A throttling device

Abstract

The present invention discloses a throttling device, which consists of a first bypass pipe, a second bypass pipe, a throttling mechanism, a first one-way valve, a second one-way valve, a third one-way valve, a fourth one-way valve, a third bypass pipe, a fifth one-way valve, and a normally open solenoid valve; the outlet end of the first one-way valve is connected to the first bypass pipe, and the inlet end of the first one-way valve is connected to the second bypass pipe in sequence through the fifty-eighth pipeline, the inlet end of the second one-way valve, and the outlet end of the second one-way valve; the inlet end of the third one-way valve is connected to the second bypass pipe, and the outlet end of the third one-way valve is connected to the first bypass pipe in sequence through the outlet end of the fourth one-way valve and the inlet end of the fourth one-way valve; the device is characterized in that during operation, a throttling mechanism can be used to realize throttling operations of multiple functions such as heating, cooling, and alternating defrosting of an outdoor heat exchanger; the operation is more stable and reliable; the structure is simple and the cost is low; the present invention is suitable for industrial and civilian air source heat pumps, and is particularly suitable for low-temperature environments.

Description

Technical Field

[0001] The invention relates to a throttling device for an air source heat pump, belonging to the technical field of refrigeration. Background Art

[0002] The invention patent number 201110355046.1 obtained by the applicant of the present invention on December 10, 2014, proposes an air conditioning refrigeration device, the system of which is as follows: Figure 4 As shown in FIG, in actual application, this patent can be used as an air source heat pump that can absorb heat from outdoor air and continuously provide heat for defrosting. Figure 4 As shown, the air source heat pump has at least two groups of outdoor heat exchangers, namely the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5; when the first outdoor heat exchanger 4 needs to be defrosted, the first four-way valve 70 is switched; while the second four-way valve 80 is not switched, the second outdoor heat exchanger 5 still operates normally, absorbing heat from the outdoor air, and part of the absorbed heat is supplied to the first outdoor heat exchanger 4 for defrosting, and the other part can continue to provide heat through the heater 3.

[0003] Similarly, when the second outdoor heat exchanger 5 needs to be defrosted, the second four-way valve 80 switches, while the first four-way valve 70 does not switch. The first outdoor heat exchanger 4 continues to operate normally, absorbing heat from the outdoor air. Part of this heat is supplied to the second outdoor heat exchanger 5 for defrosting, while the remaining heat is used by the heater 3 to continue providing heat.

[0004] During operation, the heater 3 is always under condensing pressure and there is no risk of freezing; however, this system is different from conventional air source heat pumps (such as Figure 5 As shown), there are two groups of outdoor heat exchangers, namely the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5, and the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are respectively equipped with two electronic expansion valves, namely the first electronic expansion valve 7 and the second electronic expansion valve 8. During operation, the refrigerant flow through the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 is respectively regulated by the first electronic expansion valve 7 and the second electronic expansion valve 8. Because the two electronic expansion valves will affect each other during the regulation process, Figure 5 Compared with the conventional system shown in the figure, the control requirements of the controller will be more complicated, and the time for the unit to reach a stable operating state will be longer, especially when the unit is defrosted and resumes normal operation. Summary of the Invention

[0005] The purpose of the present invention is to provide an air source heat pump that can absorb heat from outdoor air and continuously provide heat and defrost. It provides a throttling device with a simple structure that can achieve throttling operations of multiple functions such as heating, cooling, and alternating defrosting of outdoor heat exchangers using a throttling mechanism during operation.

[0006] In order to overcome the problems existing in the above technologies, the technical solution of the present invention is:

[0007] 1. A throttling device comprising a first bypass pipe (56), a second bypass pipe (57), a throttling mechanism (6), a first one-way valve (23), a second one-way valve (24), a third one-way valve (25), and a fourth one-way valve (26), wherein the throttling device further comprises a third bypass pipe (55), a fifth one-way valve (28), and a normally open solenoid valve (7);

[0008] The outlet end of the first one-way valve (23) is connected to the first bypass pipe (56), and the inlet end of the first one-way valve (23) is connected to the second bypass pipe (57) in sequence through the fifty-eighth pipeline (58), the inlet end of the second one-way valve (24), and the outlet end of the second one-way valve (24);

[0009] The inlet end of the third one-way valve (25) is connected to the second bypass pipe (57), and the outlet end of the third one-way valve (25) is connected to the first bypass pipe (56) via the outlet end of the fourth one-way valve (26) and the inlet end of the fourth one-way valve (26) in sequence;

[0010] The outlet end of the throttling mechanism (6) is connected to the fifty-eighth pipeline (58), and the inlet end of the throttling mechanism (6) is connected to the pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26);

[0011] One end of the normally open solenoid valve (7) is connected to the third bypass pipe (55), and the other end of the normally open solenoid valve (7) is connected to the pipe between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26) through the fifty-fourth pipe (54);

[0012] The inlet end of the fifth one-way valve (28) is connected to the fifty-eighth pipeline (58), and the outlet end of the fifth one-way valve (28) is connected to the third bypass pipe (55).

[0013] 2. A throttling device comprising a first bypass pipe (56), a second bypass pipe (57), a throttling mechanism (6), a first one-way valve (23), a second one-way valve (24), a third one-way valve (25), and a fourth one-way valve (26), wherein the throttling device further comprises a third bypass pipe (55) and a normally open solenoid valve (7);

[0014] The outlet end of the first one-way valve (23) is connected to the first bypass pipe (56), and the inlet end of the first one-way valve (23) is connected to the second bypass pipe (57) in sequence through the fifty-eighth pipeline (58), the inlet end of the second one-way valve (24), and the outlet end of the second one-way valve (24);

[0015] The inlet end of the third one-way valve (25) is connected to the second bypass pipe (57), and the outlet end of the third one-way valve (25) is connected to the first bypass pipe (56) via the outlet end of the fourth one-way valve (26) and the inlet end of the fourth one-way valve (26) in sequence;

[0016] The outlet end of the throttling mechanism (6) is connected to the fifty-eighth pipeline (58), and the inlet end of the throttling mechanism (6) is connected to the pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26);

[0017] One end of the normally open solenoid valve (7) is connected to the third bypass pipe (55), and the other end of the normally open solenoid valve (7) is connected to the pipe between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26) through the fifty-fourth pipe (54).

