CN108507242B

CN108507242B - Throttling device

Info

Publication number: CN108507242B
Application number: CN201710676309.6A
Authority: CN
Inventors: 季士才
Original assignee: York Wuxi Air Conditioning and Refrigeration Co Ltd; Johnson Controls Technology Co
Current assignee: York Wuxi Air Conditioning and Refrigeration Co Ltd; Johnson Controls Technology Co
Priority date: 2017-08-09
Filing date: 2017-08-09
Publication date: 2020-06-16
Anticipated expiration: 2037-08-09
Also published as: CN108507242A

Abstract

The invention provides a throttling device. The throttling device is used for controlling the pressure difference of the refrigerant between the inlet and the outlet of a liquid supply pipe in the air conditioning system, the liquid supply pipe is provided with the throttling device, and the throttling device comprises: the first throttle control device, the second throttle control device and the bypass passage which can be controllably communicated or disconnected. The first throttle control means is provided upstream of the liquid supply pipe, the second throttle control means is provided downstream of the first throttle control means, one end of the bypass passage is connected upstream of the first throttle control means, and the other end of the bypass passage is connected to a connection passage between the first throttle control means and the second throttle control means. The first and second throttle control devices have passages to allow fluid to pass through the passages to vary the pressure differential of the fluid flowing through the passages and control the pressure differential across the supply tube. And according to the running state of the air-conditioning system, the bypass channel is connected or disconnected so as to improve the application performance of the air-conditioning system and protect the safe running of the air-conditioning system.

Description

Throttling device

Technical Field

The present invention relates to a throttling device, in particular to a throttling device used in an air conditioning system.

Background

A conventional air conditioning system includes four major components of a compressor, a condenser, a throttling device, and an evaporator for circulating a refrigerant therethrough to complete a refrigeration cycle or a heating cycle by a change in state of the refrigerant.

Specifically, fig. 1 shows a schematic structural diagram of a conventional air conditioning system 100. The air conditioning system 100 mainly includes an evaporator 110, a compressor 120, a condenser 130, and a throttle device 140, which are connected by piping to form a closed system, and a refrigerant is charged in the system. As shown in fig. 1, the evaporator 110 includes an inlet 110a and an outlet 110b, the compressor 120 includes an inlet 120a and an outlet 120b, the condenser 130 includes an inlet 130a and an outlet 130b, and the throttling device 140 includes an inlet 140a and an outlet 140 b. These components are connected by piping in the following manner: the outlet 120b of the compressor 120 is connected to the inlet 130a of the condenser 130, the outlet 130b of the condenser 130 is connected to the inlet 140a of the throttling device 140, the outlet 140b of the throttling device 140 is connected to the inlet 110a of the evaporator 110, and the outlet 110b of the evaporator 110 is connected to the inlet 120a of the compressor 120.

Since the state change of the refrigerant during cooling of the air conditioning system is similar to the state change of the refrigerant during heating, the state change of the refrigerant in the air conditioning system will be briefly described below by taking the state change of the refrigerant during cooling of the air conditioning system as an example. As shown in fig. 1, during the cooling process, the throttling device 140 throttles the high-pressure liquid refrigerant from the condenser 130, so that the refrigerant passes through the throttling device 140 to generate a pressure drop; the low-pressure refrigerant is heat-exchanged with an object to be cooled (in fig. 1, an arrow entering the evaporator 110 and an arrow coming out from the evaporator 110 indicate the trend of the object to be cooled such as chilled water), and the heat absorbed by the object to be cooled is vaporized and evaporated; the refrigerant vapor generated by the vaporization is sucked by the compressor 120, compressed, and discharged at a high pressure; the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 120 exchanges heat with an ambient medium (arrows entering the condenser 130 and exiting the condenser 130 in fig. 1 indicate the trend of the ambient medium such as cooling water) in the condenser 130, and the released heat is liquefied and condensed; the high temperature refrigerant liquid again flows through the throttling device 140 to create a pressure drop. The above steps are repeated to generate continuous refrigeration effect.

