Refrigerant circulation system and control method for refrigerant circulation system

Abstract

The present disclosure provides a refrigerant circulation system and a control method of the refrigerant circulation system. The refrigerant circulation system comprises a refrigerant loop, a detection device and a control device. The refrigerant loop comprises a fluorine pump and a refrigerant collection part. The fluorine pump is connected in parallel with the compressor between the evaporator and the condenser. The refrigerant collection part comprises a collection part inlet, a collection part gas outlet and a collection part liquid outlet. The collection part inlet is connected with the evaporator, the collection part gas outlet is connected with the inlet of the compressor, and the collection part liquid outlet is connected with the inlet of the fluorine pump. The detection device detects the refrigerant parameter in the refrigerant collection part. The control device is signal connected with the detection device to control the refrigerant circulation system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to the refrigerant parameter. In the compressor refrigeration mode, the compressor is turned on, and the fluorine pump is cut off from the refrigerant loop. In the fluorine pump refrigeration mode, the fluorine pump is turned on, and the compressor is cut off from the refrigerant loop.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of refrigeration technology, and in particular, to a refrigerant circulation system and a control method of the refrigerant circulation system. BACKGROUND

[0002] In the case that the outdoor temperature is cold while the indoor temperature is still relatively high, for example, the outdoor temperature drops to-20℃ and below, while the indoor temperature is still in a temperature environment above 20℃, starting the compressor of the vapor compression refrigeration system to carry out refrigeration will cause the problem that the superheat degree at the outlet of the evaporator is low and the refrigeration system cannot operate normally. In order to solve the problem that the compressor cannot refrigerate under low temperature working condition, a fluorine pump is usually added between the outlet of the condenser and the inlet of the evaporator, so that the fluorine pump is used to replace the compressor under low temperature refrigeration working condition, thereby realizing refrigeration in a wider range of environmental temperature. However, when the supercooling degree at the outlet of the condenser is insufficient, the service life of the fluorine pump will be reduced, and the refrigeration system cannot operate normally.

[0003] In the related art, a method of simultaneously detecting the superheat degree at the outlet of the evaporator and the supercooling degree at the outlet of the condenser in the refrigeration system and adjusting the refrigeration mode of the refrigeration system according to the detection result is adopted, the compressor is started to refrigerate (compressor refrigeration mode) when the supercooling degree at the outlet of the condenser is insufficient, and the fluorine pump is started to refrigerate (fluorine pump refrigeration mode) when the superheat degree at the outlet of the evaporator is insufficient, so as to solve the problem that the compressor or the fluorine pump cannot refrigerate normally.

[0004] However, due to the need to consider factors such as size, weight and electromagnetic compatibility in air conditioner manufacturing, the heat exchanger of some air conditioners is small and the fan needs to be powered by an alternating current motor, which will cause the condensing air volume of the air conditioner to be unable to be infinitely adjusted. In this case, under the condition that the outdoor temperature is relatively cold and the load is low, for example, the outdoor temperature reaches-18℃ to-15℃ and the load is below 20%, the problem of insufficient superheat degree at the outlet of the evaporator when the compressor is refrigerating and insufficient supercooling degree at the outlet of the condenser when the fluorine pump is refrigerating will occur at the same time, which will cause the refrigerant circulation system to frequently switch between the compressor refrigeration mode and the fluorine pump refrigeration mode, and the compressor and the fluorine pump are prone to be damaged, so that the refrigeration system cannot refrigerate normally. SUMMARY

[0005] The present disclosure aims to provide a refrigerant circulation system and a control method of the refrigerant circulation system, and aims to solve the problem that refrigeration under the condition that the outdoor temperature is relatively cold and the load is low will cause insufficient superheat degree at the outlet of the evaporator and insufficient supercooling degree at the outlet of the condenser at the same time, which will cause the compressor refrigeration mode and the fluorine pump refrigeration mode to be frequently switched, and the compressor and the fluorine pump are prone to be damaged, so that the refrigeration system cannot refrigerate normally.

[0006] The first aspect of the present disclosure provides a refrigerant circulation system, comprising: a refrigerant circuit comprising a compressor, a condenser, a throttling device and an evaporator connected in series through refrigerant pipelines, a fluorine pump connected in parallel with the compressor between the evaporator and the condenser through refrigerant pipelines, and a refrigerant collection unit comprising a collection unit inlet, a collection unit gas outlet and a collection unit liquid outlet, wherein the collection unit inlet is connected to the evaporator, the collection unit gas outlet is connected to the inlet of the compressor, and the collection unit liquid outlet is connected to the inlet of the fluorine pump; a detection device configured to detect a refrigerant parameter of the refrigerant in the refrigerant collection unit; and a control device connected to the detection device and configured to control the refrigerant circulation system to switch between a compressor refrigeration mode and a fluorine pump refrigeration mode according to the refrigerant parameter, wherein in the compressor refrigeration mode, the compressor is turned on and the fluorine pump is cut off from the refrigerant circuit, and in the fluorine pump refrigeration mode, the fluorine pump is turned on and the compressor is cut off from the refrigerant circuit.

[0007] In some embodiments of the refrigerant circulation system, the refrigerant collection unit comprises a vapor-liquid separator comprising a separator inlet and a separator gas outlet; wherein,

[0008] the vapor-liquid separator further comprises a separator liquid outlet, and the separator inlet, the separator gas outlet and the separator liquid outlet form the collection unit inlet, the collection unit gas outlet and the collection unit liquid outlet, respectively; or

[0009] the refrigerant collection unit further comprises a liquid reservoir comprising a liquid reservoir inlet and a liquid reservoir outlet, the separator inlet and the liquid reservoir inlet form the collection unit inlet, the separator gas outlet forms the collection unit gas outlet, and the liquid reservoir outlet forms the collection unit liquid outlet.

[0010] In some embodiments of the refrigerant circulation system, the vapor-liquid separator comprises: a separator housing configured to receive the refrigerant output from the evaporator to the vapor-liquid separator; a separator inlet pipe comprising a separator inlet pipe first port and a separator inlet pipe second port, wherein the separator inlet pipe first port forms the separator inlet, and the separator inlet pipe second port is inserted into the gaseous refrigerant in the separator housing; and a separator gas outlet pipe comprising a separator gas pipe first port and a separator gas pipe second port, wherein the separator gas pipe first port is arranged in the gaseous refrigerant in the separator housing, and the separator gas pipe second port forms the separator gas outlet.

[0011] In some embodiments of the refrigerant circulation system, the separator gas outlet pipe comprises a bend pipe section disposed between the separator gas pipe first port and the separator gas pipe second port, the bend pipe section is located in the liquid refrigerant in the separator housing, and the bend pipe section comprises an oil inlet hole located in an oil layer deposited at the bottom of the liquid refrigerant and configured to atomize oil entering the separator gas outlet pipe through the oil inlet hole.

[0012] In some embodiments of the refrigerant circulation system, the vapor-liquid separator further comprises a liquid guide pipe, the liquid guide pipe is disposed separately from the separator inlet pipe, a liquid guide pipe inlet of the liquid guide pipe is oriented towards and larger than the separator inlet pipe second port, and the separator inlet pipe second port is located inside an opening of the liquid guide pipe inlet, a liquid guide pipe outlet of the liquid guide pipe is inserted into the liquid refrigerant and / or the oil layer in the separator housing.

[0013] In some embodiments of the refrigerant circulation system, the liquid guide pipe comprises a vertical pipe section and an inclined pipe section at an obtuse angle with the vertical pipe section, the liquid guide pipe inlet is located at an end of the inclined pipe section away from the vertical pipe section, and the liquid guide pipe outlet is located at an end of the vertical pipe section away from the inclined pipe section.

[0014] In some embodiments of the refrigerant circulation system, a cross section of the liquid guide pipe near a first end of the liquid guide pipe inlet gradually decreases from the liquid guide pipe inlet to a side near a second end of the liquid guide pipe, and an inner wall of the liquid guide pipe first end is oriented towards the separator inlet pipe second port.

[0015] In some embodiments of the refrigerant circulation system, the vapor-liquid separator further comprises a separator liquid outlet pipe, the separator liquid outlet pipe comprises a separator liquid pipe first port and a separator liquid pipe second port, the separator liquid pipe first port is inserted into the liquid refrigerant in the separator housing, and the separator liquid pipe second port forms the separator liquid outlet.

[0016] In some embodiments of the refrigerant circulation system, the refrigerant circuit further comprises: a first one-way valve connected in series between the compressor and the condenser and configured to allow one-way flow of the refrigerant from the compressor to the condenser; and a second one-way valve connected in series between the fluorine pump and the condenser and configured to allow one-way flow of the refrigerant from the fluorine pump to the condenser.