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. During operation, a throttling mechanism can be used to achieve throttling of multiple functions such as heating, cooling, and alternating defrosting of the outdoor heat exchanger according to needs;

[0020] 2. Work is more stable and reliable;

[0021] 3. Simple structure and low cost;

[0022] 4. The present invention is applicable to industrial and civil air source heat pumps, and is particularly applicable to low temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of the throttling device of the present invention;

[0024] Figure 2 This is a structural diagram of Example 1 of the present invention;

[0025] Figure 3 It is a schematic structural diagram of embodiments 2 to 5 of the present invention;

[0026] Figure 4 It is a schematic diagram of the prior art structure;

[0027] Figure 5 It is a schematic diagram of the prior art structure;

[0028] Figure 6 This is a schematic structural diagram of an improved solution for the throttling device of the present invention;

[0029] Figure 7 It is a structural diagram of Example 6 of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be described in further detail below with reference to the accompanying drawings.

[0031] Example 1

[0032] like Figure 1 The figure shows a schematic diagram of the structure of the throttling device of the present invention. The entire throttling device includes the following components: a first bypass pipe 56, a second bypass pipe 57, a throttling mechanism 6, a first one-way valve 23, a second one-way valve 24, a third one-way valve 25, and a fourth one-way valve 26. It also includes a third bypass pipe 55, a fifth one-way valve 28, and a normally open solenoid valve 7.

[0033] The connections between the various components are as follows: the outlet of the first one-way valve 23 is connected to the first bypass pipe 56, and the inlet of the first one-way valve 23 is connected to the second bypass pipe 57 via the fifty-eighth pipe 58, the inlet of the second one-way valve 24, and the outlet of the second one-way valve 24 in sequence. The inlet of the third one-way valve 25 is connected to the second bypass pipe 57, and the outlet of the third one-way valve 25 is connected to the first bypass pipe 56 via the outlet of the fourth one-way valve 26 and the inlet of the fourth one-way valve 26 in sequence. The outlet of the throttle mechanism 6 is connected to the fifty-eighth pipe 58, and the inlet of the throttle mechanism 6 is connected to the pipe between the outlets of the third one-way valve 25 and the outlets of the fourth one-way valve 26. One end of the normally open solenoid valve 7 is connected to the third bypass pipe 55, and the other end of the normally open solenoid valve 7 is connected to the pipe between the outlets of the third one-way valve 25 and the outlets of the fourth one-way valve 26 via the fifty-fourth pipe 54. The inlet of the fifth one-way valve 28 is connected to the fifty-eighth pipe 58, and the outlet of the fifth one-way valve 28 is connected to the third bypass pipe 55.

[0034] like Figure 2 Shown is a method of using Figure 1 The throttling device shown is an air source heat pump that can absorb heat from outdoor air and continuously provide heat for defrosting, and is used in situations where heating and cooling are required.

[0035] The entire device includes the following components: a compression mechanism 1, a first four-way valve 70, a second four-way valve 80, a first outdoor heat exchanger 4, a second outdoor heat exchanger 5, a user heat exchanger 3, a seventh one-way valve 21, an eighth one-way valve 22, and a throttling device 100.

[0036] During operation, the air source heat pump can realize heating, absorb heat from outdoor air and alternately defrost and cool.

[0037] The workflow for each function is described below.

[0038] (1) Heating function

[0039] During normal operation, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers, acting as evaporators to absorb heat from the environment; the user side heat exchanger 3 acts as a condenser to provide heating for the user.

[0040] The throttling mechanism 6 works normally and is used for throttling, and usually adopts an electronic expansion valve. The normally open electromagnetic valve 7 is opened and the normally closed electromagnetic valve 8 is closed.

[0041] During operation, the high-pressure node 71 of the first four-way valve 70 communicates with the first reversing node 72 of the first four-way valve 70, and the second reversing node 74 of the first four-way valve 70 communicates with the low-pressure node 73 of the first four-way valve 70. The high-pressure node 81 of the second four-way valve 80 communicates with the first reversing node 82 of the second four-way valve 80, and the second reversing node 84 of the second four-way valve 80 communicates with the low-pressure node 83 of the second four-way valve 80.

[0042] The working process is as follows: after being discharged from the outlet of the compression mechanism 1, the refrigerant enters the 60th pipeline 60 and is divided into two paths; the first path passes through the 60th pipeline 60, the high-pressure node 71 of the first four-way valve 70, the first reversing node 72 of the first four-way valve 70, the inlet end of the eighth check valve 22, and the outlet end of the eighth check valve 22, and enters the 51st pipeline 51;

[0043] The second path passes through the 60th pipeline 60, the 59th pipeline 59, the high-pressure node 81 of the second four-way valve 80, the first reversing node 82 of the second four-way valve 80, the inlet end of the seventh one-way valve 21, the outlet end of the seventh one-way valve 21, and also enters the 51st pipeline 51;

[0044] After the two flows are mixed in the fifty-first pipe 51, they enter the user heat exchanger 3 to provide heating for the user. There, the refrigerant gas releases heat and turns into liquid. After exiting the user heat exchanger 3, the refrigerant liquid passes through the third bypass pipe 55, the normally open solenoid valve 7, the fifty-fourth pipe 54, and the inlet end of the throttling mechanism 6 in sequence, entering the throttling mechanism 6 to be throttled. After exiting the outlet end of the throttling mechanism 6, the throttled refrigerant enters the fifty-eighth pipe 58 and is split into two flows.

[0045] The first path passes through the inlet of the second one-way valve 24, the outlet of the second one-way valve 24, the second bypass pipe 57, the second outdoor heat exchanger 5, the sixty-seventh pipeline 67, the second reversing node 84 of the second four-way valve 80, the low-pressure node 83 of the second four-way valve 80, and enters the sixty-fifth pipeline 65;

[0046] The second path passes through the inlet end of the first one-way valve 23, the outlet end of the first one-way valve 23, the first bypass pipe 56, the first outdoor heat exchanger 4, the sixty-fourth pipeline 64, the second reversing node 74 of the first four-way valve 70, the low-pressure node 73 of the first four-way valve 70, and also enters the sixty-fifth pipeline 65; after the two paths are mixed in the sixty-fifth pipeline 65, they return to the inlet end of the compression mechanism 1, enter the compression mechanism 1 and are compressed again, completing a cycle.

