A heat pump system and a control method of a heat pump system

Abstract

This invention belongs to the field of heat pump technology, specifically disclosing a heat pump system and a control method for the heat pump system. The heat pump system includes a compressor, a fan grille, and a heat exchanger. The fan grille includes a main body formed by coiled hollow tubes. The compressor outlet, defrost control valve, grille main body, first throttling device, heat exchanger, and compressor inlet are sequentially connected. The defrost control valve controls the flow of refrigerant between the compressor outlet and the fan grille. The heat pump control method includes: upon receiving a defrost signal, controlling the defrost control valve and the first throttling device to open, so that at least a portion of the refrigerant circulates sequentially along the compressor outlet, fan grille, first throttling device, heat exchanger, and compressor inlet. The heat pump system and control method disclosed in this invention can achieve defrosting of the fan grille, ensure the ventilation volume of the fan grille, and improve the operational reliability and energy efficiency of the heat pump system.

Description

Technical Field

[0001] This invention relates to the field of heat pump technology, and in particular to a heat pump system and a control method for the heat pump system. Background Technology

[0002] A heat pump system is a device that uses electric heating to extract energy from heat sources such as air, water, or soil and provide users with the high-quality heat energy they need. It is widely used for heating in cold winter regions.

[0003] Air source heat pump units are the most widely used heat pump systems. They typically include a compressor, an indoor heat exchanger, an outdoor evaporator, and an outdoor fan. During heating, the compressor outlet, indoor heat exchanger, outdoor evaporator, and compressor inlet are sequentially connected in a circulating manner, allowing the refrigerant to exchange heat with the heating equipment in the indoor heat exchanger. The outdoor fan is located at the outdoor evaporator and dissipates heat from it, cooling the refrigerant flowing through it. To ensure fan performance, a screen is usually installed at the fan outlet to reduce the probability of dust or foreign objects entering the fan.

[0004] In actual use, existing air source heat pump units are prone to frost or snow accumulation on their grilles due to the exposed outdoor environment, especially in low temperature, high humidity, or snowy weather. This reduces the airflow of the fan, affects the heat exchange efficiency of the outdoor unit's heat exchanger, and thus lowers the energy efficiency of the heat pump unit. Furthermore, the defrosting settings of existing air source heat pump units can only defrost the outdoor heat exchanger and cannot effectively defrost the grilles, thus affecting the performance of the heat pump system. Summary of the Invention

[0005] One of the technical problems solved by this invention is to provide a heat pump system that can effectively solve the problem that the fan grille of existing heat pump systems is difficult to defrost effectively, thus affecting the performance of the heat pump system.

[0006] The second technical problem solved by this invention is to provide a control method for a heat pump system, which can effectively solve the problem that existing heat pump systems have difficulty in effectively defrosting the fan grille, thereby improving the performance of the heat pump system.

[0007] The first technical problem mentioned above is solved by the following technical solution:

[0008] A heat pump system includes a compressor, a fan grille, and a heat exchanger. The fan grille comprises a main body formed by coiling hollow tubes. The heat pump system further includes a first throttling device and a defrost control valve. The compressor outlet, the defrost control valve, the grille main body, the first throttling device, the heat exchanger, and the compressor inlet are sequentially connected. The defrost control valve controls the flow of refrigerant between the compressor outlet and the fan grille.

[0009] The heat pump system of the present invention has the following advantages compared with the prior art: When defrosting of the fan grille is required, the outlet end of the compressor, the main body of the grille, the first throttling device, the heat exchanger, and the inlet end of the compressor are circulated and connected to form a grille defrosting circuit. The refrigerant is compressed by the compressor to form a high-temperature and high-pressure gas. When the high-temperature and high-pressure gas flows through the main body of the grille, it heats the main body of the grille, causing the fan grille to heat up and defrost, while the refrigerant cools down to form a normal-temperature and high-pressure liquid. After the normal-temperature and high-pressure liquid is throttled and cooled by the first throttling device, it becomes a low-temperature and low-pressure gas-liquid two-phase mixture. After heat exchange by the heat exchanger, it heats up and becomes a low-temperature and low-pressure gas, and then flows back to the compressor. In other words, the heat pump system provided in this embodiment has a fan grille with a hollow tube coiled into a main body, allowing the high-temperature, high-pressure refrigerant flowing from the compressor to enter the interior of the grille body, thereby heating the fan grille and defrosting it. This prevents frost or snow accumulation on the fan grille from affecting airflow and ensures the reliability and energy efficiency of the heat pump system. At the same time, the method of connecting the compressor to the fan grille for defrosting facilitates the utilization of the existing structure in the heat pump system, reduces the improvement cost of the heat pump system, and thus reduces the operating cost of the heat pump system.

[0010] In one embodiment, the heat exchanger includes an indoor heat exchanger and an outdoor heat exchanger, and the heat pump system further includes a second throttling device. The indoor heat exchanger, the second throttling device, and the outdoor heat exchanger are sequentially connected to form a heat exchange pipeline. The outlet end of the compressor can be selectively connected to one end of the heat exchange pipeline, and the inlet end of the compressor is connected to the other end of the heat exchange pipeline.

[0011] In one embodiment, the outlet end of the first throttling device is connected to the first end of a connecting pipe, the second end of the connecting pipe is connected to the heat exchange pipeline, and the second end of the connecting pipe is located between the outdoor heat exchanger and the second throttling device.

[0012] In one embodiment, the second throttling device includes a first throttling branch and a second throttling branch arranged in parallel. A first throttling component is provided on the first throttling branch, and a second throttling component and a one-way valve are provided on the second throttling branch. The one-way valve only allows refrigerant to flow from the outdoor heat exchanger to the second throttling component.

[0013] In one embodiment, the first throttling component is an electronic expansion valve, and the second throttling component is a capillary tube.

[0014] In one embodiment, the main body of the mesh cover includes a spirally arranged main disc, with connecting pipes connected to both ends of the main disc. The ends of the connecting pipes extend outward from the outside of the main disc. One connecting pipe is connected to the outlet end of the compressor, and the other connecting pipe is connected to the inlet end of the first throttling device.

