WO2022227567A1

WO2022227567A1 - Control method for dual compressor air conditioner

Info

Publication number: WO2022227567A1
Application number: PCT/CN2021/134684
Authority: WO
Inventors: 刘帅; 矫立涛; 周星宇; 陈睿
Original assignee: 青岛海尔空调器有限总公司; 青岛海尔空调电子有限公司; 海尔智家股份有限公司
Priority date: 2021-04-28
Filing date: 2021-12-01
Publication date: 2022-11-03
Also published as: CN113465021A

Abstract

A control method for a dual compressor air conditioner, relating to the technical field of air conditioners. The present invention aims to solve the problem that a defrosting effect of existing air conditioners by additionally providing a defrosting branch is poor. For this purpose, in the control method, an indoor coil (111), a first compressor (113), an outdoor coil (114), and a first throttling member (115) are successively provided on a first refrigerant circulation loop (11); an outdoor unit is also provided with a second refrigerant circulation loop (12); a first heat exchanging coil (121), a four-way valve (122), a second compressor (123), a second heat exchanging coil (124), and a second throttling member (125) are provided on the second refrigerant circulation loop (12); the first heat exchanging coil (121) can exchange heat with at least a portion of the first refrigerant circulation loop (11) located between the first throttling member (115) and the outdoor coil (114). By means of the control method, when a frosting phenomenon or frosting tendency occurs in the outdoor coil (114), the second refrigerant circulation loop (12) is controlled o perform a heating cycle, so that the first heat exchanging coil (121) is used to defrost the outdoor coil (114) as a condenser, and thus the defrosting efficiency is effectively improved.

Description

Control method for dual compressor air conditioner

technical field

The invention belongs to the technical field of air conditioners, and specifically provides a control method for a dual-compressor air conditioner.

Background technique

The air conditioner sets the refrigerant circulation loop to make the refrigerant continuously exchange heat between indoors and outdoors to meet the user's heat exchange needs. When running heating conditions in winter, the outdoor unit is prone to frost. It will greatly affect the heat exchange efficiency of the outdoor coil, and then affect the heat exchange efficiency of the entire air conditioner; therefore, the defrosting problem is a technical problem that every air conditioner must solve.

In order to effectively solve the problem that the heat exchange efficiency is affected by frost on the outdoor coil, the prior art personnel have designed many defrosting methods. Although these defrosting methods can achieve a certain defrosting effect, they also have certain problems. For example, most of the existing air conditioners achieve the defrosting effect by setting a defrosting branch. When the outdoor coil needs to be defrosted, the defrosting branch is connected, and the refrigerant in the branch is heated. After heating The refrigerant in the cooling medium first merges with the refrigerant in the refrigerant circulation loop and then enters the outdoor coil, so as to achieve the defrosting effect; and the way to heat the refrigerant can be achieved by adding a heating component or by means of another refrigerant circulation loop. heating. However, no matter what heating method is used, the heated refrigerant needs to be combined with the unheated refrigerant before entering the outdoor coil, which will not only affect the heating effect of the refrigerant, but also easily lead to the problem of unstable refrigerant state. .

Accordingly, there is a need in the art for a new control method for a dual compressor air conditioner to solve the above problems.

SUMMARY OF THE INVENTION

In order to solve the above problems in the prior art, that is, in order to solve the problem that the defrosting effect of the existing air conditioner is not good by adding a defrosting branch, the present invention provides a dual-compressor air conditioner. The control method, the dual-compressor air conditioner includes an indoor unit and an outdoor unit, a first refrigerant circulation circuit is arranged between the indoor unit and the outdoor unit, and indoor coils are sequentially arranged on the first refrigerant circulation circuit , a first compressor, an outdoor coil and a first throttling member, the indoor coil is arranged in the indoor unit, the outdoor coil is arranged in the outdoor unit, and the outdoor unit is also provided with A second refrigerant circulation loop, the second refrigerant circulation loop is provided with a first heat exchange coil, a four-way valve, a second compressor, a second heat exchange coil and a second throttling member, the first heat exchange coil The heat coil can exchange heat with at least a part of the first refrigerant circulation circuit between the first throttling member and the outdoor coil, so that the refrigerant can be heated and then enter the outdoor coil The control method of the present invention includes: when the first refrigerant circulation loop performs a heating cycle, acquiring the frosting condition of the outdoor coil; if the outdoor coil appears frosting or has a tendency to frost, Then, the second refrigerant circulation loop is controlled to perform a heating cycle, so that the first heat exchange coil is used as a condenser to perform defrosting treatment on the outdoor coil.

In a preferred technical solution of the above control method, after the step of "controlling the second refrigerant circulation loop to perform a heating cycle", the control method further includes: acquiring the defrosting situation of the outdoor coil; After the defrosting of the outdoor coil is completed, the frosting condition of the second heat exchange coil is further obtained; according to the frosting condition of the second heat exchange coil, the operation state of the second refrigerant circulation circuit is controlled accordingly.

In a preferred technical solution of the above-mentioned control method, the step of “controlling the operation state of the second refrigerant circulation loop correspondingly according to the frosting condition of the second heat exchange coil” specifically includes: if the second heat exchange coil is When the coil is frosted, the second refrigerant circulation circuit is controlled to execute a refrigeration cycle, so that the second heat exchange coil is used as a condenser to defrost itself.

