Four-pipe system, control method, device and air conditioner

Abstract

The present invention relates to a four-pipe system, a control method, a device, and an air conditioner, and relates to the field of refrigeration and heating technology. It solves the problem of poor reliability in existing four-pipe units that rely on one or more four-way valves to control switching to change the flow direction of refrigerant. The four-pipe system includes a compressor, a first control valve, an air-cooled heat exchanger, a first throttling component, a third control valve, a cold water heat exchanger, and an air intake of the compressor are connected in sequence along the compressor exhaust port to form a refrigeration circuit; a hot water heat exchanger, a second throttling component, a first throttling component, an air-cooled heat exchanger, a second control valve, and an air intake of the compressor are connected in sequence along the compressor exhaust port to form a heating circuit; and a hot water heat exchanger, a second throttling component, a third control valve, a cold water heat exchanger, and an air intake of the compressor are connected in sequence along the compressor exhaust port to form a combined cooling and heating circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration and heating, and in particular to a four-pipe system, a control method, a device and an air conditioner. Background Art

[0002] With the development of the economy and technology, people's living standards are constantly improving, and the requirements for air conditioning systems in more and more places are also increasing. Different places such as hospitals, hotels, restaurants, and shopping malls have increasingly diverse cooling and heating needs. The four-pipe chiller unit has a multi-mode design that can meet the needs of various locations under various operating conditions throughout the year. Currently, more and more users are choosing to use four-pipe chillers.

[0003] In the prior art, a four-pipe chiller is an air conditioning host system that can realize the functions of cooling water independently, heating water independently, and heating and cooling simultaneously.

[0004] Conventional four-pipe chillers typically rely on one or more four-way valves for control switching to change the refrigerant flow direction and achieve various functions. Since four-way valves are prone to failure risks such as jamming, valve core damage and refrigerant leakage, the reliability of the four-pipe system is weakened and the control is complex. At the same time, the four-way valve is the most expensive device among air-conditioning components besides the compressor, condenser and evaporator. This is particularly prominent for large chillers, increasing the cost of the unit. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a four-pipe system, control method, device and air conditioner to solve the technical problem in the prior art that the four-pipe unit relies on one or more four-way valves to control the switching to change the refrigerant flow direction and has poor reliability.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] According to a first aspect of an embodiment of the present invention, there is provided a four-pipe system, comprising a compressor, a first control valve, an air-cooled heat exchanger, a first throttling component, a third control valve, a cold water heat exchanger, and an air intake of the compressor connected in sequence along an exhaust port of the compressor to form a refrigeration circuit;

[0008] A hot water heat exchanger, a second throttling component, the first throttling component, the air-cooled heat exchanger, a second control valve, and an air intake of the compressor are sequentially connected along the exhaust port of the compressor to form a heating circuit;

[0009] The hot water heat exchanger, the second throttling component, the third control valve, the cold water heat exchanger, and the air intake of the compressor are connected in sequence along the exhaust port of the compressor to form a combined cooling and heating circuit.

[0010] As an optional embodiment of the present invention, the first control valve, the second control valve and the third control valve are all one-way solenoid valves, wherein:

[0011] The first control valve and the second control valve are respectively arranged between the compressor and the air-cooled heat exchanger, and the inlet end of the first control valve and the outlet end of the second control valve are respectively connected to the exhaust end of the compressor; the outlet end of the third control valve is connected to the cold water heat exchanger.

[0012] As an optional implementation manner of the present invention, both the first throttling component and the second throttling component are electronic expansion valves.

[0013] As an optional embodiment of the present invention, temperature sensors are installed at the water outlet end of the cold water heat exchanger and the water outlet end of the hot water heat exchanger, and the temperature sensors are used to detect the corresponding cold water outlet temperature and hot water outlet temperature.

[0014] According to a second aspect of an embodiment of the present invention, a control method for a four-control system is provided, for controlling the four-control system, comprising:

[0015] Obtain the user's cooling and heating load requirements;

[0016] Determining the operating mode of the four-pipe system according to the user's cooling and heating load requirements, wherein the operating modes include cooling mode, heating mode, and combined cooling and heating mode;

[0017] The operation of the four-control system is controlled according to the operation mode.

[0018] As optional implementation modes of the present invention, the operating modes are:

[0019] In cooling mode, the first control valve, the first throttling component and the third control valve are controlled to be open, and the second control valve and the second throttling component are controlled to be closed;

[0020] In the heating mode, the second throttling component, the first throttling component, and the second control valve are controlled to be open, and the first control valve and the third control valve are controlled to be closed;

[0021] In the combined cooling and heating mode, the second throttling component and the third control valve are controlled to be open, and the first control valve, the second control valve and the first throttling component are controlled to be closed.

[0022] As an optional embodiment of the present invention, determining the operating mode of the four-pipe system according to the user's cooling and heating load requirements includes:

[0023] If the user's cooling and heating load demand is cooling only, determining that the four-pipe system operates in cooling mode;

[0024] If the user's cooling and heating load demand is heating only, the four-pipe system is determined to operate in heating mode;

[0025] If the user's cooling and heating load demand is simultaneous cooling and heating, it is determined that the four-pipe system operates in the combined cooling and heating mode.

[0026] As an optional implementation mode of the present invention, the operating mode is a combined cooling and heating mode, and when the cooling capacity needs to be reduced separately, the first throttling component is controlled to open and the opening value is initially opened, the air-cooled heat exchanger and the second control valve are opened, and the opening of the first throttling component is adjusted according to the target water temperature on the cold water side of the cold water heat exchanger.