In the above-described conventional air conditioning system, an electronic expansion valve (EXV) or an orifice plate is generally used as the throttling device. However, for a large-cooling-capacity air-conditioning (heat pump) system, the cost is high due to the fact that a valve member such as an electronic expansion valve is used as a throttling device, and in order to reduce the cost, the existing large-cooling-capacity low-cost water-cooling air-conditioning (heat pump) system usually uses a throttling orifice plate as the throttling device.

The existing throttling device is a throttling orifice plate arranged in the refrigerant supply pipe. The orifice plate is provided with an orifice, and the orifice plate is transversely arranged in the flow passage of the refrigerant liquid supply pipe, so that the refrigerant flows through the orifice on the orifice plate, thereby changing the pressure difference of the refrigerant. For an air conditioning system, the system pressure difference (i.e., the difference between the condensing pressure and the evaporating pressure) required for the cooling state and the heating state is different, and specifically, the system pressure difference for the heating state is greater than the system pressure difference for the cooling state. For the throttling device in the prior art, the throttling device is matched only according to the refrigeration state of the air conditioning system, namely when the air conditioning system operates in the refrigeration state, the pressure difference between the inlet end and the outlet end of the throttling device can meet the system pressure difference required by the refrigeration state. When the air conditioning system operates in a heating state, the system pressure difference in the heating state is greater than the system pressure difference in the cooling state, so the orifice circulation capacity of the orifice plate is increased, the liquid supply amount is increased, the refrigerant is retained in the evaporator 110, the condenser 130 is in a liquid shortage state, and finally the system heating performance is poor due to the small supercooling degree of the condenser 130. Further, the refrigerant remains in the evaporator 110, which may cause safety problems such as liquid entrainment in the suction of the compressor 120. In other words, the throttle device of the prior art can only ensure the application performance in the cooling state, but cannot ensure the application performance in the heating state.

Therefore, for a water-cooling air conditioning (heat pump) system with large cooling capacity and low cost, a throttling device is needed, which can adapt to different system pressure differences during normal liquid supply in a refrigerating state and a heating state, so that the air conditioning system can ensure that the application performance of the air conditioning system can be fully exerted in the refrigerating state and the heating state, and the technical problem can be solved.

Disclosure of Invention

The present invention provides a throttle device that can solve at least the above problems.

According to a first aspect of the present invention, there is provided a throttling device for ensuring normal liquid supply and controlling a pressure difference of refrigerant between an inlet and an outlet of a liquid supply pipe in an air conditioning system, the liquid supply pipe having the throttling device provided therein, comprising:

a first throttle control device provided upstream of the supply pipe;

a second throttle control device disposed downstream of the first throttle control device;

a bypass passage having one end connected upstream of the first throttle control means and the other end connected to a connection passage between the first throttle control means and the second throttle control means, the bypass passage being controllably connected or disconnected;

the first and second throttle control devices have passages to allow the refrigerant to flow through the passages to vary a pressure differential of the refrigerant flowing through the passages and control a pressure differential across the supply tube.

According to the above-described throttle device, in the cooling state, the bypass passage is communicated; in the heating state, the bypass channel is disconnected.

According to the above throttle device, when the bypass passage is shut off, the pressure drops of the refrigerant generated by the first throttle control device and the second throttle control device may be superimposed; when the bypass passage is open, the first throttle control device is deactivated and the pressure drop of the refrigerant through the throttle device is the pressure drop created by the second throttle control device.

According to the above throttling device, the first throttling control means comprises at least one throttling control means.

According to the throttling device, the first throttling control device is a throttling orifice plate and/or the second throttling control device is a throttling orifice plate.

According to the throttling device, the at least one throttling control device is a throttling orifice plate.

According to the throttling device, the bypass channel is provided with the electromagnetic valve to control the connection or disconnection of the bypass channel.