[0017] In some embodiments of the refrigerant circulation system, the refrigerant collection unit comprises a vapor-liquid separator, the vapor-liquid separator comprises the separator inlet, a separator gas outlet, and a separator liquid outlet, the separator inlet, the separator gas outlet, and the separator liquid outlet form the collection unit inlet, the collection unit gas outlet, and the collection unit liquid outlet, respectively.

[0018] The detection device comprises a liquid level sensor configured to detect a liquid level H in the gas-liquid separator;

[0019] The control device is configured to control the refrigerant circulation system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to a first distance and a second distance, the first distance being a height difference between the liquid level H and a height H A of an outlet position of the collection part liquid outlet for leading out liquid refrigerant from the gas-liquid separator, and the second distance being a height difference between the liquid level H and a height H B of an outlet position of the collection part gas outlet for leading out gaseous refrigerant from the gas-liquid separator.

[0020] In some embodiments of the refrigerant circulation system, the refrigerant circulation system further comprises an outdoor fan and / or a heating device for heating the refrigerant in the gas-liquid separator of the refrigerant collection part;

[0021] The detection device further comprises a temperature sensor and a pressure sensor for detecting a refrigerant temperature and a refrigerant pressure of the gaseous refrigerant in the gas-liquid separator of the refrigerant collection part, respectively, and the refrigerant parameters comprise the refrigerant temperature and the refrigerant pressure;

[0022] The control device is configured to calculate a saturation temperature T 饱 of the refrigerant in the gas-liquid separator according to the refrigerant pressure, and calculate a temperature difference between the refrigerant temperature T 回 and the saturation temperature T 饱 , and control a rotating speed of the outdoor fan and / or control the heating device to start or stop according to the temperature difference.

[0023] In some embodiments of the refrigerant circulation system, the refrigerant circulation system further comprises a first electromagnetic valve arranged between the collection part gas outlet and the compressor and connected to the control device, the control device being configured to open the first electromagnetic valve in the compressor refrigeration mode and close the first electromagnetic valve in the fluorine pump refrigeration mode; and a second electromagnetic valve arranged between the collection part liquid outlet and the fluorine pump and connected to the control device, the control device being configured to open the second electromagnetic valve in the fluorine pump refrigeration mode and close the second electromagnetic valve in the compressor refrigeration mode.

[0024] The second aspect of the present disclosure provides a control method of the refrigerant circulation system of the first aspect of the present disclosure, the control method comprising:

[0025] The detection device detects refrigerant parameters of the refrigerant in the refrigerant collection part;

[0026] The control device controls the refrigerant circulating system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to the refrigerant parameter.

[0027] In the control method of some embodiments, the refrigerant collecting part comprises a gas-liquid separator, the gas-liquid separator comprises a separator inlet, a separator gas outlet and a separator liquid outlet, the separator inlet, the separator gas outlet and the separator liquid outlet form the collecting part inlet, the collecting part gas outlet and the collecting part liquid outlet respectively; the detection device comprises a liquid level sensor, the liquid level sensor is configured to detect the liquid level in the gas-liquid separator;

[0028] The control method further comprises:

[0029] The detection device detects the liquid level in the gas-liquid separator of the refrigerant collecting part;

[0030] The control device is configured to control the refrigerant circulating system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to a first distance and a second distance, the first distance is the height difference between the height H of the gas outlet of the collecting part and the height H of the liquid level, and the second distance is the height difference between the height H of the liquid level and the height H of the liquid outlet of the collecting part. A B

[0031] In the control method of some embodiments, the control method comprises:

[0032] In the case where the first distance is greater than or equal to the second distance, the control device controls the refrigerant circulating system to switch to the compressor refrigeration mode; and

[0033] In the case where the first distance is less than the second distance, the control device controls the refrigerant circulating system to switch to the fluorine pump refrigeration mode.

[0034] In the control method of some embodiments, the refrigerant circulating system further comprises an outdoor fan and / or a heating device for heating the refrigerant in the gas-liquid separator of the refrigerant collecting part; the detection device further comprises a temperature sensor and a pressure sensor, the temperature sensor and the pressure sensor are respectively used to detect the refrigerant temperature and the refrigerant pressure of the gaseous refrigerant in the gas-liquid separator of the refrigerant collecting part, and the refrigerant parameter comprises the refrigerant temperature and the refrigerant pressure;

[0035] The control method further comprises:

[0036] ​​The temperature sensor and the pressure sensor detect a refrigerant temperature and a refrigerant pressure of gaseous refrigerant in a gas-liquid separator of the refrigerant collecting portion, respectively;

[0037] The control device calculates a saturation temperature T 饱 of the refrigerant in the gas-liquid separator based on the refrigerant pressure, and calculates a temperature difference between the refrigerant temperature T 回 and the saturation temperature T 饱 , and controls a rotation speed of the outdoor fan and / or controls the heating device to be turned on or off based on the temperature difference.

[0038] In the control method of some embodiments, the control method includes:

[0039] In a case where the refrigerant circulation system is in the compressor refrigeration mode and the temperature difference is smaller than a first limit temperature difference, the control device controls the heating device to be turned on, in a case where the refrigerant circulation system is in the compressor refrigeration mode and the temperature difference is larger than or equal to the first limit temperature difference and the first distance is smaller than or equal to a first limit distance value, the control device controls the heating device to be turned off and controls the refrigerant circulation system to be switched to the fluorine pump refrigeration mode; and / or

[0040] In a case where the refrigerant circulation system is in the fluorine pump refrigeration mode and the temperature difference is larger than or equal to a second limit temperature difference, the control device controls the outdoor fan to be accelerated, in a case where the refrigerant circulation system is in the fluorine pump refrigeration mode and the temperature difference is smaller than the second limit temperature difference and the second distance is smaller than a second limit distance value, the control device controls the outdoor fan to return to a speed before the acceleration and controls the refrigerant circulation system to be switched to the compressor refrigeration mode.

[0041] Based on the refrigerant circulation system provided by the present disclosure, the refrigerant circuit of the refrigerant circulation system adopts the setting mode that the fluorine pump and the compressor are connected in parallel between the evaporator and the condenser, the refrigerant pipeline connecting the inlet of the compressor and the inlet of the fluorine pump is integrated in the refrigerant collecting part on the refrigerant circuit, so that the refrigerant flowing out of the outlet of the evaporator first passes through the refrigerant collecting part and then enters the compressor and the fluorine pump respectively. This setting is conducive to the detection device of the refrigerant circulation system to monitor the refrigerant parameters of the refrigerant in the refrigerant collecting part, that is, to reflect the superheat degree of the refrigerant at the inlet of the compressor or the supercooling degree of the refrigerant at the inlet of the fluorine pump through the refrigerant parameters, so that the control device controls the refrigerant circulation system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to the refrigerant parameters. The setting mode of the refrigerant circuit of the refrigerant circulation system realizes the uniqueness of the refrigerant parameters, which is conducive to avoiding the frequent switching between the compressor refrigeration mode and the fluorine pump refrigeration mode due to the simultaneous detection of insufficient supercooling degree and superheat degree of the refrigerant at the outlet of the evaporator and the outlet of the condenser in the case of relatively cold outdoor and low load operation, thereby causing the compressor and the fluorine pump to be easily damaged and unable to refrigerate, thereby being conducive to maintaining the normal operation of the refrigerant circulation system.

[0042] The control method of the refrigerant circulation system of the present disclosure is based on the refrigerant circulation system of the present disclosure, thereby having the advantages of the refrigerant circulation system of the present disclosure.

[0043] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments thereof, with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0044] The drawings described herein are intended to provide further understanding of the present disclosure, and constitute a part of the present application. The schematic embodiments of the present disclosure and their descriptions are used to explain the present disclosure, and do not constitute an improper limitation on the present disclosure. In the drawings:

[0045] Figure 1 It is a refrigerant circuit schematic diagram of a refrigerant circulation system in the related art;

[0046] Figure 2 It is a refrigerant circuit schematic diagram of another refrigerant circulation system in the related art;

[0047] Figure 3 It is a refrigerant circuit schematic diagram of a refrigerant circulation system of an embodiment of the present disclosure;

[0048] Figure 4 It is Figure 3 It is a structure schematic diagram of a vapor-liquid separator of a refrigerant collecting part of the refrigerant circuit shown;

[0049] Figure 5 It is a structure schematic diagram of a liquid accumulator of a refrigerant collecting part of a refrigerant circuit of another embodiment of the present disclosure;

[0050] Figure 6 Structure diagram of a vapor-liquid separator according to another embodiment of the present disclosure;

[0051] Figure 7 Flow chart of a control method of a refrigerant circulation system according to Figure 3

[0052] Figures 1-7 In the drawings, the same or similar reference numerals represent the same or similar elements throughout the several views.

