Water source multi-split air conditioning system and control method thereof

Abstract

The invention relates to a water source multi-split air conditioning system and a control method thereof. The water source multi-split air conditioning system comprises a control module, a refrigerant circulating pipeline, an outdoor heat exchange module and an indoor heat exchange module, wherein the outdoor heat exchange module and the indoor heat exchange module are arranged on the refrigerant circulating pipeline; wherein the outdoor heat exchange module has multiple heat exchange modes, and different types of secondary refrigerants are adopted in different heat exchange modes; the outdoor heat exchange module is electrically connected with the control module so that the control module can be used for controlling the outdoor heat exchange module to be switched to a target heat exchange mode to conduct heat exchange on refrigerants in the refrigerant circulating pipeline according to the obtained geographic position of the water source multi-split air conditioning system and the obtained operation mode of the water source multi-split air conditioning system. The target heat exchange mode refers to the heat exchange mode with the highest energy efficiency under the condition that the outdoor heat exchange module is not frozen to crack, and the target heat exchange mode belongs to multiple heat exchange modes. Therefore, the anti-freezing capability and the overall energy efficiency of the water source multi-split air conditioning system can be considered at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, in particular to a water-source multi-connected air conditioning system and a control method thereof. BACKGROUND

[0002] ‌The outdoor unit of the water-source multi-connected air conditioning system usually uses a water-cooled plate heat exchanger for heat exchange. The water-cooled plate heat exchanger is prone to freeze cracking in a low-temperature environment, which causes water to seep into the refrigerant pipeline. However, once the water-cooled plate heat exchanger freezes and cracks, a series of complex maintenance operations such as draining the refrigerant in the water-source multi-connected air conditioning system, blowing dry, replacing the heat exchanger, and refilling the refrigerant are required, which not only increases the maintenance cost, but also has the risk of wet compression damage of the compressor caused by water residue.

[0003] In order to solve the above problems, the existing technology usually uses a glycol solution to replace water to prevent the water-cooled plate heat exchanger from freezing and cracking. However, although the glycol solution can enhance the anti-freezing ability of the water-cooled plate heat exchanger to some extent, it will also significantly reduce the heat exchange efficiency of the water-cooled plate heat exchanger, thereby affecting the overall energy efficiency of the water-source multi-connected air conditioning system. Therefore, how to simultaneously consider the anti-freezing ability and overall energy efficiency of the water-source multi-connected air conditioning system has become a technical problem to be solved. SUMMARY

[0004] The present application provides a water-source multi-connected air conditioning system and a control method thereof to solve the problem that the anti-freezing ability and overall energy efficiency of the water-source multi-connected air conditioning system cannot be simultaneously considered in the prior art.

[0005] In a first aspect, the embodiments of the present application provide a water-source multi-connected air conditioning system, which comprises a control module, a refrigerant circulation pipeline, an outdoor heat exchange module and an indoor heat exchange module arranged on the refrigerant circulation pipeline. The outdoor heat exchange module has multiple heat exchange modes, and different types of cold carriers are used in different heat exchange modes. The outdoor heat exchange module is electrically connected to the control module, so as to control the outdoor heat exchange module to switch to a target heat exchange mode for heat exchange of the refrigerant in the refrigerant circulation pipeline by using the control module according to the obtained geographical position of the water-source multi-connected air conditioning system and the operating mode of the water-source multi-connected air conditioning system. The target heat exchange mode refers to the heat exchange mode with the highest energy efficiency without freeze cracking of the outdoor heat exchange module, and the target heat exchange mode belongs to the multiple heat exchange modes.

[0006] Optionally, the outdoor heat exchange module comprises a first cold carrier pipeline, a second cold carrier pipeline, a third cold carrier pipeline and a fourth cold carrier pipeline connected in sequence, and a first heat exchange unit, a second heat exchange unit, a first cold carrier providing unit and a second cold carrier providing unit; The first heat exchange unit is arranged on the refrigerant circulation pipeline and the first cold carrier pipeline to exchange heat between the cold carrier in the first cold carrier pipeline and the refrigerant in the refrigerant circulation pipeline. The second heat exchange unit is arranged on the second cold carrier pipeline and the third cold carrier pipeline to exchange heat between the cold carrier in the second cold carrier pipeline and the cold carrier in the third cold carrier pipeline. The first cold carrier providing unit is arranged on the fourth cold carrier pipeline, and the second cold carrier providing unit is arranged on the second cold carrier pipeline.

[0007] Optionally, the outdoor heat exchange module further comprises a first water pump, a second water pump and a plurality of control valves. The first water pump is arranged on the first cold carrier pipeline, the second water pump is arranged on the third cold carrier pipeline, and the plurality of control valves are arranged on the second cold carrier pipeline, the third cold carrier pipeline and the pipeline between the second cold carrier pipeline and the third cold carrier pipeline. The first water pump, the second water pump and the plurality of control valves are electrically connected with the control module, so that the control module controls the working state of the first water pump, the second water pump and the plurality of control valves to switch to the state corresponding to the target heat exchange mode according to the obtained geographical position of the water source multi-split air conditioning system and the operating mode of the water source multi-split air conditioning system.

[0008] Optionally, the plurality of control valves comprise a first control valve, a second control valve, a third control valve, a fourth control valve, a fifth control valve and a sixth control valve. The first control valve is arranged on the pipeline between the first end of the second cold carrier pipeline and the first end of the third cold carrier pipeline. The second control valve is arranged on the pipeline between the second end of the second cold carrier pipeline and the second end of the third cold carrier pipeline. The third control valve and the fourth control valve are both arranged on the second cold carrier pipeline and are located on the two sides of the second heat exchange unit respectively. The fifth control valve and the sixth control valve are both arranged on the third cold carrier pipeline and are located on the two sides of the second heat exchange unit respectively.

[0009] Optionally, the plurality of heat exchange modes comprises a first heat exchange mode, a second heat exchange mode and a third heat exchange mode, the first heat exchange mode refers to the heat exchange mode when the operation mode of the water source VRF air conditioning system is a cooling mode, the second heat exchange mode refers to the heat exchange mode when the operation mode of the water source VRF air conditioning system is a heating mode and the geographical location where the water source VRF air conditioning system is located is a non-severe cold region, and the third heat exchange mode refers to the heat exchange mode when the operation mode of the water source VRF air conditioning system is a heating mode and the geographical location where the water source VRF air conditioning system is located is a severe cold region. In the case that the target heat exchange mode is the first heat exchange mode or the second heat exchange mode, the first control valve, the second control valve and the first water pump are opened, and the third control valve, the fourth control valve, the fifth control valve, the sixth control valve and the second water pump are closed. In the case that the target heat exchange mode is the third heat exchange mode, the first control valve and the second control valve are closed, and the third control valve, the fourth control valve, the fifth control valve, the sixth control valve, the first water pump and the second water pump are opened.

[0010] Optionally, the outdoor heat exchange module further comprises a first temperature sensing bulb and a second temperature sensing bulb. The first temperature sensing bulb and the second temperature sensing bulb are both arranged on the first secondary refrigerant pipeline and located on both sides of the first heat exchange unit. The first temperature sensing bulb and the second temperature sensing bulb are both electrically connected with the control module, so as to determine whether the outdoor heat exchange module is cracked by the control module according to the secondary refrigerant temperature collected by the first temperature sensing bulb and the second temperature sensing bulb.