[0027] As an optional embodiment of the present invention, adjusting the opening of the first throttling component according to the target water temperature on the cold water side of the cold water heat exchanger includes:

[0028] detecting the actual water temperature on the cold water side of the cold water heat exchanger;

[0029] comparing the actual water temperature on the cold water side with the target water temperature on the cold water side;

[0030] The opening degree of the first throttle component is adjusted according to the comparison result.

[0031] As an optional embodiment of the present invention, adjusting the opening of the first throttle component according to the comparison result includes:

[0032] If the actual water temperature on the cold water side is lower than the target water temperature on the cold water side, adjusting and increasing the opening of the first throttling component;

[0033] If the actual water temperature on the cold water side is higher than the target water temperature on the cold water side, adjusting and reducing the opening of the first throttling component;

[0034] If the actual water temperature on the cold water side is equal to the target water temperature on the cold water side, the opening of the first throttle component is maintained.

[0035] As an optional embodiment of the present invention, the adjusting to increase the opening of the first throttle component includes:

[0036] gradually increasing the opening of the first throttling component according to a preset ratio or step size, and determining whether the actual water temperature on the cold water side is equal to the target water temperature on the cold water side after the target opening obtained after each adjustment of the preset ratio or step size persists for a preset time;

[0037] Determine whether to continue adjusting the opening of the electronic expansion valve according to the judgment result.

[0038] As an optional embodiment of the present invention, the adjusting to reduce the opening of the first throttle component includes:

[0039] gradually reducing the opening of the first throttling component according to a preset ratio or step size, and determining whether the actual water temperature on the cold water side is equal to the target water temperature on the cold water side after the target opening obtained after each adjustment of the preset ratio or step size lasts for a preset time;

[0040] Determine whether to continue adjusting the opening of the electronic expansion valve according to the judgment result.

[0041] As an optional embodiment of the present invention, determining whether to continue adjusting the opening of the electronic expansion valve according to the judgment result includes:

[0042] When the judgment result indicates that the actual water temperature on the cold water side is not equal to and lower than the target water temperature on the cold water side, determining to continue adjusting and increase the opening of the first throttling component;

[0043] When the judgment result indicates that the actual water temperature on the cold water side is not equal to and higher than the target water temperature on the cold water side, determining to continue adjusting and reduce the opening of the first throttling component;

[0044] When the judgment result indicates that the actual cold water temperature is equal to the target cold water temperature, it is determined to stop adjusting the opening of the first throttle component.

[0045] As an optional embodiment of the present invention, before adjusting the opening of the first throttling component according to the target water temperature on the cold water side of the cold water heat exchanger, the compressor is first controlled to load and unload to meet the water temperature requirement on the hot water side of the hot water heat exchanger.

[0046] As an optional implementation mode of the present invention, the operating mode is a combined cooling and heating mode, and when the heating amount needs to be reduced separately, the first throttling component is controlled to open and the opening value is initially opened, the air-cooled heat exchanger and the first control valve are opened, and the opening of the first throttling component is adjusted according to the target water temperature on the hot water side of the hot water heat exchanger.

[0047] As an optional embodiment of the present invention, adjusting the opening of the first throttling component according to the target water temperature on the hot water side of the hot water heat exchanger includes:

[0048] detecting the actual water temperature on the hot water side of the hot water heat exchanger;

[0049] comparing the actual water temperature on the hot water side with the target water temperature on the hot water side;

[0050] The opening degree of the first throttle component is adjusted according to the comparison result.

[0051] As an optional embodiment of the present invention, adjusting the opening of the first throttle component according to the comparison result includes:

[0052] If the actual water temperature on the hot water side is lower than the target water temperature on the hot water side, adjusting and reducing the opening of the first throttling component;

[0053] If the actual water temperature on the hot water side is higher than the target water temperature on the hot water side, adjusting and increasing the opening of the first throttling component;

[0054] If the actual water temperature on the hot water side is equal to the target water temperature on the hot water side, the opening of the first throttling component is maintained.

[0055] As an optional embodiment of the present invention, the adjusting to reduce the opening of the first throttle component includes:

[0056] gradually reducing the opening of the first throttling component according to a preset ratio or step size, and determining whether the actual water temperature on the hot water side is equal to the target water temperature on the hot water side after the target opening obtained after each adjustment of the preset ratio or step size lasts for a preset time;

[0057] Determine whether to continue adjusting the opening of the electronic expansion valve according to the judgment result.

[0058] As an optional embodiment of the present invention, the adjusting to increase the opening of the first throttle component includes:

[0059] gradually increasing the opening of the first throttling component according to a preset ratio or step size, and determining whether the actual water temperature on the hot water side is equal to the target water temperature on the hot water side after the target opening obtained after each adjustment of the preset ratio or step size persists for a preset time;

[0060] Determine whether to continue adjusting the opening of the electronic expansion valve according to the judgment result.

[0061] As an optional embodiment of the present invention, determining whether to continue adjusting the opening of the electronic expansion valve according to the judgment result includes:

[0062] When the judgment result indicates that the actual water temperature on the hot water side is not equal to and lower than the target water temperature on the hot water side, determining to continue adjusting and reduce the opening of the first throttling component;

[0063] When the judgment result indicates that the actual water temperature on the hot water side is not equal to but higher than the target water temperature on the hot water side, determining to continue adjusting and increase the opening of the first throttling component;

[0064] When the judgment result indicates that the actual water temperature on the hot water side is equal to the target water temperature on the hot water side, it is determined to stop adjusting the opening of the first throttle component.

[0065] As an optional embodiment of the present invention, before adjusting the opening of the first throttling component according to the target water temperature on the hot water side of the hot water heat exchanger, the compressor is first controlled to load and unload to meet the water temperature requirement on the cold water side of the cold water heat exchanger.