According to a second aspect of the present invention, there is provided an air conditioning system comprising:

an evaporator comprising an evaporator inlet and an evaporator outlet;

a compressor including a compressor inlet and a compressor outlet, the compressor inlet in communication with the evaporator outlet;

a condenser comprising a condenser inlet and a condenser outlet, the condenser inlet in communication with the compressor outlet;

the condenser is characterized by further comprising the throttling device, the throttling device comprises a throttling device inlet and a throttling device outlet, the throttling device inlet is communicated with the condenser outlet, and the throttling device outlet is communicated with the evaporator inlet.

The present invention also discloses a method for controlling a throttling device for ensuring normal liquid supply and controlling a pressure difference of refrigerant between an inlet and an outlet of a liquid supply pipe in an air conditioning system, the throttling device being provided in the liquid supply pipe, the throttling device comprising: a first throttle control device provided upstream of the supply pipe; a second throttle control device disposed downstream of the first throttle control device; a bypass passage having one end connected upstream of the first throttle control means and the other end connected to a connection passage between the first throttle control means and the second throttle control means, the bypass passage being controllably connected or disconnected; the first throttle control device and the second throttle control device having passages to allow the refrigerant to flow through the passages to vary a pressure differential of the refrigerant flowing through the passages and control a pressure differential across the supply tube; the method comprises the following steps:

when a compressor of the air-conditioning system runs, comparing the system pressure difference of the air-conditioning system with a first set value and a second set value, wherein the system pressure difference is the pressure difference between a system condensation side and a system evaporation side, and the second set value is larger than the first set value;

when the system pressure difference is less than or equal to a first set value, judging that the system is in a refrigeration state, and communicating the bypass channel so as to enable the refrigerant to flow through the second throttling control device from the bypass channel;

and when the system pressure difference is larger than or equal to a second set value, judging that the system is in a heating state, and disconnecting the bypass channel to enable the refrigerant to sequentially flow through the first throttling control device and the second throttling control device.

According to the control method, the state of the bypass passage connection or disconnection does not change during the transition of the system from the cooling state to the heating state or during the transition from the heating state to the cooling state.

According to the throttling device and the control method thereof, the throttling device can adapt to two different system pressure differences of a refrigerating state and a heating state, so that the air conditioning system can stably supply liquid to the unit no matter in the refrigerating state or in the heating state, the performance and the stability of the unit are improved, and the cost of the unit is reduced.

Other features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Furthermore, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed. However, the detailed description and specific examples merely indicate preferred embodiments of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Drawings

These and other features and advantages of the present invention will be better understood by reading the following detailed description with reference to the drawings, in which like characters represent like parts throughout the drawings, wherein:

fig. 1 shows a schematic structural view of a conventional air conditioning system 100;

FIG. 2A shows a schematic block diagram of a throttle device according to an embodiment of the present invention;

FIG. 2B illustrates a flow path of refrigerant in the throttling device of FIG. 2A in a cooling state of the air conditioning system;

fig. 2C illustrates a flow path of a refrigerant in the throttling device of fig. 2A in a heating state of the air conditioning system;

FIG. 3 is a schematic structural view showing a throttle apparatus according to another embodiment of the present invention;

FIG. 4 is a schematic diagram of an air conditioning system utilizing the throttling device of the present invention;

FIG. 5 shows a schematic internal block diagram of the controller of FIG. 4;

fig. 6 shows a control flowchart of the controller in fig. 4 for controlling the bypass passage to be connected or disconnected.

Detailed description of the preferred embodiments

Various embodiments of the present invention will now be described with reference to the accompanying drawings, which form a part hereof. It is to be understood that although directional terms, such as "front," "rear," "upper," "lower," "left," "right," etc., may be used herein to describe various example features and elements of the invention, these terms are used herein for convenience of description only and are intended to be based on the example orientations shown in the figures. Because the disclosed embodiments of the invention can be arranged in a variety of orientations, these directional terms are used for purposes of illustration only and are not to be construed as limiting. In the following drawings, like parts are given like reference numerals and similar parts are given like reference numerals to avoid repetition of the description.

