A fluorine pump multi-connected refrigeration system and a control method thereof

Abstract

The application discloses a fluorine pump multi-connected refrigerating system and a control method thereof. The fluorine pump multi-connected refrigerating system comprises an outdoor unit and an indoor unit. The outdoor unit comprises a refrigerating module and a circulating module. The refrigerating module comprises a compressor, a condenser, a first liquid accumulator, a first pump unit, a first throttler and a first evaporator which are connected in series through pipelines. The pipeline between the first evaporator and the compressor passes through the liquid stored in the first liquid accumulator. The circulating module comprises a heat exchanger, a second liquid accumulator and a second pump unit which are connected in series through pipelines. The pipeline between the heat exchanger and the second liquid accumulator is at least partially cooled by the first evaporator. The indoor unit comprises a second throttler and a second evaporator which are connected in series through pipelines between the input end and the output end of the outdoor unit. The control method adopts the above system. The fluorine pump multi-connected refrigerating system and the control method thereof can avoid cavitation of the pump and liquid strike of the compressor, and can also avoid poor oil return of the compressor.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air conditioners, in particular to a fluorine pump multi-connected refrigeration system and a control method thereof. BACKGROUND

[0002] Under the background of the national double carbon policy, energy saving has long been a topic. The direct expansion air conditioner used in the traditional old data center uses a compressor to drive the refrigerant to complete the cooling in winter, summer and transitional seasons, which has low energy efficiency and causes energy waste. In northern areas, the outdoor temperature is much lower than the indoor temperature in winter and even in transitional seasons, so the outdoor air becomes a free natural cold source, and the pump can efficiently utilize this natural cold source. By utilizing this natural cold source, the working time of the compressor is reduced to achieve the purpose of energy saving.

[0003] The pump system (also referred to as a refrigerant pump system, and the refrigerant is generally R410a) is an air conditioning system in which a pump is used to replace a compressor to drive the refrigerant. In summer, the data center dedicated air conditioner starts the refrigeration compressor to normally refrigerate, and when the outdoor temperature is lower than the temperature preset by the controller, the controller automatically switches from the compressor refrigeration to the refrigerant pump refrigeration: the refrigerant liquid cooled by the outdoor air-cooled condensing part is delivered to the evaporating part by the refrigerant pump, absorbs the heat in the room, and then the refrigerant changes from liquid to gas, enters the air-cooled condensing part, and is cooled into liquid again, and the cycle continues. Since the power of the refrigerant pump is much smaller than that of the refrigeration compressor, under the premise of the same refrigeration capacity, the energy efficiency ratio of the refrigerant pump is higher than that of the refrigeration compressor, thereby achieving cooling while saving energy.

[0004] The fluid passing through the pump should be liquid. If there is gas in the fluid passing through the pump, cavitation will occur, and the impeller surface of the pump (also referred to as a fluorine pump) will be impacted and eroded by cavitation, resulting in peeling and damage, i.e., cavitation occurs. In addition, cavitation will also cause noise and vibration of the pump, and lead to a decrease in the performance of the pump, and in severe cases, the liquid in the pump will be interrupted and cannot work normally. Therefore, before the pump system is operated, it is necessary to ensure that no gas enters the pump. Similarly, the suction of liquid by the compressor during operation should also be avoided to prevent liquid impact.

[0005] For the current fluorine pump and compressor combined air conditioning system, in order to prevent the problems of cavitation and liquid impact of the fluorine pump and the compressor respectively during the switching of the working mode, an additional electromagnetic valve needs to be arranged at the refrigerant inlet side of the fluorine pump and the compressor, and a gas-liquid separator may also need to be arranged at the inlet side of the compressor, thereby making the structure of the entire air conditioning system complex and increasing the control difficulty of the entire system.

[0006] In addition, since the pipeline of the common air conditioner is short, most of the lubricating oil flows back to the compressor along with the refrigerant, and thus the oil return problem is not considered. However, the multi-connected refrigeration system has long pipeline, large drop, many elbows, many oil storage places in the system, and difficult oil return. With the increase of the running time, more and more lubricating oil accumulates in the system, and the compressor will be damaged due to lack of oil. In order to reduce the oil return resistance and reduce the oil storage places in the pipeline, the length and diameter of the connecting pipeline are limited in the design of the multi-connected refrigeration system, and the installation is very difficult. SUMMARY

[0007] The present application aims to overcome the above-mentioned defects or problems existing in the background art, and provide a fluorine pump multi-connected refrigeration system and a control method thereof, which can avoid cavitation of the pump and liquid strike of the compressor, without borrowing external cold source. In addition, the oil return of the compressor can be avoided, the whole system structure is simple, the system operation is more reliable, the pipeline laying is simple, and the engineering application is more convenient.