[0066] According to a third aspect of an embodiment of the present invention, a control device for a four-control system is provided, comprising:

[0067] Acquisition module, used to obtain the user's cooling and heating load requirements;

[0068] a determination module, configured to determine an operating mode of the four-pipe system according to a user's cooling and heating load requirements;

[0069] A control module is used to control the operation of the four-control system according to the operation mode.

[0070] As an optional implementation manner of the present invention, the determining module includes:

[0071] The first detection unit is used to detect the actual water temperature on the cold water side of the cold water heat exchanger;

[0072] a first comparing unit, configured to compare the actual water temperature on the cold water side with the target water temperature on the cold water side;

[0073] The first regulating unit is configured to regulate the opening of the first throttling component according to a comparison result between the actual water temperature on the cold water side and the target water temperature on the cold water side.

[0074] As an optional implementation manner of the present invention, the determining module further includes:

[0075] The second detection unit is used to detect the actual water temperature on the hot water side of the hot water heat exchanger;

[0076] a second comparing unit, configured to compare the actual water temperature on the hot water side with the target water temperature on the hot water side;

[0077] The second regulating unit is configured to regulate the opening of the first throttling component according to a comparison result between the actual water temperature on the hot water side and the target water temperature on the hot water side.

[0078] According to a fourth aspect of an embodiment of the present invention, an air conditioner is provided, comprising the four-pipe system and a controller, wherein the four-pipe system and the controller are connected; the controller is configured to execute the control method of the four-pipe system.

[0079] The four-pipe system provided by the present invention eliminates the use of a four-way valve compared to conventional systems, simplifies the system structure, and can realize all the functions of the four-pipe system by using the on-off control of a conventional control valve (solenoid valve), including demand switching of cooling, heating, and combined cooling and heating, and independent adjustment of cooling and heating when supplying cooling and heating at the same time, so as to adapt to the actual needs of users, make the entire system simpler and more flexible, and improve the reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0081] Figure 1 This is a schematic diagram of the principle structure of a four-control system provided by an embodiment of the present invention;

[0082] Figure 2 This is a schematic diagram of the principle structure of the cooling mode provided by an embodiment of the present invention;

[0083] Figure 3 This is a schematic diagram of the principle structure of the heating mode provided by an embodiment of the present invention;

[0084] Figure 4 This is a schematic diagram of the principle structure of the combined cooling and heating mode provided by an embodiment of the present invention;

[0085] Figure 5 1 is a flow chart of a control method for a four-control system provided by an embodiment of the present invention;

[0086] Figure 6 This is a flow chart of an embodiment of adjusting the cooling capacity in the combined cooling and heating mode provided by an embodiment of the present invention;

[0087] Figure 7 This is a flow chart of an embodiment of adjusting the heating amount in the combined cooling and heating mode provided by an embodiment of the present invention;

[0088] Figure 8 This is a schematic diagram of the principle structure of a control device for a four-control system provided by an embodiment of the present invention;

[0089] Figure 9 It is a schematic diagram of the principle structure of the air conditioner provided by an embodiment of the present invention.

[0090] In the figure: 1. compressor; 2. hot water heat exchanger; 3. cold water heat exchanger; 4. air-cooled heat exchanger; 5. first control valve; 6. second control valve; 7. third control valve; 8. first throttling component; 9. second throttling component. DETAILED DESCRIPTION

[0091] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0092] See also Figure 1 The present invention provides a four-pipe system, including a compressor 1, a hot water heat exchanger 2, a cold water heat exchanger 3, an air-cooled heat exchanger 4, a first control valve 5, a second control valve 6, a third control valve 7, a first throttling component 8, and a second throttling component 9.

[0093] The refrigerant in the compressor 1 passes through the first control valve 5, the air-cooled heat exchanger 4, the first throttling component 8, the third control valve 7, the cold water heat exchanger 3 along the exhaust port of the compressor 1 and returns to the intake port of the compressor 1 to form a refrigeration circuit; the refrigerant in the compressor 1 passes through the hot water heat exchanger 2, the second throttling component 9, the first throttling component 8, the air-cooled heat exchanger 4, the second control valve 6 along the exhaust port of the compressor 1 and returns to the intake port of the compressor 1 to form a heating circuit; the refrigerant in the compressor 1 passes through the hot water heat exchanger 2, the second throttling component 9, the third control valve 7, the cold water heat exchanger 3 along the exhaust port of the compressor 1 and returns to the intake port of the compressor 1 to form a combined cooling and heating circuit.

[0094] For example, the four-pipe system in the above scheme can realize all the functions of the four-pipe system by using the on-off control of conventional control valves (solenoid valves), including demand switching of cooling, heating, and combined cooling and heating, and independent adjustment of cooling and heating when providing cooling and heating at the same time, so as to meet the actual needs of users. Compared with the conventional four-pipe system, the four-pipe system in the present invention eliminates the use of four-way valves, effectively avoiding the conventional four-pipe unit that usually relies on one or more four-way valves for control switching to change the refrigerant flow direction to achieve multiple functions. Since the four-way valve is prone to failure risks such as jamming, valve core damage and refrigerant leakage, the reliability of the four-pipe system is weakened, thereby improving the stability and reliability of the unit operation.

[0095] Optionally, the first control valve 5, the second control valve 6, and the third control valve 7 are all one-way solenoid valves. The first control valve 5 and the second control valve 6 are respectively arranged between the compressor 1 and the air-cooled heat exchanger 4. The inlet end of the first control valve 5 and the outlet end of the second control valve 6 are respectively connected to the exhaust end of the compressor 1; the outlet end of the third control valve 7 is connected to the cold water heat exchanger 3.