In a preferred technical solution of the above-mentioned control method, the step of “controlling the operation state of the second refrigerant circulation loop correspondingly according to the frosting condition of the second heat exchange coil” specifically includes: if the second heat exchange coil is If there is no frost formation on the coil, the second refrigerant circulation loop is controlled to stop running.

In a preferred technical solution of the above control method, the second compressor is an inverter compressor, and the control method further includes: in the case that the second refrigerant circulation loop performs a heating cycle, further obtaining the outdoor disk The degree of frost formation on the pipe; according to the degree of frost formation on the outdoor coil, the operating frequency of the second compressor is controlled.

In a preferred technical solution of the above control method, the second throttling member is an electronic expansion valve, and the control method further includes: in the case that the second refrigerant circulation loop performs a heating cycle, further obtaining the outdoor The degree of frost formation of the coil; according to the degree of frost formation of the outdoor coil, the opening degree of the second throttle member is controlled.

In a preferred technical solution of the above control method, at least a part of the intake section of the second compressor is disposed close to the control device of the outdoor unit, and the control method further includes: performing refrigeration in the first refrigerant circulation circuit In the case of circulation, the temperature of the environment where the outdoor unit is located is obtained; the operating state of the second refrigerant circulation loop is controlled according to the temperature of the environment where the outdoor unit is located.

In a preferred technical solution of the above control method, the step of "controlling the operating state of the second refrigerant circulation loop according to the temperature of the environment where the outdoor unit is located" specifically includes: if the temperature of the environment where the outdoor unit is located is greater than the first preset temperature, the second refrigerant circulation circuit is controlled to execute a refrigeration cycle.

In a preferred technical solution of the above control method, the control method further includes: in the case where the first refrigerant circulation loop performs a heating cycle and the outdoor coil does not have frost formation, obtaining the control device's temperature; according to the temperature of the control device, the operating state of the second refrigerant circulation loop is controlled.

In a preferred technical solution of the above control method, the step of "controlling the operating state of the second refrigerant circulation loop according to the temperature of the control device" specifically includes: if the temperature of the control device is greater than the second preset temperature, Then, the second refrigerant circulation loop is controlled to execute a heating cycle.

Those skilled in the art can understand that, in the technical solution of the present invention, the dual-compressor air conditioner of the present invention includes an indoor unit and an outdoor unit, and a first refrigerant circulation loop is arranged between the indoor unit and the outdoor unit , an indoor coil, a first compressor, an outdoor coil and a first throttling member are sequentially arranged on the first refrigerant circulation loop, the indoor coil is arranged in the indoor unit, and the outdoor coil is arranged In the outdoor unit, the outdoor unit is also provided with a second refrigerant circulation loop, and the second refrigerant circulation loop is provided with a first heat exchange coil, a four-way valve, a second compressor, and a second heat exchanger. a heat coil and a second throttling member, wherein the first heat exchange coil is capable of exchanging heat with at least a part of the first refrigerant circulation loop located between the first throttling member and the outdoor coil, so that the refrigerant can be heated up before entering the outdoor coil; the control method of the present invention includes: when the first refrigerant circulation loop performs a heating cycle, acquiring the frosting condition of the outdoor coil; if If the outdoor coil is frosted or tends to be frosted, the second refrigerant circulation loop is controlled to perform a heating cycle, so that the first heat exchange coil is used as a condenser and the outdoor coil is Perform defrosting. Based on the above-mentioned structural arrangement, the present invention adds the second refrigerant circulation loop to the outdoor unit, so that when the outdoor coil has a frosting phenomenon or a tendency to frost, the second refrigerant circulation loop can pass through the outdoor unit. The first heat exchange coil exchanges heat with at least a part of the first refrigerant circulation loop located between the first throttling member and the outdoor coil, so that the second refrigerant circulation loop can directly The temperature-raising treatment is performed on the refrigerant before flowing into the outdoor coil, thereby effectively ensuring that the refrigerant entering the outdoor coil is all heated, thereby effectively improving the defrosting efficiency of the air conditioner; further, this The control method of the invention can also control the second refrigerant circulation loop to execute the heating cycle according to the frosting condition of the outdoor coil when the first refrigerant circulation loop executes the heating cycle, so as to make the first refrigerant circulation loop perform the heating cycle. The heat coil is used as a condenser to perform defrosting treatment on the outdoor coil, so that defrosting is performed in time when defrosting is required, thereby effectively ensuring the heat exchange efficiency of the first refrigerant circulation loop.

Description of drawings

1 is a schematic diagram of the overall structure of the dual-compressor air conditioner of the present invention when it is in a first working state;

2 is a schematic diagram of the overall structure of the dual-compressor air conditioner of the present invention when it is in a second working state;

3 is a schematic diagram of the overall structure of the dual-compressor air conditioner of the present invention when it is in a third working state;

Fig. 4 is the main step flow chart of the control method of the dual-compressor air conditioner of the present invention;

Fig. 5 is the specific step flow chart of the preferred embodiment of the control method of the dual-compressor air conditioner of the present invention;

Reference number:

11. The first refrigerant circulation circuit; 111, the indoor coil; 112, the first four-way valve; 113, the first compressor; 114, the outdoor coil; 115, the first throttle member; 116, the first stop valve; 117. The second stop valve;

12. The second refrigerant circulation loop; 121, the first heat exchange coil; 122, the second four-way valve; 123, the second compressor; 124, the second heat exchange coil; 125, the second throttle member;

13. Shell and tube heat exchanger;

14. Control device;

15. Outdoor fan.

Detailed ways

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principle of the present invention, and are not intended to limit the protection scope of the present invention. Those skilled in the art can adjust it as needed to adapt to specific applications. For example, although the dual-compressor air conditioner described in this preferred embodiment is a one-for-one type air conditioner, the dual-compressor air conditioner can obviously also be a one-for-one multi-type air conditioner. The change of this specific application object does not deviate from the basic principle of the present invention, and belongs to the protection scope of the present invention.

