Refrigerating system

Abstract

The utility model relates to the technical field of refrigeration, and provides a refrigeration system which comprises a first standby main pipeline and at least two refrigeration units, each refrigeration unit comprises a heat exchange assembly, every two adjacent stages of heat exchange assemblies are connected through a first pipeline, and branches where the heat exchange assemblies are located are connected with the first standby main pipeline in parallel; at least two first bypass branches are connected between the first standby main pipeline and each first pipeline, the at least two first bypass branches are connected in parallel, and each first bypass branch is provided with at least one first on-off valve; at least one second on-off valve is arranged on the pipe section, located between a pair of adjacent first bypass branches, of each first pipeline. According to the refrigerating system, online isolation and maintenance of the faulted refrigerating unit can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refrigeration, in particular to a refrigeration system. BACKGROUND

[0002] In the related art, multiple refrigeration devices are connected in series, and the temperature difference between the supply water and return water of the refrigeration system is increased through the step-by-step temperature reduction of the refrigeration devices at different levels, so that the refrigeration system can have a better refrigeration effect. Although this system can achieve a large temperature difference between the supply water and return water of the refrigeration system, since the refrigeration devices at different levels are connected in series, if any of the refrigeration devices fails, the entire refrigeration system cannot operate normally. CONTENT OF THE UTILITY MODEL

[0003] The embodiments of the present application provide a refrigeration system, which can realize online isolation and maintenance of a refrigeration unit when the refrigeration unit fails.

[0004] The present application provides a refrigeration system including a first standby main pipeline and at least two refrigeration units connected in series, wherein each refrigeration unit includes a heat exchange assembly, two adjacent heat exchange assemblies are connected through a first pipeline, the water inlet of the first heat exchange assembly is connected to the water inlet of the first standby main pipeline through a water inlet pipeline, and the water outlet of the last heat exchange assembly is connected to the water outlet of the first standby main pipeline through a water outlet pipeline; at least two first bypass branches are connected between the first standby main pipeline and each first pipeline, the at least two first bypass branches are connected in parallel, and at least one first on-off valve is arranged on each first bypass branch; at least one second on-off valve is arranged on the pipeline section between each first pipeline and a pair of adjacent first bypass branches; or at least one first bypass branch is connected between the first standby main pipeline and each first pipeline, at least one first on-off valve is arranged on each first bypass branch, and at least one second on-off valve is arranged on each first pipeline and on both sides of one of the first bypass branches; a second on-off valve is also arranged on the water inlet pipeline and the water outlet pipeline, and a third on-off valve is arranged on the pipeline section of the first standby main pipeline upstream of the first bypass branch at the first level and downstream of the first bypass branch at the last level. When this scheme is adopted, the water discharged from the water outlet of the first heat exchange device can be step-by-step cooled after passing through the heat exchange assemblies at different levels, and the cooled water can enter the water inlet of the second heat exchange device for heat exchange, so that a large temperature difference between the supply water and return water of the refrigeration system can be achieved. Moreover, when this scheme is adopted, the failed refrigeration unit can be isolated online, so that the staff can maintain the failure under the condition that the refrigeration system operates normally.

[0005] In one possible embodiment, two first bypass branches are connected between the first backup main line and each first line; each first line is equipped with three second on-off valves, two of which are located between the corresponding two first bypass branches, and the remaining second on-off valve is located between the first bypass branch and the previous-stage heat exchange component; and a third on-off valve is provided on the section of the first backup main line between two adjacent first bypass branches. This solution allows for isolation and online maintenance of the faulty second on-off valve in the event of a second on-off valve failure.

[0006] In one possible embodiment, two first on-off valves are provided on each first bypass branch. This solution allows for isolation and online maintenance of the faulty first on-off valve or third on-off valve when the first on-off valve or third on-off valve fails.

[0007] In one possible embodiment, the refrigeration system includes a surface cooler, the water inlet of the first backup main line and the water inlet of the first-stage heat exchange component are both connected to the water outlet of the surface cooler, and the water outlet of the first backup main line and the water outlet of the last-stage heat exchange component are both connected to the water inlet of the surface cooler.

[0008] In a possible embodiment, the heat exchange component is a first heat exchanger, or the refrigeration unit is a compression refrigeration unit, the compression refrigeration unit includes an evaporator and an air-cooled condenser, and the heat exchange component is the evaporator.

[0009] In a possible embodiment, the at least two adjacent refrigeration units are compression refrigeration units, the compression refrigeration units include evaporators and water-cooled condensers, and the heat exchange assemblies are the evaporators; the two adjacent water-cooled condensers are connected through second pipelines, and the water inlet of the first-stage water-cooled condenser is connected with a third pipeline, and the water outlet of the last-stage water-cooled condenser is connected with a fourth pipeline; the refrigeration system further includes a second backup main pipeline, and the branch pipelines in which the water-cooled condensers are located are connected in parallel with the second backup main pipeline; at least two second bypass branches are connected between the second backup main pipeline and each second pipeline, the at least two second bypass branches are connected in parallel, at least one fourth on-off valve is arranged on each second bypass branch, and at least one fifth on-off valve is arranged on the pipeline section between each second pipeline and a pair of adjacent second bypass branches; or, at least one second bypass branch is connected between the second backup main pipeline and each second pipeline, at least one fourth on-off valve is arranged on each second bypass branch, and at least one fifth on-off valve is arranged on each second pipeline and on both sides of one second bypass branch; the third pipeline and the fourth pipeline are also provided with fifth on-off valves, and a sixth on-off valve is arranged on the pipeline section of the second backup main pipeline, located upstream of the first-stage second bypass branch and downstream of the last-stage second bypass branch. When the at least two adjacent refrigeration units are compression refrigeration units with water-cooled condensers, the compression refrigeration unit with the fault can be isolated online, so that the staff can maintain the fault under the condition that the refrigeration system is normally running.

[0010] In a possible embodiment, two second bypass branches are connected between the second backup main pipeline and each second pipeline; three fifth on-off valves are arranged on each second pipeline, two of the three fifth on-off valves are located between the corresponding two second bypass branches, and the remaining one of the three fifth on-off valves is located between the second bypass branch and the previous-stage water-cooled condenser; a sixth on-off valve is arranged on the pipeline section of the second backup main pipeline, located between the two adjacent second bypass branches. When the fifth on-off valve fails, the isolation and online maintenance of the faulty fourth on-off valve can be realized.

[0011] In a possible embodiment, two fourth on-off valves are arranged on each second bypass branch. When the fourth on-off valve and the sixth on-off valve fail, the isolation and online maintenance of the faulty fourth on-off valve and the sixth on-off valve can be realized.

[0012] In a possible embodiment, the refrigeration system includes a second heat exchanger, the second heat exchanger includes a first flow channel and a second flow channel which are isolated from each other and are in thermal connection, the water inlet of the first backup main pipeline and the water inlet of the first-stage heat exchange assembly are connected with the water outlet of the first flow channel of the second heat exchanger, and the water inlet of the second backup main pipeline and the water inlet of the first-stage water-cooled condenser are connected with the water outlet of the second flow channel of the second heat exchanger.

[0013] In a possible embodiment, the refrigeration system comprises a cooling tower, the outlet of the second standby main pipeline and the outlet of the last water-cooled condenser are connected to the inlet of the cooling tower, and the outlet of the cooling tower is connected to the inlet of the second flow channel of the second heat exchanger.

[0014] In a possible embodiment, the refrigeration system comprises a cooling tower, the outlet of the second standby main pipeline and the outlet of the last water-cooled condenser are connected to the inlet of the cooling tower, and the outlet of the cooling tower is connected to the inlet of the second flow channel of the second heat exchanger. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 FIG. 1 is a structural schematic diagram of a refrigeration system according to the present application;

[0016] Figure 2a FIG. 2 is a structural schematic diagram of a refrigeration system according to the present application;

[0017] Figure 2b FIG. 3 is a structural schematic diagram of a refrigeration system according to the present application;

[0018] Figure 3 FIG. 4 is a structural schematic diagram of a refrigeration system according to the present application;

[0019] Figure 4a FIG. 5 is a structural schematic diagram of a refrigeration system according to the present application; Figure 2a FIG. 6 shows the opening and closing of the on-off valves of the refrigeration system shown in FIG. 5 when H21 fails;

[0020] Figure 4b FIG. 7 shows the opening and closing of the on-off valves of the refrigeration system shown in FIG. 5 when M21 fails; Figure 2a

[0021] FIG. 8 shows the opening and closing of the on-off valves of the refrigeration system shown in FIG. 5 when T21 fails; Figure 4c Figure 2a FIG. 9 shows the opening and closing of the on-off valves of the refrigeration system shown in FIG. 5 when H21 fails;

[0022] Figure 5a Figure 3 FIG. 10 shows the opening and closing of the on-off valves of the refrigeration system shown in FIG. 5 when M21 fails;

[0023] Figure 5b FIG. 11 shows the opening and closing of the on-off valves of the refrigeration system shown in FIG. 5 when T21 fails; Figure 3

[0024] FIG. 12 shows the opening and closing of the on-off valves of the refrigeration system shown in FIG. 5 when H21 fails; Figure 5c Figure 3 FIG. 13 shows the opening and closing of the on-off valves of the refrigeration system shown in FIG. 5 when M21 fails;

[0025] Figure 6a ​​​This is a schematic diagram of the opening and closing conditions of each on-off valve when H31 on the first first pipeline downstream of the first-stage heat exchange component fails;

[0026] Figure 6b Schematic diagram of the opening and closing conditions of each on-off valve when M31 on the first first pipeline downstream of the first-stage heat exchange component fails;

[0027] Figure 6c Schematic diagram of the opening and closing status of each on-off valve when T31 on the first first pipeline downstream of the first-stage heat exchange component fails;