[0011] Optionally, the outdoor heat exchange module further comprises a flow regulating valve. The flow regulating valve is arranged on the pipeline between the third secondary refrigerant pipeline and the fourth secondary refrigerant pipeline. The flow regulating valve is electrically connected with the control module, so as to adjust the opening of the flow regulating valve by the control module according to the secondary refrigerant temperature collected by the first temperature sensing bulb and the second temperature sensing bulb.

[0012] Optionally, the first secondary refrigerant providing unit is a cooling water or hot water providing unit, and the second secondary refrigerant providing unit is a glycol solution providing unit.

[0013] Optionally, the first heat exchange unit and the second heat exchange unit are both plate heat exchangers.

[0014] Optionally, the water source multi-connected air conditioning system further comprises a compressor and a low pressure sensor located at a suction port of the compressor. The low pressure sensor is electrically connected to the control module, so that the control module adjusts the operating frequency of the compressor according to the pressure value collected by the low pressure sensor.

[0015] In a second aspect, the embodiments of the present application further provide a control method of a water source multi-connected air conditioning system, which is applied to the water source multi-connected air conditioning system of the first aspect, and the method comprises: obtaining a geographical location where the water source multi-connected air conditioning system is located and an operating mode of the water source multi-connected air conditioning system; controlling the outdoor heat exchange module to switch to a target heat exchange mode to exchange heat with refrigerant in a refrigerant circulation pipeline according to the obtained geographical location where the water source multi-connected air conditioning system is located and the operating mode of the water source multi-connected air conditioning system, wherein the target heat exchange mode is a heat exchange mode with the highest energy efficiency without the outdoor heat exchange module being frozen.

[0016] Optionally, the controlling the outdoor heat exchange module to switch to the target heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline according to the obtained geographical location where the water source multi-connected air conditioning system is located and the operating mode of the water source multi-connected air conditioning system comprises: in a case where the operating mode of the water source multi-connected air conditioning system is a refrigeration mode, controlling the outdoor heat exchange module to switch to a first heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline; and / or, in a case where the operating mode of the water source multi-connected air conditioning system is a heating mode and the geographical location where the water source multi-connected air conditioning system is located is a non-severe cold region, controlling the outdoor heat exchange module to switch to a second heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline; and / or, in a case where the operating mode of the water source multi-connected air conditioning system is the heating mode and the geographical location where the water source multi-connected air conditioning system is located is a severe cold region, controlling the outdoor heat exchange module to switch to a third heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline.

[0017] Optionally, the water source multi-connected air conditioning system further comprises a compressor and a low pressure sensor located at a suction port of the compressor; and the method further comprises: in a case where the outdoor heat exchange module is controlled to switch to the second heat exchange mode or the third heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline, obtaining a pressure value collected by the low pressure sensor; determining whether the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the secondary refrigerant every first preset time length and whether the duration is greater than a second preset time length; in a case where the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the secondary refrigerant and the duration is greater than the second preset time length, reducing the operating frequency of the compressor until a preset condition is met, and stopping reducing the operating frequency of the compressor, wherein the preset condition is that the operating frequency of the compressor has been reduced to a minimum frequency or the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the secondary refrigerant.

[0018] Optionally, the method further comprises: in a case where the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the secondary refrigerant and a difference between the pressure value collected by the low-pressure sensor and the pressure value corresponding to the freezing temperature of the secondary refrigerant is greater than a preset threshold, reducing or increasing the operating frequency of the compressor according to the operating requirement of the water-source VRF air conditioning system.

[0019] In a third aspect, the embodiments of the present application further provide a computer readable storage medium having stored thereon a computer program, which, when executed by a processor, implements the control method of the water-source VRF air conditioning system according to the second aspect.

[0020] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art: the water-source VRF air conditioning system provided by the embodiments of the present application comprises a control module, a refrigerant circulation pipeline, an outdoor heat exchange module and an indoor heat exchange module arranged on the refrigerant circulation pipeline; wherein the outdoor heat exchange module has multiple heat exchange modes, and the types of the secondary refrigerants used in different heat exchange modes are different; the outdoor heat exchange module is electrically connected with the control module, so as to control the outdoor heat exchange module to switch to a target heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline by using the control module according to the acquired geographical position of the water-source VRF air conditioning system and the operating mode of the water-source VRF air conditioning system, the target heat exchange mode refers to the heat exchange mode with the highest energy efficiency without the outdoor heat exchange module being frozen and cracked, and the target heat exchange mode belongs to the multiple heat exchange modes. In the above manner, the water-source VRF air conditioning system can determine the target heat exchange mode from the multiple heat exchange modes of the outdoor heat exchange module according to the geographical position and the operating mode thereof, and control the outdoor heat exchange module to switch to the target heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline, so that the energy efficiency is the highest without the outdoor heat exchange module being frozen and cracked, thereby playing a role of simultaneously taking into account the anti-freezing ability and the overall energy efficiency of the water-source VRF air conditioning system. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments consistent with the application and, together with the description, serve to explain the principles of the application.

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the accompanying drawings required to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, for those skilled in the field, under the premise of no creative labor, other drawings can also be obtained according to these drawings.

[0023] One or more embodiments are illustrated by way of example in the drawings that are not intended to be limiting of the application, and the same or similar reference numerals designate similar elements throughout the several views of the drawings, and wherein:

[0024] Figure 1 A structural schematic diagram of a water source multi-connected air conditioning system according to an embodiment of the present application; Figure 2 A flowchart of a control method of a water source multi-connected air conditioning system according to an embodiment of the present application; Figure 3 A running schematic diagram of a water source multi-connected air conditioning system in a first heat exchange mode according to an embodiment of the present application; Figure 4 A running schematic diagram of a water source multi-connected air conditioning system in a second heat exchange mode according to an embodiment of the present application; Figure 5 A running schematic diagram of a water source multi-connected air conditioning system in a third heat exchange mode according to an embodiment of the present application; Figure 6 A flowchart of a refrigerant type and regional climate type selection setting according to an embodiment of the present application; Figure 7 A flowchart of another control method of a water source multi-connected air conditioning system according to an embodiment of the present application.

[0025] Explanation of the reference numerals: 100, refrigerant circulation pipeline; 200, outdoor heat exchange module; 300, indoor heat exchange module; 211, first load carrier pipeline; 212, second load carrier pipeline; 213, third load carrier pipeline; 214, fourth load carrier pipeline; 221, first heat exchange unit; 222, second heat exchange unit; 231, first load carrier providing unit; 232, second load carrier providing unit; 241, first water pump; 242, second water pump; 251, first control valve; 252, second control valve; 253, third control valve; 254, fourth control valve; 255, fifth control valve; 256, sixth control valve; 261, first temperature sensing bulb; 262, second temperature sensing bulb; 271, flow regulating valve. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and superiorities of the embodiments of the present application clearer, the following will be a clear and complete description of the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0027] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, reference numerals and / or letters can be repeated in different examples in the present application. Such repetition is for the purpose of simplification and clarity, and does not in itself indicate a relationship between the various embodiments and / or settings discussed.

