the corresponding second end 72; the first throttling elements 413 on the remaining MN second branches 42 are closed; the second throttling elements 415 are opened, and the opening size is adjusted according to the superheat near port R; the switch valve 451 is closed; port B is connected to port AB, and port A is connected to port AB; wherein, 1≤N<M.

[0057] It can be understood that the circulation loop of the refrigerant in the four-tube refrigeration and hot water heat pump unit is: the exhaust port 11 of the compressor unit 10 - the D-E ports of each four-way reversing valve 60 - the third one-way valve 441 - the hot water heat exchanger 20 - the liquid storage tank 80 - the second one-way valve 414 - the dry filter 411. Then, the refrigerant flowing out of the dry filter 411 is divided into two paths, one of which enters the N first throttling elements 413 - the corresponding N balancing heat exchangers 70 - the corresponding N four-way reversing valves 60 C ports - S ports - the A ports - AB ports of the three-way assembly 50; the other refrigerant passes through the second throttling element 415 - the cold water heat exchanger 30 - the B ports - AB ports of the three-way assembly 50; the above two refrigerants flow to the suction port 12 of the compressor unit 10 after merging at the three-way assembly 50. That is, when operating in the partial cold recovery mode, the hot water heat exchanger 20 is used as a condenser, the N balancing heat exchangers 70 are used as evaporators, and the cold water heat exchanger 30 is used as an evaporator.

[0058] When the balancing heat exchanger 70 is configured as an air heat exchanger and is used as an evaporator in a four-pipe refrigeration and hot water heat pump unit, it is necessary to defrost the balancing heat exchanger 70. There are two forms as follows.

[0059] Defrost in heating only mode

[0060] See also Figure 7 , the D ports of the N four-way reversing valves 60 are connected to the C port, the E port is connected to the S port, and the corresponding first throttling elements 413 on the N second branches 42 are closed; the D ports of the remaining MN four-way reversing valves 60 are connected to the E port, the C port is connected to the S port, and the corresponding first throttling elements 413 on the MN second branches 42 are opened, and the opening size is adjusted according to the superheat at the corresponding position near the second end 72; the second throttling element 415 is closed; the switch valve 451 is closed; the B port is isolated from the AB port, and the A port is connected to the AB port; wherein, 1≤N<M.

[0061] It can be understood that the circulation loop of the refrigerant in the four-tube refrigeration and hot water heat pump unit is: the refrigerant flowing out of the exhaust port 11 of the compressor unit 10 is divided into two paths, one of which enters the D port-C port of N four-way reversing valves 60-the corresponding N balancing heat exchangers 70-the corresponding N first check valves 412; the other refrigerant enters the D-E port of the remaining MN four-way reversing valves 60-the corresponding MN third check valves 441-the hot water heat exchanger 20-the liquid storage tank 80-the second check valve 414. After the two refrigerant paths are merged, they flow through the drying filter 411-the corresponding MN first throttling elements 413-the corresponding MN balancing heat exchangers 70-the corresponding MN four-way reversing valves 60 C port-S port-the A port of the three-way component 50-the AB port-the suction port 12 of the compressor unit 10. That is, the hot water heat exchanger 20 is used as a condenser, the N balancing heat exchangers 70 are used as condensers for defrosting, and the cold water heat exchanger 30 is used as an evaporator.

[0062] For example, in one embodiment, M=4, N=1. That is, only one balancing heat exchanger 70 is used as a condenser, and further, by switching the connection state of the four four-way reversing valves 60, the four balancing heat exchangers 70 can be used as condensers in turn, thereby gradually defrosting the four balancing heat exchangers 70.

[0063] In one embodiment, M=4 and N=2 may be used. That is, two balanced heat exchangers 70 are used as condensers, so that the two balanced heat exchangers 70 perform defrosting work at the same time. Alternatively, M=4 and N=3 may be used. That is, three balanced heat exchangers 70 are used as condensers, so that the three balanced heat exchangers 70 perform defrosting work at the same time.