[0047] (2) Alternating defrosting function by absorbing heat from outdoor air

[0048] When this function is in operation, both the normally open solenoid valve 7 and the normally closed solenoid valve 8 are closed. The throttling mechanism 6 operates normally, and the user heat exchanger 3 does not operate. The two outdoor heat exchangers are defrosted alternately. The operating process is as follows.

[0049] 1) When the first outdoor heat exchanger 4 is defrosted, the second outdoor heat exchanger 5 operates normally, absorbing heat from the outdoor air.

[0050] At this time, the second four-way valve 80 does not operate and still maintains the state of the heating function;

[0051] The first four-way valve 70 switches, and the connection relationship between its four nodes is as follows: the high-pressure node 71 of the first four-way valve 70 is connected to the second reversing node 74 of the first four-way valve 70, and the first reversing node 72 of the first four-way valve 70 is connected to the low-pressure node 73 of the first four-way valve 70.

[0052] The working process is as follows: after the refrigerant is discharged from the outlet end of the compression mechanism 1, it passes through the 60th pipeline 60, the high-pressure node 71 of the first four-way valve 70, the second reversing node 74 of the first four-way valve 70, the 64th pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth one-way valve 26, the outlet end of the fourth one-way valve 26, the inlet end of the throttling mechanism 6, the outlet end of the throttling mechanism 6, the 58th pipeline 58, the inlet end of the second one-way valve 24, the outlet end of the second one-way valve 24, the second bypass pipe 57, the second outdoor heat exchanger 5, the 67th pipeline 67, the second reversing node 84 of the second four-way valve 80, the low-pressure node 83 of the second four-way valve 80, and enters the 65th pipeline 65; then returns to the inlet end of the compression mechanism 1, enters the compression mechanism 1 to be compressed again, and completes a cycle.

[0053] 2) When the second outdoor heat exchanger 5 is defrosted, the first outdoor heat exchanger 4 operates normally, absorbing heat from the outdoor air.

[0054] At this time, the first four-way valve 70 does not operate and still maintains the state of the heating function;

[0055] The second four-way valve 80 switches, and the connectivity relationship between its four nodes is as follows: the high-pressure node 81 of the second four-way valve 80 is connected to the second reversing node 84 of the second four-way valve 80, and the first reversing node 82 of the second four-way valve 80 is connected to the low-pressure node 83 of the second four-way valve 80.

[0056] The working process is as follows: after the refrigerant is discharged from the outlet end of the compression mechanism 1, it passes through the 60th pipeline 60, the 59th pipeline 59, the high-pressure node 81 of the second four-way valve 80, the second reversing node 84 of the second four-way valve 80, the 67th pipeline 67, the second outdoor heat exchanger 5, the second bypass pipe 57, the inlet end of the third one-way valve 25, the outlet end of the third one-way valve 25, the inlet end of the throttling mechanism 6, the outlet end of the throttling mechanism 6, the 58th pipeline 58, the inlet end of the first one-way valve 23, the outlet end of the first one-way valve 23, the first bypass pipe 56, the first outdoor heat exchanger 4, the 64th pipeline 64, the second reversing node 74 of the first four-way valve 70, the low-pressure node 73 of the first four-way valve 70, and enters the 65th pipeline 65; then returns to the inlet end of the compression mechanism 1, enters the compression mechanism 1 to be compressed again, and completes a cycle.

[0057] (3) Refrigeration function

[0058] During normal operation, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers, acting as condensers to dissipate condensation heat generated by refrigeration into the environment; the user side heat exchanger 3 acts as an evaporator to provide cooling for users.

[0059] The throttling mechanism 6 works normally for throttling. The normally open electromagnetic valve 7 is closed, and the normally closed electromagnetic valve 8 is opened.

[0060] During operation, the high-pressure node 71 of the first four-way valve 70 communicates with the second reversing node 74 of the first four-way valve 70, and the first reversing node 72 of the first four-way valve 70 communicates with the low-pressure node 73 of the first four-way valve 70. The high-pressure node 81 of the second four-way valve 80 communicates with the second reversing node 84 of the second four-way valve 80, and the first reversing node 82 of the second four-way valve 80 communicates with the low-pressure node 83 of the second four-way valve 80.

[0061] The working process is as follows: after being discharged from the outlet of the compression mechanism 1, the refrigerant enters the 60th pipeline 60 and is divided into two paths; the first path passes through the 60th pipeline 60, the high-pressure node 71 of the first four-way valve 70, the second reversing node 74 of the first four-way valve 70, the 64th pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth check valve 26, the outlet end of the fourth check valve 26, and enters the pipeline at the inlet end of the throttling mechanism 6;

[0062] The second path passes through the 60th pipeline 60, the 59th pipeline 59, the high-pressure node 81 of the second four-way valve 80, the second reversing node 84 of the second four-way valve 80, the 67th pipeline 67, the second outdoor heat exchanger 5, the second bypass pipe 57, the inlet end of the third one-way valve 25, and the outlet end of the third one-way valve 25, and also enters the inlet end pipeline of the throttling mechanism 6; after the two paths are mixed in the inlet end pipeline of the throttling mechanism 6, they enter the throttling mechanism 6 and are throttled into a low-temperature and low-pressure gas-liquid two-phase mixture. After coming out of the outlet end pipeline of the throttling mechanism 6, they pass through the 58th pipeline 58, the inlet end of the fifth one-way valve 28, the outlet end of the fifth one-way valve 28, the third bypass pipe 55, the user heat exchanger 3, the 51st pipeline 51, the normally closed solenoid valve 8, the first reversing node 82 of the second four-way valve 80, the low-pressure node 83 of the second four-way valve 80, and the 65th pipeline 65, return to the inlet end of the compression mechanism 1, enter the compression mechanism 1 and are compressed again, completing one cycle.

[0063] Example 2

[0064] By Figure 1 In the scheme shown, adding a sixth one-way valve 29 can Figure 1 The throttling device shown is further improved; Figure 3 As shown, the connection relationship of the sixth one-way valve 29 in the system is as follows: the inlet end of the sixth one-way valve 29 is connected to the third bypass pipe 55 through the normally open solenoid valve 7, and the outlet end of the sixth one-way valve 29 is connected to the fifty-fourth pipeline 54.

[0065] The benefits of adding the sixth one-way valve 29 are: Figure 2 In the scheme shown, when working under the refrigeration function, the normally open solenoid valve 7 can be non-operating, that is, not energized, and still remain in the open state; therefore, the working environment of the normally open solenoid valve 7 can be improved, and it can be avoided that it is energized for a long time when working under the refrigeration function.