[0008] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0009] Technical solution one, a fluorine pump multi-connected refrigeration system, comprising an outdoor unit and an indoor unit; the outdoor unit comprises a refrigeration module and a circulation module, the refrigeration module comprises a compressor, a condenser, a first liquid accumulator, a first pump unit, a first throttler and a first evaporator which are connected in series through pipelines, the pipeline between the first evaporator and the compressor passes through the liquid stored in the first liquid accumulator; the circulation module comprises a heat exchanger, a second liquid accumulator and a second pump unit which are connected in series through pipelines, the input end of the heat exchanger forms the input end of the outdoor unit, and the output end of the second pump unit forms the output end of the outdoor unit; the pipeline between the heat exchanger and the second liquid accumulator is at least partially through the first evaporator and cooled by the first evaporator; the indoor unit comprises a second throttler and a second evaporator which are connected in series through pipelines between the input end and the output end of the outdoor unit.

[0010] Based on technical solution one, technical solution two is further provided, in which the circulation module further comprises a third throttler, the third throttler is connected on the pipeline between the heat exchanger and the second liquid accumulator, and the pipeline between the third throttler and the second liquid accumulator is at least partially through the first evaporator and cooled by the first evaporator.

[0011] Based on technical solution two, technical solution three is further provided, in which the pipeline between the third throttler and the second liquid accumulator is divided into a heat exchange section and two non-heat exchange sections connected with both ends of the heat exchange section, the heat exchange section passes through the first evaporator and is cooled by the first evaporator, and the inlet of the heat exchange section is close to the output end of the first evaporator.

[0012] Based on technical solution two, there is also a technical solution four, in which the pipeline between the third throttler and the second liquid reservoir is divided into a heat exchange section and two non-heat exchange sections connected to both ends of the heat exchange section, the heat exchange section passes through the first evaporator and is cooled by the first evaporator, and the inlet of the heat exchange section is close to the input end of the first evaporator.

[0013] Based on technical solution one, there is also a technical solution five, in which the pipeline between the first evaporator and the compressor is provided with a cooling section extending into the first liquid reservoir, the first liquid reservoir is a liquid storage tank, and the cooling section is mirror-symmetric and each side of it is provided with a plurality of curved sections along the height direction of the liquid storage tank.

[0014] Based on technical solution one, there is also a technical solution six, in which the refrigeration module further includes a first control valve and a second control valve, the first control valve is connected in parallel between the input end and the output end of the compressor through a pipeline, and the second control valve is connected in parallel between the input end and the output end of the first pump unit through a pipeline.

[0015] Based on technical solution six, there is also a technical solution seven, in which the refrigeration module further includes a first check valve and a suction electromagnetic valve, the suction electromagnetic valve is connected in series to the input end of the compressor through a pipeline, and the first check valve is connected in series to the output end of the compressor through a pipeline; the first control valve is connected in parallel between the first check valve and the suction electromagnetic valve through a pipeline.

[0016] Based on technical solution one, there is also a technical solution eight, in which the second pump unit includes two parallel branches, a second pump and a second check valve are connected in series on each parallel branch through a pipeline, and the output ends of the two second check valves form the output end of the outdoor unit.

[0017] Based on technical solution one, there is also a technical solution nine, in which the outdoor unit is at least one, the input ends of each outdoor unit are connected in parallel, and the output ends of each outdoor unit are connected in parallel; the indoor unit includes at least one refrigeration end, each refrigeration end is connected in parallel between the input end and the output end of the outdoor unit, and each refrigeration end includes a second throttler and a second evaporator connected in sequence through a pipeline.

[0018] Ten, the application further provides a control method of the fluorine pump multi-connected refrigeration system, the fluorine pump multi-connected refrigeration system is any one of the fluorine pump multi-connected refrigeration systems in the technical solutions one to nine, the outdoor unit further comprises a sprayer, the sprayer is suitable for spraying the heat exchanger and / or the condenser, the control method comprises the following steps: obtaining the difference AT of the indoor temperature Tin and the outdoor temperature Tout, determining the working mode according to the relationship between AT and the first set value T1, the second set value T2 and the third set value T3;If AT is greater than or equal to T1, the first working mode is used;If T2 is less than or equal to AT and less than T1, it is judged whether the spraying condition is met, if the spraying condition is met, the sprayer sprays the heat exchanger and / or the condenser, and it is judged whether AT is greater than or equal to T1, if the result is yes, the first working mode is switched to;If the spraying condition is not met, the second working mode is switched to;If T3 is less than or equal to AT and less than T2, the second working mode is used;If AT is less than T3, the third working mode is used;If the current is the second working mode or the third working mode, it is judged whether the spraying condition is met, if the spraying condition is met, the sprayer sprays the heat exchanger and / or the condenser;In the first working mode, the compressor is closed, the first pump unit is opened and forms a refrigeration cycle with the condenser and the first evaporator, and the second pump unit is opened and forms a refrigeration cycle with the heat exchanger and the second evaporator;In the second working mode, the compressor and the first pump unit are both opened and form a refrigeration cycle with the condenser and the first evaporator, and the second pump unit is opened and forms a refrigeration cycle with the heat exchanger and the second evaporator;In the third working mode, the first pump unit is closed, the compressor is opened and forms a refrigeration cycle with the condenser and the first evaporator, and the second pump unit is opened and forms a refrigeration cycle with the heat exchanger and the second evaporator.