[0064] Defrost in partial cooling recovery mode

[0065] See also Figure 8 , the D ports of the N four-way reversing valves 60 are connected to the C port, the E port is connected to the S port, and the first throttling elements 413 on the corresponding N second branches 42 are closed; the D ports of the remaining MN four-way reversing valves 60 are connected to the E port, the C port is connected to the S port, and the first throttling elements 413 on the corresponding MN second branches 42 are opened, and the opening size is adjusted according to the superheat near the corresponding second end 72; the second throttling element 415 is opened, and the opening size is adjusted according to the superheat near the R port; the switch valve 451 is closed; the B port is connected to the AB port, and the A port is connected to the AB port; wherein, 1≤N<M.

[0066] It can be understood that the circulation loop of the refrigerant in the four-tube refrigeration and hot water heat pump unit is: the refrigerant flowing out of the exhaust port 11 of the compressor unit 10 is divided into two paths, one of which enters the D port and the C port of N four-way reversing valves 60, the corresponding N balancing heat exchangers 70, and the corresponding N first one-way valves 412; the other refrigerant enters the D-E port of the remaining MN four-way reversing valves 60, the corresponding MN third one-way valves 441, the hot water heat exchanger 20, the liquid storage tank 80, and the second one-way valve 414; the above two refrigerant paths merge and flow into the drying filter 411, and the refrigerant is divided into two paths after flowing out of the drying filter 411, one of which enters the corresponding MN first throttling elements 413, the corresponding MN balancing heat exchangers 70, the corresponding MN four-way reversing valves 60, the C port, the S port, and the A port of the three-way component 50; the other refrigerant flows through the second throttling element 415, the cold water heat exchanger 30, and the A port of the three-way component 50. After the two refrigerant paths are merged at the three-way assembly 50, they flow into the air intake port 12 of the compressor unit 10 through the AB port. That is, the hot water heat exchanger 20 is used as a condenser, the N balancing heat exchangers 70 are used as condensers for defrosting, the remaining MN balancing heat exchangers 70 are used as evaporators, and the cold water heat exchanger 30 is used as an evaporator.

[0067] For example, Figure 8 As shown, M = 4, N = 1. That is, only one balancing heat exchanger 70 is used as a condenser. Further, by switching the connection state of the four four-way reversing valves 60, the four balancing heat exchangers 70 can be used as condensers in turn, thereby gradually defrosting the four balancing heat exchangers 70.

[0068] In one embodiment, M=4 and N=2 may be used. That is, two balanced heat exchangers 70 are used as condensers, so that the two balanced heat exchangers 70 perform defrosting work at the same time. Alternatively, M=4 and N=3 may be used. That is, three balanced heat exchangers 70 are used as condensers, so that the three balanced heat exchangers 70 perform defrosting work at the same time.

[0069] Further, the flow area between port A and port AB is defined as S1, the flow area between port B and port AB is defined as S2, S1+S2=K, and both S1 and S2 are configured to be adjustable in size; wherein, K is the inlet flow area of ​​the three-way assembly 50 and is a constant value. In other words, the sum of S1 and S2 is a constant value, when S1 increases, S2 decreases accordingly; when S2 increases, S1 decreases accordingly. Therefore, when the four-tube refrigeration and hot water heat pump unit is operated in a partial cold recovery mode or defrosted in a partial cold recovery mode, that is, when the balancing heat exchanger 70 and the cold water heat exchanger 30 are used together as an evaporator, on the one hand, the ratio of the refrigerant flow rate entering the compressor unit 10 from the balancing heat exchanger 70 to the refrigerant flow rate entering the compressor unit 10 from the cold water heat exchanger can be adjusted according to the cold load demand of the four-tube refrigeration and hot water heat pump unit. For example, when the actual measured temperature of cold water in the cold water heat exchanger 30 is greater than the target temperature value, the flow area S2 between the B port and the AB port can be increased, while the flow area S1 between the A port and the AB port can be reduced, so that more refrigerant can enter the compressor unit 10 from the cold water heat exchanger. That is, more refrigerant can exchange heat with cold water in the cold water heat exchanger, thereby reducing the actual measured water temperature of the cold water. On the other hand, when the balancing heat exchanger 70 is configured as an air heat exchanger, when the air ambient temperature is relatively low in winter, the evaporation temperature of the balancing heat exchanger 70 is relatively low, and the refrigerant in the balancing heat exchanger 70 migrates into the cold water heat exchanger 30 through the A port, the AB port and the B port, thereby causing the evaporation temperature of the cold water heat exchanger 30 to also decrease. However, if the evaporation temperature of the cold water heat exchanger 30 is too low, the cold water heat exchanger 30 may be frozen. At this time, the flow area S2 between port B and port AB can be reduced, while the flow area S1 between port A and port AB can be increased, that is, secondary throttling of port B can be performed to reduce the influence of the balancing heat exchanger 70 on the cold water heat exchanger 30, thereby preventing the evaporation temperature of the cold water heat exchanger 30 from being too low, and further preventing the cold water heat exchanger 30 from freezing.