It should be noted that, in the description of the present invention, the terms “upper”, “left”, “right”, “inner”, “outer”, etc. indicate directions or terms in positional relationship based on the directions shown in the drawings or The positional relationship is only for the convenience of description, rather than indicating or implying that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In addition, it should be noted that, in the description of the present invention, unless otherwise expressly specified and limited, the term "connected" should be understood in a broad sense, for example, it may be directly connected, or indirectly connected through an intermediate medium, or it may be Communication within two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. Although the various steps of the control method of the present invention are described in a specific order in this application, these sequences are not limiting, and those skilled in the art can perform them in different orders without departing from the basic principles of the present invention. the steps.

1 to 3, wherein, FIG. 1 is a schematic diagram of the overall structure of the dual-compressor air conditioner of the present invention when it is in the first working state; FIG. 2 is the overall structure of the dual-compressor air conditioner of the present invention when it is in the second working state. Schematic diagram of the structure; FIG. 3 is a schematic diagram of the overall structure of the dual-compressor air conditioner of the present invention when it is in the third working state. As shown in Figures 1 to 3, the dual-compressor air conditioner of the present invention includes an indoor unit and an outdoor unit, wherein the indoor unit is the part in the left frame, and the outdoor unit is the part in the right frame. Of course, this The invention does not impose any restrictions on the specific structure and number of installations of the indoor unit and the outdoor unit, and technicians can adjust them according to actual use requirements.

Specifically, a first refrigerant circulation circuit 11 is provided between the indoor unit and the outdoor unit, and the dual-compressor air conditioner continuously exchanges heat between the indoor and outdoor through the first refrigerant circulation circuit 11 to meet the needs of users To meet the heat exchange requirements, the first refrigerant circulation circuit 11 is provided with an indoor coil 111, a first four-way valve 112, a first compressor 113, an outdoor coil 114, and a first throttling member 115. Near the outdoor coil 114 An outdoor fan 15 is provided to improve the heat exchange efficiency of the outdoor coil 114, wherein the indoor coil 111 is arranged in the indoor unit, the first four-way valve 112, the first compressor 113, the outdoor coil 114 and the first four-way valve 112. The throttling member 115 is arranged in the outdoor unit, and the flow direction of the refrigerant in the first refrigerant circulation circuit 11 can be controlled by controlling the communication state of the first four-way valve 112, thereby controlling the heat exchange state of the dual-compressor air conditioner . In addition, the first refrigerant circulation circuit 11 is also provided with a first shut-off valve 116 and a second shut-off valve 117 , and the first shut-off valve 116 and the second shut-off valve 117 are located on both sides of the indoor coil 111 respectively. As a preferred arrangement, the first throttling member 115 is an electronic expansion valve; of course, this is not a limitation, and the first throttling member 115 may also be other components having a throttling effect, such as a capillary tube and the like. It should also be noted that the present invention does not impose any restrictions on the specific structure of the first refrigerant circulation loop 11, and technicians can set them according to actual use requirements; for example, the first refrigerant circulation loop 11 may not be provided with the first four-way The valve 112 , that is, the first refrigerant circulation circuit 11 only needs to perform a heating cycle; for another example, other components may also be provided on the first refrigerant circulation circuit 11 . In addition, the present invention does not limit the specific type of each component, for example, the first compressor 113 can be either a variable frequency compressor or a fixed frequency compressor. These specific structural changes do not deviate from the basic principles of the present invention, and should belong to the protection scope of the present invention.

Further, in the technical solution of the present invention, the outdoor unit is further provided with a second refrigerant circulation circuit 12, and the second refrigerant circulation circuit 12 is provided with a first heat exchange coil 121, a second four-way valve 122, The second compressor 123, the second heat exchange coil 124 and the second throttle member 125, the first heat exchange coil 121 can communicate with at least a part of the first refrigerant located between the first throttle member 115 and the outdoor coil 114 The circulation loop 11 performs heat exchange, so that the refrigerant can enter the outdoor coil 114 after being heated up. By controlling the communication state of the second four-way valve 122, the flow direction of the refrigerant in the second refrigerant circulation loop 12 can be controlled, thereby controlling the The heat exchange state of the first heat exchange coil 121 . It should be noted that the present invention does not impose any restrictions on the specific structure of the second refrigerant circulation loop 12, and technicians can set it according to actual use requirements. As a preferred arrangement, the second compressor 123 is a variable frequency compressor, and the second throttling member 125 is an electronic expansion valve; of course, this is not a limitation, and the second compressor 123 can also be a fixed-frequency compressor The second throttling member 125 may also be other components having a throttling effect, for example, a capillary tube and the like. In addition, it should be noted that the present invention does not impose any restrictions on the specific types of the components provided on the second refrigerant circulation loop 12, and the technicians can set them according to actual use requirements. These changes in specific structures do not deviate from the basic principles of the present invention, and should belong to the protection scope of the present invention.