[0028] Figure 7a Schematic diagram of the opening and closing conditions of the on-off valves when H61 on the second first bypass branch 6 fails in the flow direction of water in the first pipeline 3;

[0029] Figure 7b Schematic diagram of the opening and closing conditions of each on-off valve when H61 on the second first bypass branch fails in the flow direction of water in the first pipeline;

[0030] Figure 7c Schematic diagram of the opening and closing conditions of the on-off valves when M61 on the first bypass branch fails in the flow direction of water in the first pipeline;

[0031] Figure 8 Schematic diagram of the opening and closing conditions of the on-off valves when the second and third on-off valves fail in the flow direction of water in the first backup main line;

[0032] Figure 9a This is a schematic diagram of the opening and closing conditions of each on-off valve when a failure occurs in the refrigeration unit where the first-stage evaporator and the final-stage condenser are located;

[0033] Figure 9b This is a schematic diagram of the opening and closing conditions of each on-off valve when a refrigeration unit where the second-stage evaporator and the second-stage condenser are located fails;

[0034] Figure 9c This is a schematic diagram of the opening and closing conditions of each on-off valve when a failure occurs in the refrigeration unit where the final-stage evaporator and the first-stage condenser are located;

[0035] Figure 10a This is a schematic diagram of the opening and closing conditions of each on-off valve when a failure occurs in the refrigeration unit where the first-stage evaporator and the final-stage condenser are located;

[0036] Figure 10b This is a schematic diagram of the opening and closing conditions of each on-off valve when a refrigeration unit where the second-stage evaporator and the second-stage condenser are located fails;

[0037] Figure 10cSchematic diagram of the opening and closing of each on-off valve when the last-stage evaporator and the first-stage condenser fail;

[0038] Figure 11a Schematic diagram of the opening and closing of each on-off valve when H81 on the first second pipeline downstream of the first-stage water-cooled condenser fails;

[0039] Figure 11b Schematic diagram of the opening and closing of each on-off valve when M81 on the first second pipeline downstream of the first-stage water-cooled condenser fails;

[0040] Figure 11c Schematic diagram of the opening and closing of each on-off valve when T81 on the first second pipeline downstream of the first-stage water-cooled condenser fails;

[0041] Figure 12a Schematic diagram of the opening and closing of each on-off valve when H301 on the second second bypass branch in the flow direction of water in the second pipeline fails;

[0042] Figure 12b Schematic diagram of the opening and closing of each on-off valve when H301 on the second second bypass branch in the flow direction of water in the second pipeline fails;

[0043] Figure 12c Schematic diagram of the opening and closing of each on-off valve when M301 on the first second bypass branch in the flow direction of water in the second pipeline 8 fails;

[0044] Figure 13 Schematic diagram of the opening and closing of each on-off valve when the second sixth on-off valve in the flow direction of water in the second standby main pipeline fails;

[0045] Figure 14a Schematic diagram of the structure of a refrigeration system;

[0046] Figure 14b Schematic diagram of the opening and closing of each on-off valve when a certain refrigeration unit fails;

[0047] Figure 15 Schematic diagram of the structure of another refrigeration system provided in the present application;

[0048] Reference numerals: 1-first backup main line; 11-third on-off valve; 2-refrigeration unit; 21-heat exchange component; 22-evaporator; 23-air-cooled condenser; 24-water-cooled condenser; 25-expansion valve; 26-compressor; 3-first pipeline; 31-second on-off valve; 4-water inlet pipeline; 5-water outlet pipeline; 6-first bypass branch; 61-first on-off valve; 7, 200'-surface cooler; 8-second pipeline; 8 1-fifth on-off valve; 9-second backup main line; 91-sixth on-off valve; 10-third pipeline; 20-fourth pipeline; 30-second bypass branch; 301-fourth on-off valve; 40-second heat exchanger; 50-cooling tower; 100'-compression refrigeration unit; 110'-evaporator; 120'-compressor; 130'-condenser; 140'-expansion valve; 300'-circulating pump; 400-data center. DETAILED DESCRIPTION

[0049] Refrigeration systems are widely used in many fields such as data centers and industrial plants. The following is a brief introduction to the composition and principles of refrigeration systems. Figure 1 A schematic diagram of the structure of a refrigeration system is shown in FIG. Figure 1 As shown, a refrigeration system includes a multi-stage compression refrigeration unit 100' connected in series. Specifically, each stage of the compression refrigeration unit includes an evaporator 110', a compressor 120', a condenser 130' and an expansion valve 140', wherein the evaporator 110' includes a refrigerant flow channel and a cooling water flow channel, the refrigerant flow channel and the cooling water flow channel are isolated from each other, and heat can be transferred between the refrigerant flow channel and the cooling water flow channel. In the same compression refrigeration unit 100', the outlet of the refrigerant flow channel of the evaporator 110' is connected to the flow channel inlet of the compressor 120', the flow channel outlet of the compressor 120' is connected to the refrigerant inlet of the condenser 130', the refrigerant outlet of the condenser 130' is connected to the fluid inlet of the expansion valve 140', and the fluid outlet of the expansion valve 140' is connected to the inlet of the refrigerant flow channel of the evaporator 110'. Between each stage of the compression and refrigeration units 100', the chilled water inlet of the evaporator 110' of the first-stage compression and refrigeration unit is connected to the water outlet of the surface cooler 200'. The chilled water outlet of the evaporator 110' of the previous-stage compression and refrigeration unit is connected to the chilled water inlet of the evaporator 110' of the next-stage compression and refrigeration unit. The chilled water outlet of the evaporator 110' of the final-stage compression and refrigeration unit is connected to the water supply port of the surface cooler 200'. In this solution, any single point failure in any compression and refrigeration unit will cause the entire refrigeration system to malfunction.

[0050] Based on this, an embodiment of the present application provides a refrigeration system that can achieve online isolation and maintenance of a refrigeration unit when a refrigeration unit fails, thereby ensuring the normal operation of the refrigeration system. To make the objectives, technical solutions, and advantages of this application more clear, this application will be further described in detail below with reference to the accompanying drawings.

[0051] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of this application, the singular expressions "a", "an", "said", "above", "the", and "this" are intended to also include expressions such as "one or more", unless the context clearly indicates otherwise.

[0052] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0053] Figure 2a This is a schematic diagram of the structure of a refrigeration system provided in this application. Figure 2a As shown, the refrigeration system includes a first backup main line 1 and at least two refrigeration units 2, and each refrigeration unit 2 is connected in series. Each refrigeration unit 2 includes a heat exchange component 21, and the two adjacent heat exchange components 21 are connected by a first pipeline 3, and the water inlet of the first-stage heat exchange component 21 is connected to the water inlet of the first backup main line 1 through the water inlet pipeline 4, and the water outlet of the last-stage heat exchange component 21 is connected to the water outlet of the first backup main line 1 through the water outlet pipeline 5. The water inlet of the first backup main line 1 and the water inlet of the water inlet pipeline 4 are connected to the water outlet of the same first heat exchange device A, and the water outlet of the first backup main line 1 and the water outlet of the water outlet pipeline 5 are connected to the water inlet of the same second heat exchange device B. In specific implementation, the water inlet of the first backup main line 1 and the water inlet of the water inlet pipeline 4 can be directly connected to the water outlet of the first heat exchange device A (such as Figure 2aAs shown, it can also be indirectly connected to the outlet of the first heat exchange device A through other components. The outlet of the first backup main line 1 and the outlet of the outlet pipe 5 can be indirectly connected to the water inlet of the second heat exchange device B through a circulating pump 300' or the like. It is not difficult to understand that the first heat exchange device A, the heat exchange component 21, and the second heat exchange device B are in the same circulation loop. In this solution, the water discharged from the outlet of the first heat exchange device A can be cooled step by step after passing through each stage of the heat exchange component 21. The cooled water can then enter the water inlet of the second heat exchange device B for heat exchange, thereby achieving a large temperature difference between the supply and return water of the refrigeration system.

[0054] It is worth noting that, in some embodiments, the first heat exchange device A connected to the first-stage heat exchange component 21 and the second heat exchange device B connected to the final-stage heat exchange component 21 can be the same heat exchange device, for example, the same heat exchange device is a surface cooler 7 ( Figure 2a (not marked in the figure), specifically, the surface cooler 7 can be a surface cooler 7 that realizes heat exchange between air and water. The water inlet of the first backup main line 1 and the water inlet of the water inlet line 4 are both connected to the water outlet of the surface cooler 7, and the water outlet of the first backup main line 1 and the water outlet of the water outlet line 5 are both connected to the water inlet of the surface cooler 7. In other embodiments, such as Figure 2b In the refrigeration system shown, the first heat exchange device A of the first stage heat exchange assembly 21 and the second heat exchange device B of the final stage heat exchange assembly 21 can also be different heat exchange devices. For example, the first heat exchange device connected to the first stage heat exchange assembly 21 is the heat exchanger C, and the second heat exchange device connected to the final stage heat exchange assembly 21 is the surface cooler 7, and the water outlet of the surface cooler 7 is connected to the water inlet of the above-mentioned heat exchanger C. Next, please continue to refer to Figure 2a and Figure 2bIn specific implementation, at least two first bypass branches 6 are connected between the first backup main line 1 and each first pipeline 3. These at least two first bypass branches 6 are connected in parallel between the first backup main line 1 and the corresponding first pipeline 3, and each first bypass branch 6 is equipped with at least one first on-off valve 61. Each first pipeline 3 section located between a pair of adjacent first bypass branches 6 is equipped with at least one second on-off valve 31, and the water inlet pipeline 4 and the water outlet pipeline 5 are also equipped with at least one second on-off valve 31. The sections of the first backup main line 1 located upstream of the first-stage first bypass branch 6 and downstream of the final-stage first bypass branch 6 are each equipped with a third on-off valve 11. Exemplarily, the refrigeration system includes three refrigeration units 2, each refrigeration unit 2 includes a heat exchange component 21, two first bypass branches 6 are connected between the first backup main line 1 and each first pipeline 3, each first bypass branch 6 is provided with a first on-off valve 61, the water inlet pipeline 4, the water outlet pipeline 5 and the pipe sections of each first pipeline 3 located between a pair of adjacent first bypass branches 6 are provided with a second on-off valve 31, and the pipe sections on the first backup main line 1, located upstream of the first-stage first bypass branch 6 and downstream of the last-stage first bypass branch 6, are provided with a third on-off valve 11.