[0053] 100', condenser, 200', expansion valve, 300', evaporator, 401', fluorine pump, 402', compressor, 408', one-way valve, 405', electromagnetic valve;

[0054] 100, condenser, 101, outdoor fan, 200, throttling device, 300, evaporator, 301, evaporator fan, 401, fluorine pump, 402, compressor, 403, vapor-liquid separator, 41, separator inlet pipe, 41a, first port of separator inlet pipe, 41b, second port of separator inlet pipe, 421, separator liquid outlet pipe, 421a, first port of separator liquid pipe, 421b, second port of separator liquid pipe, 422, separator gas outlet pipe, 422a, first port of separator gas pipe, 422b, second port of separator gas pipe, 422c, oil inlet hole, 44, liquid guide pipe, 44a, liquid guide pipe inlet, 44b, liquid guide pipe outlet, 43, separator housing, 430, liquid accumulator, 430a, liquid accumulator inlet, 430b, liquid accumulator outlet, 431, liquid accumulator inlet pipe, 432, liquid accumulator outlet pipe, 433, liquid accumulator housing, 406, first electromagnetic valve, 405, second electromagnetic valve, 407, heating device, 482, first one-way valve, 481, second one-way valve. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present disclosure.

[0056] ​The relative arrangement of parts and steps, numerical expressions, and values set forth in the examples herein are not intended to limit the scope of the present disclosure unless otherwise specifically stated. It is to be understood that the drawings are not necessarily to scale as the dimensions of the parts shown are for the purpose of illustration and description only and can not reflect the actual proportions on the disclosure. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the description of the disclosure where appropriate. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments can have different values. It should be noted that like reference numerals and letters refer to like items in the following drawings, and therefore, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0057] In the description of the present disclosure, it should be understood that the use of the words "first", "second", and the like words of similar meaning to define parts only facilitates the differentiation of the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present disclosure.

[0058] In the description of the present disclosure, it should be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, vertical, horizontal", and "top, bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and in the absence of the opposite description, these orientation words do not indicate and imply that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present disclosure; the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0059] As Figure 1 and Figure 2 The refrigerant circuit schematic diagram of two refrigerant circulation systems in the related art simultaneously using a fluorine pump 401' and a compressor 402' for refrigeration, the fluorine pump 401' of the two refrigerant circulation systems is arranged between the outlet of the condenser 100' and the inlet of the evaporator 300'. Figure 1 The fluorine pump 401' of the refrigerant circulation system shown is connected in series with the expansion valve 200', Figure 1 The fluorine pump 401' of the refrigerant circulation system shown is connected in parallel with the expansion valve 200'.

[0060] Both of the two refrigerant circulation systems control the refrigerant circulation system to select the compressor refrigeration or the fluorine pump refrigeration by detecting the refrigerant supercooling degree at the outlet of the condenser 100' and the refrigerant superheating degree at the outlet of the evaporator 300'. However, in the low-temperature working condition (for example, the outdoor temperature is minus 18-15℃, and the load is below 20%), the refrigerant circulation system may simultaneously detect that the refrigerant supercooling degree at the outlet of the condenser 100' is insufficient and the refrigerant superheating degree at the outlet of the evaporator 300' is insufficient. At this time, the multiple one-way valves 408' and the electromagnetic valve 405' connected in series or parallel in the refrigerant circulation system are frequently opened and closed to cooperate with the control of the refrigerant circulation system to select the compressor refrigeration or the fluorine pump refrigeration. In this process, the fluorine pump 401' and the compressor 402' are also frequently opened and closed, which finally causes the fluorine pump 401' and the compressor 402' to be unable to work normally, and the refrigerant circulation system to be unable to refrigerate.

[0061] To solve the above problems, the embodiment of the present disclosure provides a refrigerant circulation system and a control method of the refrigerant circulation system. As shown in the figure, Figure 3 The refrigerant circulation system includes a refrigerant circuit, a detection device and a control device. The refrigerant circuit includes a compressor 402, a condenser 100, a throttling device 200 and an evaporator 300 connected in sequence through a refrigerant pipeline. The refrigerant circuit further includes a fluorine pump 401 and a refrigerant collection part. The fluorine pump 401 is connected in parallel with the compressor 402 between the evaporator 300 and the condenser 100 through the refrigerant pipeline. The refrigerant collection part includes a collection part inlet, a collection part gas outlet and a collection part liquid outlet. The collection part inlet is connected with the evaporator 100, the collection part gas outlet is connected with the inlet of the compressor 402, and the collection part liquid outlet is connected with the inlet of the fluorine pump 401. The detection device is configured to detect the refrigerant parameter of the refrigerant in the refrigerant collection part. The control device is in signal connection with the detection device and is configured to control the refrigerant circulation system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to the refrigerant parameter. In the compressor refrigeration mode, the compressor 402 is turned on, and the fluorine pump 401 is cut off from the refrigerant circuit. In the fluorine pump refrigeration mode, the fluorine pump 401 is turned on, and the compressor 402 is cut off from the refrigerant circuit.

[0062] Based on the refrigerant circulation system provided by the present disclosure, the refrigerant circuit of the refrigerant circulation system adopts the setting mode that the fluorine pump 401 and the compressor 402 are connected in parallel between the evaporator 300 and the condenser 100, the refrigerant pipeline connecting the inlet of the compressor 402 and the inlet of the fluorine pump 401 is integrated in the refrigerant collection part on the refrigerant circuit, so that the refrigerant flowing out of the outlet of the evaporator 300 first passes through the refrigerant collection part and then enters the compressor 402 or the fluorine pump 401.

[0063] The setting is conducive to the detection device of the refrigerant circulation system monitoring the refrigerant parameter of the refrigerant in the refrigerant collection part, that is, the detection of the refrigerant supercooling degree at the outlet of the condenser 100 and the refrigerant superheating degree at the outlet of the evaporator 300 at the same time reflects the detection of the refrigerant superheating degree at the inlet of the compressor 402 or the refrigerant supercooling degree at the inlet of the fluorine pump 401, so that the control device controls the refrigerant circulation system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to the refrigerant parameter. The setting mode of the refrigerant circuit of the refrigerant circulation system realizes the uniqueness of the refrigerant parameter, which is conducive to avoiding the problem that the compressor 402 and the fluorine pump 401 are damaged and cannot refrigerate due to the need to frequently switch between the compressor refrigeration mode and the fluorine pump refrigeration mode under the condition that the outdoor is relatively cold and the low load operation, so as to cause the problem of the compressor 402 and the fluorine pump 401 being damaged and unable to refrigerate, thereby facilitating the normal operation of the refrigerant circulation system.

[0064] On the other hand, the fluorine pump 401 and the compressor 402 are connected in parallel between the evaporator 300 and the condenser 100, and the refrigerant collection part is provided, and the detection device only needs to detect the refrigerant parameter in the refrigerant collection part, which reduces the influence of the detection results of the supercooling degree and the superheating degree at different detection positions in the refrigerant circuit on the control device, and also facilitates reducing the positions in the refrigerant circuit that need to be provided with detection devices, thereby reducing the setting of the detection device, improving the efficiency of maintaining and repairing the refrigerant circulation system, and improving the operation stability of the refrigerant circulation system.

[0065] In some embodiments, the refrigerant collection part includes a vapor-liquid separator 403. The vapor-liquid separator 403 includes a separator inlet and a separator gas outlet. As shown in Figure 3 and Figure 4 In some embodiments, the vapor-liquid separator 403 also includes a separator liquid outlet. The separator inlet, the separator gas outlet and the separator liquid outlet form the collection part inlet, the collection part gas outlet and the collection part liquid outlet respectively. The setting is conducive to integrating the collection part inlet, the collection part gas outlet and the collection part liquid outlet on the vapor-liquid separator 403, so that the switching between the compressor refrigeration mode and the fluorine pump refrigeration mode can be based on the liquid level in the vapor-liquid separator 403, which is conducive to avoiding the problem of liquid hammering of the compressor 402 due to the high liquid level in the vapor-liquid separator 403 in the compressor refrigeration mode, thereby reducing the service life of the compressor 402, and also conducive to avoiding the problem of the fluorine pump 401 sucking in gaseous refrigerant due to the low liquid level in the fluorine pump refrigeration mode, thereby reducing the service life of the fluorine pump 401. On the other hand, the setting is conducive to reducing the control variables in the refrigerant parameter, thereby facilitating the reduction of the setting positions of the detection device, facilitating the detection of the refrigerant parameter, and also conducive to improving the stability of the refrigerant circulation system.