[0066] After adding the sixth one-way valve 29, the normally open solenoid valve 7 is energized for a short time only when the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are alternately defrosted in winter. When working in the cooling and heating functions, it is not energized and does not work. Therefore, the failure rate of the normally open solenoid valve 7 can be reduced and its service life can be increased.

[0067] The solution described in Example 2 is applicable to all solutions of all embodiments of the present invention.

[0068] Example 3

[0069] By Figure 1 Adding a side flow capillary to the scheme shown can Figure 1 The throttling device shown is further improved; the connection relationship of the bypass capillary in the system is as follows: one end of the bypass capillary is connected to one end of the normally open solenoid valve 7, and the other end of the bypass capillary is connected to the other end of the normally open solenoid valve 7.

[0070] The benefit of adding a bypass capillary tube is that it allows for continuous heating and defrosting when operating in an alternating defrost mode by absorbing heat from the outdoor air. In practice, by properly selecting the capillary tube length and diameter, the alternating defrost timing can be controlled, effectively adjusting the amount of heat used for defrosting and the amount of simultaneous heating. The capillary tube length is generally calculated theoretically and then verified experimentally.

[0071] In Example 1 Figure 2 After the bypass capillary tube is added to the scheme shown, the working process under the cooling function and the heating function is the same as that of Example 1, and the working process under the outdoor air heat absorption alternating defrosting function is different, as follows.

[0072] During the outdoor air heat absorption alternating defrost function, both the normally open solenoid valve 7 and the normally closed solenoid valve 8 are closed. The throttling mechanism 6 operates normally; the two outdoor heat exchangers alternately defrost, while the user heat exchanger 3 also operates. The operating process is as follows.

[0073] 1) When the first outdoor heat exchanger 4 is defrosted, the second outdoor heat exchanger 5 operates normally, absorbing heat from the outdoor air.

[0074] At this time, the second four-way valve 80 does not operate and still maintains the state of the heating function;

[0075] When the first four-way valve 70 switches, the connectivity relationship among its four nodes is as follows: the high-pressure node 71 of the first four-way valve 70 is connected to the second reversing node 74 of the first four-way valve 70 , and the first reversing node 72 of the first four-way valve 70 is connected to the low-pressure node 73 of the first four-way valve 70 .

[0076] The working process is as follows: after being discharged from the outlet of the compression mechanism 1, the refrigerant enters the 60th pipeline 60 and is divided into two paths; the first path passes through the 60th pipeline 60, the high-pressure node 71 of the first four-way valve 70, the second reversing node 74 of the first four-way valve 70, the 64th pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth check valve 26, the outlet end of the fourth check valve 26, and enters the pipeline at the inlet end of the throttling mechanism 6;

[0077] The second refrigerant flows sequentially through the 60th pipeline 60, the 59th pipeline 59, the high-pressure node 81 of the second four-way valve 80, the first reversing node 82 of the second four-way valve 80, the inlet end of the seventh one-way valve 21, the outlet end of the seventh one-way valve 21, the 51st pipeline 51, the user heat exchanger 3, the third bypass pipe 55, the bypass capillary tube, and the 54th pipeline 54, and also enters the pipeline at the inlet end of the throttling mechanism 6. After mixing with the first refrigerant at the inlet end of the throttling mechanism 6, the second refrigerant enters the throttling mechanism 6 and is throttled into a low-temperature and low-pressure gas-liquid two-phase mixture. After exiting the pipeline at the outlet end of the throttling mechanism 6, the second refrigerant flows sequentially through the 58th pipeline 58, the inlet end of the second one-way valve 24, the outlet end of the second one-way valve 24, the second bypass pipe 57, the second outdoor heat exchanger 5, the 67th pipeline 67, the second reversing node 84 of the second four-way valve 80, the low-pressure node 83 of the second four-way valve 80, and enters the 65th pipeline 65. The refrigerant then returns to the inlet end of the compression mechanism 1 and enters the compression mechanism 1 to be compressed again, completing one cycle.

[0078] 2) When the second outdoor heat exchanger 5 is defrosted, the first outdoor heat exchanger 4 operates normally, absorbing heat from the outdoor air. At this time, the first four-way valve 70 does not operate, and the heating function is maintained;

[0079] The second four-way valve 80 switches, and the connectivity relationship between its four nodes is as follows: the high-pressure node 81 of the second four-way valve 80 is connected to the second reversing node 84 of the second four-way valve 80, and the first reversing node 82 of the second four-way valve 80 is connected to the low-pressure node 83 of the second four-way valve 80.

[0080] The process is as follows: after being discharged from the outlet of the compression mechanism 1, the refrigerant enters the 60th pipeline 60 and is divided into two paths. The first path passes through the 60th pipeline 60, the high-pressure node 71 of the first four-way valve 70, the first reversing node 72 of the first four-way valve 70, the inlet end of the eighth check valve 22, the outlet end of the eighth check valve 22, and the 51st pipeline 51, and enters the user heat exchanger 3 to provide heating for the user. There, the refrigerant gas releases heat and turns into liquid. After exiting the user heat exchanger 3, the refrigerant liquid passes through the third bypass pipe 55, the bypass capillary tube, and the 54th pipeline 54, and enters the pipeline at the inlet end of the throttling mechanism 6.

[0081] The second path passes through the 60th pipeline 60, the 59th pipeline 59, the high-pressure node 81 of the second four-way valve 80, the second reversing node 84 of the second four-way valve 80, the 67th pipeline 67, the second outdoor heat exchanger 5, the second bypass pipe 57, the inlet end of the third one-way valve 25, the outlet end of the third one-way valve 25, and also enters the pipeline at the inlet end of the throttling mechanism 6;

[0082] After being mixed with the first refrigerant in the pipeline at the inlet end of the throttling mechanism 6, it enters the throttling mechanism 6 and is throttled into a low-temperature and low-pressure gas-liquid two-phase mixture. After coming out of the pipeline at the outlet end of the throttling mechanism 6, it passes through the fifty-eighth pipeline 58, the inlet end of the first one-way valve 23, the outlet end of the first one-way valve 23, the first bypass pipe 56, the first outdoor heat exchanger 4, the sixty-fourth pipeline 64, the second reversing node 74 of the first four-way valve 70, the low-pressure node 73 of the first four-way valve 70, and enters the sixty-fifth pipeline 65; then returns to the inlet end of the compression mechanism 1, enters the compression mechanism 1 and is compressed again, completing a cycle.