[0055] Obviously, the arrangement of pipes and valves in the refrigeration system is not limited to Figure 2a and Figure 2b For example, the arrangement of pipes and valves in the refrigeration system can also be as follows: Figure 3 As shown, Figure 3 The refrigeration system shown is Figure 2a The differences between the refrigeration systems shown are: Figure 3 In the refrigeration system shown, at least one first bypass branch 6 is connected between the first backup main line 1 and each first pipeline 3. Each first bypass branch 6 is provided with at least one first on-off valve 61. At least one second on-off valve 31 is provided on each first pipeline 3 and on both sides of one of the first bypass branches. In a specific implementation, Figure 3 As shown, a first bypass branch 6 is connected between the first backup main line 1 and each first pipeline 3, each first bypass branch 6 is provided with a first on-off valve 61, and each first pipeline 3 is provided with a second on-off valve 31 on both sides of the corresponding first bypass branch 6.

[0056] In a specific implementation, the heat exchange assembly 21 of each refrigeration unit 2 can have various configurations. For example, the heat exchange assembly 21 can be a first heat exchanger. Alternatively, the refrigeration unit 2 can be a compression refrigeration unit comprising an evaporator 22 and an air-cooled condenser 23, with the evaporator 22 being the heat exchange assembly 21. It is readily understood that the compression refrigeration unit also comprises an expansion valve 25 and a compressor 26. The specific operating principle of the compression refrigeration unit can be referred to in the prior art and will not be further described here.

[0057] Based on the above content, in a specific implementation, in a refrigeration system, the heat exchange component 21 of each refrigeration unit 2 can have various forms. For example: the heat exchange component 21 of each refrigeration unit 2 is the first heat exchanger; or, each refrigeration unit 2 is a compression refrigeration unit 2 using an air-cooled condenser 23, and the evaporator 22 is the above heat exchange component 21; or, the heat exchange component 21 in some refrigeration units 2 is the first heat exchanger, and the remaining refrigeration units 2 are compression refrigeration units using an air-cooled condenser 23, and the evaporator 22 is the above heat exchange component 21. Figures 4a to 5c The isolation and maintenance of a refrigeration unit 2 in the above three situations when it fails are described. In each figure, the heat exchange component 21 in the dotted box represents the heat exchange component 21 that has failed, the on-off valve interrupted by a straight line represents a closed on-off valve, and the broken dotted line indicates the flow of a section of the fluid in the refrigeration system. It is worth noting that Figures 4a to 5c Only the heat exchange assembly 21 of each refrigeration unit 2 is shown. For ease of understanding, the first-stage heat exchange assembly 21 is referred to as H21, the second-stage heat exchange assembly 21 is referred to as M21, and the third-stage heat exchange assembly 21 is referred to as T21. The first-stage and last-stage heat exchange assemblies are relative to the flow direction of water in the first pipeline. In the flow direction of water in the first pipeline, the heat exchange assembly located most upstream is the first-stage heat exchange assembly, and the heat exchange assembly located most downstream is the last-stage heat exchange assembly.

[0058] Specifically, Figure 4a for Figure 2a The diagram below shows the opening and closing status of each on-off valve when H21 fails in the refrigeration system. Figure 4a As shown, when H21 fails, the two second on-off valves 31 adjacent to H21 are closed, and the first on-off valve 61 on the first bypass branch 6 closest to H21, as well as the first on-off valves 61 on each first bypass branch 6 downstream of the heat exchange component 21 (that is, M21) of the next level below H21, and the third on-off valve 11 on the first backup main line 1, located downstream of the last-stage first bypass branch 6, are closed. The remaining on-off valves are opened, that is, the faulty H21 can be isolated online, so that the staff can maintain the faulty H21 when the refrigeration system is operating normally.

[0059] Figure 4b for Figure 2a The diagram below shows the opening and closing status of each on-off valve when M21 fails in the refrigeration system. Figure 4bAs shown, when M21 fails, the two second on-off valves 31 adjacent to M21 are closed, and the first on-off valves 61 on the two first bypass branches 6 adjacent to M21 are closed, the third on-off valve 11 on the first backup main line 1, located upstream of the first-stage first bypass branch 6, and the third on-off valve 11 located downstream of the last-stage first bypass branch 6 are closed, and the remaining on-off valves are opened, that is, the faulty M21 can be isolated online, so that the staff can maintain the faulty M21 when the refrigeration system is operating normally.

[0060] Figure 4c for Figure 2a The diagram of the opening and closing of each on-off valve in the refrigeration system shown is a schematic diagram of the opening and closing of each on-off valve when T21 (that is, the final stage heat exchange component 21) fails. Figure 4c As shown, when T21 fails, the two second on-off valves 31 adjacent to T21 are closed, and the first on-off valve 61 on the first bypass branch 6 adjacent to T21 is closed, the first on-off valves 61 on each first bypass branch 6 upstream of the previous stage heat exchange component 21 (that is, M21) of T21 and the third on-off valve 11 on the first backup main line 1, located upstream of the first stage first bypass branch 6, are closed, and the remaining on-off valves are opened, that is, the faulty T21 can be isolated online, so that the staff can maintain the faulty T21 when the refrigeration system is operating normally.

[0061] In other cases where the number of refrigeration units 2 in the refrigeration system is greater than or equal to 2, when a heat exchange component 21 fails, the opening and closing of each on-off valve can be inferred from the above three cases, which will not be explained here one by one.

[0062] use Figure 4c In the refrigeration system shown, when all refrigeration units 2 are operating normally, the first on-off valves 61 and the third on-off valves 11 can be closed, while the second on-off valves 31 can be kept open. Of course, when all refrigeration units 2 are operating normally, the opening and closing of the on-off valves are not limited to the above-mentioned conditions, as long as the water discharged from the first heat exchange device A passes through each stage of the heat exchange assembly in sequence and then enters the second heat exchange device B.

[0063] Figure 5a for Figure 3 The diagram below shows the opening and closing status of each on-off valve when H21 fails in the refrigeration system. Figure 5aAs shown in the figure, when H21 fails, the two second on-off valves 31 adjacent to H21 are closed, the first on-off valve 61 on the first bypass branch 6 downstream of the next stage heat exchange assembly 21 (i.e. M21) of H21 is closed, the third on-off valve 11 on the first standby main pipeline 1 downstream of the last stage first bypass branch 6 is closed, and the rest of the on-off valves are opened, so that the failed H21 can be isolated online, and the staff can maintain the failed H21 under the condition that the refrigeration system is running normally.

[0064] Figure 5b As shown in the figure, when M21 fails, the two second on-off valves 31 adjacent to M21 are closed, the third on-off valve 11 on the first standby main pipeline 1 upstream of the first stage first bypass branch 6 and downstream of the last stage first bypass branch 6 is closed, and the rest of the on-off valves are opened, so that the failed M21 can be isolated online, and the staff can maintain the failed M21 under the condition that the refrigeration system is running normally. Figure 3 Figure 5b As shown in the figure, when T21 fails, the two second on-off valves 31 adjacent to T21 are closed, the first on-off valve 61 on the first bypass branch 6 upstream of the previous stage heat exchange assembly 21 (i.e. M21) is closed, and the third on-off valve 11 on the first standby main pipeline 1 upstream of the first stage first bypass branch 6 is closed, and the rest of the on-off valves are opened, so that the failed T21 can be isolated online, and the staff can maintain the failed T21 under the condition that the refrigeration system is running normally.

[0065] Figure 5c Figure 3 As shown in the figure, when M21 fails, the two second on-off valves 31 adjacent to M21 are closed, the third on-off valve 11 on the first standby main pipeline 1 upstream of the first stage first bypass branch 6 and downstream of the last stage first bypass branch 6 is closed, and the rest of the on-off valves are opened, so that the failed M21 can be isolated online, and the staff can maintain the failed M21 under the condition that the refrigeration system is running normally. Figure 5c

[0066] When the number of refrigeration units 2 in the refrigeration system is greater than or equal to 2, the on-off of the on-off valves when the heat exchange assembly 21 fails can be deduced from the above three cases, which will not be described one by one here.

[0067] As shown in the figure, when all the refrigeration units 2 are working normally, the third on-off valves 11 are closed, and the first on-off valves 61 and the second on-off valves 31 are kept open; or, the first on-off valves 61 and the third on-off valves 11 are closed, and the second on-off valves 31 are kept open. Figure 5c

[0068] ​​​​During implementation, the second on-off valve 31 may also fail. In order to isolate and perform online maintenance of the failed second on-off valve 31 when the second on-off valve 31 fails, as shown in FIG. Figure 6a As shown, in a specific implementation, two first bypass branches 6 are connected between the first backup main line 1 and each first pipeline 3. Three second on-off valves 31 are provided on each first pipeline 3, two of the three second on-off valves 31 are located between the corresponding two first bypass branches 6, and the remaining second on-off valve 31 is located between the first bypass branch 6 and the previous stage heat exchange component 21. A third on-off valve 11 is provided on the pipe section of the first backup main line 1 located between two adjacent first bypass branches 6. Of course, there can be more than three second on-off valves 31 on the first pipeline 3, and there can be at least one third on-off valve 11 on the pipe section of the first backup main line 1 located between two adjacent first bypass branches 6.