[0015] And / or, the fan cover further includes support strips, the main body of the cover has a spiral disc structure, the support strips extend radially along the main body of the cover and are spaced apart circumferentially along the main body of the cover, and each support strip has multiple connection positions with the spiral disc structure.

[0016] In one embodiment, the heat pump system includes a controller, and the compressor, the defrost control valve, and the first throttling device are all communicatively connected to the controller;

[0017] The heat pump system further includes an ambient temperature sensor for detecting the ambient temperature and communicating with the controller; and / or, the heat pump system further includes a fan grille temperature sensor for detecting the temperature of the fan grille and communicating with the controller; and / or, the heat pump system further includes a heat exchanger temperature sensor for detecting the temperature of the outdoor heat exchanger and communicating with the controller.

[0018] The second technical problem mentioned above is solved by the following technical solution:

[0019] A control method for a heat pump system, applied to the heat pump system described above, the control method comprising:

[0020] Defrosting signal received;

[0021] The defrost control valve and the first throttling device are opened to allow at least a portion of the refrigerant to circulate sequentially along the compressor outlet, the fan grille, the first throttling device, the heat exchanger, and the compressor inlet.

[0022] Compared with the prior art, the control method of the heat pump system described in this invention has the following advantages: by using the high temperature and high pressure refrigerant generated by the compressor to heat the fan screen, the fan screen can be defrosted, improving the operational reliability of the heat pump system and reducing the operating cost of the heat pump system.

[0023] In one embodiment, the defrost signal includes a first defrost signal and a second defrost signal, the heat exchanger includes an indoor heat exchanger and an outdoor heat exchanger, and the heat pump system further includes a second throttling device;

[0024] The control method includes:

[0025] When the received defrost signal is the first defrost signal, the heat pump system is controlled to execute the first defrost mode, so that the outlet end of the compressor, the fan guard, the first throttling device, the indoor heat exchanger and the inlet end of the compressor are sequentially and cyclically connected to form a guard defrost circuit, and the outlet end of the compressor, the outdoor heat exchanger, the second throttling device, the indoor heat exchanger and the inlet end of the compressor are sequentially and cyclically connected to form a heat exchanger defrost circuit;

[0026] When the received defrost signal is the second defrost signal, the heat pump system is controlled to execute the second defrost mode, so that the outlet end of the compressor, the fan grille, the first throttling device, the outdoor heat exchanger and the inlet end of the compressor are sequentially connected to form a grille defrost circuit, and the outlet end of the compressor, the indoor heat exchanger, the second throttling device, the outdoor heat exchanger and the inlet end of the compressor are sequentially connected to form a heating cycle circuit.

[0027] In one embodiment, the control method further includes:

[0028] When the temperature of the outdoor heat exchanger is less than or equal to the frost point temperature, the controller determines that it has received the first defrost signal;

[0029] And / or, when the detected ambient temperature is lower than the first preset temperature for a duration greater than or equal to the preset duration, and the time interval since the last defrost is greater than the preset time interval, the controller determines that the first defrost signal has been received;

[0030] And / or, when the detected ambient temperature is lower than the second preset temperature and the temperature of the outdoor heat exchanger is higher than the frost point temperature, the controller determines that a second defrost signal has been received. Attached Figure Description

[0031] Figure 1 A schematic diagram of refrigerant flow in indoor heating mode of a heat pump system provided in an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of refrigerant flow in indoor cooling mode of a heat pump system provided in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of refrigerant flow in the first defrosting mode of a heat pump system provided in an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of refrigerant flow in the second defrosting mode of a heat pump system provided in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the structure of the fan guard provided in an embodiment of the present invention.

[0036] Label Explanation:

[0037] 1. Fan guard; 11. Guard body; 111. Main disc; 112. Connecting pipe; 12. Central fixing part; 13. Support bar;

[0038] 2. Compressor; 3. Indoor heat exchanger; 4. Outdoor heat exchanger; 5. Outdoor fan; 6. First throttling device; 7. Second throttling device; 71. First throttling branch; 72. Second throttling branch; 73. First throttling component; 74. Check valve; 75. Second throttling component; 8. Four-way reversing valve; 9. Gas-liquid separator; 10. Electric heating device; 20. Liquid storage container;

[0039] 101. Exhaust pressure sensor; 102. Return gas pressure sensor; 103. Exhaust temperature sensor; 104. Return gas temperature sensor; 105. Ambient temperature sensor; 106. Heat exchanger temperature sensor;

[0040] 201. Defrosting control valve; 202. Low-pressure switch; 203. High-pressure switch; 204. First shut-off valve; 205. Second shut-off valve;

[0041] 301. First filter; 302. Second filter; 303. Third filter;

[0042] 401. Connecting pipe; 402. Heat exchange pipe; 403. Exhaust pipe; 404. Return gas pipe;

[0043] 1000. Indoor temperature control equipment. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0046] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0047] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0048] This embodiment provides a heat pump system that can simultaneously heat the indoor environment and defrost the fan grille 1, thereby improving the operational reliability and thermal efficiency of the heat pump system.

[0049] like Figures 1 to 5 As shown, the heat pump system includes a compressor 2, a heat exchanger, and a second throttling device 7. The heat exchanger includes an indoor heat exchanger 3 and an outdoor heat exchanger 4. The indoor heat exchanger 3, the second throttling device 7, and the outdoor heat exchanger 4, along with the outlet end of the compressor 2, the indoor heat exchanger 3, the second throttling device 7, the outdoor heat exchanger 4, and the inlet end of the compressor 2, can be sequentially connected to form a heating cycle loop. The indoor heat exchanger 3 is used for heat exchange with the heat exchange medium in the indoor temperature control equipment 1000.

[0050] When using a heat pump system for heating, the refrigerant is compressed into a high-temperature, high-pressure gas by the compressor 2. When the high-temperature, high-pressure gas flows through the indoor heat exchanger 3, it exchanges heat with the heat exchange medium in the indoor temperature control equipment 1000, causing the heat exchange medium to heat the indoor environment, while the refrigerant cools down to form a room-temperature, high-pressure liquid. After the room-temperature, high-pressure liquid is throttled and cooled by the second throttling device 7, it becomes a low-temperature, low-pressure gas-liquid two-phase mixture. When it flows through the outdoor heat exchanger 4, it absorbs heat from the external environment, becomes a low-temperature, low-pressure gas, and then flows back to the compressor 2.