FIG. 2A shows a flow restriction device according to an embodiment of the present invention. In the embodiment shown in fig. 2A, the throttle means is arranged in the supply pipe 220 for the refrigerant, which comprises a first throttle control means 201, a second throttle control means 202 and a bypass channel 203. The first throttle control means 201 is arranged upstream of the supply pipe 220 and the second throttle control means 202 is arranged downstream of the first throttle control means 201. One end 210 of the bypass passage 203 is connected upstream of the first throttle control means 201, and the other end 212 of the bypass passage 203 is connected to the connection passage 207 between the first throttle control means 201 and the second throttle control means 202, wherein the bypass passage 203 is controllably connected or disconnected. The first throttle control 201 and the second throttle control 202 have

passages

208 and 209, respectively. The first throttle control device 201 and the second throttle control device 202 are arranged in the supply line 220 such that refrigerant can only flow from the

passages

208 and 209 through the first throttle control device 201 and the second throttle control device 202, thereby varying the pressure drop of refrigerant flowing through the first throttle control device 201 and the second throttle control device 202. The connection or disconnection of the bypass passage 203 is controlled by a solenoid valve 205.

According to an example of the present invention, the first throttle control device 201 and the second throttle control device 202 are a first orifice plate and a second orifice plate, respectively, which are provided with orifices through which liquid flows as passages through which refrigerant flows. The first and second orifice plates are transversely disposed in the refrigerant supply tube such that refrigerant can only flow through the first and second orifice plates through the apertures therein. Of course, the first throttle control device 201 and the second throttle control device 202 may not be an orifice plate, but may be other structures that perform a pressure control function, such as a bell mouth with a tapered opening.

Fig. 2B shows a flow path of the refrigerant in the throttling device in fig. 2A in a cooling state of the air conditioning system, wherein arrows indicate the flow path of the refrigerant. As shown in fig. 2B, when the air conditioning system is in the cooling state, the solenoid valve 205 is opened, and the bypass passage 203 is communicated. Since the resistance of the bypass passage 203 after communication is small, the refrigerant entirely flows through the bypass passage 203 without passing through the passage 208 of the first throttle control device 201. This allows refrigerant to flow through the second throttle control 202 only through the bypass passage 203, resulting in a throttle pressure drop of the refrigerant by the second throttle control 202 in the cooling state. Wherein the flow area of the bypass channel must not be less than 50% of the supply tube 220.

Fig. 2C illustrates a flow path of the refrigerant in the throttling device of fig. 2A in a heating state of the air conditioning system, wherein arrows indicate the flow path of the refrigerant. As shown in fig. 2C, when the air conditioning system is operating in the heating state, the solenoid valve 205 is closed and the bypass passage 203 is opened, so that the refrigerant entirely flows through the first throttle control device 201 without passing through the bypass passage 203. This causes the refrigerant to flow through both the first throttle control device 201 and the second throttle control device 202 in the heating state, and the first throttle control device 201 and the second throttle control device 202 jointly generate throttle pressure reduction on the refrigerant.

According to an example of the present invention, the

passages

208 and 209 of the first throttle control device 201 and the second throttle control device 202 are designed as circular passages, and the diameter of the circular passages is designed to ensure that the throttle pressure reduction of the throttle control devices during normal liquid supply meets the requirements of the refrigeration system.