[0019] From the above description of the application, the application has the following beneficial effects compared with the prior art:

[0020] 1. In technical solution one, due to the presence of the first throttling device in the refrigeration module, the gas temperature at the output end of the first evaporator is lower than the temperature of the liquid in the first receiver. The pipeline between the first evaporator and the compressor passes through the liquid stored in the first receiver, allowing for heat exchange with the liquid in the first receiver, thereby increasing the subcooling of the liquid in the first receiver. This ensures that during the start-up or switching of the operating mode of the first pump unit, the first pump unit draws in liquid refrigerant, rather than vaporized liquid refrigerant, preventing cavitation and protecting the first pump unit. Furthermore, the temperature of the pipeline between the first evaporator and the compressor increases after passing through the liquid stored in the first receiver, enabling better control of the compressor's suction superheat, thus preventing liquid slugging caused by the compressor drawing in liquid refrigerant and improving the stability and reliability of the entire air conditioning system. In the circulation module, the gas generated by the second evaporator is first cooled by a heat exchanger, then passes through the first evaporator and is cooled into liquid by the first evaporator. Since the first evaporator is the core of the refrigeration module, it acts as the cooling core in the circulation module. The condenser's function is to condense the gas into a liquid after passing through the first evaporator. This liquid has a lower temperature and a certain degree of subcooling, which in turn ensures that the liquid in the second receiver also has a certain degree of subcooling. This guarantees that the second pump unit draws in liquid refrigerant, not gaseous refrigerant, preventing cavitation and protecting the second pump unit. Since the compressor is located within the refrigeration module, which is entirely outdoors, the compressor's piping is short with minimal drop, resulting in smooth oil return. Therefore, in this technical solution, by having the piping between the first evaporator and the compressor pass through the liquid stored in the first receiver, the subcooling of the liquid in the first receiver and the superheat of the gas entering the compressor can be increased, eliminating the need for an external cold source and simplifying the overall system structure. By having at least part of the piping between the heat exchanger and the second receiver pass through and be cooled by the first evaporator, indoor cooling can be achieved, and the subcooling of the liquid in the second receiver is increased. Furthermore, this ensures smooth oil return from the compressor, making the entire system more reliable, simplifying piping installation, and facilitating engineering applications.

[0021] 2. In technical solution two, the setting of the third throttle can adjust the flow rate of gas in the pipeline passing through the first evaporator in the circulation module, so that the gas in the pipeline passing through the first evaporator in the circulation module can be fully cooled by the first evaporator, improving the condensation efficiency, ensuring the subcooling of the liquid in the second liquid receiver, and avoiding cavitation of the second pump unit.

[0022] 3. In technical solution three, the gas flowing out of the heat exchanger enters the second liquid storage tank after passing through the non-heat exchange section, the heat exchange section and the non-heat exchange section. The heat exchange section passes through the first evaporator and is cooled by the first evaporator. The inlet of the heat exchange section is close to the output end of the first evaporator, so that the flow direction of the cooling air in the first evaporator is opposite to the flow direction of the gas and liquid in the heat exchange section. The heat exchange area is large and the heat exchange efficiency is higher.

[0023] 4. In technical solution four, the gas flowing out of the heat exchanger enters the second liquid storage tank after passing through the non-heat exchange section, the heat exchange section and the non-heat exchange section. The heat exchange section passes through the first evaporator and is cooled by the first evaporator. The inlet of the heat exchange section is close to the input end of the first evaporator. Since the temperature at the input end of the first evaporator is often low, the gas in the heat exchange section can be quickly cooled into liquid after entering the first evaporator. In addition, this design is more convenient for pipeline connection and the overall pipeline length is shorter.

[0024] 5. In technical solution five, the cooling section has a large heat exchange area, which helps to reduce the temperature of the liquid in the first liquid reservoir, thereby increasing the subcooling of the liquid in the first liquid reservoir.

[0025] 6. In technical solution six, the setting of the first control valve and the second control valve is conducive to the refrigeration system operating in different refrigeration modes, which is more energy-efficient and environmentally friendly.

[0026] 7. In technical solution seven, the setting of the first one-way valve and the suction solenoid valve ensures the stable operation of the compressor.