[0051] In this embodiment, the heat pump system further includes an outdoor fan 5 and a fan grille 1. The outdoor fan 5 is positioned corresponding to the outdoor heat exchanger 4 to direct airflow towards the outdoor heat exchanger 4, thereby achieving heat exchange between the outdoor heat exchanger 4 and the outside air. The outdoor heat exchanger 4 is installed inside a casing, and the casing has ventilation openings. The fan grille 1 is located on the side of the outdoor fan 5 away from the outdoor heat exchanger 4. The relative positions and specific installation methods of the outdoor fan 5, the outdoor heat exchanger 4, and the fan grille 1 can be set with reference to existing technologies, which is not the focus of this embodiment and will not be elaborated here.

[0052] Since the fan guard 1 is exposed to the external environment, it is prone to frost formation when the external ambient temperature is low or when it snows. In this embodiment, the fan guard 1 includes a guard body 11 formed by coiling hollow tubes. The heat pump system also includes a first throttling device 6 and a defrost control valve 201. The outlet end of the compressor 2, the defrost control valve 201, the fan guard 1, the first throttling device 6, the heat exchanger, and the inlet end of the compressor 2 are connected in sequence. The defrost control valve 201 controls the flow of refrigerant between the outlet end of the compressor 2 and the fan guard 1.

[0053] In the heat pump system provided in this embodiment, when defrosting of the fan grille 1 is required, the outlet end of the compressor 2, the grille body 11, the first throttling device 6, the heat exchanger, and the inlet end of the compressor 2 are circulated and connected to form a grille defrosting circuit. The refrigerant is compressed by the compressor 2 to form a high-temperature and high-pressure gas. When the high-temperature and high-pressure gas flows through the grille body 11, it heats the grille body 11, causing the fan grille 1 to heat up and defrost, while the refrigerant cools down to form a normal-temperature and high-pressure liquid. After the normal-temperature and high-pressure liquid is throttled and cooled by the first throttling device 6, it becomes a low-temperature and low-pressure gas-liquid two-phase mixture. After heat exchange by the heat exchanger, it heats up and becomes a low-temperature and low-pressure gas, and then flows back to the compressor 2.

[0054] That is, in the heat pump system provided in this embodiment, since the fan grille 1 has a grille body 11 formed by a hollow tube coil, the high-temperature and high-pressure refrigerant flowing out of the compressor 2 can enter the interior of the grille body 11, thereby heating the fan grille 1 and realizing defrosting of the fan grille 1. This avoids affecting the ventilation volume due to frost or snow accumulation on the fan grille 1, ensuring the operational reliability and energy efficiency of the heat pump system. At the same time, the defrosting of the fan grille 1 is achieved by connecting the compressor 2 with the fan grille 1, which is conducive to utilizing the structure of the existing heat pump system, reducing the improvement cost of the heat pump system, and thus reducing the operating cost of the heat pump system.

[0055] In one embodiment, such as Figure 5 As shown, the main body 11 of the mesh cover forms a spiral disc-shaped structure that spirals from the inside out. That is, the main body 11 of the mesh cover includes a main disc portion 111 of the spiral disc-shaped structure and two connecting pipe portions 112 connected to the inner and outer ends of the main disc portion 111. The ends of the connecting pipe portions 112 extend radially out of the main disc portion 111 to facilitate the connection between the main body 11 of the mesh cover and other structures in the heat pump system.

[0056] In one embodiment, the hollow tube is made of copper to facilitate heat conduction of the mesh cover body 11. In other embodiments, the hollow tube can be made of other metals that are not easily corroded and have good thermal conductivity.

[0057] Furthermore, the inner diameter of the hollow tube is 4mm to 10mm to better control the flow rate and volume of the refrigerant in the mesh cover body 11, and to avoid the problem of the overall size of the mesh cover body 11 being too large due to the inner diameter of the hollow tube being too large.

[0058] To improve the overall structural strength and rigidity of the wind turbine cover 1, in one embodiment, the cover body 11 also includes support strips 13. The support strips 13 extend radially along the main disk 111 from the innermost circle to the outermost circle of the main disk 111. Multiple support strips 13 are provided along the circumference of the main disk 111. Each support strip 13 has multiple connection positions with the main disk 111 to ensure the structural stability of the main disk 111 and reduce the probability of deformation or relative shaking within the main disk 111.

[0059] Furthermore, the support strip 13 is welded to each ring of the central disk to ensure the overall stability and structural rigidity of the main body 11 of the wind turbine screen 1, and to reduce the probability of deformation. Preferably, the other end of the support strip 13 extends radially along the main disk 111 to extend beyond the outer side of the main disk 111.

[0060] Furthermore, the main body 11 of the fan cover also includes a central fixing part 12, which is located at the center of the main plate part 111, and the inner ends of all the support bars 13 are connected to the central fixing part 12, so as to improve the ease of setting the support bars 13 and improve the overall structural stability of the fan cover 1.

[0061] In one embodiment, an indoor heat exchanger 3, a second throttling device 7, and an outdoor heat exchanger 4 are connected in sequence to form a heat exchange pipeline 402. The end of the heat exchange pipeline 402 closest to the indoor heat exchanger 3 is the first end, and the end of the heat exchange pipeline 402 closest to the outdoor heat exchanger 4 is the second end. The inlet end of the compressor 2 can be selectively connected to either the first end or the second end of the heat exchange pipeline 402, and the outlet end of the compressor 2 can be connected to the other end of the heat exchange pipeline 402.

[0062] This configuration allows for a first conduction mode and a second conduction mode between the compressor 2 and the heat exchange pipeline 402.