[0066] As shown in Figure 5 and Figure 6As shown in some embodiments, the refrigerant collection section further comprises a liquid accumulator 430. The liquid accumulator 430 comprises a liquid accumulator inlet 430a and a liquid accumulator outlet 430b. The separator inlet forms the collection section inlet with the liquid accumulator inlet 430a, the separator gas outlet forms the collection section gas outlet, and the liquid accumulator outlet 430b forms the collection section liquid outlet. This arrangement is advantageous in that it allows the collection section gas outlet to be formed by the vapor-liquid separator 403 in the compressor refrigeration mode, so that gaseous refrigerant enters the compressor 402, thereby avoiding liquid refrigerant from entering the compressor 402 in the compressor refrigeration mode, which reduces the refrigeration efficiency and operational reliability of the compressor 402, and allows the collection section liquid outlet to be formed by the liquid accumulator 430 in the fluorine pump refrigeration mode, so that liquid refrigerant enters the fluorine pump 401, thereby avoiding gaseous refrigerant from entering the fluorine pump 401 in the fluorine pump refrigeration mode, which reduces the refrigeration efficiency and operational reliability of the fluorine pump 401.

[0067] As shown in some embodiments, the vapor-liquid separator 403 comprises a separator housing 43, a separator inlet pipe 41, and a separator gas outlet pipe 422. The separator housing 43 is configured to receive refrigerant output from the evaporator 300 to the vapor-liquid separator 403. The separator inlet pipe 41 comprises a separator inlet pipe first port 41a and a separator inlet pipe second port 41b. The separator inlet pipe first port 41a forms the separator inlet, and the separator inlet pipe second port 41b is inserted into gaseous refrigerant within the separator housing 43. The separator gas outlet pipe 422 comprises a separator gas pipe first port 422a and a separator gas pipe second port 422b. The separator gas pipe first port 422a is disposed in gaseous refrigerant within the separator housing 43, and the separator gas pipe second port 422b forms the separator gas outlet. Figure 4 , Figure 5 and Figure 6 As shown in some embodiments, the vapor-liquid separator 403 comprises a separator housing 43, a separator inlet pipe 41, and a separator gas outlet pipe 422. The separator housing 43 is configured to receive refrigerant output from the evaporator 300 to the vapor-liquid separator 403. The separator inlet pipe 41 comprises a separator inlet pipe first port 41a and a separator inlet pipe second port 41b. The separator inlet pipe first port 41a forms the separator inlet, and the separator inlet pipe second port 41b is inserted into gaseous refrigerant within the separator housing 43. The separator gas outlet pipe 422 comprises a separator gas pipe first port 422a and a separator gas pipe second port 422b. The separator gas pipe first port 422a is disposed in gaseous refrigerant within the separator housing 43, and the separator gas pipe second port 422b forms the separator gas outlet.

[0068] This arrangement utilizes the difference in weight between liquid and gas to separate, and the separation method is less resistant, making it easier to effectively separate gaseous refrigerant flowing into the refrigerant collection section from the evaporator 300, and the structure of the vapor-liquid separator 403 is simple, which is advantageous in reducing production costs.

[0069] As shown in some embodiments, the vapor-liquid separator 403 comprises a separator housing 43, a separator inlet pipe 41, and a separator gas outlet pipe 422. The separator housing 43 is configured to receive refrigerant output from the evaporator 300 to the vapor-liquid separator 403. The separator inlet pipe 41 comprises a separator inlet pipe first port 41a and a separator inlet pipe second port 41b. The separator inlet pipe first port 41a forms the separator inlet, and the separator inlet pipe second port 41b is inserted into gaseous refrigerant within the separator housing 43. The separator gas outlet pipe 422 comprises a separator gas pipe first port 422a and a separator gas pipe second port 422b. The separator gas pipe first port 422a is disposed in gaseous refrigerant within the separator housing 43, and the separator gas pipe second port 422b forms the separator gas outlet. Figure 4 Figure 6 As shown in some embodiments, the separator gas outlet pipe 422 comprises a bend section disposed between the separator gas pipe first port 422a and the separator gas pipe second port 422b. The bend section is located in liquid refrigerant within the separator housing 43, and the bend section comprises an oil inlet hole 422c located in an oil layer deposited at the bottom of the liquid refrigerant, configured to atomize oil entering the separator gas outlet pipe 422 through the oil inlet hole 422c.

[0070] ​During the process of separating gaseous and liquid refrigerant in the vapor-liquid separator, oil is also separated and deposited at the bottom of the housing 43. The oil inlet 422c facilitates oil return, allowing the deposited oil to return to the compressor 402 through the refrigerant lines. This ensures sufficient oil inside the compressor 402 for lubrication, preventing wear or malfunction due to insufficient oil. Furthermore, the oil inlet 422c is configured to atomize the oil, which helps prevent some liquid refrigerant from entering the compressor 402 and affecting its cooling efficiency.

[0071] like Figure 4 As shown, in some embodiments, the vapor-liquid separator 403 further includes a liquid guide pipe 44. The liquid guide pipe 44 is separately disposed from the separator inlet pipe 41. The liquid guide pipe inlet 44a of the liquid guide pipe 44 faces and is larger than the second port 41b of the separator inlet pipe, and the second port 41b of the separator inlet pipe is located inside the opening of the liquid guide pipe inlet 44a. The liquid guide pipe outlet 44b of the liquid guide pipe 44 is inserted into the liquid refrigerant and / or oil layer within the separator housing 43.

[0072] The aforementioned liquid guide pipe 44 is designed to directly guide the liquid refrigerant and oil flowing from the evaporator 300 into the liquid refrigerant stored in the separator housing 43. This prevents gaseous refrigerant from directly blowing onto the liquid surface or liquid refrigerant and oil from dripping and disturbing the liquid surface, thus avoiding liquid splashing and preventing some liquid refrigerant from directly entering the compressor 402 through the separator gas outlet pipe 422. On the other hand, this design helps to ensure stable liquid level changes, thereby improving the accuracy of the measurement by the detection device.

[0073] like Figure 4 As shown, in some embodiments, the liquid guide tube 44 includes a vertical tube section and an oblique tube section at an obtuse angle to the vertical tube section. The liquid guide tube inlet 44a is located at the end of the oblique tube section away from the vertical tube section, and the liquid guide tube outlet 44b is located at the end of the vertical tube section away from the oblique tube section.

[0074] The inclined section of the liquid guide pipe 44 helps to slow down and buffer the liquid refrigerant and oil received from the separator inlet pipe 41, which is beneficial for the separation of gaseous refrigerant and reduces air bubbles entrained in the liquid refrigerant and oil. The inclined section of the liquid guide pipe 44 also helps to accelerate the flow rate of the liquid refrigerant and oil, preventing the liquid refrigerant and oil from accumulating in the liquid guide pipe 44 or even overflowing from the liquid guide pipe inlet 44a.

[0075] like Figure 4 As shown, in some embodiments, the cross-section of the first end of the liquid guide tube 44 near the liquid guide tube inlet 44a gradually decreases from the liquid guide tube inlet 44a toward the second end of the liquid guide tube 44, and the second port 41b of the separator inlet tube is disposed toward the inner wall of the first end of the liquid guide tube 44.

[0076] This arrangement creates a funnel-shaped structure at the first end of the liquid guide tube 44 near the inlet 44a, which facilitates the diffusion of gaseous refrigerant and thus improves the separation effect between gaseous and liquid refrigerant.

[0077] like Figure 4 As shown, in some embodiments, the vapor-liquid separator 403 further includes a separator liquid outlet pipe 421. The separator liquid outlet pipe 421 includes a separator liquid pipe first port 421a and a separator liquid pipe second port 421b. The separator liquid pipe first port 421a is inserted into the liquid refrigerant inside the separator housing 43, and the separator liquid pipe second port 421b forms the separator liquid outlet.

[0078] The vapor-liquid separator 403, including the separator liquid outlet pipe 421, facilitates the integration of the liquid receiver function into the vapor-liquid separator 403, eliminating the need for a separate liquid receiver. It also allows for real-time monitoring of the liquid level within the vapor-liquid separator 403, enabling control of the switching between compressor refrigeration mode and refrigerant pump refrigeration mode based on the liquid level. This helps prevent the compressor 402 from drawing in liquid refrigerant in compressor refrigeration mode due to excessively high liquid levels, and also prevents the refrigerant pump 401 from drawing in gaseous refrigerant in refrigerant pump refrigeration mode due to excessively low liquid levels, thereby improving the stability of the refrigerant circulation system. Furthermore, this design reduces the amount of liquid refrigerant stored in the refrigerant collection section, improving refrigerant utilization. On the other hand, this arrangement also facilitates the centralized arrangement of detection devices at the vapor-liquid separator 403, making it easier for the detection devices to detect the refrigerant parameters of the refrigerant at the same location in the refrigerant circuit. This allows for a more accurate determination of the refrigerant overcooling or overheating status of the refrigerant circulation system based on the refrigerant parameters, which in turn enables the control device to switch the refrigerant circulation system between compressor refrigeration mode and refrigerant pump refrigeration mode.