[0069] The following combination Figures 6a to 6c This solution describes the isolation and maintenance of a faulty second on-off valve 31. In each figure, the second on-off valve 31 in the dashed box represents a faulty second on-off valve 31, the on-off valve interrupted by a straight line represents a closed on-off valve, and the broken dashed line illustrates a section of the fluid flow in the refrigeration system. For ease of understanding, the three second on-off valves 31 on the first pipeline 3 are hereinafter referred to as the upstream-most second on-off valve 31 as H31, the middle second on-off valve 31 as M31, and the downstream-most second on-off valve 31 as T31.

[0070] Figure 6a Schematic diagram of the opening and closing of each on-off valve when H31 on the first first pipeline 3 downstream of the first stage heat exchange component 21 fails. Figure 6a As shown, when the H31 fails, the two second on-off valves 31 adjacent to the H31 are closed, and the first on-off valve 61 on the first bypass branch 6 closest to the M31 is closed, as well as the third on-off valve 11 in parallel with the second-stage heat exchange component 21 and the third-stage heat exchange component 21, and the remaining on-off valves are opened, that is, the faulty H31 can be isolated online, so that the staff can maintain the faulty H31 when the refrigeration system is operating normally.

[0071] Figure 6b Schematic diagram of the opening and closing of each on-off valve when M31 on the first first pipeline 3 downstream of the first stage heat exchange component 21 fails. Figure 6bAs shown, when the M31 fails, the two second on-off valves 31 adjacent to the M31 are closed, and the second on-off valve 31 upstream of the heat exchange component 21 upstream of the M31 is closed, the first on-off valve 61 on the first bypass branch 6 between the M31 and the adjacent H31, and the third on-off valve 11 in parallel with the second-stage heat exchange component 21 and the third-stage heat exchange component 21 are closed, and the remaining on-off valves are opened, that is, the faulty M31 can be isolated online, so that the staff can maintain the faulty M31 when the refrigeration system is operating normally.

[0072] Figure 6c Schematic diagram of the opening and closing of each on-off valve when T31 on the first first pipeline 3 downstream of the first stage heat exchange component 21 fails. Figure 6c As shown, when T31 fails, the two second on-off valves 31 adjacent to T31 are closed, and the first on-off valve 61 on the first first bypass branch 6 downstream of T31 is closed, the third on-off valve 11 connected in parallel with the first-stage heat exchange component 21 and the third-stage heat exchange component 21 is closed, and the remaining on-off valves are opened, that is, the faulty T31 can be isolated online, so that the staff can maintain the faulty T31 when the refrigeration system is operating normally.

[0073] When the second on-off valve 31 on the other first pipeline 3 fails, the opening and closing of each on-off valve can be set according to the actual situation, and will not be explained here one by one. Figure 6c In the refrigeration system shown, when each refrigeration unit 2 and each on-off valve are working normally, the opening and closing conditions of each on-off valve include but are not limited to: closing each first on-off valve 61 and each third on-off valve 11, and keeping each second on-off valve 31 open.

[0074] In general, when a second on-off valve 31 fails, the two second on-off valves 31 adjacent to the failed second on-off valve 31 are closed, and the first on-off valve 6 on the first bypass branch 6 closest to the failed second on-off valve 31 is closed. If a compression refrigeration unit is included while isolating the failed second on-off valve 31, the isolated compression refrigeration unit will not be opened, and the third on-off valve 11 connected in parallel with the isolated compression refrigeration unit needs to be opened; if no compression refrigeration unit is isolated while isolating the failed second on-off valve 31, the third on-off valve 11 connected in parallel with the preceding compression refrigeration unit adjacent to the failed second on-off valve 31 needs to be opened, and the preceding compression refrigeration unit will not be opened. The first and last third on-off valves 11 on the first backup main line 1 are both closed, and the third on-off valve 11 located between the two adjacent pairs of first bypass branches 6 is closed.

[0075] During implementation, the first on-off valve 61 may also fail. In order to isolate and perform online maintenance of the failed first on-off valve 61 when the first on-off valve 61 fails, as shown in FIG.Figure 7a As shown, in a specific implementation, Figure 6c On the basis of the refrigeration system shown in FIG, each first bypass branch 6 is provided with two first on-off valves 61. Of course, each first bypass branch 6 can be provided with at least two first on-off valves 61. Figure 7a 、 Figure 7b and Figure 7c This solution illustrates the isolation and maintenance of a faulty first on-off valve 61. In the figures, the first on-off valve 61 within the dashed box represents a faulty first on-off valve 61, the on-off valve truncated by a straight line represents a closed on-off valve, and the broken dashed line illustrates a section of the fluid flow in the refrigeration system. For ease of understanding, the two first on-off valves 61 on the first bypass branch 6 are hereinafter referred to as H61 for the first on-off valve 61 closer to the first pipeline 3 and M61 for the first on-off valve 61 farther from the first pipeline 3.

[0076] Figure 7a Schematic diagram of the opening and closing of each on-off valve when H61 on the second first bypass branch 6 fails in the flow direction of water in the first pipeline 3. Figure 7a As shown, when H61 fails, M61 on the same first bypass branch 6 as H61 is closed, the first second on-off valve 31 upstream and downstream of the first bypass branch 6 is closed, and the third on-off valve 11 connected in parallel to the second-stage heat exchange assembly 21 and the third-stage heat exchange assembly 21 is closed. The remaining on-off valves are opened, thus isolating the faulty H61 online. This allows staff to perform maintenance on the faulty H61 while the refrigeration system is operating normally.

[0077] It is worth noting that if Figure 7a As shown, if the faulty first on-off valve 61 is isolated and the heat exchange component 21 is also isolated, the third on-off valve 11 connected in parallel with the isolated heat exchange component 21 needs to be opened, and when the isolated heat exchange component 21 is the evaporator 22 in the compression refrigeration unit, the compression refrigeration unit is not opened. Figure 7b If no heat exchange assembly 21 is isolated simultaneously with the faulty first on-off valve 61, the third on-off valve 11 connected in parallel to the heat exchange assembly 21 preceding the faulty first on-off valve 61 must be opened. If the preceding heat exchange assembly 21 is the evaporator 22 of a compression refrigeration unit, the compression refrigeration unit will not be turned on. It should be understood that when H61 fails, the opening and closing of the on-off valves is not limited to the above scheme; other schemes may also be employed, as long as the faulty H61 can be isolated while ensuring normal operation of the refrigeration system.

[0078] Figure 7cSchematic diagram of the opening and closing of each on-off valve when M61 on the first bypass branch 6 fails in the flow direction of water in the first pipeline 3. Figure 7c As shown, when M61 fails, H61 located on the same first bypass branch 6 as M61 is closed, and each third on-off valve 11 is closed, while the remaining on-off valves are opened. This allows the faulty M61 to be isolated online, allowing personnel to perform maintenance on the faulty M61 while the refrigeration system is operating normally. It should be understood that when M61 fails, the opening and closing of each on-off valve is not limited to the above solution, and other solutions can also be used, as long as the faulty M61 can be isolated while ensuring the normal operation of the refrigeration system.

[0079] Refrigeration system uses Figure 7c In the structure shown, when the third on-off valve 11 fails, the third on-off valve 11 can also be isolated and maintained online. Figure 8 As shown, along the direction of water flow in the first backup main line 1 (i.e., from right to left in the figure), when the second third on-off valve 11 fails, the two first on-off valves 61 adjacent to the third on-off valve 11 are closed, and each third on-off valve 11 is closed, while the remaining on-off valves are opened. This allows the failed third on-off valve 11 to be isolated online, allowing staff to perform maintenance on the failed third on-off valve 11 while the refrigeration system is operating normally. It should be understood that when the third on-off valve 11 fails, the opening and closing conditions of the various on-off valves are not limited to the above scheme, and other schemes may also be adopted, as long as the failed third on-off valve 11 can be isolated while ensuring the normal operation of the refrigeration system.

[0080] In other cases where the number of refrigeration units 2 in the refrigeration system is greater than or equal to 2, when a certain on-off valve fails, the opening and closing of the other on-off valves can be inferred from the above case, and will not be explained here one by one.

[0081] In addition to the above-mentioned cases, the heat exchange assembly 21 of each refrigeration unit 2 can also be as follows: each refrigeration unit 2 is a compression refrigeration unit, the compression refrigeration unit comprises an evaporator 22 and a water-cooled condenser 24, the evaporator 22 being the heat exchange assembly 21 of the compression refrigeration unit; or at least two adjacent refrigeration units 2 are compression refrigeration units using water-cooled condensers 24, and the heat exchange assembly 21 of at least one refrigeration unit 2 is a first heat exchanger; or at least two adjacent refrigeration units 2 are compression refrigeration units using water-cooled condensers 24, and at least one refrigeration unit 2 is a compression refrigeration unit using an air-cooled condenser 23. Generally, a compression refrigeration unit is a module, so when one of the components of the compression refrigeration unit fails, the entire compression refrigeration unit needs to be isolated to achieve online maintenance. That is, when the refrigeration unit 2 is a compression refrigeration unit using a water-cooled condenser 24, if the refrigeration unit 2 fails, the water-cooled condenser 24 side of the refrigeration unit 2 also needs to be isolated.