In addition, it should be noted that the present invention does not impose any restrictions on the specific arrangement of the first heat exchange coil 121 and at least a part of the first refrigerant circulation circuit 11 located between the first throttle member 115 and the outdoor coil 114. As long as the first heat exchange coil 121 can exchange heat with at least a part of the first refrigerant circulation circuit 11 located between the first throttling member 115 and the outdoor coil 114; for example, only the first heat exchange coil may be 121 is arranged close to at least a part of the first refrigerant circulation circuit 11 between the first throttle member 115 and the outdoor coil 114, so as to achieve the heat exchange effect, and the technician can set it according to the actual use requirements.

Based on the above settings, the present invention adds a small circulation loop, that is, the second refrigerant circulation loop 12, in the outdoor unit, so that when the outdoor coil 114 needs to be defrosted, the first refrigerant circulation loop 12 arranged on the second refrigerant circulation loop 12. The heat exchange coil 121 can heat up the refrigerant in at least a part of the first refrigerant circulation circuit 11 located between the first throttling member 115 and the outdoor coil 114, so that the refrigerant can enter the outdoor coil after the temperature increase treatment. 114 , thereby effectively improving the defrosting efficiency, thereby effectively improving the heat exchange efficiency of the first refrigerant circulation loop 11 . At the same time, since the reverse circulation of the second refrigerant circulation loop 12 does not affect the heat exchange effect of the indoor unit, after the defrosting is completed, if the second heat exchange coil 124 has frost itself, it can directly pass the The reverse circulation of the second refrigerant circulation loop 12 is controlled to eliminate the frost condensed on the second heat exchange coil 124, so that the heat exchange efficiency of the indoor unit can be effectively ensured while the defrosting effect is ensured.

Continuing to refer to FIGS. 1 to 3 , as shown in FIGS. 1 to 3 , as a preferred arrangement, the dual-compressor air conditioner further includes a shell-and-tube heat exchanger 13 , the first heat exchange coil 121 and the At least a part of the first refrigerant circulation circuit 11 between the throttling member 115 and the outdoor coil 114 conducts heat exchange through the shell and tube heat exchanger 13, so as to effectively improve the heat exchange efficiency of the shell and tube heat exchanger 13, thereby improving the removal of heat. frost efficiency.

Further, as a preferred arrangement, the shell and tube heat exchanger 13 includes a shell and a heat exchange tube, the shell is formed with a heat exchange cavity, and the heat exchange tube is arranged in the heat exchange cavity, of course , the technical personnel can set the specific structure and shape of the shell and the heat exchange cavity by themselves according to the actual use requirements, which is not limiting. Specifically, the first heat exchange coil 121 is communicated with the heat exchange tube; it should be noted that the first heat exchange coil 121 can be disconnected here, and the two fractures are respectively connected with the heat exchange tube The two ends of the heat exchange tube are connected to make the first heat exchange coil 121 communicate with the heat exchange tube; the first heat exchange coil 121 can also be directly regarded as the heat exchange tube (that is, as shown in FIGS. 1 to 3 ). The solution shown) is not limiting, as long as the refrigerant in the first heat exchange coil 121 can achieve heat exchange in the shell and tube heat exchanger 13 through the heat exchange tubes. At least a part of the first refrigerant circulation circuit 11 located between the first throttling member 115 and the outdoor coil 114 is communicated with the heat exchange chamber, that is, the first refrigerant circulation circuit 11 is disconnected here, and the two fractures are respectively It is connected to both ends of the heat exchange cavity, so that the refrigerant in the first refrigerant circulation loop 11 can flow through the heat exchange cavity, and the refrigerant flowing through the heat exchange cavity can be connected with the heat exchange tube. The refrigerant in the first heat exchange coil 121 can heat the refrigerant in the first refrigerant circulation loop 11 .

Further, as another preferred arrangement, the shell and tube heat exchanger 13 includes a shell, a first heat exchange tube and a second heat exchange tube, the shell is formed with a heat exchange cavity, and the first heat exchange tube The tube and the second heat exchange tube are arranged in the heat exchange cavity. Of course, the technical personnel can set the specific structure and shape of the shell and the heat exchange cavity according to the actual use requirements. This is not a limitation. sexual. Specifically, the first heat exchange coil 121 is communicated with the first heat exchange tube. It should be noted that the first heat exchange coil 121 can be disconnected here, and the two fractures are respectively connected to the first heat exchange tube. The two ends of the heat exchange tube are connected to make the first heat exchange coil 121 communicate with the first heat exchange tube; the first heat exchange coil 121 can also be directly regarded as the first heat exchange tube. Neither is limiting, as long as the refrigerant in the first heat exchange coil 121 can achieve heat exchange in the shell-and-tube heat exchanger 13 through the first heat exchange tube. At least a part of the first refrigerant circulation loop 11 located between the first throttling member 115 and the outdoor coil 114 is communicated with the second heat exchange tube. It should be noted that the first refrigerant circulation loop 11 can be interrupted here. open, and the two fractures are respectively connected to both ends of the second heat exchange tube, so that the first refrigerant circulation loop 11 is connected to the second heat exchange tube; it is also possible to connect the first refrigerant circulation loop of this part 11 is directly regarded as the second heat exchange tube, which is not restrictive, as long as the refrigerant in the first refrigerant circulation loop 11 can achieve heat exchange in the shell and tube heat exchanger 13 through the second heat exchange tube That's it. Further preferably, the heat exchange cavity is filled with a heat exchange medium, and the heat exchange medium is preferably water, and the first heat exchange tube and the second heat exchange tube can pass through the heat exchange medium filled in the heat exchange cavity. The heat exchange medium achieves better heat exchange effect, so as to further improve the defrosting efficiency. Of course, heat exchange can also be performed directly through air, which is not limiting.