[0063] When there is a first conduction mode between the compressor 2 and the heat exchange pipeline 402: the outlet end of the compressor 2, the first end of the heat exchange pipeline 402, the indoor heat exchanger 3, the second throttling device 7, the outdoor heat exchanger 4, the second end of the heat exchange pipeline 402 and the inlet end of the compressor 2 are connected in sequence to form a first circulation loop, which is the heating circulation loop.

[0064] When there is a second conduction mode between compressor 2 and heat exchange pipeline 402, the outlet end of compressor 2, the second end of heat exchange pipeline 402, outdoor heat exchanger 4, indoor heat exchanger 3, the first end of heat exchange pipeline 402, and compressor 2 are sequentially connected to form a second circulation loop. The refrigerant is compressed by compressor 2 to form a high-temperature and high-pressure gas. When the high-temperature and high-pressure gas flows through outdoor heat exchanger 4, it exchanges heat with the air and condenses to form a room-temperature and high-pressure liquid. After the room-temperature and high-pressure liquid is throttled and cooled by the second throttling device 7, it becomes a low-pressure gaseous two-phase mixture. After heat exchange by indoor heat exchanger 3, it becomes a low-temperature and low-pressure gas and then flows back to compressor 2.

[0065] It is worth noting that when the compressor 2 and heat exchange pipeline 402 are in the second conduction mode and the outdoor ambient temperature is low, such as on a snowy day, the flow of refrigerant in the second circulation loop can defrost the outdoor heat exchanger 4, thereby ensuring the reliability of the outdoor heat exchanger 4. That is, the second circulation loop forms a heat exchanger defrosting loop. When the compressor 2 and heat exchange pipeline 402 are in the second conduction mode and the outdoor temperature is high, the heat exchange of refrigerant with the heat exchange medium in the indoor temperature control device 1000 at the indoor heat exchanger 3 can cool the heat exchange medium, thereby achieving cooling of the indoor environment. That is, the second circulation loop forms a refrigeration circulation loop.

[0066] To improve the ease of connection between the compressor 2 and the heat exchange pipeline 402, in one embodiment, the heat pump system includes a four-way reversing valve 8. The four-way reversing valve 8 has ports A, B, C, and D. The outlet end of the compressor 2 is connected to port A, the inlet end of the compressor 2 is connected to port B, the first end of the heat exchange pipeline 402 is connected to port D, and the second end of the heat exchange pipeline 402 is connected to port C. The four-way reversing valve 8 has a first conducting state and a second conducting state. When the four-way reversing valve 8 is in the first conducting state, ports A and D are connected, and ports B and C are connected to form a first circulation loop. When the four-way reversing valve 8 is in the second conducting state, ports A and B are connected, and ports C and D are connected to form a second circulation loop.

[0067] In one embodiment, the outlet end of the first throttling device 6 is connected to the first end of a connecting pipe 401, which is connected to a heat exchange pipe 402. The connection point between the connecting pipe 401 and the heat exchange pipe 402 is located between the indoor heat exchanger 3 and the outdoor heat exchanger 4. With this configuration, when both the defrost control valve 201 and the first throttling device 6 are open, the refrigerant flowing out of the first throttling device 6 can return to the compressor 2 via the connecting pipe 401 and the indoor heat exchanger 3. Thus, the refrigerant flowing out of the first throttling device 6 can exchange heat with the heat exchange medium at the indoor heat exchanger 3, increasing the amount of heat the refrigerant can absorb. This effectively ensures that the refrigerant is in a gaseous state before returning to the compressor 2, thereby avoiding wear and impact on the compressor 2, extending the service life of the compressor 2, and reducing the operating noise of the compressor 2.

[0068] In one embodiment, the outlet end of compressor 2 is connected to fan guard 1 and four-way reversing valve 8 via a tee connector. Specifically, the tee connector and the inlet end of guard body 11 are connected via an inlet pipe, and defrost control valve 201 is installed on the inlet pipe. This arrangement ensures that when defrost control valve 201 is opened, the outlet end of compressor 2 is connected to both the inlet pipe and heat exchange pipe 402, thereby enabling the heat pump system to have indoor heating mode, first defrost mode, second defrost mode, and indoor cooling mode.

[0069] When the heat pump system is in indoor cooling mode, the defrost control valve 201 and the first throttling device 6 are closed to prevent the refrigerant from flowing to the fan screen 1 and causing the fan screen 1 to heat up in a high-temperature environment; the four-way reversing valve 8 is in the second conducting state so that the refrigerant flowing out of the compressor 2 flows through the outdoor heat exchanger 4 and the indoor heat exchanger 3 in sequence to condense and cool the heat exchange medium, thereby achieving cooling of the indoor environment.

[0070] When the heat pump system is in indoor heating mode, the defrost control valve 201 and the first throttling device 6 are both closed, and the four-way reversing valve 8 is in the first conducting state, so that the high-temperature and high-pressure refrigerant flowing out from the compressor 2 can exchange heat with the heat exchange medium in the indoor temperature control equipment 1000 at the indoor heat exchanger 3.

[0071] When the heat pump system is in the first defrost mode, the defrost control valve 201, the first throttling device 6, and the second throttling device 7 are all open, and the four-way reversing valve 8 is in the second conducting state. The compressor 2 starts, and the refrigerant is compressed by the compressor 2 to form a high-temperature, high-pressure gas. One path of the refrigerant flows through ports A and B of the four-way reversing valve 8 to the outdoor heat exchanger 4, where it condenses and cools to form a normal-temperature, high-pressure liquid. Simultaneously, the outdoor heat exchanger 4 heats up to defrost. The refrigerant flowing out of the outdoor heat exchanger 4 is throttled and cooled by the second throttling device 7 to form a low-temperature, low-pressure gas-liquid two-phase mixture, which then flows to the indoor heat exchanger 3. At the indoor heat exchanger 3, the refrigerant exchanges heat with the heat exchange medium in the indoor temperature control equipment 1000, forming a low-temperature, low-pressure gas, which then flows through port C of the four-way reversing valve 8. The refrigerant flows back to compressor 2 after passing through port D; the other refrigerant flowing out of compressor 2 flows to the mesh cover body 11 after passing through defrost control valve 201, and exchanges heat with the mesh cover body 11, the refrigerant cools down and condenses to form a normal temperature high pressure liquid, while the mesh cover body 11 heats up to defrost; the refrigerant flowing out of mesh cover body 11 is throttled and cooled by the first throttling device 6 to form a low temperature low pressure gas-liquid mixture, and then flows to indoor heat exchanger 3; the refrigerant heats up after exchanging heat with the heat exchange medium in indoor heat exchanger 3 to form a low temperature low pressure gas, and then flows back to compressor 2 after passing through four-way reversing valve 8.