[0096] Optionally, the first throttling component 8 and the second throttling component 9 are both configured as electronic expansion valves.

[0097] By arranging three one-way solenoid valves and two electronic expansion valves in the four-pipe system, the piping settings of the four-pipe system can be effectively optimized, saving costs while ensuring the normal operation of the system.

[0098] In the embodiment of the present invention, temperature sensors are installed at the water outlet of the cold water heat exchanger 3 and the water outlet of the hot water heat exchanger 2. The temperature sensors are used to detect the corresponding cold water outlet temperature and hot water outlet temperature.

[0099] In a specific four-pipe system, the switching between cooling mode, heating mode and combined cooling and heating mode can be achieved by controlling the on and off of the first control valve 5, the second control valve 6 and the third control valve 7 and the switch of the first throttle component 8 and the second throttle component 9, thereby realizing different functions.

[0100] In order to more clearly illustrate the four-control system loop control in the technical solution of the present invention, the four-control system loop control is defined and described in the following multiple working modes by way of example:

[0101] Cooling mode: the first control valve 5 is open, the second control valve 6 is closed, the third control valve 7 is open, the first throttle component 8 is open, and the second throttle component 9 is closed; the refrigerant cycle at this time is: compressor 1 exhaust port → first control valve 5 → air-cooled heat exchanger 4 → first throttle component 8 → third control valve 7 → cold water heat exchanger 3 → compressor 1 intake port (such as Figure 2 It should be noted that, since the second throttle component 9 is closed, although the exhaust gas will enter the hot water heat exchanger 2, the hot water side will not continue to exchange heat in the state of no water flow, so it has no effect on the cooling side.

[0102] Heating mode: the first control valve 5 is closed, the second control valve 6 is open, the third control valve 7 is closed, the second throttle component 9 is open, and the first throttle component 8 is open; the refrigerant cycle at this time is: the exhaust port of the compressor 1 → the hot water heat exchanger 2 → the second throttle component 9 → the first throttle component 8 → the air-cooled heat exchanger 4 → the second control valve 6 → the intake port of the compressor 1 (such as Figure 3 shown).

[0103] Combined cooling and heating mode: the first control valve 5 is closed, the second control valve 6 is closed, the third control valve 7 is open, the first throttle component 8 is closed, and the second throttle component 9 is open; the refrigerant cycle at this time is: the exhaust port of the compressor 1 → the hot water heat exchanger 2 → the second throttle component 9 → the third control valve 7 → the cold water heat exchanger 3 → the intake port of the compressor 1 (such as Figure 4 shown).

[0104] When the cooling capacity needs to be reduced during combined cooling and heating mode operation, the first throttling component 8 opens, simultaneously opening the fan of the air-cooled heat exchanger 4 and the second control valve 6, using the air-cooled heat exchanger 4 as a bypass to the evaporator and bypassing some of the throttled refrigerant. The first throttling component 8 is then controlled based on the target water temperature on the cold water side. When the heating capacity needs to be reduced during combined cooling and heating mode operation, the first throttling component 8 opens, simultaneously opening the fan of the air-cooled heat exchanger 4 and the first control valve 5, using the air-cooled heat exchanger 4 as a bypass to the condenser and bypassing some of the exhaust gas. The first throttling component 8 is then controlled based on the target water temperature on the hot water side.

[0105] Based on a general inventive concept, an embodiment of the present invention further provides a control method for a four-control system. Figure 2 This is a flow chart of an embodiment of the control method of the four-control system of the present invention. Figure 2 The control method of the four-control system of the present invention can be applied to the four-control system described in any of the above embodiments, and can include the following steps:

[0106] S21. Obtain the user's cooling and heating load requirements;

[0107] S22. Determine an operating mode of the four-pipe system based on the user's cooling and heating load requirements, where the operating modes include cooling mode, heating mode, and combined cooling and heating mode;

[0108] If the user's cooling and heating load demand is cooling only, the four-pipe system is determined to operate in cooling mode; if the user's cooling and heating load demand is heating only, the four-pipe system is determined to operate in heating mode; if the user's cooling and heating load demand is simultaneous cooling and heating, the four-pipe system is determined to operate in combined cooling and heating mode;

[0109] S23. Control the operation of the four-control system according to the operation mode.

[0110] Optional operation modes:

[0111] In cooling mode, the first control valve 5, the first throttle component 8 and the third control valve 7 are opened, and the second control valve 6 and the second throttle component 9 are closed;

[0112] In heating mode, the second throttle component 9, the first throttle component 8, and the second control valve 6 are opened, and the first control valve 5 and the third control valve 7 are closed;

[0113] In the combined cooling and heating mode, the second throttling component 9 and the third control valve 7 are controlled to be open, and the first control valve 5, the second control valve 6 and the first throttling component 8 are closed.

[0114] For example, in a specific regulatory control process:

[0115] In the cooling mode, the first control valve 5 is opened, the second control valve 6 is closed, the third control valve 7 is opened, the first throttling component 8 is opened, and the second throttling component 9 is closed; the refrigerant at the exhaust port of the compressor 1 enters the air-cooled heat exchanger 4 through the first control valve 5, and then enters the cold water heat exchanger 3 through the first throttling component 8 and the third control valve 7, and finally returns to the intake port of the compressor 1.

[0116] In the heating mode, the first control valve 5 is closed, the second control valve 6 is open, the third control valve 7 is closed, the second throttle component 9 is open, and the first throttle component 8 is open; the refrigerant at the exhaust port of the compressor 1 enters the hot water heat exchanger 2, and then enters the air-cooled heat exchanger 4 through the second throttle component 9 and the first throttle component 8, and then returns to the intake port of the compressor 1 through the second control valve 6.