In addition, as a preferred arrangement, the second heat exchange coil 124 is arranged close to the outdoor coil 114 . Of course, this is only a preferred setting manner, and is not restrictive. Based on this arrangement, when the second heat exchange coil 124 is used as a condenser and the outdoor coil 114 is used as an evaporator, the outdoor coil 114 can absorb the heat released by the second heat exchange coil 124 in order to lift the outdoor coil and, when the second heat exchange coil 124 is used as an evaporator and the outdoor coil 114 is used as a condenser, the second heat exchange coil 124 is also capable of absorbing the heat released by the outdoor coil 114 so as to The condensation efficiency of the outdoor coil 114 is improved.

Continuing to refer to FIGS. 1 to 3 , as shown in FIGS. 1 to 3 , the dual-compressor air conditioner further includes a control device 14 , the control device 14 is arranged in the outdoor unit, and at least a portion of the intake section of the second compressor 123 A part is arranged close to the control device 14, so that as long as the second refrigerant circulation circuit 12 is running, the intake section of the second compressor 123 can cool the control device 14, thereby effectively reducing the temperature of the control device 14 and ensuring its operation. reliability. Specifically, the control device 14 includes a controller (not shown in the figure) and a radiator (not shown in the figure) connected to the controller, the radiator can improve the heat dissipation efficiency of the controller, so as to Ensure the operating temperature of the controller. Of course, the present invention does not impose any limitation on the specific structure of the control device 14, and the technical personnel can set it according to the actual use requirements, as long as the control device 14 includes a controller. Based on this, at least a part of the intake section of the second compressor 123 is disposed close to the radiator of the control device 14 to further enhance the cooling effect. Further preferably, at least a part of the intake section of the second compressor 123 is arranged in a curved manner, preferably by bending back and forth, and the curved portion of the intake section of the second compressor 123 is arranged close to the radiator of the control device 14 , so as to maximize the cooling effect of this part of the pipeline on the control device 14 .

In addition, the controller can obtain the frosting condition and the frosting degree of each coil, and can also obtain the temperature of the environment where the outdoor unit is located and the temperature of the control device 14; of course, the present invention does not specifically obtain the method. For any restrictions, technicians can set them according to actual use requirements. For example, the above parameters can be obtained by setting a temperature sensor. Based on the acquired data, the controller can also control the operating state of the dual-compressor air conditioner, for example, controlling the operating state of the second refrigerant circulation loop 12, controlling the operating frequency of the compressor, and controlling the opening of the throttling member. degree, etc. In addition, those skilled in the art can also understand that the present invention does not impose any restrictions on the specific structure and model of the controller, and the controller can be either the original controller of the dual-compressor air conditioner, or the controller. It can be a controller set separately for executing the control method of the present invention, and the technical personnel can set the structure and model of the controller according to the actual use requirements.

Next, refer to FIG. 4 , which is a flow chart of the main steps of the control method of the dual-compressor air conditioner of the present invention. As shown in FIG. 4, based on the air conditioner described in the above embodiment, the control method of the present invention mainly includes the following steps:

S1: Obtain the frosting condition of the outdoor coil when the first refrigerant circulation loop performs the heating cycle;

S2: If the outdoor coil is frosted or prone to frost, the second refrigerant circulation loop is controlled to perform a heating cycle, so that the first heat exchange coil is used as a condenser and the outdoor coil is defrosted.

Further, in step S1, when the first refrigerant circulation circuit 11 performs a heating cycle, that is, the high-temperature gaseous refrigerant discharged from the first compressor 113 enters the indoor coil 111 after passing through the first four-way valve 112 (as shown in FIG. 1 ). and 2 dashed lines), at this time, the indoor coil 111 is used as a condenser, and the outdoor coil 114 is used as an evaporator. In this case, the frosting condition of the outdoor coil 114 is obtained; it should be noted that the present invention does not impose any restrictions on the specific method for the controller to obtain the frosting condition of the outdoor coil 114, and the technical personnel can use it according to actual use requirements. Set it by yourself; for example, you can determine the frosting situation by acquiring the temperature of the outdoor coil 114, or you can determine the frosting situation by acquiring the current value of the outdoor fan 15, and you can also determine the frosting situation by acquiring the temperature of the outdoor coil 114. Image information to judge its frosting condition, which is not limiting.