[0027] 8. In technical solution eight, the setting of two second pumps ensures that even if one second pump fails, it will not affect the operation of the circulation module, making the entire refrigeration system more stable and reliable.

[0028] 9. In technical solution nine, adjustments can be made according to actual conditions. It can be used to realize one outdoor unit corresponding to multiple cooling terminals to reduce the number of outdoor units and the floor space, or to realize multiple outdoor units corresponding to one cooling terminal, or multiple outdoor units corresponding to multiple cooling terminals, simplifying indoor and outdoor connection pipelines.

[0029] 10. In technical solution ten, the present invention also provides a control method for a multi-unit refrigeration system using a refrigerant pump. The refrigeration system using the above-mentioned technical solution has the same advantages as described above. In this technical solution, the working mode is determined based on the relationship between the indoor and outdoor temperature difference (△T=Tin-Tout) and three set values, which is more in line with actual usage conditions, thereby ensuring that the refrigeration system can always meet the refrigeration requirements and ensuring stable operation of the indoor working conditions. Among them, the spraying condition generally refers to whether the water source in the current area is sufficient. Sufficient water source means that spraying can be carried out. Attached Figure Description

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiment description are briefly introduced as follows. Obviously, the drawings in the embodiment description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0031] Figure 1 A schematic diagram of a refrigeration system according to an embodiment of the present application;

[0032] Figure 2 A schematic diagram of a refrigeration system according to another embodiment of the present application.

[0033] Explanation of main reference signs:

[0034] Outdoor unit 100; refrigeration module 10; compressor 11; condenser 12; first liquid accumulator 13; first pump unit 14; first throttling device 15; first evaporator 16; first control valve 17; second control valve 18; first check valve 191; suction electromagnetic valve 192; first branch 01; second branch 02; cooling section 03; heat exchanger 21; third throttling device 22; second liquid accumulator 23; second pump unit 24; second pump 241; second check valve 242; heat exchange section 04; non-heat exchange section 05; indoor unit 200; refrigeration end 201; second throttling device 2011; second evaporator 2012. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are preferred embodiments of the present application, and should not be regarded as exclusive to other embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the scope of protection of the present application.

[0036] In the claims, specification and above drawings of the present application, unless otherwise explicitly defined, the terms such as "first", "second" or "third" are used only to distinguish different objects, and are not used to describe a specific sequence.

[0037] In the claims, the specification, and the drawings of the present application, terms such as "center", "transverse", "longitudinal", "horizontal", "vertical", "top", "bottom", "inner", "outer", "upper", "lower", "front", "rear", "left", "right", "clockwise", "counterclockwise", etc. are used as terms of reference and are not intended to limit the specific orientation or configuration of the apparatus or elements thereof, unless otherwise specifically indicated. Therefore, these terms are used in the description and claims only to facilitate the description of the application and to simplify the description, and should not be construed as limiting the specific protection scope of the present application.

[0038] In the claims, the specification, and the drawings of the present application, unless otherwise specifically indicated, the term "fixedly connected" or "fixedly connected" should be understood in a broad sense, that is, any connection mode without displacement relationship and relative rotation relationship between the two, that is, it includes non-detachable fixed connection, detachable fixed connection, integration and fixed connection through other devices or elements.

[0039] In the claims, the specification, and the drawings of the present application, the terms "including", "having" and their variants are intended to mean "containing but not limited to".

[0040] Referring to Figures 1-2 , Figures 1-2 A fluorine pump multi-connected refrigeration system is shown, which comprises an outdoor unit 100 and an indoor unit 200, Figures 1-2 In the present application, two outdoor units 100 and an indoor unit 200 are provided.

[0041] The outdoor unit 100 comprises a refrigeration module 10 and a circulation module.

[0042] The refrigeration module 10 comprises a compressor 11, a condenser 12, a first liquid accumulator 13, a first pump unit 14, a first throttling device 15, a first evaporator 16, a first control valve 17, a first check valve 191 and a suction solenoid valve 192. The compressor 11, the condenser 12, the first liquid accumulator 13, the first pump unit 14, the first throttling device 15 and the first evaporator 16 are connected in series by pipelines. The first control valve 17 is connected in parallel by pipelines between the input and output ends of the compressor 11 to form a first branch 01. The second control valve 18 is connected in parallel by pipelines between the input and output ends of the first pump unit 14 to form a second branch 02. In the present embodiment, the first control valve 17 and the second control valve 18 are both check valves, and the first throttling device 15 is an electronic expansion valve. The suction solenoid valve 192 is connected in series by pipelines to the input end of the compressor 11, and the first check valve 191 is connected in series by pipelines to the output end of the compressor 11. The first control valve 17 is connected in parallel by pipelines between the first check valve 191 and the suction solenoid valve 192. Among them, the first pump unit 14 is a fluorine pump.