According to the present invention, the throttling and pressure reducing capability of the second throttling control device 202 when ensuring the normal liquid supply of the refrigerant is designed to meet the standard system pressure drop required by the refrigeration state of the air conditioning system when the refrigerant only flows through the second throttling control device 202. And the throttling and pressure reducing capacity of the first throttling control device 201 when the normal liquid supply of the refrigerant is ensured is designed to meet the standard system pressure drop required by the heating state of the air conditioning system when the refrigerant flows through the first throttling control device 201 and the second throttling control device 202. Specifically, the size of the passage 209 in the second throttle control 202 is matched to the refrigerant flow and pressure drop required for standard cooling conditions of the air conditioning system. Therefore, in the cooling state of the air conditioning system, the refrigerant flows only through the second throttle control device 202 to achieve the pressure drop required by the system. In the heating state of the air conditioning system, the system pressure drop is increased, and therefore the first throttle control device 201 and the second throttle control device 202 need to be matched to achieve the refrigerant flow and the pressure drop required by the heating state of the air conditioning system. Therefore, the size of the passage 208 of the first throttle control device 201 should be designed such that the refrigerant flow and the pressure drop of the system can satisfy the requirement of the heating state of the air conditioning system after the refrigerant flows through both the first throttle control device 201 and the second throttle control device 202.

Therefore, the throttling device can meet different system pressure differences of a refrigerating state and a heating state in the large-refrigerating-capacity low-cost water-cooling air-conditioning system, so that the air-conditioning system can be ensured to play the best performance no matter in the refrigerating state or in the heating state.

Fig. 3 shows a throttle device according to another embodiment of the invention. The arrangement of the components is the same as that in fig. 2A except that the arrangement of the first throttle control device 201 is different from that in fig. 2A, and the description thereof is omitted. In the embodiment shown in fig. 3, the first throttle control means 201 is provided as a plurality of throttle control means (201.1,201.2, … …. n), the plurality of throttle control means (201.1,201.2, … …. 201.n) being fluidly connected together in series, the pressure drop across the plurality of throttle control means (201.1,201.2, … …. n) being the same as the pressure drop across the first throttle control means 201 in fig. 2A.

Providing the first throttle control means 201 as a plurality of throttle control means (201.1,201.2, … …. n) also has the advantage that the amount of liquid supplied can be accurately adjusted at part load. This is because, when the refrigerant passes through each throttle control device, the refrigerant gradually changes from a liquid state to a gas-liquid mixed state due to the gradual decrease in pressure of the refrigerant passing through each throttle control device, the refrigerant flow rate in the gas-liquid mixed state is fast and the pressure drop generated when passing through the plurality of throttle control devices is larger than that when passing through one throttle control device, and therefore, particularly at part load, the liquid supply control capability of the plurality of throttle control devices (201.1,201.2, … …. n) of the present embodiment is superior to that of the single throttle control device 201, thereby achieving the advantageous effect of more accurately adjusting the liquid supply amount.

It can be seen that although the present invention is not shown, it is anticipated that one skilled in the art will readily appreciate that it is within the scope of the present invention to use a plurality of throttle controls in place of the first throttle control 201 and/or a plurality of throttle controls in place of the second throttle control 202, for example, to achieve the same purpose.

Fig. 4 is a schematic structural diagram of an air conditioning system 400 using the throttling device of the present invention, wherein the evaporator 110, the compressor 120, the condenser 130 and the throttling device 440 are connected to the evaporator 110, the compressor 120, the condenser 130 and the throttling device 140 of the air conditioning system 100 of fig. 1, and therefore, the detailed description thereof is omitted. Unlike the air conditioning system 100 of fig. 1, fig. 4 shows an air conditioning system 400 that uses a throttling device 440 according to the present invention, and a controller 406, a first sensor 408, and a second sensor 410 are provided in the air conditioning system for controlling the operation of the throttling device. Wherein the first sensor 408 is disposed in the condenser 130 for detecting a condensing pressure of the condenser 130. The second sensor 410 is provided in the evaporator 110 to detect the evaporation pressure of the evaporator 110. The controller 406, the first sensor 408, the second sensor 410, and the throttling device 440 are communicatively coupled such that the controller 406 receives the condensing pressure and the evaporating pressure and sends a control signal to the throttling device 440 based on a difference between the condensing pressure and the evaporating pressure.