[0083] The solution described in Example 3 is applicable to all solutions of all embodiments of the present invention.

[0084] Example 4

[0085] like Figure 3 As shown in Figure 1 In the solution shown, adding a liquid reservoir 11 can Figure 1 The throttling device shown is further improved; the connection relationship of the liquid reservoir 11 in the system is as follows:

[0086] The inlet end of the liquid reservoir 11 is connected to the pipeline between the outlet end of the third one-way valve 25 and the outlet end of the fourth one-way valve 26; the outlet end of the liquid reservoir 11 is connected to the pipeline at the inlet end of the throttling mechanism 6.

[0087] For a larger heat pump unit, the presence of the liquid storage tank 11 can well adjust the refrigerant circulation flow rate during the operation of the heat pump system.

[0088] The scheme described in Example 4 is applicable to all schemes of all embodiments of the present invention.

[0089] Example 5

[0090] like Figure 3 As shown in Figure 1 In the scheme shown, adding an economizer 10 can Figure 1 The throttling device shown is further improved; the connection relationship of the economizer 10 in the system is as follows.

[0091] 1) The high-pressure side inlet of the economizer 10 is connected to the pipeline between the outlet of the third one-way valve 25 and the outlet of the fourth one-way valve 26; the high-pressure side outlet of the economizer 10 is connected to the pipeline at the inlet of the throttling mechanism 6; the inlet of the auxiliary throttling mechanism 9 is connected to the pipeline at the high-pressure side inlet of the economizer 10 or the pipeline at the high-pressure side outlet of the economizer 10, and the outlet of the auxiliary throttling mechanism 9 is connected to the middle air supply port of the compression mechanism 1 through the low-pressure side inlet of the economizer 10 and the low-pressure side outlet of the economizer 10 in sequence.

[0092] 2) When Figure 1When the throttling device shown in the figure also includes a liquid reservoir 11, the economizer 10 is installed on the pipeline between the inlet end of the throttling mechanism 6 and the outlet end of the liquid reservoir 11; therefore, the connection relationship of the economizer 10 in the system is as follows:

[0093] The high-pressure side inlet end of the economizer 10 is connected to the outlet end of the liquid storage tank 11; the high-pressure side outlet end of the economizer 10 is connected to the pipeline at the inlet end of the throttling mechanism 6; the inlet end of the auxiliary throttling mechanism 9 is connected to the high-pressure side inlet end pipeline of the economizer 10 or the high-pressure side outlet end pipeline of the economizer 10, and the outlet end of the auxiliary throttling mechanism 9 is connected to the middle air supply port of the compression mechanism 1 through the low-pressure side inlet end of the economizer 10 and the low-pressure side outlet end of the economizer 10 in sequence.

[0094] During operation, the economizer uses the intermediate-pressure refrigerant to supercool the high-pressure liquid refrigerant entering the throttling mechanism 6 and to increase enthalpy by replenishing air.

[0095] For extremely cold and cold regions with low ambient temperatures, the use of an economizer to add air and increase enthalpy can improve the performance of the heat pump.

[0096] The solution described in Example 5 is also applicable to all solutions of all embodiments of the present invention.

[0097] Example 6

[0098] Figure 1 When the throttling device shown is used for a pure heating air source heat pump, further improvements can be made. Figure 6 As shown, Figure 6 The scheme shown is Figure 1 The differences between the shown schemes are: Figure 6 The fifth one-way valve 28 is omitted in the illustrated embodiment. The entire throttling device comprises the following components: a first bypass pipe 56, a second bypass pipe 57, a throttling mechanism 6, a first one-way valve 23, a second one-way valve 24, a third one-way valve 25, a fourth one-way valve 26, a third bypass pipe 55, and a normally open solenoid valve 7.

[0099] The connection relationship of each component is as follows: the outlet end of the first one-way valve 23 is connected to the first bypass pipe 56, and the inlet end of the first one-way valve 23 is connected to the second bypass pipe 57 through the fifty-eighth pipeline 58, the inlet end of the second one-way valve 24, and the outlet end of the second one-way valve 24 in sequence; the inlet end of the third one-way valve 25 is connected to the second bypass pipe 57, and the outlet end of the third one-way valve 25 is connected to the first bypass pipe 56 through the outlet end of the fourth one-way valve 26 and the inlet end of the fourth one-way valve 26 in sequence; the outlet end of the throttling mechanism 6 is connected to the fifty-eighth pipeline 58, and the inlet end of the throttling mechanism 6 is connected to the pipeline between the outlet end of the third one-way valve 25 and the outlet end of the fourth one-way valve 26; one end of the normally open solenoid valve 7 is connected to the third bypass pipe 55, and the other end of the normally open solenoid valve 7 is connected to the pipeline between the outlet end of the third one-way valve 25 and the outlet end of the fourth one-way valve 26 through the fifty-fourth pipeline 54.

[0100] like Figure 7 Shown is a method of using Figure 6 The throttling device shown is an air source heat pump that can absorb heat from outdoor air and continuously provide heat for defrosting, and is used in situations where heating is required.

[0101] The entire device includes the following components: a compression mechanism 1, a first four-way valve 70, a second four-way valve 80, a first outdoor heat exchanger 4, a second outdoor heat exchanger 5, a user heat exchanger 3, a seventh one-way valve 21, an eighth one-way valve 22, and a throttling device 100.

[0102] During operation, the air source heat pump can realize the functions of heating and absorbing heat from outdoor air for alternating defrosting.

[0103] The workflow for each function is described below.

[0104] (1) Heating function

[0105] During normal operation, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers, acting as evaporators to absorb heat from the environment; the user side heat exchanger 3 acts as a condenser to provide heating for the user.

[0106] During operation, the throttling mechanism 6 works normally for throttling, and usually adopts an electronic expansion valve. The normally open solenoid valve 7 is opened.

[0107] During operation, the high-pressure node 71 of the first four-way valve 70 communicates with the first reversing node 72 of the first four-way valve 70, and the second reversing node 74 of the first four-way valve 70 communicates with the low-pressure node 73 of the first four-way valve 70. The high-pressure node 81 of the second four-way valve 80 communicates with the first reversing node 82 of the second four-way valve 80, and the second reversing node 84 of the second four-way valve 80 communicates with the low-pressure node 83 of the second four-way valve 80.