[0082] Specifically, in some embodiments, at least two adjacent refrigeration units 2 are compression refrigeration units, the compression refrigeration unit comprises an evaporator 22 and a water-cooled condenser 24, and the evaporator 22 is the heat exchange assembly 21 of the compression refrigeration unit. It is not difficult to understand that the compression refrigeration unit also comprises a compressor 26 and an expansion valve 25. In order to isolate the refrigeration unit 2 with a failed water-cooled condenser 24 when the refrigeration unit 2 fails, as shown in Figure 9a two adjacent water-cooled condensers 24 are connected by a second pipeline 8, and the water inlet of the first water-cooled condenser 24 is connected with a third pipeline 10, and the water outlet of the last water-cooled condenser 24 is connected with a fourth pipeline 20. The refrigeration system further comprises a second standby main pipeline 9, and the branches in which the water-cooled condensers 24 are located are connected in parallel with the second standby main pipeline 9. In implementation, the water inlets of the two branches can be directly or indirectly connected to the water outlet of the same third heat exchange device D, and the water outlets of the two branches can be directly or indirectly connected to the water inlet of the same fourth heat exchange device E, and the third heat exchange device D, the water-cooled condensers 24 and the fourth heat exchange device E are in the same circulation loop. Exemplarily, the third heat exchange device D is a heat exchanger, and the fourth heat exchange device E is a cooling tower 50. It is not difficult to understand that when the heat exchange assembly 21 of the refrigeration unit 2 is a first heat exchanger, or when the refrigeration unit 2 is a compression refrigeration unit using an air-cooled condenser 23, only the heat exchange assembly 21 side of the refrigeration unit 2 needs to be isolated when the corresponding first heat exchanger or compression refrigeration unit using an air-cooled condenser 23 fails, so that the maintenance of the refrigeration unit 2 with a failure can be achieved. In this embodiment, each refrigeration unit 2 is taken as an example of a compression refrigeration unit using a water-cooled condenser 24 for description.

[0083] Please continue to refer to Figure 9aIn specific implementation, at least two second bypass branches 30 are connected between the second backup main line 9 and each second pipeline 8. The at least two second bypass branches 30 are connected in parallel, and each second bypass branch 30 is provided with at least one fourth on-off valve 301. The pipe section of each second pipeline 8 located between a pair of adjacent second bypass branches 30, as well as the third pipeline 10 and the fourth pipeline 20 are provided with at least one fifth on-off valve 81. The pipe section of the second backup main line 9 located upstream of the first-stage second bypass branch 30 and downstream of the last-stage second bypass branch 30 is provided with a sixth on-off valve 91. Obviously, the arrangement of pipelines and valves in the refrigeration system is not limited to Figure 9a For example, the arrangement of pipes and valves in the refrigeration system can also be as follows: Figure 10a As shown, Figure 10a The refrigeration system shown is Figure 9a The differences between the refrigeration systems shown are: Figure 10a In the refrigeration system shown, at least one second bypass branch 30 is connected between the second backup main line 9 and each second pipeline 8, each second bypass branch 30 is provided with at least one fourth on-off valve 301, and at least one fifth on-off valve 81 is provided on each second pipeline 8 and on both sides of one of the second bypass branches 30.

[0084] In this solution, when each refrigeration unit 2 is operating normally, the two third on-off valves 11 on the first backup main line 1 can be closed, and the other on-off valves are in the normally open state. The two sixth on-off valves 91 on the second backup main line 9 are closed, and the other on-off valves are in the normally open state. Of course, the first on-off valve 61 and the fourth on-off valve 301 can also be closed, as long as the water entering the first-stage evaporator 22 can pass through each lower-stage evaporator 22 in sequence, and the water entering the first-stage condenser can pass through each lower-stage condenser in sequence. The first-stage evaporator 22 and the last-stage evaporator 22 are relative to the flow direction of water in the first pipeline 3, and the first-stage condenser and the last-stage condenser are relative to the flow direction of water in the second pipeline 8. Depending on the specific settings, the flow direction of water in the first pipeline 3 may be the same as the flow direction of water in the second pipeline 8, or it may be opposite to the flow direction of water in the second pipeline 8. Therefore, the condenser in the refrigeration unit 2 where the first-stage evaporator 22 is located may be a first-stage condenser or a last-stage condenser. For example, Figure 9c and Figure 10a In the embodiment, the condenser in the refrigeration unit 2 where the first-stage evaporator 22 is located is the final-stage condenser, and the condenser in the refrigeration unit 2 where the final-stage evaporator 22 is located is the first-stage condenser.

[0085] The following combination Figures 9a to 10cThe isolation and maintenance of the evaporator side and the condenser side when a failure occurs in the refrigeration unit 2 are explained. In each figure, the refrigeration unit 2 in the dotted box represents the failed refrigeration unit 2, the on-off valve cut off by a straight line represents a closed on-off valve, and the broken dotted line indicates a section of the fluid direction on the corresponding evaporator side or condenser side in the refrigeration system.

[0086] like Figure 9a As shown, the refrigeration system includes three compression refrigeration units connected in series. When the refrigeration unit 2 where the first-stage evaporator 22 and the final-stage condenser are located fails, on the evaporator side, the two second on-off valves 31 adjacent to the first-stage evaporator 22 are closed, and the first on-off valve 61 on the first bypass branch 6 closest to the first-stage evaporator 22 is closed, as well as the first on-off valves 61 on each first bypass branch 6 downstream of the next-stage evaporator 22 (that is, the second-stage evaporator 22) of the first-stage evaporator 22, the third on-off valve 11 on the first backup main line 1, located downstream of the final-stage first bypass branch 6, is closed, and the remaining on-off valves are opened, so that the faulty first-stage evaporator 22 can be isolated online. On the condenser side, close the two fifth on-off valves 81 adjacent to the final-stage condenser, and close the fourth on-off valve 301 on the second bypass branch 30 adjacent to the final-stage condenser, close the fourth on-off valves 301 on each second bypass branch 30 upstream of the first-stage condenser (that is, the second-stage condenser) before the final-stage condenser, and close the sixth on-off valve 91 on the second backup main line 9, located upstream of the first-stage second bypass branch 30, and open the remaining on-off valves, so that the faulty final-stage condenser can be isolated online, so that the staff can maintain the faulty refrigeration unit 2 when the refrigeration system is operating normally.

[0087] like Figure 9b As shown, when the refrigeration unit 2 where the second-stage evaporator 22 and the second-stage condenser are located fails, on the evaporator side, the two second on-off valves 31 adjacent to the second-stage evaporator 22 are closed, and the first on-off valves 61 on the two first bypass branches 6 adjacent to the second-stage evaporator 22 are closed, the third on-off valve 11 on the first backup main line 1, located upstream of the first-stage first bypass branch 6, and the third on-off valve 11 located downstream of the last-stage first bypass branch 6 are closed, and the remaining on-off valves are opened, so that the faulty second-stage evaporator 22 can be isolated online. On the condenser side, close the two fifth on-off valves 81 adjacent to the second-stage condenser, close the fourth on-off valve 301 on the two second bypass branches 30 adjacent to the second-stage condenser, close the sixth on-off valve 91 on the second backup main line 9, located upstream of the first-stage second bypass branch 30, and the sixth on-off valve 91 located downstream of the last-stage second bypass branch 30, and open the remaining on-off valves, so that the faulty second-stage condenser can be isolated online, so that the staff can maintain the faulty refrigeration unit 2 when the refrigeration system is operating normally.

[0088] like Figure 9c As shown, when the refrigeration unit 2 where the last-stage evaporator 22 and the first-stage condenser are located fails, on the evaporator side, the two second on-off valves 31 adjacent to the last-stage evaporator 22 are closed, and the first on-off valve 61 on the first bypass branch 6 adjacent to the last-stage evaporator 22 is closed, the first on-off valves 61 on each first bypass branch 6 upstream of the previous-stage evaporator 22 (that is, the second-stage evaporator 22) of the last-stage evaporator 22 and the third on-off valve 11 on the first spare main line 1, located downstream of the last-stage first bypass branch 6, are closed, and the remaining on-off valves are opened, so that the faulty last-stage evaporator 22 can be isolated online. On the condenser side, close the two fifth on-off valves 81 adjacent to the first-stage condenser, and close the fourth on-off valve 301 on the second bypass branch 30 closest to the first-stage condenser, as well as the fourth on-off valves 301 on each second bypass branch 30 downstream of the condenser of the next stage below the first-stage condenser (that is, the second-stage condenser), close the sixth on-off valve 91 on the second backup main line 9, located downstream of the last-stage second bypass branch 30, and open the remaining on-off valves, so that the faulty first-stage condenser can be isolated online, so that the staff can maintain the faulty refrigeration unit 2 when the refrigeration system is operating normally.

[0089] like Figure 10a As shown, the refrigeration system includes three compression refrigeration units connected in series. When the refrigeration unit 2 where the first-stage evaporator 22 and the final-stage condenser are located fails, on the evaporator side, the two second on-off valves 31 adjacent to the first-stage evaporator 22 are closed, and the first on-off valve 61 on the first bypass branch 6 downstream of the next-stage evaporator 22 (that is, the second-stage evaporator 22) of the first-stage evaporator 22 is closed, as well as the third on-off valve 11 on the first backup main line 1, located downstream of the final-stage first bypass branch 6, is closed, and the remaining on-off valves are opened, so that the faulty first-stage evaporator 22 can be isolated online. On the condenser side, close the two fifth on-off valves 81 adjacent to the last-stage evaporator 22, and close the fourth on-off valve 301 on the second bypass branch 30 upstream of the previous-stage condenser (that is, the second-stage condenser), as well as the sixth on-off valve 91 on the second backup main line 9, located upstream of the first-stage second bypass branch 30, and open the remaining on-off valves, so that the faulty last-stage condenser can be isolated online, so that the staff can maintain the faulty refrigeration unit 2 when the refrigeration system is operating normally.