[0070] Optionally, the three-way assembly 50 may be configured as an electric three-way proportional control valve to continuously adjust S1 and S2; or, the three-way assembly 50 may also be configured to include two continuously adjustable proportional two-way valves.

[0071] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. A four-tube refrigeration and hot water heat pump unit, characterized in that: The four-tube refrigeration and hot water heat pump unit comprises a compressor unit (10), a hot water heat exchanger (20), a cold water heat exchanger (30), M first branches (41), M second branches (42), a third branch (43), M fourth branches (44), a three-way assembly (50), M four-way reversing valves (60) and M balancing heat exchangers (70), wherein the hot water heat exchanger (20) has an O port and a P port, the cold water heat exchanger (30) has an R port and a T port, the three-way assembly (50) has an A port, a B port and an AB port, each of the balancing heat exchangers (70) has a first end (71) and a second end (72), and each of the four-way reversing valves (60) has a D port, an E port, an S port and a C port; The exhaust port (11) of the compressor unit (10) is connected in parallel with the M D ports, the M C ports are connected in one-to-one correspondence with the M first ends (71), the M second ends (72) are connected in one-to-one correspondence with the M first branches (41), the M second ends (72) are connected in one-to-one correspondence with the M second branches (42), each second end (72) is connected in parallel with one first branch (41) and one second branch (42), the M first branches (41) and the M second branches (42) are connected in parallel with the third branch (41), the M second branches (42) are connected in one-to-one correspondence with the third branch (41), the M second branches (42) are connected in parallel with the third branch (41), the M first branches (41) and the M second branches (42) are connected in one-to-one correspondence with the third branch (41), ... The third branch (43) is connected to the P port and the R port, the O port is connected in parallel with the M fourth branches (44), the M fourth branches (44) are connected in one-to-one correspondence with the M E ports, the T port is connected to the B port, the AB port is connected to the suction port (12) of the compressor unit (10), and the A port is connected in parallel with the M S ports; wherein M≥2, each of the second branches (42) is provided with a first throttling element (413), and the third branch is provided with a second throttling element (415).

2. The four-pipe refrigeration and hot water heat pump unit according to claim 1, characterized in that: The third branch (43) comprises a second pipe section (404), a first pipe section (401) and a third pipe section (405) which are connected in sequence from the P port to the R port, the second pipe section (404) is provided with a second one-way valve (414) which conducts one-way from the P port to the first pipe section (401), and the second throttling element (415) is provided on the third pipe section (405); The M first branches (41) are respectively connected to the connection between the second pipe section (404) and the first pipe section (401), and each of the first branches (41) is provided with a first one-way valve (412) that conducts one-way from the second end (72) to the first pipe section (401); The M second branches (42) are respectively connected to the connection between the first pipe section (401) and the third pipe section (405); Each of the fourth branches (44) is provided with a third one-way valve (441) which conducts one-way flow from the E port to the O port.

3. The four-pipe refrigeration and hot water heat pump unit according to claim 2, characterized in that: The four-pipe refrigeration and hot water heat pump unit further comprises a liquid reservoir (80) and an auxiliary branch (45); the liquid reservoir (80) is located on the second pipe section (404) and is connected in series between the P port and the second one-way valve (414); one end of the auxiliary branch (45) is connected to the liquid reservoir (80), and the other end is connected between the second throttling element (415) and the R port; and a switch valve (451) is provided on the auxiliary branch (45); When the four-pipe refrigeration and hot water heat pump unit is in single cooling mode, the D port is connected to the C port, and the E port is connected to the S port; the first throttling element (413) is closed; the second throttling element (415) is opened, and the opening size is adjusted according to the superheat near the R port; the switch valve (451) is opened; the B port is connected to the AB port, and the A port is isolated from the AB port.