[0043] The embodiment avoids the occurrence of cavitation and liquid hammer mainly through pipeline design. Specifically, the pipeline between the first evaporator 16 and the compressor 11 passes through the liquid stored in the first liquid accumulator 13. In the embodiment, the pipeline between the first evaporator 16 and the compressor 11 is provided with a cooling section 03 extending into the first liquid accumulator 13, and the first liquid accumulator 13 is a liquid storage tank. The cooling section 03 is mirror-symmetric, and each side of the cooling section 03 is provided with a plurality of curved sections along the height direction of the liquid storage tank. In the embodiment, each side of the cooling section 03 is zigzag-shaped. The structure of the cooling section 03 has a large heat exchange area, which is conducive to reducing the temperature of the liquid in the first liquid accumulator 13, thereby increasing the supercooling degree of the liquid in the first liquid accumulator 13.

[0044] The circulation module includes a heat exchanger 21, a third throttling device 22, a second liquid accumulator 23, and a second pump unit 24 connected in sequence by pipelines. The input end of the heat exchanger 21 forms the input end of the outdoor unit 100, and the output end of the second pump unit 24 forms the output end of the outdoor unit 100. The pipeline between the heat exchanger 21 and the second liquid accumulator 23 at least partially passes through and is cooled by the first evaporator 16. In the embodiment, the pipeline between the third throttling device 22 and the second liquid accumulator 23 at least partially passes through and is cooled by the first evaporator 16. The heat exchanger 21 is a wind-cooled heat exchanger 21, which can be cooled by natural wind in the outdoor environment. The wind-cooled heat exchanger 21 belongs to the prior art, and will not be described here. The second liquid accumulator 23 is a liquid storage tank, which can further realize gas-liquid separation.

[0045] Specifically, the pipeline between the heat exchanger 21 and the second liquid accumulator 23 is divided into a heat exchange section 04 and two non-heat exchange sections 05 connected to both ends of the heat exchange section 04. The heat exchange section 04 passes through and is cooled by the first evaporator 16. In one embodiment, the inlet of the heat exchange section 04 is close to the output end of the first evaporator 16 (see Figure 2 ). At this time, the flow direction of the cooling gas flow in the first evaporator 16 is opposite to the flow direction of the gas-liquid in the heat exchange section 04, the heat exchange area is large, and the heat exchange efficiency is higher. In another embodiment, the inlet of the heat exchange section 04 is close to the input end of the first evaporator 16 (see Figure 1 ). Since the temperature at the input end of the first evaporator 16 is often low, the gas in the heat exchange section 04 can be quickly cooled into liquid after entering the first evaporator 16. Moreover, this design is more convenient in pipeline connection, and the overall pipeline length is shorter.

[0046] The second pump unit 24 comprises two parallel branches, each of which is connected in series with the second pump 241 and the second check valve 242 through a pipeline, and the output ends of the two second check valves 242 form the output end of the outdoor unit 100. The arrangement of the two second pumps 241 ensures that even if one second pump 241 is damaged, the operation of the circulating module will not be affected, so that the entire refrigeration system is more stable and reliable.

[0047] The indoor unit 200 comprises the second throttles 2011 and the second evaporators 2012 connected in series through pipelines between the input end and the output end of the outdoor unit 100. Specifically, the indoor unit 200 comprises at least one refrigeration end 201, in this embodiment, the indoor unit 200 comprises three refrigeration ends 201, each of which is connected in parallel between the input end and the output end of the outdoor unit 100, and each refrigeration end 201 comprises the second throttle 2011 and the second evaporator 2012 connected in series through pipelines. In this embodiment, the input ends of the outdoor units 100 are connected in parallel, and the output ends of the outdoor units 100 are connected in parallel. In actual application, the number of outdoor units 100 and the floor area can be reduced by adjusting the number of outdoor units 100 corresponding to the number of refrigeration ends 201, or the number of outdoor units 100 corresponding to the number of refrigeration ends 201, or the number of outdoor units 100 corresponding to the number of refrigeration ends 201, which simplifies the indoor and outdoor connection pipelines.

[0048] In actual application, the air conditioning system further comprises a controller and a sprayer (not shown in the figure), the controller is electrically connected with the refrigeration module 10 and the circulating module and controls them. The sprayer is suitable for spraying the condenser 12 and the heat exchanger 21, and the sprayer can realize spraying by using a spraying pump. This part is suitable for the prior art, and this embodiment will not be described in detail.

[0049] Based on the above-mentioned fluorine pump multi-connected system, the fluorine pump multi-connected system of the present application can operate in three working modes, namely the first working mode, the second working mode and the third working mode.