[0072] When the heat pump system is in the second defrost mode, the defrost control valve 201, the first throttling device 6, and the second throttling device 7 are open, and the four-way reversing valve 8 is in the first conducting state. The compressor 2 starts, and the refrigerant is compressed by the compressor 2 to form a high-temperature, high-pressure gas. One path of the refrigerant flows through ports A and D of the four-way reversing valve 8 to the indoor heat exchanger 3, where it exchanges heat with the heat exchange medium of the indoor temperature control equipment 1000. The high-temperature, high-pressure refrigerant condenses and cools down to form a normal-temperature, high-pressure liquid, while the heat exchange medium heats up, thus heating the indoor environment. The refrigerant flowing out of the indoor heat exchanger 3 is throttled and cooled by the second throttling device 7, forming a low-temperature, low-pressure gas-liquid two-phase substance, and then flows to the outdoor heat exchanger 4. The low-temperature, low-pressure gas-liquid two-phase refrigerant exchanges heat with the air at the outdoor heat exchanger 4. The refrigerant undergoes a heat exchange process, causing the low-temperature, low-pressure gas-liquid two-phase substance to absorb heat and rise in temperature, forming a low-temperature, low-pressure gas. This gas then flows back to the compressor 2 through ports C and B of the four-way reversing valve 8. Another path of refrigerant flowing out of the compressor 2 passes through the defrost control valve 201 and flows to the mesh cover body 11, where it exchanges heat with the mesh cover body 11. The refrigerant condenses and cools down to form a low-temperature, high-pressure liquid, and the mesh cover body 11 heats up to defrost. The refrigerant flowing out of the mesh cover body 11 is throttled and cooled by the first throttling device 6 to form a low-temperature, low-pressure gas-liquid two-phase substance. It then flows to the outdoor heat exchanger 4, where it is evaporated to form a low-temperature, low-pressure gas before flowing back to the compressor 2.

[0073] That is, when the heat pump system is in the first defrost mode, both the fan grille 1 and the outdoor heat exchanger 4 can be heated through heat exchange with the refrigerant, thereby achieving defrosting of the fan grille 1 and the outdoor heat exchanger 4 and improving the defrosting effect of the heat pump system; when the heat pump system is in the second defrost mode, the compressor 2, the indoor heat exchanger 3, the second throttling device 7 and the outdoor heat exchanger 4 are connected end to end to form a heating circulation loop to achieve heating of the indoor environment, avoiding the problem of the refrigerant absorbing heat at the indoor heat exchanger 3 and causing the indoor temperature to drop. At the same time, the refrigerant heats the fan grille 1 so that the fan grille 1 is heated to defrost. That is, in the second defrost mode, only the fan grille 1 is defrosted.

[0074] It is worth noting that in the first defrost mode and the second defrost mode, the amount of refrigerant flowing through the fan screen 1 can be adjusted by adjusting the opening of the first throttling device 6, thereby adjusting the amount of refrigerant in the two circuits to ensure that the two circuits of refrigerant are in gaseous form before flowing back to the compressor 2.

[0075] In one embodiment, a water collection tray is provided at the bottom of the outdoor heat exchanger 4, and the fan screen 1 is located above the water collection tray. An electric heating device 10 is provided at the water collection tray. The projections of the outdoor heat exchanger 4 and the fan screen 1 on the horizontal plane are both within the projection range of the water collection tray on the horizontal plane. This allows the condensate generated by defrosting of the outdoor heat exchanger 4 and the fan screen 1 to drip into the water collection tray during defrosting, where it is collected and recycled. This prevents condensate from flowing turbulently and causing ice formation in other locations, ensuring the reliability of the heat pump system. At the same time, the electric heating device 10 at the water collection tray prevents water from freezing at the water collection tray and being unable to drain smoothly.

[0076] In other embodiments, the heat pump system may also have only one of a first defrost mode and a second defrost mode.

[0077] When the heat pump system is in indoor heating mode, the refrigerant first flows through the indoor heat exchanger 3 for condensation and cooling, and then flows to the second throttling device 7 for throttling and cooling. Therefore, in indoor heating mode, the throttling degree required by the second throttling device 7 does not need to be too large to avoid insufficient heat absorption at the outdoor heat exchanger 4 due to the refrigerant temperature being too low after throttling, resulting in a partial liquid state between the refrigerant and the return compressor 2. However, when the heat pump system is in indoor cooling mode, the refrigerant flows through the indoor heat exchanger 3 for condensation and cooling, and then flows through the second throttling device 7 for throttling and cooling. Since the condensation effect of the outdoor heat exchanger 4 on the refrigerant is limited by the heat exchange with the air, the throttling degree of the second throttling device 7 should be larger to achieve the effect of indoor cooling, ensuring that the temperature of the refrigerant reaching the indoor heat exchanger 3 should be relatively low.

[0078] Therefore, in order to better meet the different throttling requirements of the second throttling device 7 in indoor heating mode and outdoor cooling mode, in one embodiment, the second throttling device 7 includes a first throttling branch 71 and a second throttling branch 72 arranged in parallel. The first throttling branch 71 is provided with a first throttling component 73, and the second throttling branch 72 is provided with a second throttling component 75 and a one-way valve 74. The one-way valve 74 is located between the outdoor heat exchanger 4 and the second throttling component 75, and the one-way valve 74 only allows the refrigerant to flow from the outdoor heat exchanger 4 to the second throttling component 75.