[0028] In order to solve the problem that the anti-freezing ability and overall energy efficiency of the water source multi-connected air conditioning system cannot be considered simultaneously in the prior art, the present application provides a water source multi-connected air conditioning system and a control method thereof, which can simultaneously consider the anti-freezing ability and overall energy efficiency of the water source multi-connected air conditioning system.

[0029] Referring to Figure 1 , Figure 1 A structural schematic diagram of a water source multi-connected air conditioning system provided by the embodiments of the present application is shown. As Figure 1 shown, the water source multi-connected air conditioning system comprises a control module (not shown in the figure), a refrigerant circulation pipeline 100, an outdoor heat exchange module 200 and an indoor heat exchange module 300 arranged on the refrigerant circulation pipeline 100; Among them, the outdoor heat exchange module 200 has multiple heat exchange modes, and the types of load carriers used in different heat exchange modes are different; The outdoor heat exchange module 200 is electrically connected with the control module, so as to control the outdoor heat exchange module 200 to switch to a target heat exchange mode to exchange heat of the refrigerant in the refrigerant circulation pipeline 100 according to the obtained geographical position of the water source VRF air conditioning system and the operation mode of the water source VRF air conditioning system by the control module. The target heat exchange mode refers to a heat exchange mode with the highest energy efficiency without frost crack of the outdoor heat exchange module 200, and the target heat exchange mode belongs to multiple heat exchange modes.

[0030] Specifically, the indoor heat exchange module 300 refers to a heat exchange module in an indoor unit of the water source VRF air conditioning system. The number of the indoor heat exchange module 300 corresponds to the number of the indoor units, that is, one indoor heat exchange module 300 is arranged in each indoor unit. The indoor heat exchange module 300 is used to exchange heat of the refrigerant in the refrigerant circulation pipeline 100 and indoor air, so as to achieve the purpose of indoor heating or indoor cooling.

[0031] The outdoor heat exchange module 200 refers to a heat exchange module in an outdoor unit of the water source VRF air conditioning system. Multiple heat exchange units are arranged in the outdoor heat exchange module 200. The working states of the multiple heat exchange units are different in different heat exchange modes, and the types of the cold carriers used are also different. Because the freezing temperatures of different cold carriers are different (that is, the temperatures at which frost cracking occurs are different), and the heat exchange efficiencies are different, a heat exchange mode that can prevent frost cracking and improve energy efficiency can be selected according to the geographical position of the water source VRF air conditioning system and the operation mode of the water source VRF air conditioning system, so as to avoid the drawbacks of the conventional outdoor heat exchange module 200 that can only consider frost prevention or energy efficiency.

[0032] It should be noted that the number of the heat exchange units in the outdoor heat exchange module 200 can be set according to actual needs, such as 2, 3, etc., which is not limited in the embodiments of the present application. The outdoor heat exchange module 200 is used to exchange heat of the refrigerant in the refrigerant circulation pipeline 100 and the cold and heat source side cold carrier, so as to achieve the purpose of heating or cooling the refrigerant. The refrigerant refers to a medium that directly absorbs and releases heat through phase change (gaseous-liquid phase change) to realize energy transfer, such as ammonia, freon, carbon dioxide, etc. The cold carrier refers to a medium that transfers energy of the refrigerant through sensible heat transfer (that is, temperature change) without phase change, such as water, ethylene glycol, propylene glycol, methanol, etc.

[0033] The operation mode of the water source multi-connected air conditioning system can include a cooling mode and a heating mode. In the cooling mode (outdoor temperature is generally high), the problem of frost cracking of the outdoor heat exchange module 200 does not need to be considered, but in the heating mode (outdoor temperature is generally low), a comprehensive judgment can be made in combination with the geographical location where the water source multi-connected air conditioning system is located. For example, if the geographical location where the water source multi-connected air conditioning system is located is a severe cold region (such as an area where the outdoor temperature is usually below 0°C), the problem of frost cracking of the outdoor heat exchange module 200 needs to be considered. If the geographical location where the water source multi-connected air conditioning system is located is a non-severe cold region (such as an area where the outdoor temperature is usually above 0°C), the problem of frost cracking of the outdoor heat exchange module 200 does not need to be considered, and thus the problem of energy efficiency improvement of the water source multi-connected air conditioning system can be focused on.

[0034] In this way, the water source multi-connected air conditioning system can determine the target heat exchange mode from the multiple heat exchange modes of the outdoor heat exchange module 200 according to the geographical location and the operation mode of the system, and control the outdoor heat exchange module 200 to switch to the target heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline 100, so that the energy efficiency is the highest when the outdoor heat exchange module 200 does not crack, and the anti-freezing ability and overall energy efficiency of the water source multi-connected air conditioning system are simultaneously considered.

[0035] In an optional embodiment, continuing to refer to Figure 1 The outdoor heat exchange module 200 includes first, second, third, and fourth cold carrier pipelines 211, 212, 213, and 214 connected in cascade, and first and second heat exchange units 221 and 222, and first and second cold carrier providing units 231 and 232; The first heat exchange unit 221 is arranged on the refrigerant circulation pipeline 100 and the first cold carrier pipeline 211 to exchange heat between the cold carrier in the first cold carrier pipeline 211 and the refrigerant in the refrigerant circulation pipeline 100. The second heat exchange unit 222 is arranged on the second cold carrier pipeline 212 and the third cold carrier pipeline 213 to exchange heat between the cold carrier in the second cold carrier pipeline 212 and the cold carrier in the third cold carrier pipeline 213. The first cold carrier providing unit 231 is arranged on the fourth cold carrier pipeline 214, and the second cold carrier providing unit 232 is arranged on the second cold carrier pipeline 212.

[0036] Specifically, the first heat exchange unit 221 and the second heat exchange unit 222 can be plate heat exchangers, tube heat exchangers or other types of heat exchangers. The first cold carrier providing unit 231 is configured to provide the outdoor heat exchange module 200 with a first cold carrier, such as cold water / warm water, etc. The second cold carrier providing unit 232 is configured to provide the outdoor heat exchange module 200 with a second cold carrier, such as glycol, etc. As an optional embodiment, the first cold carrier providing unit 231 can be a water tank, a cooling tower, etc., and the second cold carrier providing unit 232 can be a glycol solution tank, etc.

[0037] In this way, the outdoor heat exchange module 200 can use the first heat exchange unit 221 and / or the second heat exchange unit 222 to exchange heat with the refrigerant in the refrigerant circulation pipeline 100, and achieve flexible switching among multiple heat exchange modes.

[0038] In an optional embodiment, the outdoor heat exchange module 200 further comprises a first water pump 241, a second water pump 242 and a plurality of control valves. The first water pump 241 is arranged on the first cold carrier pipeline 211, the second water pump 242 is arranged on the third cold carrier pipeline 213, and the plurality of control valves are arranged on the second cold carrier pipeline, the third cold carrier pipeline 213 and the pipeline between the second cold carrier pipeline and the third cold carrier pipeline 213. The first water pump 241, the second water pump 242 and the plurality of control valves are electrically connected to the control module, so as to control the working state of the first water pump 241, the second water pump 242 and the plurality of control valves to switch to a state corresponding to a target heat exchange mode according to the geographical location of the water source VRF air conditioning system and the operation mode of the water source VRF air conditioning system obtained by the control module.