[0050] In the first working mode, the first check valve 191 and the suction electromagnetic valve 192 are closed, the first control valve 17 is opened, the second control valve 18 is closed, the first throttling device 15 is opened, the compressor 11 is closed, the first pump is opened and forms a refrigeration cycle with the condenser 12 and the first evaporator 16, specifically, the refrigerant from the first evaporator 16 enters the condenser 12 through the first branch 01 to condense into refrigerant liquid, the refrigerant liquid flows to the first evaporator 16 through the first accumulator 13, the first pump and the first throttling device 15, the liquid refrigerant evaporates through the first evaporator 16 and enters the compressor 11, completing a refrigeration cycle; the second pump 241 and the second check valve 242 on one parallel branch in the second pump unit 24 are opened and form a refrigeration cycle with the heat exchanger 21 and the second evaporator 2012, specifically, the high-temperature gas generated by the second evaporator 2012 is cooled after heat exchange through the heat exchanger 21, enters the first evaporator 16 after throttling through the third throttling device 22 to cool into liquid, then enters the second accumulator 23, and is transported to each second evaporator 2012 of the indoor unit 200 by one of the second pumps 241.

[0051] In the second working mode, the first check valve 191, the suction electromagnetic valve 192, the compressor 11 and the first pump are opened and form a refrigeration cycle with the condenser 12 and the first evaporator 16, the first control valve 17 and the second control valve 18 are closed, specifically, the refrigerant from the compressor 11 enters the condenser 12 to condense into refrigerant liquid, the refrigerant liquid flows to the first evaporator 16 through the first accumulator 13, the first pump and the first throttling device 15, the liquid refrigerant evaporates through the first evaporator 16 and enters the compressor 11, completing a refrigeration cycle. The second pump 241 and the second check valve 242 on one parallel branch in the second pump unit 24 are opened and form a refrigeration cycle with the heat exchanger 21 and the second evaporator 2012, specifically, the high-temperature gas generated by the second evaporator 2012 is cooled after heat exchange through the heat exchanger 21, enters the first evaporator 16 after throttling through the third throttling device 22 to cool into liquid, then enters the second accumulator 23, and is transported to each second evaporator 2012 of the indoor unit 200 by one of the second pumps 241.

[0052] In the third working mode, the first pump is closed, the second control valve 18 is opened, the first control valve 17 is closed, the compressor 11 is opened, the first one-way valve 191 is opened, the suction electromagnetic valve 192 is opened, and the condenser 12 and the first evaporator 16 form a refrigeration cycle. Specifically, the compressor 11 compresses the refrigerant circulating from the first evaporator 16, compresses the gaseous refrigerant into a high-temperature and high-pressure state, and sends it to the condenser 12 to condense into low-temperature and high-pressure refrigerant liquid. The refrigerant liquid flows to the first evaporator 16 through the second branch 02 and the first throttling device 15. The liquid refrigerant is evaporated by absorbing heat through the first evaporator 16 and enters the compressor 11, completing a refrigeration cycle. The open one of the parallel branches in the second pump unit 24 and the heat exchanger 21 and the second evaporator 2012 form a refrigeration cycle. Specifically, the high-temperature gas generated by the second evaporator 2012 is cooled after heat exchange through the heat exchanger 21, enters the first evaporator 16 after throttling through the second throttling device 2011, and is cooled into a liquid. Subsequently, it enters the second liquid accumulator 23 and is transported to each second evaporator 2012 of the indoor unit 200 by one of the second pumps 241.

[0053] It can be seen that, due to the presence of the first throttling device 15 in the refrigeration module 10, the gas temperature at the output end of the first evaporator 16 is lower than the temperature of the liquid in the first liquid accumulator 13, the pipeline between the first evaporator 16 and the compressor 11 exchanges heat with the liquid stored in the first liquid accumulator 13, thereby increasing the subcooling degree of the liquid in the first liquid accumulator 13, ensuring that the first pump unit 14 sucks in liquid refrigerant rather than gaseous refrigerant during the starting or switching process of the working mode of the first pump unit 14, preventing the first pump unit 14 from cavitation, thereby protecting the first pump unit 14, and the temperature of the pipeline between the first evaporator 16 and the compressor 11 increases after passing through the liquid stored in the first liquid accumulator 13, which can better control the suction superheat degree of the compressor 11, thereby preventing the compressor 11 from being subjected to liquid impact due to the suction of liquid refrigerant, improving the stability and reliability of the entire air conditioning system; in the circulation module, the gas generated by the second evaporator 2012 is first cooled by the heat exchanger 21, then passes through the first evaporator 16 and is cooled into a liquid state by the first evaporator 16, since the first evaporator 16 is the refrigeration core of the refrigeration module 10, the first evaporator 16 functions as a condenser in the circulation module, the gas is condensed into a liquid by the first evaporator 16, and the liquid has a relatively low temperature and a certain subcooling degree, that is, the liquid in the second liquid accumulator 23 has a certain subcooling degree, thereby ensuring that the second pump unit 24 sucks in liquid refrigerant rather than gaseous refrigerant during the working process of the second pump unit 24, preventing the second pump unit 24 from cavitation, thereby protecting the second pump unit 24; the third throttling device 22 is arranged to adjust the flow of the gas passing through the pipeline of the first evaporator 16 in the circulation module, so that the gas passing through the pipeline of the first evaporator 16 in the circulation module can be fully cooled by the first evaporator 16, ensuring the subcooling degree of the liquid in the second liquid accumulator 23 and avoiding cavitation of the second pump unit 24; since the compressor 11 is arranged in the refrigeration module 10, the entire refrigeration module 10 is located outdoors, the pipeline of the compressor 11 is short and has a small drop, and oil return is smooth; therefore, in the technical solution, the subcooling degree of the liquid in the first liquid accumulator 13 and the superheat degree of the gas at the inlet of the compressor 11 can be increased by causing the pipeline between the first evaporator 16 and the compressor 11 to pass through the liquid stored in the first liquid accumulator 13, without using an external cold source, and the entire system structure is simple; the indoor refrigeration effect can be achieved by causing the pipeline between the heat exchanger 21 and the second liquid accumulator 23 to pass through the first evaporator 16 at least partially and be cooled by the first evaporator 16, and the subcooling degree of the liquid in the second liquid accumulator 23 is increased; in addition, the oil return of the compressor 11 is smooth, the entire system runs more reliably, the pipeline is simple to lay, and engineering application is more convenient.