[0079] This configuration ensures that in indoor heating mode, the refrigerant flowing out of the indoor heat exchanger 3 can only flow to the outdoor heat exchanger 4 through the first throttling branch 71, meaning that only the first throttling component 73 acts as a throttling and cooling device for the refrigerant. In indoor cooling mode, the refrigerant flowing out of the outdoor heat exchanger 4 can flow to the indoor heat exchanger 3 through the first throttling branch 71 and the second throttling branch 72, respectively. That is, the refrigerant is subjected to the throttling and cooling effect of the first throttling component 73 in the first throttling branch 71 and the throttling and cooling effect of the second throttling component 75 in the second throttling branch 72, thus ensuring the throttling and cooling effect of the second throttling device 7 on the refrigerant in indoor cooling mode.

[0080] In one embodiment, the first throttling component 73 is an electronic expansion valve, and the second throttling component 75 is a capillary tube. This allows the main throttling effect of the second throttling device 7 to be concentrated at the first throttling branch 71, ensuring the throttling and cooling effect of the refrigerant by the second throttling device 7 in both indoor heating mode and indoor heating mode. Simultaneously, setting the second throttling component 75 as a capillary tube effectively reduces the cost of the second throttling device 7, thereby reducing the cost of the entire heat pump system. In other embodiments, the second throttling component 75 can also be an electronic expansion valve.

[0081] In one embodiment, a first filter 301 is provided on the connecting pipe 401. The first filter 301 is located upstream of the first throttling device 6 to prevent pipe oxide scale, impurities, etc. in the pipeline from entering the first throttling device 6 and causing blockage, thus ensuring the smooth operation of the first throttling device 6. The first throttling device 6 is preferably an electronic expansion valve.

[0082] A second filter 302 and a third filter 303 are installed on the heat exchange pipeline 402. The second filter 302 is located between the second throttling device 7 and the indoor heat exchanger 3, and the third filter 303 is located between the second throttling device 7 and the outdoor heat exchanger 4. The installation of the second filter 302 and the third filter 303 can prevent impurities in the heat exchange pipeline 402 from entering the second throttling device 7 and causing blockage, thus ensuring the reliable operation of the second throttling device 7.

[0083] In one embodiment, the second end of the connecting pipe 401 is connected between the outdoor heat exchanger 4 and the second throttling device 7. In another embodiment, the second end of the connecting pipe 401 is connected between the second throttling device 7 and the indoor heat exchanger 3. Thus, when the heat pump system is in the first defrost mode, the refrigerant flowing out of the connecting pipe 401 does not need to undergo throttling and cooling again through the second throttling device 7 and flows directly to the indoor heat exchanger 3, reducing the condensation effect of the refrigerant on the heat exchange medium at the indoor heat exchanger 3. Specifically, the second end of the connecting pipe 401 is connected between the second throttling device 7 and the second filter 302, thereby preventing impurities in the heat exchange tubes from flowing into the first throttling device 6 through the connecting pipe 401.

[0084] To improve the operational stability of the heat pump system, a liquid storage container 20 is installed on the heat exchange pipeline 402. The liquid storage container 20 is located between the second throttling device 7 and the indoor heat exchanger 3 to balance the flow rate at various points in the heat exchange pipeline 402 and avoid instability in the heat pump system performance caused by fluctuations in refrigerant flow and pressure. Furthermore, the liquid storage container 20 is located between the indoor heat exchanger 3 and the second filter 302.

[0085] In one embodiment, a first shut-off valve 204 and a second shut-off valve 205 are provided on the heat exchange pipeline 402. The first shut-off valve 204 is located between the four-way reversing valve 8 and the indoor heat exchanger 3, and the second shut-off valve 205 is located between the outdoor heat exchanger 4 and the four-way reversing valve 8. Thus, by closing the first shut-off valve 204 and the second shut-off valve 205, the heat exchange pipeline 402 and the four-way reversing valve 8 can be disassembled and repaired, thereby improving the maintenance convenience of the heat pump system.

[0086] To further improve the operational safety and reliability of the heat pump system, in one embodiment, the outlet end of the compressor 2 and the four-way reversing valve 8 are connected through an exhaust pipe 403. An exhaust pressure sensor 101 and a high-pressure switch 203 are installed on the exhaust pipe 403. The high-pressure switch 203 is located upstream of the exhaust pressure sensor 101. The exhaust pressure sensor 101 is used to detect the pressure of the high-temperature and high-pressure refrigerant flowing out of the compressor 2 to determine whether the compressor 2 is operating within its working pressure range, so as to avoid damage to the compressor 2 and other components of the heat pump system due to excessive refrigerant pressure. The high-pressure switch 203 can switch the pipeline when the pipeline pressure is greater than a first preset pressure.

[0087] The inlet of compressor 2 and port C of four-way reversing valve 8 are connected via return gas line 404. A low-pressure switch 202 and a return gas pressure sensor 102 are installed on return gas line 404. The return gas pressure sensor 102 detects the pressure of the refrigerant returning to compressor 2 to ensure the stability and reliability of compressor 2's operation. The low-pressure switch 202 can switch return gas line 404 when the pressure is less than or equal to a second preset pressure. The low-pressure switch 202 is located downstream of the return gas pressure sensor 102.

[0088] Furthermore, the heat pump system also includes a gas-liquid separator 9, which is installed on the return gas line 404 to separate the refrigerant into gas and liquid phases before it returns to the compressor 2, ensuring that the refrigerant returning to the compressor 2 is in a gaseous state. Specifically, the gas-liquid separator 9 is located between the low-pressure switch 202 and the inlet end of the compressor 2.

[0089] Furthermore, an exhaust temperature sensor 103 is installed on the exhaust pipe 403 to detect the temperature of the medium discharged from the compressor 2. A return gas temperature sensor 104 is installed on the return gas pipe 404 to detect the temperature of the refrigerant before it flows back to the compressor 2. Both the exhaust temperature sensor 103 and the return gas temperature sensor 104 are communicatively connected to the controller. Furthermore, the exhaust temperature sensor 103 is located between the compressor 2 and the high-pressure switch 203, and the return gas temperature sensor 104 is located between the low-pressure switch 202 and the gas-liquid separator 9.