Further, in step S2, if the outdoor coil 114 is frosted or prone to frost, the technician can set its specific judgment method according to the actual use requirements; for example, the temperature of the outdoor coil 114 is lower than a predetermined temperature. When the temperature is set, it is determined that the outdoor coil 114 has been frosted; for another example, when the temperature of the outdoor coil 114 is lower than a preset temperature and the outdoor humidity is greater than a preset humidity, it is determined that the outdoor coil 114 has a tendency to frost . In this case, the controller controls the second refrigerant circulation loop 12 to perform a heating cycle, that is, the high-temperature gaseous refrigerant discharged from the second compressor 123 passes through the second four-way valve 122 and then enters the first heat exchange coil 121 ( 1), at this time, the first heat exchange coil 121 is used as a condenser, the second heat exchange coil 124 is used as an evaporator, and the first heat exchange coil 121 can pass the shell-and-tube heat exchange The device 13 heats up the refrigerant before flowing into the outdoor coil 114 , and further has a defrosting effect on the outdoor coil 114 .

Next, refer to FIG. 5 , which is a flow chart of specific steps of a preferred embodiment of the control method for the dual-compressor air conditioner of the present invention. As shown in FIG. 5, based on the air conditioner described in the above preferred embodiment, the preferred embodiment of the control method of the present invention specifically includes the following steps:

S101: When the first refrigerant circulation loop performs the heating cycle, obtain the frosting condition of the outdoor coil;

S102: If the outdoor coil is frosted or tends to be frosted, control the second refrigerant circulation loop to perform a heating cycle, so that the first heat exchange coil is used as a condenser and the outdoor coil is defrosted;

S103: further obtain the frosting degree of the outdoor coil;

S104: Control the operating frequency of the second compressor and/or the opening degree of the second throttle member according to the frosting degree of the outdoor coil;

S105: Obtain the defrosting status of the outdoor coil;

S106: Determine whether the defrosting of the outdoor coil ends; if yes, execute step S107; if not, execute step S103 again;

S107: further obtain the frosting condition of the second heat exchange coil;

S108: Determine whether frosting occurs on the second heat exchange coil; if yes, go to step S110; if not, go to step S109;

S109: control the second refrigerant circulation loop to stop running;

S110: Control the second refrigerant circulation circuit to execute a refrigeration cycle, so that the second heat exchange coil is used as a condenser to perform a defrosting process on itself.

Further, in step S101, when the first refrigerant circulation loop 11 performs a heating cycle, that is, the high-temperature gaseous refrigerant discharged from the first compressor 113 enters the indoor coil 111 after passing through the first four-way valve 112. At this time, The indoor coil 111 is used as a condenser, and the outdoor coil 114 is used as an evaporator. In this case, the frosting condition of the outdoor coil 114 is obtained; it should be noted that the present invention does not impose any restrictions on the specific method for the controller to obtain the frosting condition of the outdoor coil 114, and the technical personnel can use it according to actual use requirements. Set it by yourself; for example, you can determine the frosting situation by acquiring the temperature of the outdoor coil 114, or you can determine the frosting situation by acquiring the current value of the outdoor fan 15, and you can also determine the frosting situation by acquiring the temperature of the outdoor coil 114. Image information to judge its frosting condition, which is not limiting.

Further, in step S102, if the outdoor coil 114 is frosted or prone to frost, the technician can set its specific judgment method according to the actual use requirements; for example, the temperature of the outdoor coil 114 is lower than a predetermined When the temperature is set, it is determined that the outdoor coil 114 has been frosted; for another example, when the temperature of the outdoor coil 114 is lower than a preset temperature and the outdoor humidity is greater than a preset humidity, it is determined that the outdoor coil 114 has a tendency to frost . In this case, the controller controls the second refrigerant circulation loop 12 to perform a heating cycle, that is, the high-temperature gaseous refrigerant discharged from the second compressor 123 passes through the second four-way valve 122 and then enters the first heat exchange coil 121 ( 1), at this time, the first heat exchange coil 121 is used as a condenser, the second heat exchange coil 124 is used as an evaporator, and the first heat exchange coil 121 can pass the shell-and-tube heat exchange The device 13 heats up the refrigerant before flowing into the outdoor coil 114 , and further has a defrosting effect on the outdoor coil 114 .

Further, when the second refrigerant circulation circuit 12 performs a heating cycle, step S103 is performed, that is, the controller further acquires the degree of frost formation on the outdoor coil 114 . It should be noted that the present invention does not limit the specific method of the controller for judging the frosting degree of the outdoor coil 114, and the technical personnel can set it according to the actual use requirements. For example, the outdoor can be judged by image comparison. The degree of frost formation on the coil 114; for another example, the degree of frost formation on the outdoor coil 114 can also be determined by the numerical range in which the current value of the outdoor fan 15 is located.

Based on the judgment result of step S103, the controller can control the operating frequency of the second compressor 123 and/or the opening degree of the second throttle member 125 according to the frosting degree of the outdoor coil 114; The actual use needs to set its specific control method by itself. As a preferred control method, the more serious the frosting degree of the outdoor coil 114 is, the higher the operating frequency of the second compressor 123 is, and the greater the opening degree of the second throttle member 125 is; The milder the degree of frost formation, the lower the operating frequency of the second compressor 123, and the smaller the opening degree of the second throttle member 125, so that the defrosting effect can be ensured while the defrosting energy consumption can be effectively saved. Of course, the corresponding defrosting effect can also be achieved only by controlling the operating frequency of the second compressor 123 or the opening degree of the second throttle member 125 .