[0039] Specifically, the number of control valves can be set according to actual needs, which is not limited herein. The control valve can be a ball valve, an electronic expansion valve, etc. The control valve can be connected to the control module, so as to realize the conduction and disconnection of different cold carrier pipelines under the control of the control module.

[0040] The first water pump 241 is arranged on the first cold carrier pipeline 211, and is configured to provide power for the cold carrier flowing into the first heat exchange unit 221. The second water pump 242 is arranged on the third cold carrier pipeline 213, and is configured to provide power for the cold carrier flowing into the second heat exchange unit 222.

[0041] Since the control module is electrically connected with the first water pump 241, the second water pump 242 and the plurality of control valves respectively, the control module can control the working state of the first water pump 241, the second water pump 242 and the plurality of control valves to switch to the state corresponding to the target heat exchange mode according to the obtained geographical position of the water source VRF air conditioning system and the operation mode of the water source VRF air conditioning system, so that the outdoor heat exchange module 200 can perform heat exchange on the refrigerant in the refrigerant circulation pipeline 100 in the target heat exchange mode, while taking into account the anti-freezing ability and overall energy efficiency of the water source VRF air conditioning system.

[0042] In an optional embodiment, the plurality of control valves include a first control valve 251, a second control valve 252, a third control valve 253, a fourth control valve 254, a fifth control valve 255 and a sixth control valve 256. The first control valve 251 is arranged on the pipeline between the first end of the second carrier refrigerant pipeline 212 and the first end of the third carrier refrigerant pipeline 213. The second control valve 252 is arranged on the pipeline between the second end of the second carrier refrigerant pipeline 212 and the second end of the third carrier refrigerant pipeline 213. The third control valve 253 and the fourth control valve 254 are both arranged on the second carrier refrigerant pipeline 212 and are located on the two sides of the second heat exchange unit 222 respectively. The fifth control valve 255 and the sixth control valve 256 are both arranged on the third carrier refrigerant pipeline 213 and are located on the two sides of the second heat exchange unit 222 respectively.

[0043] In this way, when the first control valve 251 and the second control valve 252 are both opened, and the third control valve 253, the fourth control valve 254, the fifth control valve 255 and the sixth control valve 256 are all closed, the second carrier refrigerant pipeline 212 and the third carrier refrigerant pipeline 213 are in the off state, and the first carrier refrigerant pipeline 211 and the fourth carrier refrigerant pipeline 214 are in the on state. At this time, the first carrier refrigerant provided by the first carrier refrigerant providing unit 231 flows from the first carrier refrigerant pipeline 211 to the fourth carrier refrigerant pipeline 214, and flows through the first heat exchange unit 221 to perform heat exchange with the refrigerant in the refrigerant circulation pipeline 100. That is, at this time, the water source VRF air conditioning system directly uses the first carrier refrigerant (i.e. water) to perform heat exchange on the refrigerant in the refrigerant circulation pipeline 100, thereby improving the overall energy efficiency of the water source VRF air conditioning system.

[0044] When the first control valve 251 and the second control valve 252 are both closed, and the third control valve 253, the fourth control valve 254, the fifth control valve 255 and the sixth control valve 256 are all opened, the first coolant pipeline 211 and the second coolant pipeline 212 form a first heat exchange circulation loop, and the third coolant pipeline 213 and the fourth coolant pipeline 214 form a second heat exchange circulation loop. At this time, the second coolant provided by the second coolant providing unit 232 flows from the second coolant pipeline 212 into the first coolant pipeline 211, and flows through the first heat exchange unit 221 to exchange heat with the refrigerant in the refrigerant circulation pipeline 100. At the same time, the first coolant provided by the first coolant providing unit 231 flows from the fourth coolant pipeline 214 into the third coolant pipeline 213, and flows through the second heat exchange unit 222 to exchange heat with the second refrigerant in the first heat exchange circulation loop. That is, at this time, the water source VRF air conditioning system uses the first coolant (i.e. water) to perform first-stage heat exchange, and uses the second coolant (i.e. ethylene glycol) to perform second-stage heat exchange, which not only prevents the outdoor heat exchange module 200 from being frozen and cracked, but also improves the heat exchange efficiency of the outdoor heat exchange module 200 as much as possible.

[0045] In an optional embodiment, the plurality of heat exchange modes includes a first heat exchange mode, a second heat exchange mode and a third heat exchange mode. The first heat exchange mode refers to the heat exchange mode when the operation mode of the water source VRF air conditioning system is a cooling mode. The second heat exchange mode refers to the heat exchange mode when the operation mode of the water source VRF air conditioning system is a heating mode, and the geographical location of the water source VRF air conditioning system is a non-severe cold region. The third heat exchange mode refers to the heat exchange mode when the operation mode of the water source VRF air conditioning system is a heating mode, and the geographical location of the water source VRF air conditioning system is a severe cold region. When the target heat exchange mode is the first heat exchange mode or the second heat exchange mode, the first control valve 251, the second control valve 252 and the first water pump 241 are opened, and the third control valve 253, the fourth control valve 254, the fifth control valve 255, the sixth control valve 256 and the second water pump 242 are closed. When the target heat exchange mode is the third heat exchange mode, the first control valve 251 and the second control valve 252 are closed, and the third control valve 253, the fourth control valve 254, the fifth control valve 255, the sixth control valve 256, the first water pump 241 and the second water pump 242 are opened.

[0046] Specifically, the first heat exchange mode is used when the operation mode of the water source VRF air conditioning system is a cooling mode. The first heat exchange mode refers to a mode of directly using cold water to exchange heat with the refrigerant in the refrigerant circulation pipeline 100.

[0047] The second heat exchange mode is used in the case that the operation mode of the water source VRF air conditioning system is a heating mode and the geographical location of the water source VRF air conditioning system is a non-severe cold region. The second heat exchange mode refers to a mode of directly using hot water to exchange heat with the refrigerant in the refrigerant circulation pipeline 100.

[0048] The third heat exchange mode is used in the case that the operation mode of the water source VRF air conditioning system is a heating mode and the geographical location of the water source VRF air conditioning system is a severe cold region. The third heat exchange mode refers to a mode of using hot water to exchange heat with the glycol solution in the first stage, and using the glycol solution to exchange heat with the refrigerant in the refrigerant circulation pipeline 100 in the second stage.

[0049] Therefore, the control module can control the switching states of the first water pump 241, the second water pump 242, the first control valve 251, the second control valve 252, the third control valve 253, the fourth control valve 254, the fifth control valve 255, and the sixth control valve 256 according to the target heat exchange mode currently required by the outdoor heat exchange module 200, so as to switch the heat exchange mode of the outdoor heat exchange module 200 to the target heat exchange mode.

[0050] In an optional embodiment, the outdoor heat exchange module 200 further comprises a first temperature sensing bag 261 and a second temperature sensing bag 262. The first temperature sensing bag 261 and the second temperature sensing bag 262 are arranged on the first cold carrier pipeline 211 and located on both sides of the first heat exchange unit 221. The first temperature sensing bag 261 and the second temperature sensing bag 262 are electrically connected to the control module, so as to determine whether the outdoor heat exchange module 200 is cracked according to the carrier temperature collected by the first temperature sensing bag 261 and the second temperature sensing bag 262.