[0079] In some embodiments, the refrigerant circuit further includes a first check valve 482 and a second check valve 481. The first check valve 482 is connected in series between the compressor 402 and the condenser 100 and is configured to allow refrigerant to flow unidirectionally from the compressor 402 to the condenser 100. The second check valve 481 is connected in series between the refrigerant pump 401 and the condenser 100 and is configured to allow refrigerant to flow unidirectionally from the refrigerant pump 401 to the condenser 100.

[0080] Setting up a first check valve 482 helps to prevent backflow into the refrigerant pump 401 during the operation of the compressor 402, which could damage the refrigerant pump 401. Setting up a second check valve 481 helps to prevent backflow into the compressor 402 during the operation of the refrigerant pump 401, which could damage the compressor 402.

[0081] In some embodiments, the detection device includes a liquid level sensor. The liquid level sensor is configured to detect the liquid level H within the vapor-liquid separator 403. The control device is configured to control the refrigerant circulation system to switch between compressor refrigeration mode and refrigerant pump refrigeration mode based on a first distance and a second distance. The first distance is the height H of the outlet position from which gaseous refrigerant is drawn from the vapor-liquid separator 403. A The second distance is the height difference between the liquid level H and the liquid outlet of the collection section from the vapor-liquid separator 403. B The height difference. (Refer to...) Figure 4 In the illustrated embodiment, the liquid outlet of the collection section draws out the liquid refrigerant from the vapor-liquid separator 403 at the midpoint of the first port 421a of the separator's liquid pipe. The gas outlet of the collection section draws out the gaseous refrigerant from the vapor-liquid separator 403 at the midpoint of the first port 422a of the separator's gas pipe.

[0082] The first and second distances can intuitively and accurately reflect the proportion of liquid and gaseous refrigerant in the vapor-liquid separator 403, that is, reflect the subcooling and superheating in the refrigerant collection section. This allows the control device to switch the refrigerant circulation system between compressor refrigeration mode and refrigerant pump refrigeration mode based on the first and second distances, which is beneficial to improving the refrigeration efficiency of the refrigerant circulation system and maintaining the stable operation of the refrigerant circulation system.

[0083] In some embodiments, the refrigerant circulation system further includes an outdoor fan 101 and / or a heating device 407 for heating the refrigerant within the vapor-liquid separator 403 of the refrigerant collection section. The detection device also includes a temperature sensor and a pressure sensor. The temperature sensor and pressure sensor are used to detect the refrigerant temperature and refrigerant pressure of the gaseous refrigerant within the vapor-liquid separator 403 of the refrigerant collection section, respectively. The refrigerant parameters include refrigerant temperature and refrigerant pressure. The control device is configured to calculate the saturation temperature T of the refrigerant within the vapor-liquid separator 403 based on the refrigerant pressure. 饱 And calculate the refrigerant temperature T 回 With saturation temperature T 饱 The temperature difference is used to control the speed of the outdoor fan 101 and / or to control the heating device 407 to start or stop.

[0084] The temperature difference can reflect whether the refrigerant in the refrigerant collection section is undercooled or overheated. The control device controls the speed of the outdoor fan 101 according to the temperature difference, which is beneficial to adjust the undercooling of the refrigerant entering the refrigerant pump 401 in the refrigerant pump refrigeration mode. The control device also controls the heating device 407 to heat the refrigerant according to the temperature difference, which is beneficial to adjust the overheating of the refrigerant entering the compressor 402 in the compressor refrigeration mode.

[0085] In some embodiments, the refrigerant circulation system further comprises a first electromagnetic valve 406 and a second electromagnetic valve 405. The first electromagnetic valve 406 is arranged between the collection portion gas outlet and the compressor 402, and is in signal connection with the control device. The control device is configured to open the first electromagnetic valve 406 in the compressor refrigeration mode, and close the first electromagnetic valve 406 in the fluorine pump refrigeration mode. The second electromagnetic valve 405 is arranged between the collection portion liquid outlet and the fluorine pump 401, and is in signal connection with the control device. The control device is configured to open the second electromagnetic valve 405 in the fluorine pump refrigeration mode, and close the second electromagnetic valve 405 in the compressor refrigeration mode.

[0086] The arrangement is conducive to the control device quickly switching the refrigerant circulation system between the compressor refrigeration mode and the fluorine pump refrigeration mode through the first electromagnetic valve 406 and the second electromagnetic valve 405, thereby being conducive to improving the operation efficiency of the refrigerant circulation system.

[0087] Another aspect of the embodiments of the present disclosure provides a control method of the refrigerant circulation system of the embodiments of the present disclosure. The control method comprises: a detection device detecting a refrigerant parameter of refrigerant in a refrigerant collection portion. A control device controls the refrigerant circulation system to switch between a compressor refrigeration mode and a fluorine pump refrigeration mode according to the refrigerant parameter.

[0088] The control method of the embodiments of the present disclosure adopts the refrigerant circulation system of the embodiments of the present disclosure and has the advantages of the refrigerant circulation system. Based on the control method, the detection device detects a refrigerant parameter of refrigerant in a refrigerant collection portion, for example, detects a liquid level of refrigerant in a vapor-liquid separator 403, so that the control device controls the refrigerant circulation system to switch between a compressor refrigeration mode and a fluorine pump refrigeration mode according to the refrigerant parameter (for example, including the liquid level of refrigerant in the vapor-liquid separator 403). The refrigerant circulation system adopting the control method is conducive to preventing the refrigerant circulation system from frequently switching between the compressor refrigeration mode and the fluorine pump refrigeration mode in the case of relatively cold outdoor and low load, thereby being conducive to maintaining normal refrigeration operation of the refrigerant circulation system under low-temperature working conditions.

[0089] In some embodiments, the control method further comprises: the detection device detecting a liquid level in a vapor-liquid separator 403 of the refrigerant collection portion. The control device is configured to control the refrigerant circulation system to switch between a compressor refrigeration mode and a fluorine pump refrigeration mode according to the first distance and the second distance.

[0090] The control device controls the refrigerant circulation system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to the first distance and the second distance. Since other parameters for calculating the first distance and the second distance are fixed values except for the liquid level, the parameters for the control device to control the refrigerant circulation system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode are unique, which is beneficial to improve the control accuracy, reduce the switching frequency, improve the refrigeration efficiency of the refrigerant circulation system, reduce the fluctuation of the refrigerant parameters, and maintain the stable operation of the refrigerant circulation system.

[0091] In some embodiments, the control method further includes: in the case that the first distance is greater than or equal to the second distance, the control device controls the refrigerant circulation system to switch to the compressor refrigeration mode; and in the case that the first distance is less than the second distance, the control device controls the refrigerant circulation system to switch to the fluorine pump refrigeration mode.

[0092] The first distance greater than or equal to the second distance indicates that the liquid level in the vapor-liquid separator 403 is at a lower position, and the amount of liquid refrigerant is relatively small, which can indicate that the subcooling degree in the refrigerant collection part is insufficient. In this case, the fluorine pump 401 is not suitable for refrigeration, so the control device controls the refrigerant circulation system to start the compressor refrigeration mode and use the compressor 402 for refrigeration.

[0093] The first distance less than the second distance indicates that the liquid level in the vapor-liquid separator 403 is at a higher position, and the amount of liquid refrigerant is relatively large, which can indicate that the superheating degree of the refrigerant in the refrigerant collection part is insufficient. In this case, the compressor 402 cannot normally refrigerate, so the control device controls the refrigerant circulation system to switch to the fluorine pump refrigeration mode and use the fluorine pump 401 for refrigeration.

[0094] The control method is beneficial to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to the subcooling or superheating of the refrigerant in the refrigerant collection part, avoids the use of the fluorine pump 401 for refrigeration in the case of insufficient subcooling, which reduces the service life of the fluorine pump 401, and avoids the use of the compressor 402 for refrigeration in the case of insufficient superheating, which reduces the service life of the compressor 402, thereby maintaining the normal operation of the refrigerant circulation system under low-temperature working conditions.