Next, in step S105, the controller can acquire the defrosting condition of the outdoor coil 114. Of course, the present invention does not limit the specific acquisition method, and the technical personnel can set it according to the actual use requirements. Based on the obtained result in step S105, in step S106, the controller can determine whether the defrosting of the outdoor coil 114 is completed, so as to perform different operations accordingly.

Based on the judgment result of step S106, if the defrosting of the outdoor coil 114 has not ended, step S103 is performed again, so as to control the operating frequency and/or the operating frequency of the second compressor 123 according to the degree of frost formation of the outdoor coil 114 in different periods. Or the opening of the second throttle member 125, so that the defrosting capability of the second refrigerant circulation circuit 12 is always compatible with the frosting degree of the outdoor coil 114, thereby effectively ensuring the defrosting efficiency. At the same time, if the defrosting of the outdoor coil 114 is completed, step S107 is executed, that is, the controller further acquires the frosting condition of the second heat exchange coil 124; it should be noted that the present invention does not affect the specific acquisition method. Any restrictions can be set by technicians according to actual use requirements, as long as the controller can obtain the frosting condition of the second heat exchange coil 124 .

Based on the result obtained in step S107, the controller can control the operation state of the second refrigerant circulation loop 12 according to the frosting condition of the second heat exchange coil 124, so as to take into account both the defrosting efficiency and the defrosting cost. Further, in step S108, the controller can determine whether the second heat exchange coil 124 is frosted, so as to correspondingly control the operation state of the second refrigerant circulation loop 12 according to the determination result.

Specifically, if the second heat exchange coil 124 is not frosted, step S109 is executed, that is, the controller controls the second refrigerant circulation loop 12 to stop running, so as to effectively save energy. At the same time, if frost occurs on the second heat exchange coil 124, step S110 is executed, the controller controls the second four-way valve 122 to change direction, and the second refrigerant circulation circuit 12 is switched to the refrigeration cycle (as shown in FIG. 2 ). The situation shown), that is, the high-temperature gaseous refrigerant discharged from the second compressor 123 passes through the second four-way valve 122 and then enters the second heat exchange coil 124 (the path of the dotted line in FIG. 2 ). At this time, the first heat exchange The coil 121 is used as an evaporator, and the second heat exchange coil 124 is used as a condenser, so that the second heat exchange coil 124 can defrost itself. Since the reverse circulation of the second refrigerant circulation loop 12 does not affect the heat exchange effect of the indoor unit, after the defrosting is completed, if the second heat exchange coil 124 has frost itself, it can be directly controlled by the The second refrigerant circulation loop 12 reversely circulates to eliminate the frost condensed on the second heat exchange coil 124, so as to ensure the defrosting effect and also effectively ensure the heat exchange efficiency of the indoor unit.

In addition, in view of the problem that the control device 14 is easily damaged due to high temperature, the present invention also provides the following control methods:

When the first refrigerant circulation loop 11 performs a refrigeration cycle, the controller can obtain the temperature of the environment where the outdoor unit is located, which can be obtained through its own temperature sensor or through a network connection. Under the condition of high temperature refrigeration, the operating load of the entire air conditioner will be affected by the outdoor ambient temperature, and the control device 14 itself is also in the outdoor environment. Therefore, in this case, the present invention uses the environment in which the outdoor unit is located. The temperature of the control device 14 is determined to determine the cooling demand of the control device 14, so as to effectively ensure the accuracy of the determination. Next, the controller controls the operating state of the second refrigerant circulation loop 12 according to the temperature of the environment where the outdoor unit is located. Specifically, if the temperature of the environment where the outdoor unit is located is greater than the first preset temperature, the controller controls the second refrigerant circulation circuit 12 to execute a refrigeration cycle (as shown in FIG. 3 ), that is, the first The high-temperature gaseous refrigerant discharged from the second compressor 123 passes through the second four-way valve 122 and then enters the second heat exchange coil 124 (the path shown by the dotted line in FIG. 3 ). At this time, the first heat exchange coil 121 is used as an evaporator , the second heat exchange coil 124 acts as a condenser. In this case, the second refrigerant circulation loop 12 can not only have a cooling effect on the control device 14 to effectively protect the safety of the controller, but also the first heat exchange coil 121 can pass through the shell-and-tube heat exchanger 13 A cooling treatment is performed on the refrigerant in the first refrigerant circulation circuit 11 to further increase the degree of subcooling of the refrigerant, thereby effectively increasing the cooling capacity. It should be noted that the technical personnel can set the specific value of the first preset temperature by themselves according to the actual use requirements, as long as the temperature of the environment where the outdoor unit is located is greater than the first preset temperature, the control can be determined. The device 14 only needs to have a cooling requirement; preferably, the first preset temperature is set to 40°C.