Fig. 5 shows a schematic internal block diagram of the controller 406 of fig. 4. As shown in fig. 5, the controller 406 includes a bus 502, a processor 504, an input device (wired) 508, an output device (wired) 512, a wireless communication device 514, and a memory 518 with a control program 502. Various components of controller 406, including processor 504, input device (wired) 508, output device (wired) 512, wireless communication device 514, and memory 518, are communicatively coupled to bus 502 such that processor 504 can control the operation of input device (wired) 508, output device (wired) 512, wireless communication device 514, and memory 518. In particular, memory 518 is used to store programs, instructions and data, and processor 504 reads programs, instructions and data from memory 518 and can write data to memory 518. The processor 504 controls the operation of the input device (wired) 508, the output device (wired) 512, and the wireless communication device 514 by executing programs and instructions read from the memory 518.

An input device (wired) 508 receives signals and data from the air conditioning system, including signals and data from the first sensor 408 and the second sensor 410, via a connection 509. Via connection 511, an output device (wired) 512 sends control signals to the outside, including a control signal to close or open the solenoid valve 205. Through the wireless channel 513, the wireless communication device 514 sends out control signals to the outside, including a control signal for closing or opening the solenoid valve 205; and receives signals and data from the air conditioning system, including signals and data from the first sensor 408 and the second sensor 410.

It should be noted that in an embodiment of the present invention, a program implementing the flowchart shown in fig. 6 is stored in the memory 518 of the controller 406. The controller 406 controls the solenoid valve 205 by the processor 504 executing a program stored in the controller 406.

Fig. 6 shows a control flow diagram 600 for the controller 406 to control the bypass path 203 to be connected or disconnected. As shown in fig. 6, the controller 406 controls the bypass path 203 to be connected or disconnected as follows:

in step 602, the processor 504 determines whether the compressor 120 of the air conditioning system 400 is operating. If the compressor 120 is not running, the processor 504 returns operation to step 602 until the processor 504 determines that the compressor 120 is beginning to run and the processor 504 transfers operation to step 604.

In step 604, the processor 504 receives the condensing pressure of the condenser 130 and the evaporating pressure of the evaporator 110 according to the input device (wired) 508 and/or the wireless communication device 514, and calculates a system pressure difference, wherein the system pressure difference is the condensing pressure minus the evaporating pressure. Processor 504 then transfers operation to step 606 based on the calculated system pressure differential.

In step 606, the processor 504 determines whether the system pressure difference is less than or equal to a first predetermined value. When the system pressure difference is less than or equal to the first set value, it is determined that the air conditioning system 400 is in a cooling state, and the processor 504 transfers the operation to step 610; when the system pressure difference is greater than the first set point, it is determined that the air conditioning system 400 is not in the cooling state and the processor 504 transfers operation to step 608.

In step 608, the processor 504 determines whether the system pressure differential is greater than or equal to a second set point. Wherein the second set value is greater than the first set value. According to one example, the second set value is the first set value + a. Wherein a is 1-5 bar. When the system pressure difference is less than the second set point, the processor 504 returns operation to step 602; when the system pressure difference is greater than or equal to the second set value, it is determined that the air conditioning system is in a heating state, and the processor 504 transfers the operation to step 620.

It is noted that when the system pressure difference is less than the second set point in step 608, it indicates that the air conditioning system 300 is in a transition region between the cooling state and the heating state, so the solenoid valve 205 will not be activated in this case, and the processor 504 will return to step 602 to determine whether the compressor 120 of the air conditioning system 300 is running again.

In step 620, the processor 504 sends a close control signal to the solenoid valve 205 via the output device (wired) 412 and/or the wireless communication device 414. Processor 504 then transfers operation to step 624.

In step 624, the processor 504 determines whether the system pressure differential is less than or equal to a first set point. When the system pressure difference is greater than the first set point, indicating that the air conditioning system is still in the heating state, the processor 504 returns operation 608 to operation 624; when the system pressure differential is less than or equal to the first set point, indicating that the air conditioning system is in a cooling state, the processor 504 transfers operation to step 626.