[0051] Specifically, the first temperature sensing bag 261 and the second temperature sensing bag 262 are arranged on both sides of the first heat exchange unit 221, so that the first temperature sensing bag 261 and the second temperature sensing bag 262 can collect the temperature of the carrier flowing into the first heat exchange unit 221 and the temperature of the carrier flowing out of the first heat exchange unit 221, facilitate the control module to timely understand the temperature of the carrier flowing into the first heat exchange unit 221 and the temperature of the carrier flowing out of the first heat exchange unit 221, and determine whether the outdoor heat exchange module 200 will be cracked according to the obtained temperature, thereby effectively avoiding the case that the outdoor heat exchange module 200 is cracked.

[0052] In an optional embodiment, the outdoor heat exchange module 200 further comprises a flow regulating valve 271. The flow regulating valve 271 is arranged on a pipeline between the third refrigerant pipeline 213 and the fourth refrigerant pipeline 214. The flow regulating valve 271 is electrically connected with the control module, so that the control module adjusts the opening of the flow regulating valve 271 according to the refrigerant temperature collected by the first temperature sensing bulb 261 and the second temperature sensing bulb 262.

[0053] Specifically, the flow regulating valve 271 is used to regulate the flow of the refrigerant in the outdoor heat exchange module 200.

[0054] When the refrigerant temperature collected by the first temperature sensing bulb 261 and the second temperature sensing bulb 262 is too high or too low, the control module can adjust the opening of the flow regulating valve 271 to reduce or increase the flow of the refrigerant flowing into the first heat exchange unit 221 and / or the second heat exchange unit 222, thereby reducing or increasing the heat exchange efficiency of the outdoor heat exchange module 200.

[0055] In an optional embodiment, the first refrigerant providing unit 231 is a chilled water or hot water providing unit, and the second refrigerant providing unit 232 is a glycol solution providing unit.

[0056] Specifically, the first refrigerant providing unit 231 can be a chilled water or hot water providing unit, i.e., the first refrigerant providing unit 231 is used to provide pure water as the refrigerant for the outdoor heat exchange module 200. The second refrigerant providing unit 232 can be a glycol solution providing unit, i.e., the second refrigerant providing unit 232 is used to provide glycol solution as the refrigerant for the outdoor heat exchange module 200. It should be noted that the initial freezing temperature tf of pure water and glycol solution with different concentrations is different. Since the physical properties of pure water change relatively small at different temperatures, the initial freezing temperature tf of pure water can be calculated as 0℃. The initial freezing temperature tf of glycol solution with different concentrations is shown in the following table:

[0057] As can be seen, the initial freezing temperature tf of glycol solution is generally lower than that of pure water, so when the water source multi-split air conditioning system operates in the heating mode in a severe cold region, pure water can be used for primary heat exchange, and glycol solution can be used for secondary heat exchange, which can effectively prevent the outdoor heat exchange module 200 from being frozen and cracked. When the water source multi-split air conditioning system operates in the cooling mode in a severe cold region or operates in any mode in a non-severe cold region, pure water can be directly used for heat exchange without using glycol solution for heat exchange, which can effectively improve the overall energy efficiency of the water source multi-split air conditioning system.

[0058] In an optional embodiment, the first heat exchange unit 221 and the second heat exchange unit 222 are both plate heat exchangers.

[0059] Specifically, the first heat exchange unit 221 and the second heat exchange unit 222 are both plate heat exchangers. The plate heat exchanger refers to a high-efficiency heat exchange device formed by a series of metal sheets with corrugated shapes. Heat exchange is achieved through thin rectangular channels formed between the sheets. The plate heat exchanger has the advantages of efficient heat transfer, compact structure, and convenient installation. Therefore, using the plate heat exchanger as the first heat exchange unit 221 and the second heat exchange unit 222 can improve the heat exchange efficiency of the outdoor heat exchange module 200 and reduce the occupied space of the outdoor heat exchange module 200.

[0060] In an optional embodiment, the water source multi-connected air conditioning system further comprises a compressor and a low-pressure sensor located at the suction port of the compressor. The low-pressure sensor is electrically connected to the control module to adjust the operating frequency of the compressor based on the pressure value collected by the low-pressure sensor.

[0061] Specifically, the low-pressure sensor is used to collect the pressure value at the suction port of the compressor. The pressure value detected by the low-pressure sensor can be converted into the saturation temperature of the refrigerant according to the properties of the refrigerant, and the calculation is performed in Celsius (℃) units.

[0062] When the control module controls the outdoor heat exchange module 200 to switch to the second heat exchange mode or the third heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline 100, it needs to obtain the pressure value collected by the low-pressure sensor and determine whether the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the secondary refrigerant every preset time interval (such as 40 seconds) and whether the duration is greater than the preset time interval (such as 10 minutes). If the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the secondary refrigerant and the duration is greater than the second preset time interval, the operating frequency of the compressor can be reduced until the operating frequency of the compressor has been reduced to the minimum frequency or the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the secondary refrigerant, and the reduction of the operating frequency of the compressor is stopped. In this way, the situation of freeze cracking can be avoided when the outdoor heat exchange module 200 uses pure water or glycol solution for heat exchange.

[0063] Referring to Figure 2 , Figure 2 is a flowchart of a control method of a water source multi-connected air conditioning system provided by an embodiment of the present application. As Figure 2 shown, the control method of the water source multi-connected air conditioning system is applied to the water source multi-connected air conditioning system in the foregoing embodiments. The method comprises: Step S201, obtaining the geographical location of the water source multi-connected air conditioning system and the operating mode of the water source multi-connected air conditioning system.

[0064] Specifically, the geographical location of the water source multi-connected air conditioning system can be selected by the maintenance personnel according to the installation area of the water source multi-connected air conditioning system, and the water source multi-connected air conditioning system is built-in with two selection items of "severe cold area" and "non-severe cold area". The operation mode of the water source multi-connected air conditioning system can be set by the user when using the water source multi-connected air conditioning system, such as heating mode operation, cooling mode operation, etc. In addition, before the water source multi-connected air conditioning system is first installed or when the subsequent load refrigerant is changed, the maintenance personnel needs to select the corresponding refrigerant type through the outdoor unit main control board button, and the refrigerant type and attribute have been built-in to the main control board program in advance. After the setting is completed, the water source multi-connected air conditioning system will retrieve the related parameters (such as the initial freezing temperature tf of the load refrigerant) according to the selection of the load refrigerant.

[0065] In step S202, according to the obtained geographical location of the water source multi-connected air conditioning system and the operation mode of the water source multi-connected air conditioning system, the outdoor heat exchange module is controlled to switch to the target heat exchange mode to exchange heat for the refrigerant in the refrigerant circulation pipeline, wherein the target heat exchange mode refers to the heat exchange mode with the highest energy efficiency without the outdoor heat exchange module being frozen and cracked.

[0066] Specifically, the target heat exchange mode can be a first heat exchange mode, a second heat exchange mode, or a third heat exchange mode, which needs to be determined according to the obtained geographical location of the water source multi-connected air conditioning system and the operation mode of the water source multi-connected air conditioning system.

[0067] After determining the target heat exchange mode, the control module in the water source multi-connected air conditioning system can control the outdoor heat exchange module to switch to the target heat exchange mode to exchange heat for the refrigerant in the refrigerant circulation pipeline.