[0090] like Figure 10bAs shown, when the refrigeration unit 2 where the second-stage evaporator 22 and the second-stage condenser are located fails, on the evaporator side, the two second on-off valves 31 adjacent to the second-stage evaporator 22 are closed, and the third on-off valve 11 on the first backup main line 1, located upstream of the first-stage first bypass branch 6 and downstream of the last-stage first bypass branch 6, is closed, and the remaining on-off valves are opened, so that the faulty second-stage evaporator 22 can be isolated online. On the condenser side, the two fifth on-off valves 81 adjacent to the second-stage condenser are closed, and the sixth on-off valve 91 on the second backup main line 9, located upstream of the first-stage second bypass branch 30 and downstream of the last-stage second bypass branch 30, is opened, and the remaining on-off valves are opened, so that the faulty condenser can be isolated online, thereby allowing staff to perform maintenance on the faulty refrigeration unit 2 while the refrigeration system is operating normally.

[0091] like Figure 10c As shown, when a refrigeration unit 2 where the final-stage evaporator 22 and the first-stage condenser are located fails, on the evaporator side, the two second on-off valves 31 adjacent to the final-stage evaporator 22 are closed, and the first on-off valve 61 on the first bypass branch 6 upstream of the previous-stage evaporator 22 (i.e., the second-stage evaporator 22) and the third on-off valve 11 on the first backup main line 1, located upstream of the first-stage first bypass branch 6, are closed. The remaining on-off valves are opened, thereby isolating the failed evaporator 22 online. On the condenser side, the two fifth on-off valves 81 adjacent to the first-stage condenser are closed, and the fourth on-off valve 301 on the second bypass branch 30 downstream of the condenser below the first-stage condenser (i.e., the second-stage condenser) and the sixth on-off valve 91 on the second backup main line 9, located downstream of the final-stage second bypass branch 30, are closed. The remaining on-off valves are opened, thereby isolating the failed first-stage condenser online, thereby allowing staff to perform maintenance on the failed refrigeration unit 2 while the refrigeration system is operating normally.

[0092] In other cases where the number of compression refrigeration units using water-cooled condensers 24 in the refrigeration system is greater than or equal to 2, when a compression refrigeration unit fails, the opening and closing of each on-off valve can be inferred from the above-mentioned cases, and will not be explained one by one here.

[0093] It should be understood that the arrangement of the evaporator side and condenser side piping and on-off valves is not limited to the above combination, and other combination directions can also be adopted, for example: the evaporator side piping and on-off valve are arranged in a Figure 9c The structure of the evaporator side pipeline and on-off valve, the condenser side pipeline and on-off valve adopt Figure 10a The structure of the pipeline and on-off valve on the condenser side; or, the pipeline and on-off valve on the evaporator side adopt Figure 10a The structure of the evaporator side pipeline and on-off valve, the condenser side pipeline and on-off valve adopt Figure 9cThe structure of the condenser side pipeline and the on-off valve; or, the structure of the evaporator side pipeline and the on-off valve Figure 8 , the structure of the condenser side pipeline and the on-off valve Figure 9c , or Figure 10a the structure of the condenser side pipeline and the on-off valve, etc. In each of the above cases, the opening and closing of the on-off valve in the case of a specific fault can be derived from the foregoing and will not be described one by one here.

[0094] Figure 11a A structure schematic diagram of a refrigeration system is provided in the present application. As shown in Figures 11a to 11c , in a specific implementation, two second bypass branches 30 are connected between each second standby main pipeline 9 and each second pipeline 8; three fifth on-off valves 81 are arranged on each second pipeline 8, two of the three fifth on-off valves 81 are located between the corresponding two second bypass branches 30, and the remaining one of the three fifth on-off valves 81 is located between the two second bypass branches 30 and the preceding stage water-cooled condenser 24; a sixth on-off valve 91 is arranged on the pipeline section between the two adjacent second bypass branches 30 of the second standby main pipeline 9. Of course, at least three fifth on-off valves 81 can be arranged on the second pipeline 8, and at least one sixth on-off valve 91 can be arranged on the pipeline section between the two adjacent second bypass branches 30 of the second standby main pipeline 9. When this scheme is adopted, the fault fifth on-off valve 81 can also be isolated when the condenser side fifth on-off valve 81 fails. The opening and closing of the valves when the evaporator side fails can be referred to the foregoing, and will not be described here. The opening and closing of each on-off valve when the condenser side fifth on-off valve 81 fails will be briefly described below. Figure 11a In each of the figures, the fifth on-off valve 81 in the dashed box represents the fault fifth on-off valve 81, the on-off valve truncated by the straight line represents the closed on-off valve, and the broken line in the zigzag shape schematically shows the flow direction of the fluid in the refrigeration system. In order to facilitate understanding, in the following, of the three fifth on-off valves 81 on the second pipeline 8, the fifth on-off valve 81 located at the most upstream is denoted as H81, the fifth on-off valve 81 located at the middle is denoted as M81, and the fifth on-off valve 81 located at the most downstream is denoted as T81.

[0095] Figure 11a The opening and closing of each on-off valve when the H81 on the first second pipeline 8 downstream of the first stage water-cooled condenser 24 fails is shown in FIG. 2. As shown in Figure 11bAs shown, when the H81 fails, the two fifth on-off valves 81 adjacent to the H81 are closed, the fourth on-off valve 301 on the second bypass branch 30 closest to the H81 is closed, and the sixth on-off valve 91 parallel to the second-stage water-cooled condenser 24 and the third-stage water-cooled condenser 24 is closed, while the remaining on-off valves are opened, so that the failed H81 can be isolated online, and the maintenance of the failed H81 can be performed under the normal operation of the refrigeration system.

[0096] Figure 11b As shown, when the H81 fails, the two fifth on-off valves 81 adjacent to the H81 are closed, the fourth on-off valve 301 on the second bypass branch 30 closest to the H81 is closed, and the sixth on-off valve 91 parallel to the second-stage water-cooled condenser 24 and the third-stage water-cooled condenser 24 is closed, while the remaining on-off valves are opened, so that the failed H81 can be isolated online, and the maintenance of the failed H81 can be performed under the normal operation of the refrigeration system. Figure 11c

[0097] Figure 11c As shown, when the H81 fails, the two fifth on-off valves 81 adjacent to the H81 are closed, the fourth on-off valve 301 on the second bypass branch 30 closest to the H81 is closed, and the sixth on-off valve 91 parallel to the second-stage water-cooled condenser 24 and the third-stage water-cooled condenser 24 is closed, while the remaining on-off valves are opened, so that the failed H81 can be isolated online, and the maintenance of the failed H81 can be performed under the normal operation of the refrigeration system. Figure 11c

[0098] When the fifth on-off valve 81 on the other second pipeline 8 fails, the opening and closing of each on-off valve can be set according to the actual situation, which will not be described one by one here. In addition, when the refrigeration system shown in FIG. 8 is used, the opening and closing strategy of each on-off valve when each refrigeration unit 2 and each on-off valve are working normally includes but is not limited to: closing each first on-off valve 61, third on-off valve 11, fourth on-off valve 301, and each sixth on-off valve 91, and keeping the remaining on-off valves open. Figure 12a

[0099] ​​​Figure 12a This is a structural diagram of a refrigeration system provided in this application. Figure 11c The refrigeration system shown is Figure 12a The difference between the refrigeration system shown is that: two fourth on-off valves 301 are provided on each second bypass branch 30. Of course, at least two fourth on-off valves 301 can be provided on each second bypass branch 30. When this solution is adopted, when the fourth on-off valve 301 fails, the faulty fourth on-off valve 301 can be isolated and maintained online. Figure 12b 、 Figure 12c and Figure 12a This solution illustrates the isolation and maintenance of a faulty fourth on-off valve 301. In the figures, the fourth on-off valve 301 in the dashed box represents a faulty fourth on-off valve 301, the on-off valve 301 interrupted by a straight line represents a closed on-off valve, and the broken dashed line illustrates a section of the fluid flow in the refrigeration system. For ease of understanding, the fourth on-off valve 301 on the second bypass branch 30, closer to the second pipeline 8, is designated H301, while the fourth on-off valve 301 farther from the second pipeline 8 is designated M301.

[0100] Figure 12a Schematic diagram of the opening and closing of each on-off valve when H301 on the second bypass branch 30 fails in the flow direction of water in the second pipeline 8. Figure 12a As shown, when H301 fails, M301 located on the same second bypass branch 30 as H301 is closed, the first fifth on-off valve 81 upstream and downstream of the second bypass branch 30 is closed, and the sixth on-off valve 91 connected in parallel with the first-stage water-cooled condenser 24 and the third-stage water-cooled condenser 24 is closed, and the remaining on-off valves are opened. In other words, the fifth on-off valve 81 closest to the faulty fourth on-off valve 301 upstream and downstream is closed, the other fourth on-off valve 301 on the second bypass branch 30 where the faulty fourth on-off valve 301 is located is closed, and the sixth on-off valve 91 connected in parallel with the first-stage water-cooled condenser 24 and the third-stage water-cooled condenser 24 is closed, and the remaining on-off valves are opened, thereby isolating the faulty H301 online. This allows staff to perform maintenance on the faulty H301 while the refrigeration system is operating normally.

[0101] It is worth noting that if Figure 12b As shown, if the faulty fourth on-off valve 301 is isolated and the water-cooled condenser 24 is also isolated, the sixth on-off valve 91 connected in parallel with the isolated water-cooled condenser 24 needs to be opened, and the compression refrigeration unit is not turned on. Figure 12cIf no water-cooled condenser 24 is isolated simultaneously with the faulty fourth on-off valve 301, the sixth on-off valve 91 connected in parallel to the preceding water-cooled condenser 24 adjacent to the faulty fourth on-off valve 301 must be opened, and the compression refrigeration unit containing the preceding water-cooled condenser 24 must remain closed. It should be understood that when H301 fails, the opening and closing of the on-off valves is not limited to the above scheme; other schemes may also be employed, as long as the faulty H301 is isolated while ensuring normal operation of the refrigeration system.