[0095] In some embodiments, the control method further includes: the temperature sensor and the pressure sensor detect the refrigerant temperature and the refrigerant pressure of the gaseous refrigerant in the vapor-liquid separator 403 of the refrigerant collection part, respectively. The control device calculates the saturation temperature T 饱 of the refrigerant in the vapor-liquid separator 403 according to the refrigerant pressure, calculates the temperature difference between the refrigerant temperature T 回 and the saturation temperature T 饱 , and controls the rotation speed of the outdoor fan 101 and / or controls the heating device 407 to start or stop according to the temperature difference.

[0096] The temperature difference can reflect the supercooling or superheating in the refrigerant collecting part. The method of controlling the outdoor fan 101 speed and / or starting / stopping the heating device 407 according to the temperature difference is advantageous for adjusting the supercooling degree in the fluorine pump refrigeration mode and / or for adjusting the superheating degree in the compressor refrigeration mode, thereby maintaining the normal refrigeration of the refrigerant circulation system in the corresponding refrigeration mode.

[0097] In some embodiments, the control method further comprises:

[0098] In the case that the refrigerant circulation system is in the compressor refrigeration mode and the temperature difference is less than the set first limit temperature difference, the control device controls the heating device 407 to start. In the case that the temperature difference is greater than or equal to the first limit temperature difference and the first distance is less than or equal to the set first limit distance value, the control device controls the heating device 407 to stop and controls the refrigerant circulation system to switch from the compressor refrigeration mode to the fluorine pump refrigeration mode.

[0099] In the compressor refrigeration mode, the refrigerant circulation system uses the compressor 402 for refrigeration. If the temperature difference is less than the set first limit temperature difference, it indicates that the superheating degree is insufficient and the liquid level is still at a low position. Therefore, the control device is configured to control the heating device 407 to start to heat the refrigerant, which is advantageous for restoring the superheating degree in the compressor refrigeration mode. Conversely, if the temperature difference is greater than or equal to the first limit temperature difference and the first distance is less than or equal to the set first limit distance value, it indicates that the refrigerant circulation system is close to the supercooling state, and the heating device 407 needs to be stopped and switched to the fluorine pump refrigeration mode. The above settings make it possible that, during the operation of the refrigerant circulation system, when the liquid level is at an intermediate appropriate position, if the superheating degree is small when the compressor refrigeration mode is running, the liquid level will gradually increase. In order to slow down or reverse this trend, the superheating degree needs to be increased, i.e. the heating device 407 needs to be started. If the superheating degree is still small after the heating device 407 is started, the liquid level will continue to rise, and the fluorine pump refrigeration mode can be switched to when the liquid level is too high, thereby avoiding frequent switching between the compressor refrigeration mode and the fluorine pump refrigeration mode.

[0100] In some embodiments, the control method further comprises: in the case that the refrigerant circulation system is in the fluorine pump refrigeration mode and the temperature difference is greater than or equal to the set second limit temperature difference, the control device controls the outdoor fan 101 to speed up. In the case that the refrigerant circulation system is in the fluorine pump refrigeration mode and the temperature difference is less than the second limit temperature difference and the second distance is less than the set second limit distance value, the control device controls the outdoor fan 101 to restore the speed before the speed-up and controls the refrigerant circulation system to switch to the compressor refrigeration mode.

[0101] In refrigerant pump cooling mode, the refrigerant circulation system uses refrigerant pump 401 for cooling. If the temperature difference is greater than or equal to the set second limit temperature difference, it indicates insufficient subcooling, but the liquid level is still at a high level. Therefore, setting a control device to increase the speed of outdoor fan 101 in this situation helps to restore subcooling in refrigerant pump cooling mode. Conversely, if the temperature difference is less than the second limit temperature difference and the second distance is less than the set second limit distance value, it indicates that the refrigerant circulation system is approaching a superheated state. In this case, it is necessary to restore the outdoor fan 101, which has already been increased in speed, to its previous speed and switch to compressor cooling mode. The above settings ensure that when the refrigerant circulation system is running and the liquid level is at a suitable intermediate position, if the subcooling is insufficient while the refrigerant pump refrigeration mode is in operation, the liquid level will gradually decrease. To slow down or reverse this trend, the subcooling needs to be increased, i.e., the outdoor fan 101 needs to be accelerated. If the subcooling is still too low after accelerating the outdoor fan 101, the liquid level will continue to decrease. When the liquid level is too low, the system can switch to compressor refrigeration mode, thus avoiding frequent switching between refrigerant pump refrigeration mode and compressor refrigeration mode.

[0102] In some embodiments, the heating device 407 may be, for example, an electric heating element. The range of the first limiting temperature difference may be, for example, 0~5°C, such as 3°C. The range of the second limiting temperature difference may be, for example, -5~0°C, such as -3°C. The range of the first limiting distance value may be, for example, 10~15mm, such as 12mm. The range of the second limiting distance value may be, for example, 10~15mm, such as 12mm.

[0103] The following combination Figures 3 to 7 The refrigerant circulation system and control method according to embodiments of this disclosure will be described in detail. The refrigerant circulation system includes a refrigerant circuit, a detection device, and a control device. Figure 3 In the illustrated embodiment, the refrigerant circuit connects the compressor 402, condenser 100, throttling device 200, and evaporator 300 in series via refrigerant piping. An evaporator fan 301 is installed outside the evaporator 300. A refrigerant pump 401 and compressor 402 are connected in parallel between the evaporator 300 and condenser 100. The refrigerant circuit also includes a refrigerant collection section, which includes a vapor-liquid separator 403. The vapor-liquid separator 403 includes a separator housing 43, a separator inlet pipe 41, a separator gas outlet pipe 422, a separator liquid outlet pipe 421, and a liquid guide pipe 44.

[0104] The separator housing 43 stores the refrigerant outputted from the evaporator 100 into the vapor-liquid separator 403. The separator inlet pipe first port 41a of the separator inlet pipe 41 is formed as a collection inlet of the refrigerant collection portion, and is connected with the evaporator 100 to receive the refrigerant outputted from the evaporator 100. The pipe section of the separator inlet pipe 41 close to the separator inlet pipe second port 41b gradually inclines to the obliquely downward direction at an angle of 45° to the vertical direction, and the refrigerant is decelerated in the inclined pipe section of the separator inlet pipe 41. The separator inlet pipe second port 41b is located in the gaseous refrigerant in the separator housing 43.

[0105] The liquid guide pipe 44 is located below the separator inlet pipe 41, the liquid guide pipe inlet 44a of the liquid guide pipe 44 faces and is larger than the separator inlet pipe second port 41b, and the separator inlet pipe second port 41b is located inside the opening of the liquid guide pipe inlet 44a. The refrigerant flowing out of the separator inlet pipe second port 41b directly enters the liquid guide pipe 44, the gaseous refrigerant diffuses from the liquid guide pipe inlet 44a into the gaseous refrigerant stored in the separator housing 43 due to the small density and light weight, and the liquid refrigerant and oil liquid flow along the pipe wall of the inclined pipe section of the liquid guide pipe 44 to the oil liquid layer stored in the separator housing 43. The oil liquid is deposited in the oil liquid layer, and the liquid refrigerant floats due to the small density. The inclined pipe section of the liquid guide pipe 44 gradually inclines to the obliquely upward direction at an angle of 45° to the vertical direction to the side close to the separator liquid outlet pipe 421.

[0106] The end of the inclined pipe section of the liquid guide pipe 44 close to the liquid guide pipe inlet 44a is formed as a funnel-shaped pipe section, and the liquid guide pipe inlet 44a is the position with the largest opening. The refrigerant flowing out of the separator inlet pipe second port 41b impacts on the inner wall at the funnel-shaped liquid guide pipe 44, so that the gaseous refrigerant diffuses upward through the funnel-shaped pipe section of the liquid guide pipe 44, and the liquid refrigerant and oil liquid are buffered and decelerated through the funnel-shaped pipe section of the liquid guide pipe 44, and gradually flow along the vertical pipe section of the liquid guide pipe 44 to the oil liquid layer.

[0107] The separator gas outlet pipe 422 is a U-shaped pipe, and the bottom of the separator gas outlet pipe 422 is provided with an oil inlet hole 422c in communication with the oil liquid layer. The separator gas pipe first port 422a of the separator gas outlet pipe 422 is arranged in the gaseous refrigerant in the separator housing 43, and the separator gas pipe second port 422b is located outside the separator housing 43 and is in communication with the gas inlet of the compressor 402. The separator gas pipe second port 422b forms a collection gas outlet of the refrigerant collection portion. When the compressor 402 is working, the gaseous refrigerant in the vapor-liquid separator 403 is sucked into the separator gas outlet pipe 422 through the separator gas pipe first port 422a, and the oil liquid enters the separator gas outlet pipe 422 through the oil inlet hole 422c. The oil liquid atomized by the oil inlet hole 422c flows to the compressor 402 together with the gaseous refrigerant through the separator gas pipe second port 422b.