[0054] Example 2

[0055] The application also provides a control method of the fluorine pump multi-connected refrigeration system.

[0056] The difference AT between the indoor temperature Tin and the outdoor temperature Tout is obtained, AT=Tin-Tout, and the working mode is determined according to the relationship between AT and the first set value T1, the second set value T2 and the third set value T3.

[0057] If AT is greater than or equal to T1, the first working mode is adopted; if T2 is less than AT and AT is less than T1, it is determined whether the spraying condition is met (the spraying condition generally refers to whether the water source in the current region is sufficient, and the sufficient water source means that the spraying can be performed), if the spraying condition is met, the heat exchanger 21 and / or the condenser 12 are sprayed by the sprayer, and it is determined whether AT is greater than or equal to T1, and the result is yes, and the first working mode is switched to; if the spraying condition is not met, the second working mode is switched to; if T3 is less than AT and AT is less than T2, the second working mode is adopted; if AT is less than T3, the third working mode is adopted.

[0058] If the current working mode is the second working mode or the third working mode, it is determined whether the spraying condition is met, and if the spraying condition is met, the heat exchanger 21 and / or the condenser 12 are sprayed by the sprayer.

[0059] In the specific implementation, the temperature sensor can be arranged to collect the outdoor temperature and the indoor temperature, and this part belongs to the prior art, and will not be described here.

[0060] The control method of the application has the same advantages as the above-mentioned refrigeration system, and the working mode is determined according to the relationship between the indoor and outdoor temperature difference and the three set values, which is more in line with the actual use, so as to ensure that the refrigeration system can always meet the refrigeration demand and ensure the stable operation of the indoor working condition.

[0061] The description of the above specification and examples is used to explain the protection scope of the application, but does not constitute the limitation of the protection scope of the application. Through the inspiration of the application or the above-mentioned examples, the modification, equivalent replacement or other improvement of the embodiments of the application or part of the technical features can be obtained by the ordinary skilled in the art combining with the common knowledge, the ordinary technical knowledge in the art and / or the prior art through the logical analysis, reasoning or limited test, which should be included in the protection scope of the application.

Claims

1. A multi-connected fluorine pump refrigeration system, characterized in that, The air conditioner comprises an outdoor unit (100) and an indoor unit (200); The outdoor unit (100) comprises a refrigeration module (10) and a circulation module, the refrigeration module (10) comprises a compressor (11), a condenser (12), a first liquid accumulator (13), a first pump unit (14), a first throttler (15) and a first evaporator (16) connected in sequence by pipelines, the pipeline between the first evaporator (16) and the compressor (11) passes through the liquid stored in the first liquid accumulator (13); the circulation module comprises a heat exchanger (21), a second liquid accumulator (23) and a second pump unit (24) connected in sequence by pipelines, the input end of the heat exchanger (21) forms the input end of the outdoor unit (100), and the output end of the second pump unit (24) forms the output end of the outdoor unit (100); the pipeline between the heat exchanger (21) and the second liquid accumulator (23) at least partially passes through and is cooled by the first evaporator (16); The indoor unit (200) comprises a second throttler (2011) and a second evaporator (2012) connected in sequence by pipelines between the input end and the output end of the outdoor unit (100); The circulation module further comprises a third throttler (22) connected in the pipeline between the heat exchanger (21) and the second liquid accumulator (23), and the pipeline between the third throttler (22) and the second liquid accumulator (23) at least partially passes through and is cooled by the first evaporator (16); The pipeline between the first evaporator (16) and the compressor (11) is provided with a cooling section (03) extending into the first liquid accumulator (13), the first liquid accumulator (13) is a liquid storage tank, and each side of the cooling section (03) is provided with a plurality of curved sections along the height direction of the liquid storage tank.