[0102] Figure 12c Schematic diagram of the opening and closing of each on-off valve when M301 on the first second bypass branch 30 fails in the flow direction of water in the second pipeline 8. Figure 12c As shown, when M301 fails, H301 located on the same second bypass branch 30 as M301 is closed, and each sixth on-off valve 91 is closed, while the remaining on-off valves are opened. This allows the failed M301 to be isolated online, allowing personnel to perform maintenance on the failed M301 while the refrigeration system is operating normally. It should be understood that when M301 fails, the opening and closing of the on-off valves is not limited to the above scheme, and other schemes may also be adopted, as long as the normal operation of the refrigeration system is ensured while isolating the failed M301.

[0103] Refrigeration system uses Figure 13 In the structure shown, when the sixth on-off valve 91 fails, the online isolation and maintenance of the sixth on-off valve 91 can also be achieved. Figure 14a As shown, along the direction of water flow in the second backup main line 9 (i.e., from left to right in the figure), when the second sixth on-off valve 91 fails, the two fourth on-off valves 301 adjacent to the sixth on-off valve 91 are closed, and each of the sixth on-off valves 91 is closed, while the remaining on-off valves are opened. This allows the failed sixth on-off valve 91 to be isolated online, allowing staff to perform maintenance on the failed sixth on-off valve 91 while the refrigeration system is operating normally. It should be understood that when the sixth on-off valve 91 fails, the opening and closing conditions of the various on-off valves are not limited to the above scheme, and other schemes may also be adopted, as long as the failed sixth on-off valve 91 can be isolated while ensuring the normal operation of the refrigeration system.

[0104] It should be understood that each on-off valve mentioned in this application can be either a manual valve or an electrically controlled valve.

[0105] Figure 14a A schematic diagram of the structure of a refrigeration system is shown in FIG. Figure 14aAs shown, the refrigeration system comprises a second heat exchanger 40, the second heat exchanger 40 comprising a first flow channel and a second flow channel which are isolated from each other and in heat conduction connection, the water inlet of the first standby main pipeline 1 and the water inlet of the first-stage heat exchange assembly 21 are connected with the water outlet of the first flow channel of the second heat exchanger 40, and the water inlet of the second standby main pipeline 9 and the water inlet of the first-stage water-cooled condenser 24 are connected with the water outlet of the second flow channel of the second heat exchanger 40. Exemplarily, the refrigeration system comprises a cooling tower 50, the water outlet of the second standby main pipeline 9 and the water outlet of the last-stage water-cooled condenser 24 are connected with the water inlet of the cooling tower 50, and the water outlet of the cooling tower 50 is connected with the water inlet of the second flow channel of the second heat exchanger 40. The refrigeration system further comprises a surface cooler 7, the water inlet of the first flow channel of the second heat exchanger 40 is connected with the water outlet of the surface cooler 7, and the water outlet of the first standby main pipeline 1 and the water outlet of the last-stage heat exchange assembly 21 are connected with the water inlet of the surface cooler 7. The surface cooler 7 can be arranged in the data center 400 or the industrial plant which needs refrigeration, so as to realize refrigeration of the corresponding data center 400 or the industrial plant.

[0106] The specific embodiments of the refrigeration system provided in the present application will be described below. Figure 14a The specific embodiments of the refrigeration system provided in the present application will be described below. Figure 14aAs shown, the refrigeration system includes three compression refrigeration units connected in series: a second heat exchanger 40, an air-to-water cooler 7, and a cooling tower 50. On the evaporator side, the water outlet of the air-to-water cooler 7 is connected to the water inlet of the first flow channel of the second heat exchanger 40 (i.e., the secondary water inlet). The water outlet of the first flow channel of the second heat exchanger 40 is connected to the water inlet of the evaporator 22 via an inlet pipe 4. Each stage of the evaporator 22 is connected in series via a corresponding first pipe 3. The water outlet of the last stage of the evaporator 22 is connected to the water inlet of the air-to-water cooler 7 via an outlet pipe 5 and a circulating pump 300'. A first backup main line 1 is connected in parallel with the branches of each evaporator 22. That is, the water inlet of the first backup main line 1 is connected to the water outlet of the first flow channel of the second heat exchanger 40. The water outlet of the first backup main line 1 is also connected to the water inlet of the air-to-water cooler 7 via a circulating pump 300'. In order to improve the reliability of the refrigeration system operation, the water outlet of the first backup main line 1 and the water outlet of the water outlet pipe 5 can be connected to the water inlet of the air-water cooler 7 after merging through at least two parallel circulation pumps 300' and corresponding pipes. The air-water cooler 7 is used to cool the data center 400 or the corresponding industrial plant. Furthermore, two first bypass branches 6 are connected between the first backup main line 1 and each first pipe 3, and two first on-off valves 61 are provided on each first bypass branch 6. Three second on-off valves 31 are provided on each first pipe 3, two of the three second on-off valves 31 are located between the corresponding two first bypass branches 6, and the remaining second on-off valve 31 is located between the first bypass branch 6 and the previous stage heat exchange component 21. A third on-off valve 11 is provided on the pipe section of the first backup main line 1 between two adjacent first bypass branches 6.

[0107] On the condenser side, two adjacent water-cooled condensers 24 are connected via a second pipeline 8. The water inlet of the first-stage water-cooled condenser 24 is connected to a third pipeline 10, and the water outlet of the final-stage water-cooled condenser 24 is connected to a fourth pipeline 20. The branch lines containing each water-cooled condenser 24 are connected in parallel with the second backup main pipeline 9. The water inlet of the second backup main pipeline 9 and the water inlet of the third pipeline 10 are both connected to the water outlet of the second flow channel of the second heat exchanger 40 (i.e., the water outlet on the primary side). The water outlet of the second backup main pipeline 9 and the water outlet of the fourth pipeline 20 are both connected to the water inlet of the cooling tower 50. The water outlet of the cooling tower 50 is connected to the water inlet of the second flow channel of the second heat exchanger 40 via at least two circulating pumps 300' connected in parallel. Two second bypass branches 30 are connected between the second backup main line 9 and each second line 8. These two second bypass branches 30 are connected in parallel, and each second bypass branch 30 is equipped with two fourth on-off valves 301. The section of each second line 8 between a pair of adjacent second bypass branches 30 is equipped with two fifth on-off valves 81. Each second line 8 upstream of the corresponding two second bypass branches 30 is also equipped with a fifth on-off valve 81. The section of the second backup main line 9 between two adjacent second bypass branches 30 is equipped with a sixth on-off valve 91.

[0108] application Figure 14b In the refrigeration system shown, when all refrigeration units 2 are operating normally, the first and last third on-off valves 11 on the first backup main line 1 are closed, the third on-off valves 11 between two adjacent pairs of first bypass branches 6 are closed, and the remaining on-off valves are opened. The first and last sixth on-off valves 91 on the second backup main line 9 are closed, the sixth on-off valves 91 between two adjacent pairs of second bypass branches 30 are closed, and the remaining on-off valves are opened. A pair of first bypass branches 6 refers to two first bypass branches 6 connected to the same first pipeline 3, and a pair of second bypass branches refers to two second bypass branches 30 connected to the same second pipeline 8.

[0109] Please refer to Figure 6c When a refrigeration unit 2 fails, on the evaporator side of the failed refrigeration unit 2, the second on-off valves 31 on both sides of the evaporator 22 are closed, the third on-off valve 11 connected in parallel with the evaporator 22 is opened, and the remaining on-off valves remain in the same state as during normal operation, thereby isolating the evaporator 22 of the failed refrigeration unit 2. On the condenser side of the failed refrigeration unit 2, the fifth on-off valves 81 on both sides of the condenser are closed, the sixth on-off valve 91 connected in parallel with the condenser is opened, and the remaining on-off valves remain in the same state as during normal operation, thereby isolating the condenser of the failed refrigeration unit 2.

[0110] Please refer to Figure 7aWhen a second on-off valve 31 fails, the two second on-off valves 31 closest to the second on-off valve 31 are closed, and the first on-off valve 61 on the first bypass branch 6 closest to the second on-off valve 31 is closed. If the refrigeration unit 2 is isolated at the same time as the second on-off valve 31, the third on-off valve 11 connected in parallel with the isolated refrigeration unit 2 is opened, and the isolated refrigeration unit 2 is not opened. If the refrigeration unit 2 is not isolated at the same time as the second on-off valve 31 is isolated, the third on-off valve 11 connected in parallel with the previous refrigeration unit 2 adjacent to the second on-off valve 31 is opened, and the previous refrigeration unit 2 is not opened. The status of the remaining on-off valves remains the same as when the refrigeration system is operating normally.

[0111] Please refer to Figure 7c When a first on-off valve 61 far away from the first backup main line 1 fails, the second on-off valve 31 closest to the left and right sides of the first on-off valve 61 is closed, and the other first on-off valve 61 located on the same first bypass branch 6 as the first on-off valve 61 is closed. If the refrigeration unit 2 is isolated while the faulty first on-off valve 61 is isolated, the third on-off valve 11 connected in parallel with the isolated refrigeration unit 2 is opened, and the isolated refrigeration unit 2 is not opened. If the refrigeration unit 2 is not isolated while the faulty first on-off valve 61 is isolated, the third on-off valve 11 connected in parallel with the preceding refrigeration unit 2 adjacent to the faulty first on-off valve 61 is opened, and the preceding refrigeration unit 2 is not opened. The status of the other on-off valves remains the same as during normal operation, that is, the isolation and maintenance of the faulty first on-off valve 61 can be achieved on the basis of the normal operation of the refrigeration system.