[0117] In the combined cooling and heating mode, the first control valve 5 is closed, the second control valve 6 is closed, the third control valve 7 is open, the first throttling component 8 is closed, and the second throttling component 9 is opened; the refrigerant at the exhaust port of the compressor 1 first flows into the hot water heat exchanger 2, then flows into the cold water heat exchanger 3 through the second throttling component 9 and the third control valve 7, and finally returns to the intake port of the compressor 1.

[0118] When the operating mode is the combined cooling and heating mode and the cooling capacity needs to be reduced separately, the first throttling component 8 is controlled to open and the opening value is initially opened, the air-cooled heat exchanger 4 and the second control valve 6 are opened, and the opening of the first throttling component 8 is adjusted according to the target water temperature on the cold water side of the cold water heat exchanger 3.

[0119] Optionally, adjusting the opening of the first throttling component 8 according to the target water temperature on the cold water side of the cold water heat exchanger 3 includes:

[0120] Detecting the actual water temperature on the cold water side of the cold water heat exchanger 3;

[0121] Compare the actual water temperature on the cold water side with the target water temperature on the cold water side;

[0122] The opening degree of the first throttle component 8 is adjusted according to the comparison result.

[0123] Optionally, adjusting the opening of the first throttle component 8 according to the comparison result includes:

[0124] If the actual water temperature on the cold water side is lower than the target water temperature on the cold water side, the opening of the first throttle component 8 is increased;

[0125] If the actual water temperature on the cold water side is higher than the target water temperature on the cold water side, the opening of the first throttle component 8 is adjusted to decrease;

[0126] If the actual water temperature on the cold water side is equal to the target water temperature on the cold water side, the opening of the first throttle component 8 is maintained.

[0127] Optionally, adjusting and increasing the opening of the first throttle component 8 includes:

[0128] gradually increasing the opening of the first throttle component 8 according to a preset ratio or step size, and after the target opening obtained after each adjustment of the preset ratio or step size persists for a preset time, determining whether the actual water temperature on the cold water side is equal to the target water temperature on the cold water side;

[0129] Determine whether to continue adjusting the opening of the electronic expansion valve based on the judgment result.

[0130] Optionally, adjusting and reducing the opening of the first throttle component 8 includes:

[0131] The opening of the first throttle component 8 is gradually adjusted and reduced according to a preset ratio or step size, and after the target opening obtained after each adjustment of the preset ratio or step size lasts for a preset time, it is determined whether the actual water temperature on the cold water side is equal to the target water temperature on the cold water side;

[0132] Determine whether to continue adjusting the opening of the electronic expansion valve based on the judgment result.

[0133] The above-mentioned determination of whether to continue adjusting the opening of the electronic expansion valve according to the judgment result includes:

[0134] When the judgment result indicates that the actual water temperature on the cold water side is not equal to and lower than the target water temperature on the cold water side, it is determined to continue adjusting and increase the opening of the first throttle component 8;

[0135] When the judgment result indicates that the actual water temperature on the cold water side is not equal to and higher than the target water temperature on the cold water side, it is determined to continue adjusting and reduce the opening of the first throttle component 8;

[0136] When the judgment result indicates that the actual water temperature on the cold water side is equal to the target water temperature on the cold water side, it is determined to stop adjusting the opening degree of the first throttle component 8 .

[0137] It should be noted that when adjusting the opening of the first throttling component 8, the water temperature on the hot water side must also be detected, and the compressor 1 is loaded and unloaded according to the water temperature on the hot water side. Ultimately, while ensuring that the actual water temperature on the cold water side is equal to the target water temperature on the cold water side, the actual water temperature on the hot water side is equal to the target water temperature on the hot water side.

[0138] Optionally, before adjusting the opening of the first throttling component 8 according to the target water temperature on the cold water side of the cold water heat exchanger 3, the compressor 1 is first controlled to load and unload to meet the water temperature requirement on the hot water side of the hot water heat exchanger 2, that is, considering reducing the cooling capacity only after giving priority to meeting the heating side demand.

[0139] like Figure 6 The figure shows a specific control process for when cooling capacity needs to be reduced during combined cooling and heating operation. The first electronic expansion valve opens to an initial opening of X (a recommended value for X is 1% to 5%). The fan of the air-cooled heat exchanger 4 and the second control valve 6 are simultaneously turned on, using the air-cooled heat exchanger 4 as a bypass evaporator, bypassing some of the throttled refrigerant. The first throttling element 8 is now controlled based on the target water temperature on the cold water side. When the actual water temperature on the cold water side is lower than the target water temperature, the valve is opened by 1% until the actual water temperature on the cold water side equals the target water temperature. When the actual water temperature on the cold water side is higher than the target water temperature on the cold water side, the valve is closed by 1% until the first throttling element 8 closes, at which point the compressor 1 is used to adjust the water temperature.

[0140] If the heating capacity is increased alone, the compressor 1 needs to be loaded first to meet the heating demand, and then the cooling capacity is reduced through the above-mentioned action to meet the demand of unchanged cooling capacity.

[0141] In an embodiment of the present invention, when the operating mode is the combined cooling and heating mode and the heating amount needs to be reduced separately, the first throttling component 8 is controlled to be opened and the opening value is initially opened, the air-cooled heat exchanger 4 and the first control valve 5 are opened, and the opening of the first throttling component 8 is adjusted according to the target water temperature on the hot water side of the hot water heat exchanger 2.