[0068] In this way, the water source multi-connected air conditioning system can determine the target heat exchange mode from the multiple heat exchange modes of the outdoor heat exchange module according to the geographical location and the operation mode of the water source multi-connected air conditioning system, and control the outdoor heat exchange module to switch to the target heat exchange mode to exchange heat for the refrigerant in the refrigerant circulation pipeline, so that the energy efficiency is the highest without the outdoor heat exchange module being frozen and cracked, which plays a role of simultaneously considering the anti-freezing ability and the overall energy efficiency of the water source multi-connected air conditioning system.

[0069] In an optional embodiment, the step S202 of controlling the outdoor heat exchange module to switch to the target heat exchange mode to exchange heat for the refrigerant in the refrigerant circulation pipeline according to the obtained geographical location of the water source multi-connected air conditioning system and the operation mode of the water source multi-connected air conditioning system comprises: In the case that the operation mode of the water source multi-connected air conditioning system is the cooling mode, the outdoor heat exchange module is controlled to switch to the first heat exchange mode to exchange heat for the refrigerant in the refrigerant circulation pipeline; and / or, In a case where the operation mode of the water source VRF air conditioning system is the heating mode and the geographical location of the water source VRF air conditioning system is a non-severe cold region, the outdoor heat exchange module is controlled to switch to the second heat exchange mode to exchange heat for the refrigerant in the refrigerant circulation pipeline; and / or, In a case where the operation mode of the water source VRF air conditioning system is the heating mode and the geographical location of the water source VRF air conditioning system is a severe cold region, the outdoor heat exchange module is controlled to switch to the third heat exchange mode to exchange heat for the refrigerant in the refrigerant circulation pipeline.

[0070] Specifically, in a case where the operation mode of the water source VRF air conditioning system is the cooling mode, the outdoor heat exchange module is controlled to switch to the first heat exchange mode to exchange heat for the refrigerant in the refrigerant circulation pipeline, at this time, the flow directions of the refrigerant and the secondary refrigerant in the water source VRF air conditioning system can be as shown in FIG. 1. Figure 3 Specifically, in the cooling mode, the outdoor environment temperature is generally high, and the temperatures of the secondary refrigerant and the refrigerant passing through the first heat exchange unit in the outdoor unit are generally high, so there is basically no risk of freezing and cracking the first heat exchange unit, and therefore, in the cooling mode, the system is operated in the conventional mode, that is, the pure water is flowed into the first heat exchange unit to exchange heat for the refrigerant in the refrigerant circulation pipeline. At this time, the first control valve, the second control valve and the first water pump in the outdoor heat exchange module are opened, and the third control valve, the fourth control valve, the fifth control valve, the sixth control valve and the second water pump are closed.

[0071] In a case where the operation mode of the water source VRF air conditioning system is the heating mode and the geographical location of the water source VRF air conditioning system is a non-severe cold region, the outdoor heat exchange module is controlled to switch to the second heat exchange mode to exchange heat for the refrigerant in the refrigerant circulation pipeline, at this time, the flow directions of the refrigerant and the secondary refrigerant in the water source VRF air conditioning system can be as shown in FIG. 2. Figure 4 Specifically, in the non-severe cold region, the outdoor environment temperature is generally higher than 0°C, and the temperatures of the secondary refrigerant and the refrigerant passing through the first heat exchange unit in the outdoor unit are generally also higher than 0°C, so there is basically no risk of freezing and cracking the first heat exchange unit, and therefore, in the non-severe cold region, the system is operated in the conventional mode when heating, that is, the pure water is flowed into the first heat exchange unit to exchange heat for the refrigerant in the refrigerant circulation pipeline, so as to improve the heat exchange efficiency. At this time, the first control valve, the second control valve and the first water pump in the outdoor heat exchange module are opened, and the third control valve, the fourth control valve, the fifth control valve, the sixth control valve and the second water pump are closed. In this mode, the pure water is circulated on the secondary refrigerant side, which is the same as the conventional water source VRF air conditioning system.

[0072] When the water source multi-split air conditioning system is operating in heating mode and is located in a frigid region, the control module can control the outdoor heat exchange module to switch to the third heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipe. At this time, the flow direction of the refrigerant and the secondary cooling agent in the water source multi-split air conditioning system can be as follows: Figure 5 As shown. Specifically, when operating in heating mode in extremely cold regions, ethylene glycol solution serves as an intermediate heat exchanger (because the freezing point of ethylene glycol solution is much lower than that of water, it is less likely to freeze). The heat source, pure water, circulates through a second water pump, transferring heat to the ethylene glycol solution within the second heat exchange unit. The ethylene glycol solution is then driven to circulate by a first water pump, transferring heat to the refrigerant at the first heat exchange unit. The refrigerant then circulates within the air conditioning system. At this time, the first and second control valves in the outdoor heat exchange module are closed, while the third, fourth, fifth, and sixth control valves, as well as the first and second water pumps, are open.

[0073] Therefore, the on / off status of the first water pump, the second water pump, and each control valve is shown in the table below:

[0074] In this way, users can select the type of refrigerant (here, refrigerant mainly refers to ethylene glycol solution or pure water, and the types include ethylene glycol solutions of different concentrations, each concentration being a type) according to their needs and actual conditions. They can also select whether the region is a severely cold or non-severely cold area based on the local climate type. The water source multi-split air conditioning system will adaptively match the corresponding control strategy according to the user's selection.

[0075] In an optional embodiment, the water source multi-split air conditioning system further includes: a compressor and a low-pressure sensor located at the compressor's suction port; the method further includes: When the outdoor heat exchange module switches to the second or third heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline, the pressure value collected by the low-pressure sensor is obtained. Every first preset time interval, it is determined whether the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the solidification temperature of the refrigerant, and whether the duration is greater than the second preset time interval. If the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the refrigerant, and the duration is longer than the second preset duration, the operating frequency of the compressor is reduced until a preset condition is met, at which point the reduction of the compressor's operating frequency stops. The preset condition is that the operating frequency of the compressor has been reduced to the lowest frequency or the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the refrigerant.

[0076] Specifically, the first and second preset durations can be set according to actual needs, and no specific limitations are made here.

[0077] In the process that the control module controls the outdoor heat exchange module to switch to the second heat exchange mode or the third heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline, the control module can acquire the pressure value collected by the low-pressure sensor in real time or at a fixed time, and determine whether the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the carrier refrigerant every first preset time length, and whether the duration is greater than a second preset time length. If the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the carrier refrigerant, and the duration is greater than the second preset time length, it indicates that the carrier refrigerant has a risk of freezing, and at this time, the capacity of the unit needs to be limited, and the operating frequency of the compressor needs to be reduced until the preset condition is met, and the reduction of the operating frequency of the compressor is stopped, wherein the preset condition is that the operating frequency of the compressor has been reduced to the minimum frequency or the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the carrier refrigerant.

[0078] It should be noted that when the outdoor heat exchange module exchanges heat in the second heat exchange mode, the freezing temperature of the carrier refrigerant herein refers to the freezing temperature of pure water, such as 0℃. When the outdoor heat exchange module exchanges heat in the third heat exchange mode, the freezing temperature of the carrier refrigerant herein refers to the freezing temperature of the ethylene glycol solution. The amplitude of the frequency reduction of the compressor each time can be set according to actual conditions, such as reducing by 10% each time.