[0112] Please refer to Figure 8 If a first on-off valve 61 near the first backup main line 1 fails, the third on-off valves closest to the left and right sides of the first on-off valve 61 are closed, and the other first on-off valve 61 on the same first bypass branch line 6 as the first on-off valve 61 is closed. The remaining on-off valves remain in the same state as during normal operation. This allows the faulty first on-off valve 61 to be isolated and maintained while the refrigeration system remains operating normally.

[0113] Please refer to Figure 11c When a third on-off valve 11 fails, the third on-off valves 11 adjacent to the faulty third on-off valve 11 on its left and right sides are closed. The first on-off valves 61 on the two first bypass branches 6 adjacent to the faulty third on-off valve 11, which are close to the first backup main line 1, are also closed. The remaining on-off valves remain in the same state as during normal operation. This allows the faulty third on-off valve 11 to be isolated and maintained while the refrigeration system is operating normally.

[0114] Please refer to Figure 11b, if a fifth shutoff valve 81 fails, the two fifth shutoff valves 81 closest to the fifth shutoff valve 81 are closed, and the fourth shutoff valve 301 on the second bypass branch 30 closest to the fifth shutoff valve 81 is closed. If the fifth shutoff valve 81 is isolated, the sixth shutoff valve 91 in parallel with the refrigeration unit 2 being isolated is opened, and the refrigeration unit 2 being isolated is not started. Please refer to Figure 12a , if the fifth shutoff valve 81 is isolated, the sixth shutoff valve 91 in parallel with the preceding refrigeration unit 2 adjacent to the fifth shutoff valve 81 is opened, and the preceding refrigeration unit 2 is not started. The states of the remaining shutoff valves remain the same as when the refrigeration system is normally operating.

[0115] Please refer to Figure 12b , if a fourth shutoff valve 301 far from the second standby main pipeline 9 fails, the fifth shutoff valves 81 closest to the fourth shutoff valve 301 on the left and right sides are closed, and the other fourth shutoff valve 301 on the same second bypass branch 30 as the fourth shutoff valve 301 is closed. If the fourth shutoff valve 301 that fails is isolated, the sixth shutoff valve 91 in parallel with the refrigeration unit 2 being isolated is opened, and the refrigeration unit 2 being isolated is not started. Please refer to Figure 12c , if the fourth shutoff valve 301 that fails is isolated, the sixth shutoff valve 91 in parallel with the preceding refrigeration unit 2 adjacent to the fourth shutoff valve 301 that fails is opened, and the preceding refrigeration unit 2 is not started. The states of the remaining shutoff valves remain the same as when the refrigeration system is normally operating. Thus, the isolation and maintenance of the fourth shutoff valve 301 that fails can be realized on the basis of normal operation of the refrigeration system.

[0116] Please refer to Figure 13 , if a fourth shutoff valve 301 close to the second standby main pipeline 9 fails, the sixth shutoff valves 91 closest to the fourth shutoff valve 301 on the left and right sides are closed, and the other fourth shutoff valve 301 on the same second bypass branch 30 as the fourth shutoff valve 301 is closed. The states of the remaining shutoff valves remain the same as when the refrigeration system is normally operating, that is, the isolation and maintenance of the fourth shutoff valve 301 that fails can be realized on the basis of normal operation of the refrigeration system.

[0117] Please refer to Figure 15 , if a sixth shutoff valve 91 fails, the sixth shutoff valves 91 adjacent to the sixth shutoff valve 91 that fails on the left and right sides are closed, and the fourth shutoff valves 301 on the two second bypass branches 30 adjacent to the second standby main pipeline 9 adjacent to the sixth shutoff valve 91 that fails are closed. The states of the remaining shutoff valves remain the same as when the refrigeration system is normally operating. Thus, the isolation and maintenance of the sixth shutoff valve 91 that fails can be realized on the basis of normal operation of the refrigeration system.

[0118] Figure 15This is a schematic diagram of another refrigeration system provided in this application. Figure 14b The refrigeration system shown is Figure 14b The difference between the refrigeration systems shown is that each refrigeration unit 2 is a compression refrigeration unit using an air-cooled condenser 23. The condenser side has only a condenser, and there is no connection between the condensers at each level. The water inlet of the water inlet pipe 4 and the water inlet of the first backup main pipe 1 are connected to the water outlet of the surface cooler 7, and the water outlet of the water outlet pipe 5 and the water outlet of the first backup main pipe 1 are connected to the water inlet of the surface cooler 7. In this solution, when the refrigeration unit 2 and the on-off valves fail, the opening and closing conditions of the on-off valves in the refrigeration system can be referred to. ​ When the same fault occurs in the refrigeration system shown, the opening and closing states of the on-off valves at various locations on the evaporator side are not described in detail here.

[0119] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A refrigeration system, characterized in that: The invention comprises a first backup main line and at least two refrigeration units connected in series, wherein each refrigeration unit comprises a heat exchange assembly, two adjacent stages of the heat exchange assemblies are connected via a first pipeline, the water inlet of the first stage of the heat exchange assembly is connected to the water inlet of the first backup main line via the water inlet pipeline, and the water outlet of the last stage of the heat exchange assembly is connected to the water outlet of the first backup main line via the water outlet pipeline; At least two first bypass branches are connected between the first backup main line and each of the first pipelines, the at least two first bypass branches are connected in parallel, and each of the first bypass branches is provided with at least one first on-off valve; a section of each first pipeline located between a pair of adjacent first bypass branches is provided with at least one second on-off valve; or at least one first bypass branch is connected between the first backup main line and each of the first pipelines, each of the first bypass branches is provided with at least one first on-off valve, and at least one second on-off valve is provided on each side of one of the first bypass branches on each of the first pipelines; The water inlet pipeline and the water outlet pipeline are also each provided with a second on-off valve, and the first backup main pipeline, the pipe sections located upstream of the first bypass branch of the first stage and downstream of the first bypass branch of the last stage are each provided with a third on-off valve.

2. The refrigeration system according to claim 1, wherein: Two first bypass branches are connected between the first backup main line and each of the first pipelines; three second on-off valves are provided on each of the first pipelines, two of the three second on-off valves are located between the corresponding two first bypass branches, and the remaining one of the three second on-off valves is located between the first bypass branch and the heat exchange component of the previous stage; A third on-off valve is provided on the pipe section of the first backup main pipe located between two adjacent first bypass branches.

3. The refrigeration system according to claim 2, wherein: Each of the first bypass branches is provided with two first on-off valves.

4. The refrigeration system according to claim 1, wherein: It includes a surface cooler, the water inlet of the first backup main line and the water inlet of the first-stage heat exchange component are both connected to the water outlet of the surface cooler, and the water outlet of the first backup main line and the water outlet of the last-stage heat exchange component are both connected to the water inlet of the surface cooler.

5. The refrigeration system according to any one of claims 1 to 4, characterized in that: The heat exchange component is a first heat exchanger, or the refrigeration unit is a compression refrigeration unit, the compression refrigeration unit includes an evaporator and an air-cooled condenser, and the heat exchange component is the evaporator.

6. The refrigeration system according to claim 1, wherein: At least two adjacent refrigeration units are compression refrigeration units, each comprising an evaporator and a water-cooled condenser, wherein the heat exchange component is the evaporator; the two adjacent water-cooled condensers are connected via a second pipeline, and the water inlet of the first-stage water-cooled condenser is connected to a third pipeline, and the water outlet of the last-stage water-cooled condenser is connected to a fourth pipeline; the refrigeration system further comprises a second backup main pipeline, and the branches where the water-cooled condensers are located are connected in parallel with the second backup main pipeline; At least two second bypass branches are connected between the second backup main line and each of the second pipelines, the at least two second bypass branches are connected in parallel, and each of the second bypass branches is provided with at least one fourth on-off valve, and a section of each second pipeline located between a pair of adjacent second bypass branches is provided with at least one fifth on-off valve; or at least one second bypass branch is connected between the second backup main line and each of the second pipelines, and each of the second bypass branches is provided with at least one fifth on-off valve on both sides; The third pipeline and the fourth pipeline are also both provided with a fifth on-off valve, and the pipeline sections on the second backup main pipeline located upstream of the first-stage second bypass branch and downstream of the last-stage second bypass branch are both provided with a sixth on-off valve.

7. The refrigeration system according to claim 6, wherein: Two second bypass branches are connected between the second backup main line and each of the second pipelines; each of the second pipelines is provided with three fifth on-off valves, two of the three fifth on-off valves are located between the corresponding two second bypass branches, and the remaining one of the three fifth on-off valves is located between the second bypass branch and the previous stage water-cooled condenser; A sixth on-off valve is provided on the pipe section of the second backup main pipe located between two adjacent second bypass branches.

8. The refrigeration system according to claim 7, wherein: Each of the second bypass branches is provided with two fourth on-off valves.

9. The refrigeration system according to claim 6, wherein: It includes a second heat exchanger, which includes a first flow channel and a second flow channel that are isolated from each other and thermally connected. The water inlet of the first backup main line and the water inlet of the first-stage heat exchange component are both connected to the water outlet of the first flow channel of the second heat exchanger, and the water inlet of the second backup main line and the water inlet of the first-stage water-cooled condenser are both connected to the water outlet of the second flow channel of the second heat exchanger.

10. The refrigeration system according to claim 9, wherein: It includes a cooling tower, the water outlet of the second backup main line and the water outlet of the last-stage water-cooled condenser are both connected to the water inlet of the cooling tower, and the water outlet of the cooling tower is connected to the water inlet of the second flow channel of the second heat exchanger.

11. The refrigeration system according to claim 9, wherein: It includes a surface cooler, the water inlet of the first flow channel of the second heat exchanger is connected to the water outlet of the surface cooler, and the water outlet of the first backup main line and the water outlet of the last stage heat exchange component are both connected to the water inlet of the surface cooler.

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