In step 626, the processor 504 determines whether the compressor 120 of the air conditioning system 300 is running. If the compressor 120 has stopped, the processor 504 returns operation to step 602; if the processor 504 determines that the compressor 120 is still running, the processor 504 transfers operation to step 610.

It should be noted that, when the air conditioning system is operating, there may be a case where the heating state is changed to the cooling state. The operations of

steps

624 and 626 ensure that when the system is going to change from a heating state to a cooling state without stopping the operation of the compressor 120, the solenoid valve 205 is kept closed during the transition from the heating state to the cooling state until the system pressure difference is less than or equal to the first set value. That is, the operation is transferred to step 610 after the air conditioning system 400 is completely transitioned to the cooling state. This is to prevent the solenoid valve 205 from being frequently opened and closed due to frequent changes in the heating state and the cooling state, thereby affecting the lifespan of the air conditioning system 400.

It is possible to move to step 610 for both the operations of step 606 and step 626. That is, step 610 has two entries. Transitioning from step 606 to step 610 indicates that air conditioning system 300 is set to the cooling state immediately after startup. Transitioning from step 626 to step 610 indicates that air conditioning system 300 transitions from a heating state to a cooling state during ongoing operation.

At step 610, the processor 504 sends an open control signal to the solenoid valve 205 via the output device (wired) 412 and/or the wireless communication device 414. Processor 504 then transfers operation to step 614.

At step 614, processor 504 determines whether the system pressure differential is greater than or equal to a second set point. When the system pressure difference is greater than or equal to the second set value, indicating that the air conditioning system 300 is in a cooling state, the processor 504 transfers the operation to step 620; when the system pressure differential < the second set point, the processor 504 transfers operation to step 616.

In step 616, the processor 504 determines whether the compressor 120 of the air conditioning system 300 is operating. If the compressor 120 has stopped running, the processor 504 returns operation to step 602; if the processor 504 determines that the compressor 120 is still running, the processor 504 returns operation to step 614.

It should be noted that, when the air conditioning system 300 is operating, there may be a case where the cooling state is changed to the heating state. The operations of step 614 and step 616 ensure that the solenoid valve is kept open during the transition from the cooling state to the heating state until the system pressure difference is greater than or equal to the second set value when the system is to change from the cooling state to the heating state without stopping the operation of the compressor 120. That is, after the system is completely transitioned to the heating state, the operation is transferred to step 620. This is to prevent the electromagnetic valve from being frequently opened and closed due to frequent changes of the heating state and the cooling state, thereby affecting the service life of the air conditioning system.

As can also be seen in fig. 6, it is possible to move to step 620 for both the operations of step 608 and step 614. That is, step 620 has two entries. The transition from step 608 to step 620 indicates that the air conditioning system 300 is set to the heating state immediately after being started. The transition from step 614 to step 620 indicates that air conditioning system 300 transitions from the cooling state to the heating state during ongoing operation.

While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. A throttling arrangement (440) for controlling a pressure difference of a refrigerant between an inlet and an outlet of a supply pipe (220) in an air conditioning system (400), characterized in that the throttling arrangement (440) is provided in the supply pipe, the throttling arrangement (440) comprising:

-first throttle control means (201), said first throttle control means (201) being arranged upstream of said supply pipe;

-a second throttle control means (202), said second throttle control means (202) being arranged downstream of said first throttle control means (201);

a bypass passage (203), one end (210) of the bypass passage (203) is connected to the upstream of the first throttle control device (201), the other end (212) of the bypass passage (203) is connected to a connecting passage (207) between the first throttle control device (201) and the second throttle control device (202), and the bypass passage (203) is controllably connected or disconnected;

the first throttle control means (201) and the second throttle control means (202) have passages to allow the refrigerant to flow therethrough, thereby varying a pressure difference of the refrigerant flowing through the passages and controlling a pressure difference across the liquid supply pipe (220).