[0079] In the above manner, the risk of the first heat exchange unit cracking during heating operation of the water source multi-split air conditioning system can be avoided.

[0080] In an optional embodiment, the method further comprises: In the case that the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the carrier refrigerant, and the difference between the pressure value collected by the low-pressure sensor and the pressure value corresponding to the freezing temperature of the carrier refrigerant is greater than a preset threshold, the operating frequency of the compressor is reduced or increased according to the operating requirement of the water source multi-split air conditioning system.

[0081] Specifically, when the compressor is frequency-reduced, the pressure value collected by the low-pressure sensor will rise again. When the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the secondary refrigerant, and the difference between the pressure value collected by the low-pressure sensor and the pressure value corresponding to the freezing temperature of the secondary refrigerant is greater than a preset threshold, the compressor can be allowed to increase its operating frequency. For example, when the outdoor heat exchange module is performing heat exchange in the second heat exchange mode, the freezing temperature of the secondary refrigerant here refers to the freezing temperature of pure water (e.g. 0℃). When the pressure value collected by the low-pressure sensor rises to be higher than the freezing temperature of pure water by 5℃ or more, the compressor can be allowed to increase its frequency according to the actual capacity requirement. When the outdoor heat exchange module is performing heat exchange in the third heat exchange mode, the freezing temperature of the secondary refrigerant here refers to the freezing temperature of the glycol solution. When the pressure value collected by the low-pressure sensor rises to be higher than the freezing temperature of the glycol solution by 5℃ or more, the compressor can be allowed to increase its frequency according to the actual capacity requirement.

[0082] In this way, the compressor can be controlled to operate according to actual needs while ensuring that the outdoor heat exchange module does not freeze and crack.

[0083] In an optional embodiment, the setting of the type of secondary refrigerant and the type of regional climate is as shown in Figure 6 and specifically includes the following steps: Step S601: The user sets the type of secondary refrigerant and the type of regional climate through the outdoor unit main control board.

[0084] Step S602: The main control board reads the freezing temperature corresponding to the type of secondary refrigerant according to the set type of secondary refrigerant.

[0085] If the type of secondary refrigerant and the type of regional climate are not set, the engineering defaults to pure water only, and the heat pump mode is allowed to perform heat exchange only in the second heat exchange mode.

[0086] Step S603: The main control board selects a suitable heat pump mode for heat exchange according to the type of regional climate.

[0087] In this way, the user can select the type of secondary refrigerant and the type of regional climate according to needs and actual conditions, so that the water source multi-split air conditioning system can adaptively match the corresponding control strategy according to the user's selection.

[0088] In an optional embodiment, the control process of the water source multi-split air conditioning system is as shown in Figure 7 and specifically includes the following steps: Step S701: The water source multi-split air conditioning system is debugged.

[0089] Step S702: The type of secondary refrigerant and the type of regional climate are set through the outdoor unit main control board.

[0090] Step S703, when heating in the cold region, the third heat exchange mode is used for heat exchange at start-up.

[0091] Step S704, the antifreeze is judged according to the physical properties of the ethylene glycol solution during operation.

[0092] Step S705, whether the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the ethylene glycol solution, and the duration reaches the preset duration.

[0093] If yes, step S706 is executed, and if no, step S713 is executed.

[0094] Step S706, the frequency of the compressor is reduced by 10% each time until the operating frequency of the compressor has been reduced to the minimum frequency or the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the ethylene glycol solution.

[0095] Step S707, when cooling, the first heat exchange mode is used for heat exchange at start-up.

[0096] Step S708, normal operation, no antifreeze judgment.

[0097] Step S709, when heating in the non-cold region, the second heat exchange mode is used for heat exchange at start-up.

[0098] Step S710, the antifreeze is judged according to the physical properties of the pure water during operation.

[0099] Step S711, whether the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the pure water, and the duration reaches the preset duration.

[0100] If yes, step S712 is executed, and if no, step S713 is executed.

[0101] Step S712, the frequency of the compressor is reduced by 10% each time until the operating frequency of the compressor has been reduced to the minimum frequency or the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the pure water.

[0102] Step S713, keep normal operation.

[0103] In this way, by adding a second heat exchange unit in the outdoor heat exchange module and configuring a second cold carrier providing unit, the water source VRF air conditioning system adopts glycol solution for secondary heat exchange in a low temperature environment, avoids pure water directly entering the first heat exchange unit in the outdoor unit, and thus eliminates the risk of freezing and cracking. Meanwhile, in non-severe cold regions or in a non-low temperature operation mode, the water source VRF air conditioning system can be switched to pure water circulation, ensuring heat exchange efficiency and energy saving. In this way, the water source VRF air conditioning system can ensure equipment safety and improve overall energy efficiency in all-year operation, achieving the dual technical effects of energy saving and freeze protection.

[0104] The embodiments of the present application further provide a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the control method of the water source VRF air conditioning system provided by any one of the preceding method embodiments.

[0105] The device embodiments described above are merely illustrative, wherein the units illustrated as separate components can or can not be physically separated, and the components illustrated as units can or can not be physical units, i.e., can be located in one place or distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiments.

[0106] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be implemented by means of software plus a general hardware platform, and of course can also be implemented by hardware. Based on such understanding, the above technical solutions or the part that contributes to the related art can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in the embodiments or some parts of the embodiments.

[0107] It should be understood that the terms used herein are for the purpose of describing particular example embodiments only and are not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are to be construed as containing, comprising, including or having, as set forth herein, and therefore should be understood to be appropriate in the context with the statement that the features, steps, operations, elements, and / or components so described are included in the application, but not limiting or excluding the possession of additional features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order in which they are described, unless otherwise specifically identified as an order dependent step. It is also to be understood that additional or alternative steps can be employed.

[0108] The foregoing detailed description of the application has been presented for purposes of illustration and description. Various modifications and changes can be made to these embodiments without departing from the spirit and scope of the application. It is intended that the scope of the application should not be limited by the particular representative embodiments described above. Rather, the general scope of the application is to be determined by the appended claims and their equivalents.

Claims

1. A water source multi-split air conditioning system, characterized in that, The water source multi-split air conditioning system includes: a control module, a refrigerant circulation pipeline, an outdoor heat exchange module and an indoor heat exchange module installed on the refrigerant circulation pipeline; The outdoor heat exchange module has multiple heat exchange modes, and different types of refrigerants are used in different heat exchange modes. The outdoor heat exchange module is electrically connected to the control module so that the control module can control the outdoor heat exchange module to switch to a target heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline based on the obtained geographical location and operating mode of the water source multi-split air conditioning system. The target heat exchange mode refers to the heat exchange mode with the highest energy efficiency without freezing and cracking of the outdoor heat exchange module. The target heat exchange mode belongs to the multiple heat exchange modes.

2. The water source multi-split air conditioning system according to claim 1, characterized in that, The outdoor heat exchange module includes a first refrigerant pipe, a second refrigerant pipe, a third refrigerant pipe and a fourth refrigerant pipe connected in sequence, as well as a first heat exchange unit, a second heat exchange unit, a first refrigerant supply unit and a second refrigerant supply unit. The first heat exchange unit is disposed on the refrigerant circulation pipe and the first refrigerant pipe to exchange heat between the refrigerant in the first refrigerant pipe and the refrigerant in the refrigerant circulation pipe. The second heat exchange unit is disposed on the second refrigerant pipe and the third refrigerant pipe to exchange heat between the refrigerant in the second refrigerant pipe and the refrigerant in the third refrigerant pipe; The first refrigerant supply unit is disposed on the fourth refrigerant pipeline, and the second refrigerant supply unit is disposed on the second refrigerant pipeline.