[0090] To better determine the appropriate mode for the heat pump system, in one embodiment, the heat pump system further includes an ambient temperature sensor 105. The ambient temperature sensor 105 is used to detect the external ambient temperature and is communicatively connected to the controller. Based on the external ambient temperature detected by the ambient temperature sensor 105, the controller can determine the probability of frost formation on the fan grille 1 and / or the outdoor heat exchanger 4, thereby determining whether a first defrost mode or a second defrost mode needs to be executed.

[0091] In one embodiment, the heat pump system further includes a heat exchange temperature sensor 106, which is used to detect the temperature of the outdoor heat exchanger 4, thereby determining the probability of frost formation on the outdoor heat exchanger 4 based on the detected value of the heat exchange temperature sensor 106, so as to help the controller determine whether the outdoor heat exchanger 4 needs to be defrosted.

[0092] In one embodiment, the heat pump system further includes a fan grille temperature sensor, which is used to detect the temperature of the fan grille 1, thereby determining whether there is a probability of ice formation on the fan grille 1, and then determining whether the fan grille 1 needs to be defrosted.

[0093] It is worth noting that the aforementioned indoor heat exchanger 3 refers to the heat exchanger that exchanges heat with the indoor temperature control equipment 1000, and it can be installed indoors or outdoors. The indoor heat exchanger 3 can be, but is not limited to, a plate heat exchanger. The outdoor heat exchanger 4 refers to the heat exchanger that exchanges heat with the outside air, and it is installed in the outdoor environment.

[0094] Example 2

[0095] This embodiment provides a control method for a heat pump system to control the operation of the heat pump system and reduce the probability of frost formation on the fan grille 1. The control method provided in this embodiment is applied to the heat pump system in Embodiment 1.

[0096] The control method provided in this embodiment includes:

[0097] Defrosting signal received;

[0098] The defrost control valve 201 and the first throttling device 6 are opened to allow at least a portion of the refrigerant to circulate sequentially along the outlet end of the compressor 2, the fan guard 1, the first throttling device 6, the heat exchanger, and the inlet end of the compressor 2.

[0099] That is, the control method provided in this embodiment opens the defrost control valve 201 and the first throttling device 6 when defrosting of the fan screen 1 is required, and the compressor 2 starts running, so that the high temperature and high pressure gas flowing out of the compressor 2 can heat the fan screen 1, thereby melting the frost or snow on the fan screen 1, realizing the defrosting of the fan screen 1, ensuring the normal air volume of the fan screen 1, and ensuring the performance of the heat pump system.

[0100] In one embodiment, the defrost signal includes a first defrost signal and a second defrost signal, and the control method further includes:

[0101] When the received defrost signal is the first defrost signal, the heat pump system is controlled to execute the first defrost mode, so that the outlet end of compressor 2, fan guard 1, first throttling device 6, indoor heat exchanger 3 and the inlet end of compressor 2 are sequentially connected to form a guard defrost circuit, and the outlet end of compressor 2, outdoor heat exchanger 4, second throttling device 7, indoor heat exchanger 3 and the inlet end of compressor 2 are sequentially connected to form a heat exchanger defrost circuit.

[0102] When the received defrost signal is the second defrost signal, the heat pump system is controlled to execute the second defrost mode, so that the outlet end of compressor 2, fan guard 1, first throttling device 6, outdoor heat exchanger 4 and the inlet end of compressor 2 are sequentially connected to form a guard defrost circuit, and the outlet end of compressor 2, indoor heat exchanger 3, second throttling device 7, outdoor heat exchanger 4 and the inlet end of compressor 2 are sequentially connected to form a heating cycle circuit.

[0103] By recognizing the first defrost signal and the second defrost signal, the controller can determine whether the heat pump system is performing defrost in the first defrost mode or the second defrost mode. This allows the fan screen 1 to be defrosted when the outdoor heat exchanger 4 does not need defrosting but the fan screen 1 does, while avoiding a significant drop in indoor ambient temperature caused by the defrosting process, saving energy consumption of the heat pump system and improving the user experience of the heat pump system.

[0104] In one embodiment, when the detected ambient temperature is lower than a first preset temperature for a duration greater than or equal to a preset duration, and the time interval since the last defrost is greater than a preset time interval, the controller determines that a first defrost signal has been received. Under this setting, when the ambient temperature is low, the probability of frost or snow accumulation on the fan grille 1 and the evaporator is relatively high. Therefore, a timed defrost method can be used to simultaneously defrost the fan grille 1 and the outdoor heat exchanger 4, simplifying the defrost logic and reducing the difficulty of defrost control.

[0105] In this implementation, if the ambient temperature remains at the first preset temperature, the preset time interval between two consecutive defrost cycles is 30 min to 60 min, specifically 35 min, 40 min, 45 min, min, 20 min, etc.

[0106] In one embodiment, when the temperature of the outdoor heat exchanger 4 is less than or equal to the frost point temperature, the controller determines that a first defrost signal has been received. That is, when the temperature of the outdoor heat exchanger 4 is lower than the frost point temperature, the outdoor heat exchanger 4 has a higher probability of frosting, and at this time, both the fan grille 1 and the outdoor heat exchanger 4 can be defrosted simultaneously.

[0107] It is worth noting that the frost point of the outdoor heat exchanger 4 is the same as that of the ambient temperature and humidity. The frost point of the outdoor heat exchanger 4 under different ambient temperatures and humidity can be set with reference to the existing technology. This embodiment does not limit or elaborate on this.

[0108] During the execution of the first defrosting mode, the defrosting process can be completed by judging the temperature rise status of the outdoor heat exchanger 4 and the air outlet screen during defrosting, or the defrosting time can be preset to control the duration of defrosting.

[0109] That is, the control methods also include:

[0110] When the temperature of the outdoor heat exchanger 4 rises to the first temperature and the temperature of the fan cover 1 rises to the second temperature, the first defrosting mode is exited; and / or, when the duration of the heat pump system executing the first defrosting mode is greater than or equal to the preset defrosting duration, the first defrosting mode is exited.