2. The throttling device (440) according to claim 1, wherein:

in a cooling state, the bypass passage (203) is communicated; in the heating state, the bypass channel (203) is disconnected.

3. The throttling device (440) according to claim 1, wherein:

when the bypass passage (203) is disconnected, the pressure drops of the refrigerant generated by the first throttle control device (201) and the second throttle control device (202) may be superimposed; when the bypass passage (203) is open, the first throttle control device (201) is deactivated and the pressure drop of the refrigerant through the throttle device (440) is the pressure drop created by the second throttle control device (202).

4. The throttle device (440) of claim 1, characterized in that the first throttle control device (201) comprises at least one throttle control device (201.1,201.2, … …. n).

5. An orifice device (440) according to claim 1, characterized in that the first orifice control device (201) is an orifice plate and/or the second orifice control device (202) is an orifice plate.

6. The throttle device (440) of claim 4, wherein the at least one throttle control device (201.1,201.2, … …. n) is an orifice plate.

7. The throttling device (440) according to claim 1, wherein a solenoid valve (205) is provided on the bypass passage (203) to control the connection or disconnection of the bypass passage (203).

8. An air conditioning system (400), comprising:

an evaporator (110), the evaporator (110) comprising an evaporator inlet (110a) and an evaporator outlet (110 b);

a compressor (120) comprising a compressor inlet (120a) and a compressor outlet (120b), the compressor inlet (120a) in communication with the evaporator outlet (110 b);

a condenser (130), the condenser (130) comprising a condenser inlet (130a) and a condenser outlet (130b), the condenser inlet (130a) communicating with the compressor outlet (120 b);

it is characterized in that the preparation method is characterized in that,

further comprising a throttle device (440) according to any one of claims 1-7, said throttle device (440) comprising a throttle device inlet (440a) and a throttle device outlet (440b), said throttle device inlet (440a) communicating with said condenser outlet (130b), said throttle device outlet (440b) communicating with said evaporator inlet (110 a).

9. A method for controlling a throttling device for controlling a pressure difference of a refrigerant between an inlet and an outlet of a supply pipe (220) in an air conditioning system (400), characterized in that the throttling device (440) is arranged in the supply pipe, the throttling device (440) comprising: -first throttle control means (201), said first throttle control means (201) being arranged upstream of said supply pipe; -a second throttle control means (202), said second throttle control means (202) being arranged downstream of said first throttle control means (201); a bypass passage (203), one end (210) of the bypass passage (203) is connected to the upstream of the first throttle control device (201), the other end (212) of the bypass passage (203) is connected to a connecting passage (207) between the first throttle control device (201) and the second throttle control device (202), and the bypass passage (203) is controllably connected or disconnected; the first throttle control means (201) and the second throttle control means (202) have passages to allow the refrigerant to flow therethrough, thereby varying a pressure difference of the refrigerant flowing through the passages and controlling a pressure difference across the liquid supply pipe (220); the method comprises the following steps:

when a compressor (120) of the air conditioning system (400) operates, comparing the system pressure difference of the air conditioning system (400) with a first set value and a second set value respectively, wherein the system pressure difference is the pressure difference between the condensation side and the evaporation side of the system, and the second set value is larger than the first set value;

when the system pressure difference is less than or equal to the first set value, judging that the system is in a refrigeration state, and communicating the bypass passage (203) so as to enable refrigerant to flow from the bypass passage (203) through the second throttling control device (202);

and when the system pressure difference is larger than or equal to the second set value, judging that the system is in a heating state, and disconnecting the bypass channel (203) so as to enable the refrigerant to sequentially flow through the first throttling control device (201) and the second throttling control device (202).

10. The method for controlling a throttle device according to claim 9, characterized in that the state in which the bypass passage (203) is communicated or disconnected does not change during the transition of the system from the cooling state to the heating state or from the heating state to the cooling state.