[0108] The working process is as follows: after being discharged from the outlet of the compression mechanism 1, the refrigerant enters the 60th pipeline 60 and is divided into two paths; the first path passes through the 60th pipeline 60, the high-pressure node 71 of the first four-way valve 70, the first reversing node 72 of the first four-way valve 70, the inlet end of the eighth check valve 22, and the outlet end of the eighth check valve 22, and enters the 51st pipeline 51;

[0109] The second path passes through the 60th pipeline 60, the 59th pipeline 59, the high-pressure node 81 of the second four-way valve 80, the first reversing node 82 of the second four-way valve 80, the inlet end of the seventh one-way valve 21, the outlet end of the seventh one-way valve 21, and also enters the 51st pipeline 51;

[0110] After the two flows are mixed in the fifty-first pipe 51, they enter the user heat exchanger 3 to provide heating for the user. There, the refrigerant gas releases heat and turns into liquid. After exiting the user heat exchanger 3, the refrigerant liquid passes through the third bypass pipe 55, the normally open solenoid valve 7, the fifty-fourth pipe 54, and the inlet end of the throttling mechanism 6 in sequence, entering the throttling mechanism 6 to be throttled. After exiting the outlet end of the throttling mechanism 6, the throttled refrigerant enters the fifty-eighth pipe 58 and is split into two flows.

[0111] The first path passes through the inlet of the second one-way valve 24, the outlet of the second one-way valve 24, the second bypass pipe 57, the second outdoor heat exchanger 5, the sixty-seventh pipeline 67, the second reversing node 84 of the second four-way valve 80, the low-pressure node 83 of the second four-way valve 80, and enters the sixty-fifth pipeline 65;

[0112] The second path passes through the inlet end of the first one-way valve 23, the outlet end of the first one-way valve 23, the first bypass pipe 56, the first outdoor heat exchanger 4, the sixty-fourth pipeline 64, the second reversing node 74 of the first four-way valve 70, the low-pressure node 73 of the first four-way valve 70, and also enters the sixty-fifth pipeline 65; after the two paths are mixed in the sixty-fifth pipeline 65, they return to the inlet end of the compression mechanism 1, enter the compression mechanism 1 and are compressed again, completing a cycle.

[0113] (2) Alternating defrosting function by absorbing heat from outdoor air

[0114] When this function is in operation, the normally open solenoid valve 7 is closed. The throttling mechanism 6 operates normally, and the user heat exchanger 3 does not operate. The two outdoor heat exchangers are defrosted alternately. The operating process is as follows.

[0115] 1) When the first outdoor heat exchanger 4 is defrosted, the second outdoor heat exchanger 5 operates normally, absorbing heat from the outdoor air.

[0116] At this time, the second four-way valve 80 does not operate and still maintains the state of the heating function;

[0117] The first four-way valve 70 switches, and the connection relationship between its four nodes is as follows: the high-pressure node 71 of the first four-way valve 70 is connected to the second reversing node 74 of the first four-way valve 70, and the first reversing node 72 of the first four-way valve 70 is connected to the low-pressure node 73 of the first four-way valve 70.

[0118] The working process is as follows: after the refrigerant is discharged from the outlet end of the compression mechanism 1, it passes through the 60th pipeline 60, the high-pressure node 71 of the first four-way valve 70, the second reversing node 74 of the first four-way valve 70, the 64th pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth one-way valve 26, the outlet end of the fourth one-way valve 26, the inlet end of the throttling mechanism 6, the outlet end of the throttling mechanism 6, the 58th pipeline 58, the inlet end of the second one-way valve 24, the outlet end of the second one-way valve 24, the second bypass pipe 57, the second outdoor heat exchanger 5, the 67th pipeline 67, the second reversing node 84 of the second four-way valve 80, the low-pressure node 83 of the second four-way valve 80, and enters the 65th pipeline 65; then returns to the inlet end of the compression mechanism 1, enters the compression mechanism 1 to be compressed again, and completes a cycle.

[0119] 2) When the second outdoor heat exchanger 5 is defrosted, the first outdoor heat exchanger 4 operates normally, absorbing heat from the outdoor air.

[0120] At this time, the first four-way valve 70 does not operate and still maintains the state of the heating function;

[0121] The second four-way valve 80 switches, and the connectivity relationship between its four nodes is as follows: the high-pressure node 81 of the second four-way valve 80 is connected to the second reversing node 84 of the second four-way valve 80, and the first reversing node 82 of the second four-way valve 80 is connected to the low-pressure node 83 of the second four-way valve 80.

[0122] The working process is as follows: after the refrigerant is discharged from the outlet end of the compression mechanism 1, it passes through the 60th pipeline 60, the 59th pipeline 59, the high-pressure node 81 of the second four-way valve 80, the second reversing node 84 of the second four-way valve 80, the 67th pipeline 67, the second outdoor heat exchanger 5, the second bypass pipe 57, the inlet end of the third one-way valve 25, the outlet end of the third one-way valve 25, the inlet end of the throttling mechanism 6, the outlet end of the throttling mechanism 6, the 58th pipeline 58, the inlet end of the first one-way valve 23, the outlet end of the first one-way valve 23, the first bypass pipe 56, the first outdoor heat exchanger 4, the 64th pipeline 64, the second reversing node 74 of the first four-way valve 70, the low-pressure node 73 of the first four-way valve 70, and enters the 65th pipeline 65; then returns to the inlet end of the compression mechanism 1, enters the compression mechanism 1 to be compressed again, and completes a cycle.

[0123] Figure 7 If the reverse cycle hot gas defrost function is required in the scheme shown, for use in special circumstances (for example: emergency defrost), Figure 7The scheme shown is further improved.

[0124] Improvement plan 1: Add a normally closed solenoid valve 8 and a defrost capillary.

[0125] At this time, the connection method of the normally closed solenoid valve 8 in the system is as follows Figure 2 As shown; the normally closed solenoid valve 8 is in a closed state under the heating and alternating defrosting functions of absorbing heat from the outdoor air; and is in an open state under the reverse cycle hot gas defrosting function.

[0126] The defrost capillary is used for refrigerant throttling in the reverse cycle hot gas defrosting function of the system. Its connection relationship in the system is as follows: one end of the defrost capillary is connected to one end of the normally open solenoid valve 7, and the other end of the defrost capillary is connected to the other end of the normally open solenoid valve 7.