[0142] Optionally, adjusting the opening of the first throttling component 8 according to the target water temperature on the hot water side of the hot water heat exchanger 2 includes:

[0143] Detecting the actual water temperature on the hot water side of the hot water heat exchanger 2;

[0144] Compare the actual water temperature on the hot water side with the target water temperature on the hot water side;

[0145] The opening degree of the first throttle component 8 is adjusted according to the comparison result.

[0146] Optionally, adjusting the opening of the first throttle component 8 according to the comparison result includes:

[0147] If the actual water temperature on the hot water side is lower than the target water temperature on the hot water side, the opening of the first throttle component 8 is adjusted to decrease;

[0148] If the actual water temperature on the hot water side is higher than the target water temperature on the hot water side, the opening of the first throttle component 8 is increased;

[0149] If the actual water temperature on the hot water side is equal to the target water temperature on the hot water side, the opening of the first throttle component 8 is maintained.

[0150] Optionally, adjusting and reducing the opening of the first throttle component 8 includes:

[0151] The opening of the first throttle component 8 is gradually adjusted and reduced according to a preset ratio or step size, and after the target opening obtained after each adjustment of the preset ratio or step size lasts for a preset time, it is determined whether the actual water temperature on the hot water side is equal to the target water temperature on the hot water side;

[0152] Determine whether to continue adjusting the opening of the electronic expansion valve based on the judgment result.

[0153] Optionally, adjusting and increasing the opening of the first throttle component 8 includes:

[0154] The opening of the first throttle component 8 is gradually increased according to a preset ratio or step size, and after the target opening obtained after each adjustment of the preset ratio or step size persists for a preset time, it is determined whether the actual water temperature on the hot water side is equal to the target water temperature on the hot water side;

[0155] Determine whether to continue adjusting the opening of the electronic expansion valve based on the judgment result.

[0156] Optionally, determining whether to continue adjusting the opening of the electronic expansion valve according to the judgment result includes:

[0157] When the judgment result indicates that the actual water temperature on the hot water side is not equal to and lower than the target water temperature on the hot water side, it is determined to continue adjusting and reduce the opening of the first throttle component 8;

[0158] When the judgment result indicates that the actual water temperature on the hot water side is not equal to and higher than the target water temperature on the hot water side, it is determined to continue adjusting and increase the opening of the first throttle component 8;

[0159] When the judgment result indicates that the actual water temperature on the hot water side is equal to the target water temperature on the hot water side, it is determined to stop adjusting the opening of the first throttle component 8.

[0160] It should be noted that when adjusting the opening of the first throttling component 8, the water temperature on the cold water side must also be detected, and the compressor 1 is loaded and unloaded according to the water temperature on the cold water side. Ultimately, while ensuring that the actual water temperature on the hot water side is equal to the target water temperature on the hot water side, the actual water temperature on the cold water side is equal to the target water temperature on the cold water side.

[0161] Optionally, before adjusting the opening of the first throttling component 8 according to the target water temperature on the hot water side of the hot water heat exchanger 2, the compressor 1 is first controlled to load and unload to meet the water temperature requirement on the cold water side of the cold water heat exchanger 3, that is, the reduction of the heating amount is considered only after the demand on the cooling side is met first.

[0162] like Figure 7The figure shows a specific regulation and control process for situations where heating capacity needs to be reduced during combined cooling and heating operation. First throttle 8 is opened to an initial opening X (a value of 1% to 5% is recommended). The fan of air-cooled heat exchanger 4 and first control valve 5 are simultaneously turned on, using air-cooled heat exchanger 4 as a bypass condenser to partially bypass the exhaust gas. First throttle 8 is now controlled based on the target water temperature on the hot water side. When the actual water temperature on the hot water side is lower than the target water temperature, it is closed by 1%. When the actual water temperature on the hot water side is higher than the target water temperature, it is opened by 1%. Only after first throttle 8 closes does compressor 1 begin to regulate the water temperature.

[0163] If the cooling capacity is increased alone, the compressor 1 needs to be loaded first to meet the cooling air demand, and then the heating capacity is reduced through the above-mentioned action to meet the demand of unchanged cooling capacity.

[0164] Based on a general inventive concept, an embodiment of the present invention further provides a control device for a four-control system.

[0165] Figure 8 This is a schematic diagram of the structure of an embodiment of the control device of the four-control system of the present invention. Figure 8 A control device for a four-control system may include: an acquisition module, a determination module and a control module.

[0166] An acquisition module 31 is used to obtain the user's cooling and heating load requirements;

[0167] A determination module 32 is used to determine the operation mode of the four-pipe system according to the user's cooling and heating load requirements;

[0168] The control module 33 is used to control the operation of the four-control system according to the operation mode.

[0169] In a specific embodiment of the present invention, the determination module 32 includes:

[0170] The first detection unit is used to detect the actual water temperature on the cold water side of the cold water heat exchanger 3;

[0171] The first comparison unit is used to compare the actual water temperature on the cold water side with the target water temperature on the cold water side;

[0172] The first regulating unit is used to regulate the opening of the first throttling component 8 according to the comparison result between the actual water temperature on the cold water side and the target water temperature on the cold water side.

[0173] Optionally, the determining module 32 further includes:

[0174] The second detection unit is used to detect the actual water temperature on the hot water side of the hot water heat exchanger 2;

[0175] The second comparison unit is used to compare the actual water temperature on the hot water side with the target water temperature on the hot water side;

[0176] The second regulating unit is used to regulate the opening of the first throttling component 8 according to the comparison result between the actual water temperature on the hot water side and the target water temperature on the hot water side.