[0111] In one embodiment, when the detected ambient temperature is lower than the second preset temperature and the temperature of the outdoor heat exchanger 4 is higher than the frost point temperature, the controller determines that a second defrost signal has been received. That is, when the ambient temperature is low and the temperature of the outdoor heat exchanger 4 is higher than the frost point temperature, the probability of frost formation on the outdoor heat exchanger 4 is relatively low, while the probability of frost formation on the fan grille 1 is relatively high. At this time, only the second defrost mode can be executed to defrost only the air outlet grille.

[0112] Furthermore, in this implementation, the defrosting process can be determined by controlling the defrosting time or by detecting the temperature of the air outlet screen.

[0113] The control method includes: if the temperature of the fan screen 1 is higher than the second temperature during the execution of the second defrosting mode, the second defrosting mode is exited; and / or, if the duration of the second defrosting mode is greater than or equal to the preset defrosting duration, the second defrosting mode is exited.

[0114] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0115] The specific embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A control method for a heat pump system, characterized in that, The system includes a heat pump system comprising a compressor (2), an outdoor fan (5), a fan grille (1), and a heat exchanger. The fan grille (1) comprises a grille body (11) formed by coiling hollow tubes. The heat pump system also includes a first throttling device (6) and a defrost control valve (201). The outlet end of the compressor (2), the defrost control valve (201), the grille body (11), the first throttling device (6), the heat exchanger, and the inlet end of the compressor (2) are connected in sequence. The defrost control valve (201) controls the refrigerant flow between the outlet end of the compressor (2) and the fan grille (1). The control method includes: Defrosting signal received; Control the defrost control valve (201) and the first throttling device (6) to open so that at least part of the refrigerant circulates sequentially along the outlet end of the compressor (2), the fan guard (1), the first throttling device (6), the heat exchanger and the inlet end of the compressor (2); The defrost signal includes a first defrost signal and a second defrost signal. The heat exchanger includes an indoor heat exchanger (3) and an outdoor heat exchanger (4). The fan screen (1) is located on the side of the outdoor fan (5) away from the outdoor heat exchanger (4). The heat pump system also includes a second throttling device (7). When the received defrost signal is the first defrost signal, the heat pump system is controlled to execute the first defrost mode so that the outlet end of the compressor (2), the fan screen (1), the first throttling device (6), the indoor heat exchanger (3) and the inlet end of the compressor (2) are sequentially connected to form a screen defrost circuit, and the outlet end of the compressor (2), the outdoor heat exchanger (4), the second throttling device (7), the indoor heat exchanger (3) and the inlet end of the compressor (2) are sequentially connected to form a heat exchanger defrost circuit; When the received defrost signal is the second defrost signal, the heat pump system is controlled to execute the second defrost mode so that the outlet end of the compressor (2), the fan screen (1), the first throttling device (6), the outdoor heat exchanger (4) and the inlet end of the compressor (2) are sequentially connected to form a screen defrost circuit, and the outlet end of the compressor (2), the indoor heat exchanger (3), the second throttling device (7), the outdoor heat exchanger (4) and the inlet end of the compressor (2) are sequentially connected to form a heating cycle circuit; The control method further includes: when the temperature of the outdoor heat exchanger (4) is less than or equal to the frost point temperature, the controller determines that a first defrosting signal has been received; When the detected ambient temperature is lower than the first preset temperature for a duration greater than or equal to the preset duration, and the time interval since the last defrost is greater than the preset time interval, the controller determines that the first defrost signal has been received. When the detected ambient temperature is lower than the second preset temperature and the temperature of the outdoor heat exchanger (4) is higher than the frost point temperature, the controller determines that it has received the second defrost signal.

2. The control method for a heat pump system according to claim 1, characterized in that, The indoor heat exchanger (3), the second throttling device (7) and the outdoor heat exchanger (4) are connected in sequence to form a heat exchange pipeline (402). The outlet end of the compressor (2) can be selectively connected to one end of the heat exchange pipeline (402), and the inlet end of the compressor (2) is connected to the other end of the heat exchange pipeline (402).

3. The control method for a heat pump system according to claim 2, characterized in that, The outlet end of the first throttling device (6) is connected to the first end of the connecting pipe (401), the second end of the connecting pipe (401) is connected to the heat exchange pipeline (402), and the second end of the connecting pipe (401) is located between the outdoor heat exchanger (4) and the second throttling device (7).

4. The control method for a heat pump system according to claim 2, characterized in that, The second throttling device (7) includes a first throttling branch (71) and a second throttling branch (72) arranged in parallel. The first throttling branch (71) is provided with a first throttling component (73), and the second throttling branch (72) is provided with a second throttling component (75) and a one-way valve (74). The one-way valve (74) only allows refrigerant to flow from the outdoor heat exchanger (4) to the second throttling component (75).

5. The control method for a heat pump system according to claim 4, characterized in that, The first throttling component (73) is an electronic expansion valve, and the second throttling component (75) is a capillary tube.

6. The control method for a heat pump system according to any one of claims 1-5, characterized in that, The main body of the mesh cover (11) includes a spirally arranged main disc (111), and two ends of the main disc (111) are respectively connected to connecting pipes (112). The ends of the connecting pipes (112) extend out of the outside of the main disc (111). One connecting pipe (112) is connected to the outlet end of the compressor (2), and the other connecting pipe (112) is connected to the inlet end of the first throttling device (6). And / or, the fan cover (1) further includes a support strip (13), the cover body (11) is a spiral disc structure, the support strip (13) extends radially along the cover body (11) and is provided in multiple circumferentially along the cover body (11), and each support strip (13) has multiple connection positions with the spiral disc structure.

7. The control method for a heat pump system according to any one of claims 1-5, characterized in that, The heat pump system includes a controller, and the compressor (2), the defrost control valve (201) and the first throttling device (6) are all communicatively connected to the controller; The heat pump system further includes an ambient temperature sensor (105) for detecting the ambient temperature and communicating with the controller; and / or, the heat pump system further includes a mesh cover temperature sensor for detecting the temperature of the fan mesh cover (1) and communicating with the controller; and / or, the heat pump system further includes a heat exchange temperature sensor (106) for detecting the temperature of the outdoor heat exchanger (4) and communicating with the controller.

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