[0127] At this time, the working process of the heat pump system under the reverse cycle hot gas defrost function is as follows:

[0128] During operation, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers. As condensers, they use the heat absorbed from the heating return water to simultaneously melt the frost on the outer surfaces of the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5; the user side heat exchanger 3 acts as an evaporator, absorbing heat from the heating return water.

[0129] When in operation, the throttling mechanism 6 does not work; the defrosting capillary tube is used for refrigerant throttling. The normally open solenoid valve 7 is closed, and the normally closed solenoid valve 8 is opened.

[0130] During operation, the high-pressure node 71 of the first four-way valve 70 communicates with the second reversing node 74 of the first four-way valve 70, and the first reversing node 72 of the first four-way valve 70 communicates with the low-pressure node 73 of the first four-way valve 70. The high-pressure node 81 of the second four-way valve 80 communicates with the second reversing node 84 of the second four-way valve 80, and the first reversing node 82 of the second four-way valve 80 communicates with the low-pressure node 83 of the second four-way valve 80.

[0131] The working process is as follows: after being discharged from the outlet of the compression mechanism 1, the refrigerant enters the 60th pipeline 60 and is divided into two paths; the first path passes through the 60th pipeline 60, the high-pressure node 71 of the first four-way valve 70, the second reversing node 74 of the first four-way valve 70, the 64th pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth check valve 26, the outlet end of the fourth check valve 26, and enters the 54th pipeline 54;

[0132] The second route passes through the 60th pipeline 60, the 59th pipeline 59, the high-pressure node 81 of the second four-way valve 80, the second reversing node 84 of the second four-way valve 80, the 67th pipeline 67, the second outdoor heat exchanger 5, the second bypass pipe 57, the inlet end of the third one-way valve 25, the outlet end of the third one-way valve 25, and also enters the 54th pipeline 54; after the two routes are mixed in the 54th pipeline 54, they enter the defrost capillary and are throttled into a low-temperature and low-pressure gas-liquid two-phase mixture. After coming out of the defrost capillary, they pass through the third bypass pipe 55, the user heat exchanger 3, the 51st pipeline 51, the normally closed solenoid valve 8, the first reversing node 82 of the second four-way valve 80, the low-pressure node 83 of the second four-way valve 80, and the 65th pipeline 65, return to the inlet end of the compression mechanism 1, enter the compression mechanism 1 and are compressed again, completing a cycle.

[0133] Similar to Example 2, in order to avoid the normally open solenoid valve 7 from operating under the reverse cycle hot gas defrosting function, a sixth one-way valve 29 can also be added to the system. The advantages of doing so are: Figure 7 Improved solution 1 of the illustrated solution: When working under the reverse cycle hot gas defrost function, the normally open solenoid valve 7 may not work, that is, it is not energized and remains in the open state.

[0134] After adding the sixth one-way valve 29, the normally open solenoid valve 7 is energized for a short time only when the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are alternately defrosted in winter. When working in the heating and reverse cycle hot gas defrosting functions, it is not energized and does not work. Therefore, the failure rate of the normally open solenoid valve 7 can be reduced and its service life can be increased.

[0135] At this time, if Figure 3 As shown, the sixth one-way valve 29 is connected in the system as follows: its inlet is connected to the third bypass pipe 55 via the normally open solenoid valve 7, and its outlet is connected to the fifty-fourth pipe 54. The defrost capillary tube is connected in the system as follows: one end of the defrost capillary tube is connected to the third bypass pipe 55, and the other end of the defrost capillary tube is connected to the fifty-fourth pipe 54.

[0136] Improvement plan 2: Add a normally closed solenoid valve 8 and replace the normally open solenoid valve 7 with an electric ball valve. For example, Sanhua's electric ball valve can be fully opened and fully closed, playing the role of a solenoid valve. It also has the function of an electronic expansion valve for throttling the refrigerant. Therefore, it can play the role of an electronic expansion valve for throttling the refrigerant under the reverse cycle hot gas defrost function; and play the role of the normally open solenoid valve 7 under the heating and heat absorption from outdoor air alternating defrost functions.

[0137] At this time, the connection method of the normally closed solenoid valve 8 in the system is as follows Figure 2As shown; the normally closed solenoid valve 8 is in a closed state under the heating and alternating defrosting functions of absorbing heat from the outdoor air; and is in an open state under the reverse cycle hot gas defrosting function.

[0138] When working, the heat pump system works as follows under the reverse cycle hot gas defrost function:

[0139] During operation, the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5 are both heat source side heat exchangers. As condensers, they use the heat absorbed from the heating return water to simultaneously melt the frost on the outer surfaces of the first outdoor heat exchanger 4 and the second outdoor heat exchanger 5; the user side heat exchanger 3 acts as an evaporator, absorbing heat from the heating return water.

[0140] During operation, the throttling mechanism 6 does not work; the normally open solenoid valve 7 is used for refrigerant throttling; and the normally closed solenoid valve 8 is open.

[0141] During operation, the high-pressure node 71 of the first four-way valve 70 communicates with the second reversing node 74 of the first four-way valve 70, and the first reversing node 72 of the first four-way valve 70 communicates with the low-pressure node 73 of the first four-way valve 70. The high-pressure node 81 of the second four-way valve 80 communicates with the second reversing node 84 of the second four-way valve 80, and the first reversing node 82 of the second four-way valve 80 communicates with the low-pressure node 83 of the second four-way valve 80.

[0142] The working process is as follows: after being discharged from the outlet of the compression mechanism 1, the refrigerant enters the 60th pipeline 60 and is divided into two paths; the first path passes through the 60th pipeline 60, the high-pressure node 71 of the first four-way valve 70, the second reversing node 74 of the first four-way valve 70, the 64th pipeline 64, the first outdoor heat exchanger 4, the first bypass pipe 56, the inlet end of the fourth check valve 26, the outlet end of the fourth check valve 26, and enters the 54th pipeline 54;

[0143] The second path passes through the 60th pipeline 60, the 59th pipeline 59, the high-pressure node 81 of the second four-way valve 80, the second reversing node 84 of the second four-way valve 80, the 67th pipeline 67, the second outdoor heat exchanger 5, the second bypass pipe 57, the inlet end of the third one-way valve 25, the outlet end of the third one-way valve 25, and also enters the 54th pipeline 54; after the two paths are mixed in the 54th pipeline 54, they enter the normally open solenoid valve 7 and are throttled into a low-temperature and low-pressure gas-liquid two-phase mixture. After coming out of the normally open solenoid valve 7, they pass through the third bypass pipe 55, the user heat exchanger 3, the 51st pipeline 51, the normally closed solenoid valve 8, the first reversing node 82 of the second four-way valve 80, the low-pressure node 83 of the second four-way valve 80, and the 65th pipeline 65, return to the inlet end of the compression mechanism 1, enter the compression mechanism 1 and are compressed again, completing a cycle.