[0177] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0178] The control device of the four-pipe system provided in the embodiment of the present invention can realize all the functions of the four-pipe system by utilizing the on-off control of a conventional control valve (solenoid valve), including demand switching of cooling, heating, and combined cooling and heating, and independent adjustment of cooling and heating when supplying cooling and heating at the same time, so as to adapt to the actual needs of users, eliminate the use of a four-way valve, and effectively avoid the risk of failure of the four-way valve such as jamming, valve core damage, and refrigerant leakage, thereby improving the stability and reliability of the unit operation.

[0179] Based on a general inventive concept, an embodiment of the present invention further provides an air conditioner.

[0180] Figure 9 This is a schematic diagram of the structure of an embodiment of the air conditioner of the present invention, see Figure 9 The air conditioner of this embodiment may include: the above-mentioned four-pipe system and a controller, the four-pipe system and the controller are connected; the controller is used to execute the control method of the above-mentioned four-pipe system.

[0181] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0182] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A four-pipe system, characterized in that: A refrigeration circuit is formed by sequentially connecting a first control valve, an air-cooled heat exchanger, a first throttling component, a third control valve, a cold water heat exchanger, and an air intake of the compressor along the exhaust port of the compressor. A hot water heat exchanger, a second throttling component, the first throttling component, the air-cooled heat exchanger, a second control valve, and an air intake of the compressor are sequentially connected along the exhaust port of the compressor to form a heating circuit; The hot water heat exchanger, the second throttling component, the third control valve, the cold water heat exchanger, and the air intake of the compressor are sequentially connected along the exhaust port of the compressor to form a combined cooling and heating circuit; The first control valve, the second control valve and the third control valve are all one-way solenoid valves, wherein: the first control valve and the second control valve are respectively arranged between the compressor and the air-cooled heat exchanger, the inlet end of the first control valve and the outlet end of the second control valve are respectively connected to the exhaust end of the compressor; the outlet end of the third control valve is connected to the cold water heat exchanger.

2. The four-pipe system according to claim 1, characterized in that: The first throttling component and the second throttling component are both electronic expansion valves.

3. The four-pipe system according to claim 1, characterized in that: The water outlet end of the cold water heat exchanger and the water outlet end of the hot water heat exchanger are both installed with temperature sensors, and the temperature sensors are used to detect the corresponding cold water outlet temperature and hot water outlet temperature.

4. A method for controlling a four-pipe system, for controlling the four-pipe system according to any one of claims 1 to 3, characterized in that: include: Obtain the user's cooling and heating load requirements; Determining the operating mode of the four-pipe system according to the user's cooling and heating load requirements, wherein the operating modes include cooling mode, heating mode, and combined cooling and heating mode; The operation of the four-control system is controlled according to the operation mode.

5. The control method of the four-control system according to claim 4, characterized in that: The operating modes are: In cooling mode, the first control valve, the first throttling component and the third control valve are controlled to be open, and the second control valve and the second throttling component are controlled to be closed; In the heating mode, the second throttling component, the first throttling component, and the second control valve are controlled to be open, and the first control valve and the third control valve are controlled to be closed; In the combined cooling and heating mode, the second throttling component and the third control valve are controlled to be open, and the first control valve, the second control valve and the first throttling component are controlled to be closed.

6. The control method of the four-control system according to claim 4, characterized in that: Determining the operating mode of the four-pipe system according to the user's cooling and heating load requirements includes: If the user's cooling and heating load demand is cooling only, determining that the four-pipe system operates in cooling mode; If the user's cooling and heating load demand is heating only, the four-pipe system is determined to operate in heating mode; If the user's cooling and heating load demand is simultaneous cooling and heating, it is determined that the four-pipe system operates in the combined cooling and heating mode.

7. The control method of the four-control system according to claim 4, characterized in that: The operating mode is the combined cooling and heating mode, and when the cooling capacity needs to be reduced separately, the first throttling component is controlled to be opened and the opening value is initially opened, the air-cooled heat exchanger and the second control valve are opened, and the opening of the first throttling component is adjusted according to the target water temperature on the cold water side of the cold water heat exchanger.

8. The control method of the four-control system according to claim 7, characterized in that: Adjusting the opening of the first throttling component according to the target water temperature on the cold water side of the cold water heat exchanger includes: detecting the actual water temperature on the cold water side of the cold water heat exchanger; comparing the actual water temperature on the cold water side with the target water temperature on the cold water side; The opening degree of the first throttle component is adjusted according to the comparison result.

9. The control method of the four-control system according to claim 8, characterized in that: The adjusting the opening of the first throttling component according to the comparison result includes: If the actual water temperature on the cold water side is lower than the target water temperature on the cold water side, adjusting and increasing the opening of the first throttling component; If the actual water temperature on the cold water side is higher than the target water temperature on the cold water side, adjusting and reducing the opening of the first throttling component; If the actual water temperature on the cold water side is equal to the target water temperature on the cold water side, the opening of the first throttle component is maintained.

10. The control method of the four-pipe system according to claim 9, characterized in that: The adjusting and increasing the opening of the first throttle component includes: gradually increasing the opening of the first throttling component according to a preset ratio or step size, and determining whether the actual water temperature on the cold water side is equal to the target water temperature on the cold water side after the target opening obtained after each adjustment of the preset ratio or step size persists for a preset time; Determine whether to continue adjusting the opening of the electronic expansion valve based on the judgment result.

11. The control method of the four-pipe system according to claim 9, characterized in that: The adjusting and reducing the opening of the first throttle component includes: gradually reducing the opening of the first throttling component according to a preset ratio or step size, and determining whether the actual water temperature on the cold water side is equal to the target water temperature on the cold water side after the target opening obtained after each adjustment of the preset ratio or step size lasts for a preset time; Determine whether to continue adjusting the opening of the electronic expansion valve based on the judgment result.