4. The four-pipe refrigeration and hot water heat pump unit according to claim 2, characterized in that: When the four-pipe refrigeration and hot water heat pump unit is in a single heating mode, the D port is connected to the E port, and the C port is connected to the S port; the first throttling element (413) is opened, and the opening size is adjusted according to the superheat at a position close to the corresponding second end (72); the second throttling element (415) is closed; the A port is connected to the AB port, and the B port is isolated from the AB port.

5. The four-pipe refrigeration and hot water heat pump unit according to claim 2, characterized in that: When the four-pipe refrigeration and hot water heat pump unit is in full heat recovery mode, the D port is connected to the E port, and the C port is connected to the S port; the first throttling element (413) is closed; the second throttling element (415) is opened, and the opening size is adjusted according to the superheat near the R port; the B port is connected to the AB port, and the A port is isolated from the AB port.

6. The four-pipe refrigeration and hot water heat pump unit according to claim 2, characterized in that: When the four-pipe refrigeration and hot water heat pump unit is in a partial heat recovery mode, the D ports of the N four-way reversing valves (60) are connected to the C port, the E port is connected to the S port, and the corresponding N first throttling elements (413) on the second branches (42) are closed; the D ports of the remaining MN four-way reversing valves (60) are connected to the E port, the C port is connected to the S port, and the corresponding MN first throttling elements (413) on the second branches (42) are closed; the second throttling element (415) is opened, and the opening size is adjusted according to the superheat near the R port; the B port is connected to the AB port, and the A port is isolated from the AB port; wherein 1≤N<M.

7. The four-pipe refrigeration and hot water heat pump unit according to claim 2, characterized in that: When the four-pipe refrigeration and hot water heat pump unit is in a partial cold recovery mode, the D port is connected to the E port, the C port is connected to the S port, the first throttling elements (413) on the N second branches (42) are opened, and the opening size is adjusted according to the superheat at the position close to the corresponding second end (72); the first throttling elements (413) on the remaining MN second branches (42) are closed; the second throttling elements (415) are opened; the B port is connected to the AB port, and the A port is connected to the AB port; wherein 1≤N<M.

8. The four-pipe refrigeration and hot water heat pump unit according to claim 2, characterized in that: The balancing heat exchanger (70) is configured as an air-refrigerant heat exchanger, and when the four-tube refrigeration and hot water heat pump unit is defrosted in the single heating mode, the D ports of the N four-way reversing valves (60) are connected to the C port, the E port is connected to the S port, and the corresponding N first throttling elements (413) on the second branches (42) are closed; the D ports of the remaining MN four-way reversing valves (60) are connected to the E port, the C port is connected to the S port, and the corresponding MN first throttling elements (413) on the second branches (42) are opened, and the opening size is adjusted according to the superheat at the position close to the corresponding second end (72); the second throttling element (415) is closed; the B port is isolated from the AB port, and the A port is connected to the AB port; wherein 1≤N<M.

9. The four-pipe refrigeration and hot water heat pump unit according to claim 2, characterized in that: The balancing heat exchanger (70) is configured as an air-refrigerant heat exchanger, and when the four-tube refrigeration and hot water heat pump unit is defrosted in a partial cold recovery mode, the D ports of the N four-way reversing valves (60) are connected to the C port, the E port is connected to the S port, and the corresponding N first throttling elements (413) on the second branches (42) are closed; the D ports of the remaining MN four-way reversing valves (60) are connected to the E port, the C port is connected to the S port, and the corresponding MN first throttling elements (413) on the second branches (42) are opened, and the opening size is adjusted according to the superheat at the position close to the corresponding second end (72); the second throttling element (415) is opened, and the opening size is adjusted according to the superheat at the position close to the R port; the B port is connected to the AB port, and the A port is connected to the AB port; wherein 1≤N<M.

10. The four-pipe refrigeration and hot water heat pump unit according to claim 1, characterized in that: The flow area between the A port and the AB port is defined as S1, the flow area between the B port and the AB port is defined as S2, S1+S2=K, and the sizes of S1 and S2 are adjustable; Wherein, K is the inlet flow area of ​​the three-way component (50) and is a constant value.

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