[0108] The separator liquid outlet pipe 421 and the separator gas outlet pipe 422 are arranged on both sides of the separator inlet pipe 41 and the liquid guide pipe 44. The separator liquid outlet pipe 421 is a vertical pipe segment. The separator liquid pipe first port 421a of the separator liquid outlet pipe 421 is inserted into the liquid refrigerant in the separator housing 43. The separator liquid pipe second port 421b is located outside the separator housing 43 and connected to the inlet of the fluorine pump 401. The separator liquid pipe second port 421b forms a liquid outlet of the refrigerant collection part. When the fluorine pump 401 is working, the liquid refrigerant in the vapor-liquid separator 403 is sucked into the separator liquid outlet pipe 421 through the separator liquid pipe first port 421a, and then flows to the fluorine pump 401 through the separator liquid pipe second port 421b.

[0109] As shown in Figure 7 The control method of the refrigerant circuit of the refrigerant circulation system based on Figure 3 The flow chart of the control method of the refrigerant circuit of the refrigerant circulation system based on Figure 7 H represents the liquid level in the vapor-liquid separator 403, H A represents the height of the separator gas pipe first port 422a, H B represents the height of the separator liquid pipe first port 421a. The first distance is H A and the height of H. The second distance is H B and the height of H. T 回 represents the refrigerant temperature of the gaseous refrigerant in the vapor-liquid separator 403, T 饱 represents the saturation temperature calculated according to the refrigerant pressure of the gaseous refrigerant in the vapor-liquid separator 403. The temperature difference is T 回 and T 饱 . In this embodiment, the heating device 407 is an electric heating belt. The first limit distance value is 15 mm, the second limit distance value is 15 mm, the first limit temperature difference is 2℃, and the second limit temperature difference is -2℃.

[0110] The control method comprises:

[0111] Step 1: start the refrigerant circulation system;

[0112] Step 2: calculate the first distance and the second distance according to the refrigerant parameters detected by the detection device, and compare the sizes of the first distance and the second distance. If the first distance is greater than or equal to the second distance, the control device controls the refrigerant circulation system to start the compressor refrigeration mode, otherwise the fluorine pump refrigeration mode is started.

[0113] Step 3: Calculate the temperature difference in compressor cooling mode. If the temperature difference is less than 2℃, start the electric heating belt; otherwise, compare the first distance with the first limit distance. Alternatively, calculate the temperature difference in refrigerant pump cooling mode. If the temperature difference is greater than or equal to -2℃, control the outdoor fan 101 to speed up; otherwise, compare the second distance with the second limit distance.

[0114] Step 4: If it is determined in Step 3 that the first distance is less than or equal to the first limit distance value, then turn off the electric heating belt and switch the refrigerant circulation system to the refrigerant pump cooling mode; otherwise, return to Step 3. Or if it is determined in Step 3 that the second distance is less than the second limit distance value, then restore the outdoor fan 101 to the speed before the speed increase and switch the refrigerant circulation system to the compressor cooling mode; otherwise, return to Step 3.

[0115] Step 5: Repeat steps 2 through 4.

[0116] According to the above control method, when the refrigerant circulation system uses compressor 402 for cooling in compressor refrigeration mode, the intake port of compressor 402 meets the superheat requirement. It also helps the refrigerant circulation system to use refrigerant pump 401 for cooling in refrigerant pump refrigeration mode, so that the inlet of refrigerant pump 401 meets the subcooling requirement. This helps the refrigerant circulation system maintain normal cooling under low temperature conditions and avoids frequent starting and stopping of refrigerant pump 401 or compressor 402.

[0117] Furthermore, such as Figure 4 The vapor-liquid separator 403 shown has minimal disturbance to the liquid surface during the vapor-liquid separation process, which helps maintain a stable rise and fall of the liquid level. Therefore, the control method of this disclosure is based on the cooling parameters of the vapor-liquid separator 403, including the liquid level, to determine whether the liquid is undercooled or overheated. This helps improve the accuracy of the determination and reduce the fluctuations in the cooling cycle system when switching refrigeration modes.

[0118] The first limit distance value, the second limit distance value, the first limit temperature difference, and the second limit temperature difference can be adjusted according to the actual situation.

[0119] like Figure 5The diagram shows a refrigerant collection unit reservoir 430 according to another embodiment of this disclosure. The reservoir 430 includes a reservoir inlet pipe 431 and a reservoir outlet pipe 432 extending vertically and passing through a reservoir housing 433. The top opening of the reservoir inlet pipe 431 forms a reservoir inlet 430a. The bottom opening of the reservoir inlet pipe 431 is inserted into the liquid refrigerant within the reservoir housing 433. The top opening of the reservoir outlet pipe 432 forms a reservoir outlet 430b. The bottom opening of the reservoir outlet pipe 432 is inserted into the liquid refrigerant within the reservoir housing 433. The reservoir inlet 430a forms the collection unit inlet and communicates with the evaporator 300. The separator gas outlet forms the collection unit gas outlet, and the reservoir outlet 430b forms the collection unit liquid outlet. The reservoir outlet 430b forms the collection unit liquid outlet and communicates with the inlet of the refrigerant pump 401.

[0120] like Figure 6 The following is included Figure 5 The vapor-liquid separator 403 of the refrigerant collection section of the liquid reservoir 430 is shown. The vapor-liquid separator 403 includes a separator inlet pipe 41 and a separator gas outlet pipe 422. The section of the separator inlet pipe 41 near the second port 41b is configured as an inclined section extending at a 45° angle to the vertical and gradually sloping downwards. The opening directions of the second port 41b of the separator inlet pipe and the first port 422a of the separator gas outlet pipe 422 are opposite to each other to prevent liquid refrigerant and oil entering the vapor-liquid separator 403 from the separator inlet pipe 41 from entering the separator gas outlet pipe 422. The separator gas outlet pipe 422 is a U-shaped pipe, and an oil inlet hole 422c is provided at the bottom of the separator gas outlet pipe 422, which communicates with the oil layer. The first port 422a of the separator gas outlet pipe 422 is located in the gaseous refrigerant inside the separator housing 43, while the second port 422b is located outside the separator housing 43 and communicates with the air inlet of the compressor 402. The second port 422b forms the gas outlet of the refrigerant collection section. When the compressor 402 is working, the gaseous refrigerant in the vapor-liquid separator 403 is drawn into the separator gas outlet pipe 422 through the first port 422a, while oil enters the separator gas outlet pipe 422 through the oil inlet 422c. The oil atomized by the oil inlet 422c flows together with the gaseous refrigerant through the second port 422b to the compressor 402.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure and not to limit them; although this disclosure has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this disclosure or equivalent substitutions can be made to some technical features, all of which should be covered within the scope of the technical solutions claimed in this disclosure.

Claims

1. A refrigerant circulating system characterized by comprising: Comprising: The refrigerant circuit comprises a compressor (402), a condenser (100), a throttling device (200) and an evaporator (300) connected in sequence through a refrigerant pipeline, further comprises a fluorine pump (401) and a refrigerant collecting part, the fluorine pump (401) is connected between the evaporator (300) and the condenser (100) in parallel with the compressor (402) through the refrigerant pipeline, the refrigerant collecting part comprises a collecting part inlet, a collecting part gas outlet and a collecting part liquid outlet, the collecting part inlet is connected with the evaporator (300), the collecting part gas outlet is connected with the inlet of the compressor (402), the collecting part liquid outlet is connected with the inlet of the fluorine pump (401), the refrigerant collecting part comprises a vapor-liquid separator (403), the vapor-liquid separator (403) comprises a separator inlet, a separator liquid outlet and a separator gas outlet, the separator inlet, the separator gas outlet and the separator liquid outlet form the collecting part inlet, the collecting part gas outlet and the collecting part liquid outlet respectively; a detection device configured to detect a refrigerant parameter of the refrigerant in the refrigerant collecting part, the refrigerant parameter comprises a first distance, a second distance and a liquid level H in the vapor-liquid separator (403), the first distance is the height difference between the height H of the gas outlet position of the collecting part gas outlet from the vapor-liquid separator (403) and the height H of the liquid level H A The second distance is the height difference between the height H of the liquid level H and the height H of the liquid outlet position of the collecting part liquid outlet from the vapor-liquid separator (403) B . And The control device, in signal connection with the detection device, is configured to control the refrigerant circulating system to switch between a compressor refrigeration mode and a fluorine pump refrigeration mode according to the refrigerant parameter, wherein in the compressor refrigeration mode, the compressor (402) is turned on, and the fluorine pump (401) is cut off from the refrigerant circuit; in the fluorine pump refrigeration mode, the fluorine pump (401) is turned on, and the compressor (402) is cut off from the refrigerant circuit.