12. The control method of the four-control system according to claim 10 or 11, characterized in that: The step of determining whether to continue adjusting the opening of the electronic expansion valve according to the judgment result includes: When the judgment result indicates that the actual water temperature on the cold water side is not equal to and lower than the target water temperature on the cold water side, determining to continue adjusting and increase the opening of the first throttling component; When the judgment result indicates that the actual water temperature on the cold water side is not equal to and higher than the target water temperature on the cold water side, determining to continue adjusting and reduce the opening of the first throttling component; When the judgment result indicates that the actual cold water temperature is equal to the target cold water temperature, it is determined to stop adjusting the opening of the first throttle component.

13. The control method of the four-pipe system according to claim 7, characterized in that: Before adjusting the opening of the first throttling component according to the target water temperature on the cold water side of the cold water heat exchanger, the compressor is first controlled to load and unload to meet the water temperature requirement on the hot water side of the hot water heat exchanger.

14. The control method of the four-pipe system according to claim 4, characterized in that: When the operating mode is the combined cooling and heating mode and the heating amount needs to be reduced separately, the first throttling component is controlled to be opened and the opening value is initially opened, the air-cooled heat exchanger and the first control valve are opened, and the opening of the first throttling component is adjusted according to the target water temperature on the hot water side of the hot water heat exchanger.

15. The control method of the four-pipe system according to claim 14, characterized in that: Adjusting the opening of the first throttling component according to the target water temperature on the hot water side of the hot water heat exchanger includes: detecting the actual water temperature on the hot water side of the hot water heat exchanger; comparing the actual water temperature on the hot water side with the target water temperature on the hot water side; The opening degree of the first throttle component is adjusted according to the comparison result.

16. The control method of the four-pipe system according to claim 15, characterized in that: The adjusting the opening of the first throttling component according to the comparison result includes: If the actual water temperature on the hot water side is lower than the target water temperature on the hot water side, adjusting and reducing the opening of the first throttling component; If the actual water temperature on the hot water side is higher than the target water temperature on the hot water side, adjusting and increasing the opening of the first throttling component; If the actual water temperature on the hot water side is equal to the target water temperature on the hot water side, the opening of the first throttling component is maintained.

17. The control method of the four-pipe system according to claim 16, characterized in that: The adjusting and reducing the opening of the first throttle component includes: gradually reducing the opening of the first throttling component according to a preset ratio or step size, and determining whether the actual water temperature on the hot water side is equal to the target water temperature on the hot water side after the target opening obtained after each adjustment of the preset ratio or step size lasts for a preset time; Determine whether to continue adjusting the opening of the electronic expansion valve based on the judgment result.

18. The control method of the four-pipe system according to claim 16, characterized in that: The adjusting and increasing the opening of the first throttle component includes: gradually increasing the opening of the first throttling component according to a preset ratio or step size, and determining whether the actual water temperature on the hot water side is equal to the target water temperature on the hot water side after the target opening obtained after each adjustment of the preset ratio or step size persists for a preset time; Determine whether to continue adjusting the opening of the electronic expansion valve based on the judgment result.

19. The control method of the four-control system according to claim 17 or 18, characterized in that: The step of determining whether to continue adjusting the opening of the electronic expansion valve according to the judgment result includes: When the judgment result indicates that the actual water temperature on the hot water side is not equal to and lower than the target water temperature on the hot water side, determining to continue adjusting and reduce the opening of the first throttling component; When the judgment result indicates that the actual water temperature on the hot water side is not equal to but higher than the target water temperature on the hot water side, determining to continue adjusting and increase the opening of the first throttling component; When the judgment result indicates that the actual water temperature on the hot water side is equal to the target water temperature on the hot water side, it is determined to stop adjusting the opening of the first throttle component.

20. The control method of the four-pipe system according to claim 14, characterized in that: Before adjusting the opening of the first throttling component according to the target water temperature on the hot water side of the hot water heat exchanger, the compressor is first controlled to load and unload to meet the water temperature requirement on the cold water side of the cold water heat exchanger.

21. A control device for a four-pipe system, based on the four-pipe system according to any one of claims 1 to 3, characterized in that: include: Acquisition module, used to obtain the user's cooling and heating load requirements; a determination module, configured to determine an operating mode of the four-pipe system according to a user's cooling and heating load requirements; A control module is used to control the operation of the four-control system according to the operation mode.

22. The control device of the four-pipe system according to claim 21, characterized in that: The determination module includes: The first detection unit is used to detect the actual water temperature on the cold water side of the cold water heat exchanger; a first comparing unit, configured to compare the actual water temperature on the cold water side with the target water temperature on the cold water side; The first regulating unit is used to regulate the opening of the first throttling component according to a comparison result between the actual water temperature on the cold water side and the target water temperature on the cold water side.

23. The control device of the four-pipe system according to claim 22, characterized in that: The determining module further includes: The second detection unit is used to detect the actual water temperature on the hot water side of the hot water heat exchanger; a second comparing unit, configured to compare the actual water temperature on the hot water side with the target water temperature on the hot water side; The second regulating unit is configured to regulate the opening of the first throttling component according to a comparison result between the actual water temperature on the hot water side and the target water temperature on the hot water side.

24. An air conditioner, characterized in that: include: The four-pipe system and controller according to any one of claims 1 to 3, wherein the four-pipe system and the controller are connected; The controller is used to execute the control method of the four-control system described in any one of claims 4-20 above.

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