Under the circumstance that the first refrigerant circulation loop 11 performs the heating cycle and the outdoor coil 114 does not form frost, it can be understood that when the outdoor coil 114 forms frost, the internal temperature of the outdoor unit is very low , the control device 14 usually does not overheat; the outdoor temperature is low, so the controller directly obtains the temperature of the control device 14 to determine whether it is overheated, so as to effectively ensure the accuracy of the determination. Next, the controller controls the operating state of the second refrigerant circulation circuit 12 according to the temperature of the control device 14 . Specifically, if the temperature of the control device 14 is greater than the second preset temperature, the controller controls the second refrigerant circulation circuit 12 to perform a heating cycle (as shown in FIG. 1 ), that is, the second compressor The high-temperature gaseous refrigerant discharged from 123 passes through the second four-way valve 122 and then enters the first heat exchange coil 121 (the path of the dotted line in Figure 1). At this time, the first heat exchange coil 121 is used as a condenser, and the second The heat exchange coil 124 acts as an evaporator. In this case, the second refrigerant circulation loop 12 can not only have a cooling effect on the control device 14 to effectively protect the safety of the controller, but also the first heat exchange coil 121 can pass through the shell-and-tube heat exchanger 13 The temperature rise treatment is performed on the refrigerant before flowing into the outdoor coil 114 , thereby effectively preventing the occurrence of frost on the outdoor coil 114 . It should be noted that the technical personnel can set the specific value of the second preset temperature according to the actual use requirements. As long as the temperature of the control device 14 is greater than the second preset temperature, it can be determined that the control device 14 has a cooling effect. Need it.

So far, the technical solutions of the present invention have been described with reference to the preferred embodiments shown in the accompanying drawings, however, those skilled in the art can easily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

A control method for a dual-compressor air conditioner, characterized in that the dual-compressor air conditioner includes an indoor unit and an outdoor unit, wherein a first refrigerant circulation is arranged between the indoor unit and the outdoor unit The first refrigerant circulation loop is provided with an indoor coil, a first compressor, an outdoor coil and a first throttling member in sequence, the indoor coil is arranged in the indoor unit, and the outdoor coil is Set in the outdoor unit, the outdoor unit is also provided with a second refrigerant circulation loop, and the second refrigerant circulation loop is provided with a first heat exchange coil, a four-way valve, a second compressor, a second A heat exchange coil and a second throttling member, the first heat exchange coil capable of exchanging heat with at least a portion of the first refrigerant circulation loop located between the first throttling member and the outdoor coil , so that the refrigerant can enter the outdoor coil after heating treatment;

The control method includes:

Acquire the frosting condition of the outdoor coil when the first refrigerant circulation loop performs a heating cycle;

If the outdoor coil is frosted or prone to frost, the second refrigerant circulation circuit is controlled to perform a heating cycle, so that the first heat exchange coil is used as a condenser and the outdoor coil is Tubes are defrosted.
The control method according to claim 1, wherein after the step of "controlling the second refrigerant circulation loop to perform a heating cycle", the control method further comprises:

Obtain the defrosting condition of the outdoor coil;

After the defrosting of the outdoor coil is completed, further acquire the frosting condition of the second heat exchange coil;

According to the frosting condition of the second heat exchange coil, the operating state of the second refrigerant circulation circuit is controlled accordingly.
The control method according to claim 2, wherein the step of "controlling the operating state of the second refrigerant circulation loop correspondingly according to the frosting condition of the second heat exchange coil" specifically comprises:

If frosting occurs on the second heat exchange coil, the second refrigerant circulation circuit is controlled to execute a refrigeration cycle, so that the second heat exchange coil is used as a condenser to defrost itself.
The control method according to claim 2, wherein the step of "controlling the operating state of the second refrigerant circulation loop correspondingly according to the frosting condition of the second heat exchange coil" specifically comprises:

If the second heat exchange coil has no frosting phenomenon, the second refrigerant circulation loop is controlled to stop running.
The control method according to claim 1, wherein the second compressor is an inverter compressor, and the control method further comprises:

In the case where the second refrigerant circulation loop performs a heating cycle, further obtain the frosting degree of the outdoor coil;

The operating frequency of the second compressor is controlled according to the degree of frosting of the outdoor coil.
The control method according to claim 1, wherein the second throttling member is an electronic expansion valve, and the control method further comprises:

In the case where the second refrigerant circulation loop performs a heating cycle, further obtain the frosting degree of the outdoor coil;

The opening degree of the second throttle member is controlled according to the degree of frosting of the outdoor coil.
The control method according to any one of claims 1 to 6, wherein at least a part of the intake section of the second compressor is disposed close to the control device of the outdoor unit, and the control method further comprises:

Obtaining the temperature of the environment where the outdoor unit is located in the case that the first refrigerant circulation circuit performs a refrigeration cycle;

The operating state of the second refrigerant circulation loop is controlled according to the temperature of the environment where the outdoor unit is located.
The control method according to claim 7, wherein the step of "controlling the operating state of the second refrigerant circulation loop according to the temperature of the environment where the outdoor unit is located" specifically comprises:

If the temperature of the environment where the outdoor unit is located is greater than the first preset temperature, the second refrigerant circulation circuit is controlled to execute a refrigeration cycle.
The control method according to claim 7, wherein the control method further comprises:

Obtain the temperature of the control device when the first refrigerant circulation loop performs a heating cycle and the outdoor coil has no frosting phenomenon;

The operating state of the second refrigerant circulation circuit is controlled according to the temperature of the control device.
The control method according to claim 9, wherein the step of "controlling the operating state of the second refrigerant circulation loop according to the temperature of the control device" specifically comprises:

If the temperature of the control device is greater than the second preset temperature, the second refrigerant circulation circuit is controlled to execute a heating cycle.