[0144] In all of the above embodiments of the present invention, any one of the first one-way valve 23, the second one-way valve 24, the third one-way valve 25, the fourth one-way valve 26, the fifth one-way valve 28, the sixth one-way valve 29, the seventh one-way valve 21, and the eighth one-way valve 22 can be replaced by a solenoid valve, a throttling mechanism with a shut-off function (e.g., an electronic expansion valve), or a flow regulating mechanism. The housing of the one-way valve body is made of copper, brass, or red copper.

[0145] The valve body shell material of the normally open solenoid valve 7 and the normally closed solenoid valve 8 is also copper, brass or copper.

[0146] In all the above embodiments of the present invention, the throttling mechanism 6 and the auxiliary throttling mechanism 9 can adopt any one of the following throttling components:

[0147] 1) Electronic expansion valve, the brand can be any of Sanhua, Dunan, Japan Miyagi, Danfoss, Carel, Emerson, etc.

[0148] 2) Thermostatic expansion valve; the brand can also be any one of Sanhua, Dunan, Japan Miyagi, Danfoss, Carel, Emerson, etc.; a one-way thermal expansion valve can be used;

[0149] 3) Other throttling components, or valve groups, can all be unidirectional.

[0150] The economizer can adopt any one of volumetric heat exchanger, plate heat exchanger, shell and tube heat exchanger or double-tube heat exchanger, and its material is copper, copper alloy or stainless steel; or titanium metal.

Claims

1. A throttling device comprising a first bypass pipe (56), a second bypass pipe (57), a throttling mechanism (6), a first one-way valve (23), a second one-way valve (24), a third one-way valve (25), and a fourth one-way valve (26), wherein: The throttling device further comprises a third bypass pipe (55), a fifth one-way valve (28), and a normally open electromagnetic valve (7); The outlet end of the first one-way valve (23) is connected to the first bypass pipe (56), and the inlet end of the first one-way valve (23) is connected to the second bypass pipe (57) in sequence through the fifty-eighth pipeline (58), the inlet end of the second one-way valve (24), and the outlet end of the second one-way valve (24); The inlet end of the third one-way valve (25) is connected to the second bypass pipe (57), and the outlet end of the third one-way valve (25) is connected to the first bypass pipe (56) via the outlet end of the fourth one-way valve (26) and the inlet end of the fourth one-way valve (26) in sequence; The outlet end of the throttling mechanism (6) is connected to the fifty-eighth pipeline (58), and the inlet end of the throttling mechanism (6) is connected to the pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26); One end of the normally open solenoid valve (7) is connected to the third bypass pipe (55), and the other end of the normally open solenoid valve (7) is connected to the pipe between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26) through the fifty-fourth pipe (54); The inlet end of the fifth one-way valve (28) is connected to the fifty-eighth pipeline (58), and the outlet end of the fifth one-way valve (28) is connected to the third bypass pipe (55).

2. The throttling device according to claim 1, characterized in that The inlet end of a sixth one-way valve (29) is connected to the third bypass pipe (55) through the normally open electromagnetic valve (7), and the outlet end of the sixth one-way valve (29) is connected to the fifty-fourth pipeline (54).

3. The throttling device according to any one of claims 1 to 2, characterized in that One end of a side flow capillary is connected to one end of the normally open electromagnetic valve (7), and the other end of the side flow capillary is connected to the other end of the normally open electromagnetic valve (7).

4. The throttling device according to any one of claims 1 to 2, characterized in that The inlet end of a liquid reservoir (11) is connected to a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26); the outlet end of the liquid reservoir (11) is connected to the pipeline at the inlet end of the throttling mechanism (6).

5. The throttling device according to claim 3, characterized in that The inlet end of a liquid reservoir (11) is connected to a pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26); the outlet end of the liquid reservoir (11) is connected to the pipeline at the inlet end of the throttling mechanism (6).

6. The throttling device according to any one of claims 1 to 2, characterized in that An economizer (10) is installed on the inlet pipe of the throttling mechanism (6).

7. The throttling device according to claim 3, characterized in that An economizer (10) is installed on the inlet pipe of the throttling mechanism (6).

8. The throttling device according to claim 4, characterized in that An economizer (10) is installed on the pipeline between the inlet end of the throttling mechanism (6) and the outlet end of the liquid storage container (11).

9. The throttling device according to claim 5, characterized in that An economizer (10) is installed on the pipeline between the inlet end of the throttling mechanism (6) and the outlet end of the liquid storage container (11).

10. A throttling device comprising a first bypass pipe (56), a second bypass pipe (57), a throttling mechanism (6), a first one-way valve (23), a second one-way valve (24), a third one-way valve (25), and a fourth one-way valve (26), wherein: The throttling device further includes a third bypass pipe (55) and a normally open electromagnetic valve (7); The outlet end of the first one-way valve (23) is connected to the first bypass pipe (56), and the inlet end of the first one-way valve (23) is connected to the second bypass pipe (57) in sequence through the fifty-eighth pipeline (58), the inlet end of the second one-way valve (24), and the outlet end of the second one-way valve (24); The inlet end of the third one-way valve (25) is connected to the second bypass pipe (57), and the outlet end of the third one-way valve (25) is connected to the first bypass pipe (56) via the outlet end of the fourth one-way valve (26) and the inlet end of the fourth one-way valve (26) in sequence; The outlet end of the throttling mechanism (6) is connected to the fifty-eighth pipeline (58), and the inlet end of the throttling mechanism (6) is connected to the pipeline between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26); One end of the normally open solenoid valve (7) is connected to the third bypass pipe (55), and the other end of the normally open solenoid valve (7) is connected to the pipe between the outlet end of the third one-way valve (25) and the outlet end of the fourth one-way valve (26) through the fifty-fourth pipe (54).

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