2. The refrigerant cycle system according to claim 1, characterized by The vapor-liquid separator (403) comprises: A separator housing (43) configured to receive the refrigerant output from the evaporator (300) to the vapor-liquid separator (403); A separator inlet pipe (41) comprising a separator inlet pipe first port (41a) forming the separator inlet and a separator inlet pipe second port (41b) inserted into the gaseous refrigerant in the separator housing (43); and A separator gas outlet pipe (422) comprising a separator gas pipe first port (422a) disposed in the gaseous refrigerant in the separator housing (43) and a separator gas pipe second port (422b) forming the separator gas outlet.

3. The refrigerant cycle system according to claim 2, characterized by The separator gas outlet pipe (422) comprises a bend pipe section disposed between the separator gas pipe first port (422a) and the separator gas pipe second port (422b), the bend pipe section is located in the liquid refrigerant in the separator housing (43), and the bend pipe section comprises an oil inlet hole (422c) located in an oil layer deposited at the bottom of the liquid refrigerant and configured to atomize the oil entering the separator gas outlet pipe (422) through the oil inlet hole (422c).

4. The refrigerant cycle system according to claim 2, characterized by The vapor-liquid separator (403) further comprises a liquid guide pipe (44) disposed separately from the separator inlet pipe (41), a liquid guide pipe inlet (44a) of the liquid guide pipe (44) is directed to and larger than the separator inlet pipe second port (41b), and the separator inlet pipe second port (41b) is located inside the opening of the liquid guide pipe inlet (44a), and a liquid guide pipe outlet (44b) of the liquid guide pipe (44) is inserted into the liquid refrigerant and / or oil layer in the separator housing (43).

5. The refrigerant cycle system according to claim 4, characterized in that, The liquid guide pipe (44) comprises a vertical pipe section and an inclined pipe section at an obtuse angle with the vertical pipe section, the liquid guide pipe inlet (44a) is located at one end of the inclined pipe section away from the vertical pipe section, and the liquid guide pipe outlet (44b) is located at one end of the vertical pipe section away from the inclined pipe section.

6. The refrigerant cycle system according to claim 4, characterized by The cross section of the first end of the liquid guide pipe (44) near the liquid guide pipe inlet (44a) gradually decreases from the liquid guide pipe inlet (44a) to the side near the second end of the liquid guide pipe (44), and the separator inlet pipe second port (41b) is disposed towards the inner wall of the first end of the liquid guide pipe (44).

7. The refrigerant cycle system according to claim 2, characterized by The vapor-liquid separator (403) further comprises a separator liquid outlet pipe (421), the separator liquid outlet pipe (421) comprising a separator liquid pipe first port (421a) and a separator liquid pipe second port (421b), the separator liquid pipe first port (421a) being inserted into the liquid refrigerant in the separator housing (43), and the separator liquid pipe second port (421b) forming the separator liquid outlet.

8. The refrigerant cycle system according to claim 1, characterized by The refrigerant circuit further comprises: a first one-way valve (482) connected in series between the compressor (402) and the condenser (100) and configured to allow one-way flow of the refrigerant from the compressor (402) to the condenser (100); and a second one-way valve (481) connected in series between the fluorine pump (401) and the condenser (100) and configured to allow one-way flow of the refrigerant from the fluorine pump (401) to the condenser (100).

9. The refrigerant circulation system according to claim 1, wherein the refrigerant circulation system further comprises an outdoor fan (101) and / or a heating device (407) for heating the refrigerant in the vapor-liquid separator (403) of the refrigerant collection part; the detection device further comprises a temperature sensor and a pressure sensor for detecting a refrigerant temperature and a refrigerant pressure of the gaseous refrigerant in the vapor-liquid separator (403) of the refrigerant collection part, respectively, and the refrigerant parameter comprises the refrigerant temperature and the refrigerant pressure; The control device is configured to calculate a saturation temperature T of the refrigerant in the gas-liquid separator (403) from the refrigerant pressure 饱 and to calculate a temperature difference between the refrigerant temperature T 回 and the saturation temperature T 饱 , and to control the rotation speed of the outdoor fan (101) and / or to control the heating device (407) to be turned on or off, based on the temperature difference.

10. The refrigerant cycle system according to any one of claims 1 to 9, characterized in that, the refrigerant circulation system further comprises: a first electromagnetic valve (406) disposed between the collection part gas outlet and the compressor (402) and connected to the control device, the control device being configured to open the first electromagnetic valve (406) in the compressor refrigeration mode and to close the first electromagnetic valve (406) in the fluorine pump refrigeration mode; and a second electromagnetic valve (405) disposed between the collection part liquid outlet and the fluorine pump (401) and connected to the control device, the control device being configured to open the second electromagnetic valve (405) in the fluorine pump refrigeration mode and to close the second electromagnetic valve (405) in the compressor refrigeration mode.

11. A control method of the refrigerant cycle system according to any one of claims 1 to 10, characterized by, comprising: the detection device detecting a refrigerant parameter of the refrigerant in the refrigerant collection part; the control device controlling the refrigerant circulation system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to the refrigerant parameter.

12. The control method according to claim 11, wherein the control method further comprises: the detection device detecting a liquid level in the vapor-liquid separator (403) of the refrigerant collection part; The control device is configured to control the refrigerant circulation system to switch between the compressor refrigeration mode and the fluorine pump refrigeration mode according to a first distance and a second distance, the first distance being a height difference between the height H of the collection part gas outlet from which the gaseous refrigerant is led out of the gas-liquid separator (403) and the height H of the liquid level H A The second distance is a height difference between the height H of the liquid level H and the height H of the collection part liquid outlet from which the liquid refrigerant is led out of the gas-liquid separator (403). B The second distance is a height difference between the height H of the liquid level H and the height H of the collection part liquid outlet from which the liquid refrigerant is led out of the gas-liquid separator (403).

13. The control method according to claim 12, characterized by, comprising: in the case that the first distance is greater than or equal to the second distance, the control device controls the refrigerant circulation system to switch to the compressor refrigeration mode; and in the case that the first distance is less than the second distance, the control device controls the refrigerant circulation system to switch to the fluorine pump refrigeration mode.

14. The control method according to claim 12, wherein The refrigerant circulation system further comprises an outdoor fan (101) and / or a heating device (407) for heating the refrigerant in a vapor-liquid separator (403) of the refrigerant collection part; The detection device further comprises a temperature sensor and a pressure sensor, the temperature sensor and the pressure sensor are respectively used for detecting a refrigerant temperature and a refrigerant pressure of the gaseous refrigerant in the vapor-liquid separator (403) of the refrigerant collection part, and the refrigerant parameters comprise the refrigerant temperature and the refrigerant pressure; The control method further comprises: The temperature sensor and the pressure sensor respectively detect a refrigerant temperature and a refrigerant pressure of the gaseous refrigerant in the vapor-liquid separator (403) of the refrigerant collection part; The control device calculates the saturated temperature T of the refrigerant in the gas-liquid separator (403) from the refrigerant pressure 饱 and calculates the temperature difference between the refrigerant temperature T 回 and the saturated temperature T 饱 , and controls the rotation speed of the outdoor fan (101) and / or controls the heating device (407) to be turned on or off, based on the temperature difference.

15. The control method according to claim 14, characterized by, Comprise: In the case that the refrigerant circulation system is in the compressor refrigeration mode and the temperature difference value is less than a set first limit temperature difference, the control device controls the heating device (407) to start; in the case that the refrigerant circulation system is in the compressor refrigeration mode and the temperature difference value is greater than or equal to the first limit temperature difference and the first distance is less than or equal to a set first limit distance value, the control device controls the heating device (407) to be closed and controls the refrigerant circulation system to switch to the fluorine pump refrigeration mode; and / or In the case that the refrigerant circulation system is in the fluorine pump refrigeration mode and the temperature difference value is greater than or equal to a set second limit temperature difference, the control device controls the outdoor fan (101) to speed up; in the case that the refrigerant circulation system is in the fluorine pump refrigeration mode and the temperature difference value is less than the second limit temperature difference and the second distance is less than a set second limit distance value, the control device controls the outdoor fan (101) to restore the speed before the speed up and controls the refrigerant circulation system to switch to the compressor refrigeration mode.

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