2. A multiple refrigerant system of the scroll pump type as set forth in claim 1, wherein The pipeline between the third throttler (22) and the second liquid accumulator (23) is divided into a heat exchange section (04) and two non-heat exchange sections (05) connected with both ends of the heat exchange section (04), the heat exchange section (04) passes through and is cooled by the first evaporator (16), and the inlet of the heat exchange section (04) is close to the output end of the first evaporator (16).

3. A multiple refrigerant system of the scroll pump type as set forth in claim 1, wherein The pipeline between the third throttler (22) and the second liquid accumulator (23) is divided into a heat exchange section (04) and two non-heat exchange sections (05) connected with both ends of the heat exchange section (04), the heat exchange section (04) passes through and is cooled by the first evaporator (16), and the inlet of the heat exchange section (04) is close to the output end of the first evaporator (16).

4. A multiple refrigerant system of the scroll pump type as set forth in claim 1 wherein, The refrigeration module (10) further comprises a first control valve (17) and a second control valve (18), the first control valve (17) is connected in parallel by pipelines between the input end and the output end of the compressor (11), and the second control valve (18) is connected in parallel by pipelines between the input end and the output end of the first pump unit (14).

5. A multiple refrigerant system as set forth in claim 4 wherein said compressor is a scroll compressor. The refrigeration module (10) further comprises a first check valve (191) and a suction solenoid valve (192), the suction solenoid valve (192) being connected in series with the input end of the compressor (11) through a pipeline, and the first check valve (191) being connected in series with the output end of the compressor (11) through a pipeline; the first control valve (17) is connected in parallel between the first check valve (191) and the suction solenoid valve (192) through a pipeline.

6. A multiple refrigerant system of the scroll pump type as set forth in claim 1 wherein, The second pump unit (24) comprises two parallel branches, each parallel branch being connected in series with a second pump (241) and a second check valve (242) through a pipeline, and the output ends of the two second check valves (242) forming the output end of the outdoor unit (100).

7. A multiple refrigerant system of the scroll pump type as set forth in claim 1 wherein, The outdoor unit (100) is at least one, the input ends of each outdoor unit (100) being connected in parallel, and the output ends of each outdoor unit (100) being connected in parallel; the indoor unit (200) comprises at least one refrigeration end (201), each refrigeration end (201) being connected in parallel between the input end and the output end of the outdoor unit (100), and each refrigeration end (201) comprising a second throttling device (2011) and a second evaporator (2012) connected in series through a pipeline.

8. A control method of a fluoro-pump multi-connected refrigeration system, characterized by, The control method comprises obtaining a difference △T of the indoor temperature Tin and the outdoor temperature Tout, and determining the working mode according to the relationship between △T and a first set value T1, a second set value T2 and a third set value T3; if △T≥T1, the first working mode is adopted; if T2≤△T<T1, it is determined whether the spraying condition is met, if the spraying condition is met, the sprayer sprays the heat exchanger (21) and / or the condenser (12), and it is determined whether △T is greater than or equal to T1, and if the result is yes, the first working mode is switched to; if the spraying condition is not met, the second working mode is switched to; if T3≤△T<T2, the second working mode is adopted; if △T<T3, the third working mode is adopted; if the current working mode is the second working mode or the third working mode, it is determined whether the spraying condition is met, if the spraying condition is met, the sprayer sprays the heat exchanger (21) and / or the condenser (12); in the first working mode, the compressor (11) is closed, the first pump unit (14) is opened and forms a refrigeration cycle with the condenser (12) and the first evaporator (16), and the second pump unit (24) is opened and forms a refrigeration cycle with the heat exchanger (21) and the second evaporator (2012); in the second working mode, the compressor (11) and the first pump unit (14) are both opened and form a refrigeration cycle with the condenser (12) and the first evaporator (16), and the second pump unit (24) is opened and forms a refrigeration cycle with the heat exchanger (21) and the second evaporator (2012); in the third working mode, the compressor (11), the first pump unit (14) and the second pump unit (24) are all opened and form a refrigeration cycle with the condenser (12), the first evaporator (16), the heat exchanger (21) and the second evaporator (2012). In the third working mode, the first pump unit (14) is closed, the compressor (11) is started and forms a refrigeration cycle with the condenser (12) and the first evaporator (16), and the second pump unit (24) is started and forms a refrigeration cycle with the heat exchanger (21) and the second evaporator (2012).

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