3. The water source multi-split air conditioning system according to claim 2, characterized in that, The outdoor heat exchange module also includes a first water pump, a second water pump, and multiple control valves; The first water pump is installed on the first refrigerant pipeline, the second water pump is installed on the third refrigerant pipeline, and the plurality of control valves are installed on the second refrigerant pipeline, the third refrigerant pipeline, and the pipeline between the second refrigerant pipeline and the third refrigerant pipeline. The first water pump, the second water pump, and the plurality of control valves are all electrically connected to the control module, so that the control module can control the working state of the first water pump, the second water pump, and the plurality of control valves to switch to the state corresponding to the target heat exchange mode based on the obtained geographical location of the water source multi-split air conditioning system and the operating mode of the water source multi-split air conditioning system.

4. The water source multi-split air conditioning system according to claim 3, characterized in that, The plurality of control valves includes a first control valve, a second control valve, a third control valve, a fourth control valve, a fifth control valve, and a sixth control valve; The first control valve is located on the pipe between the first end of the second refrigerant pipe and the first end of the third refrigerant pipe. The second control valve is located on the pipe between the second end of the second refrigerant pipe and the second end of the third refrigerant pipe; The third control valve and the fourth control valve are both installed on the second refrigerant pipeline and are located on both sides of the second heat exchange unit, respectively. The fifth control valve and the sixth control valve are both installed on the third refrigerant pipeline and are located on both sides of the second heat exchange unit, respectively.

5. The water source multi-split air conditioning system according to claim 4, characterized in that, The multiple heat exchange modes include a first heat exchange mode, a second heat exchange mode, and a third heat exchange mode. The first heat exchange mode refers to the heat exchange mode when the water source multi-split air conditioning system is operating in cooling mode. The second heat exchange mode refers to the heat exchange mode when the water source multi-split air conditioning system is operating in heating mode and the geographical location of the water source multi-split air conditioning system is not in a severely cold region. The third heat exchange mode refers to the heat exchange mode when the water source multi-split air conditioning system is operating in heating mode and the geographical location of the water source multi-split air conditioning system is in a severely cold region. Wherein, when the target heat exchange mode is the first heat exchange mode or the second heat exchange mode, the first control valve, the second control valve and the first water pump are turned on, and the third control valve, the fourth control valve, the fifth control valve, the sixth control valve and the second water pump are turned off; When the target heat exchange mode is the third heat exchange mode, the first control valve and the second control valve are closed, and the third control valve, the fourth control valve, the fifth control valve, the sixth control valve, the first water pump, and the second water pump are turned on.

6. The water source multi-split air conditioning system according to claim 3, characterized in that, The outdoor heat exchange module also includes a first temperature sensing bulb and a second temperature sensing bulb. The first temperature sensor and the second temperature sensor are both installed on the first refrigerant pipe and located on both sides of the first heat exchange unit. Both the first and second temperature sensors are electrically connected to the control module, so that the control module can determine whether the outdoor heat exchange module has frozen and cracked based on the refrigerant temperature collected by the first and second temperature sensors.

7. The water source multi-split air conditioning system according to claim 6, characterized in that, The outdoor heat exchange module also includes a flow regulating valve; The flow regulating valve is located on the pipe between the third refrigerant pipe and the fourth refrigerant pipe. The flow regulating valve is electrically connected to the control module so that the control module can adjust the opening degree of the flow regulating valve according to the refrigerant temperature collected by the first temperature sensing bulb and the second temperature sensing bulb.

8. The water source multi-split air conditioning system according to claim 2, characterized in that, The first refrigerant supply unit is a cooling water or hot water supply unit, and the second refrigerant supply unit is an ethylene glycol solution supply unit.

9. The water source multi-split air conditioning system according to claim 2, characterized in that, Both the first heat exchange unit and the second heat exchange unit are plate heat exchangers.

10. The water source multi-split air conditioning system according to claim 1, characterized in that, The water source multi-split air conditioning system also includes: a compressor and a low-pressure sensor located at the air intake of the compressor; The low-pressure sensor is electrically connected to the control module so that the control module can adjust the operating frequency of the compressor based on the pressure value collected by the low-pressure sensor.

11. A control method for a water source multi-split air conditioning system, characterized in that, The control method for the water source multi-split air conditioning system is applied to the water source multi-split air conditioning system according to any one of claims 1-10, and the method includes: Obtain the geographical location of the water source multi-split air conditioning system and the operating mode of the water source multi-split air conditioning system; Based on the obtained geographical location of the water source multi-split air conditioning system and the operating mode of the water source multi-split air conditioning system, the outdoor heat exchange module is controlled to switch to the target heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline. The target heat exchange mode refers to the heat exchange mode with the highest energy efficiency without the outdoor heat exchange module freezing and cracking.

12. The control method for a water source multi-split air conditioning system according to claim 11, characterized in that, The step of controlling the outdoor heat exchange module to switch to the target heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline, based on the obtained geographical location and operating mode of the water source multi-split air conditioning system, includes: When the operating mode of the water source multi-split air conditioning system is cooling mode, the outdoor heat exchange module is controlled to switch to the first heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline; and / or, When the water source multi-split air conditioning system is operating in heating mode and the geographical location of the system is not in a severely cold region, the outdoor heat exchange module is controlled to switch to the second heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline; and / or, When the water source multi-split air conditioning system is in heating mode and the geographical location of the water source multi-split air conditioning system is in a frigid region, the outdoor heat exchange module is controlled to switch to the third heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipeline.

13. The control method for a water source multi-split air conditioning system according to claim 12, characterized in that, The water source multi-split air conditioning system further includes: a compressor and a low-pressure sensor located at the compressor's suction port; the method further includes: When the outdoor heat exchange module is switched to the second heat exchange mode or the third heat exchange mode to exchange heat with the refrigerant in the refrigerant circulation pipe, the pressure value collected by the low pressure sensor is obtained. Every first preset time interval, it is determined whether the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the solidification temperature of the refrigerant, and whether the duration is greater than a second preset time interval. If the pressure value collected by the low-pressure sensor is less than or equal to the pressure value corresponding to the freezing temperature of the refrigerant, and the duration is greater than a second preset duration, the operating frequency of the compressor is reduced until a preset condition is met, at which point the reduction of the compressor's operating frequency stops. The preset condition is that the operating frequency of the compressor has been reduced to the lowest frequency or the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the refrigerant.

14. The control method for a water source multi-split air conditioning system according to claim 13, characterized in that, The method further includes: If the pressure value collected by the low-pressure sensor is greater than the pressure value corresponding to the freezing temperature of the refrigerant, and the difference between the pressure value collected by the low-pressure sensor and the pressure value corresponding to the freezing temperature of the refrigerant is greater than a preset threshold, the operating frequency of the compressor shall be reduced or increased according to the operating requirements of the water source multi-split air conditioning system.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the control method of the water source multi-split air conditioning system according to any one of claims 11-14.

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