Multi-system water chiller and control method thereof

Abstract

The application discloses a multi-system water chiller and a control method thereof. The water chiller comprises at least two heat exchange systems, at least two water systems and a combined heat exchanger. By switching the series or parallel state and the open or closed state of the combined heat exchanger, the heat exchange systems can be combined to form or separately constitute independent heat exchange circulation loops. The water systems can be combined to form or separately constitute independent water circulation loops, thereby significantly increasing the heating or refrigeration capacity of the unit, i.e. improving the hot water or cold water output capacity. Furthermore, the application switches and controls different heat exchange circulation loops by adjusting the refrigerant flow path between multiple heat exchange systems and the combined heat exchanger, and switches and controls different water circulation loops by adjusting the water medium flow path of multiple water systems. Therefore, after the water chiller is installed, different operation modes can be selected and switched according to different heat or cold requirements, and hot water or cold water with corresponding capacity and temperature can be output, so that the heating or refrigeration capacity of the unit can be matched with the actual requirement, without the need to replace the whole device or part of the elements, which is low in cost and convenient to maintain.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat exchange equipment, and in particular to a water chiller with multiple systems and a control method thereof. BACKGROUND

[0002] The water chiller is a common heat exchange equipment in the refrigeration industry, which has the characteristics of stable heat exchange, low running noise and small influence on the surrounding environment, and is currently widely used in new large buildings such as hotels, office buildings, various factory buildings and other use scenarios.

[0003] The single-system water chiller has limited refrigeration or heating capacity, especially in office buildings, shopping malls and other use scenarios. The past method is to purchase high-power imported compressors (commonly known as 1000-1400KW) from abroad, which is high in cost and difficult to maintain. If a series or hybrid multi-head mode is used, the refrigeration or heating capacity of the water chiller can be increased to some extent, but the unit can only run according to the preset conditions of adding or reducing machines during the process of loading from full load to minimum load or unloading from minimum load to full load, which is high in power consumption and low in energy efficiency ratio, and the working effect is not ideal. Moreover, the unit using the series or hybrid multi-head mode has poor adaptability, and after installation, it cannot match the corresponding load according to the heat or cold demand of different use scenarios, or realize load control adjustment according to different cold or heat demand. Replacing the entire device or part of the elements after installation will result in extremely high cost and inconvenience in maintenance.

[0004] Therefore, there is an urgent need in the prior art to invent a water chiller with large refrigeration or heating capacity and wide use scenarios and a control method thereof. SUMMARY

[0005] In order to overcome the technical problems of insufficient refrigeration or heating capacity and poor adaptability in different use scenarios of the water chiller described in the prior art, the present application provides a multi-system water chiller and a control method thereof, which can significantly improve the refrigeration or heating capacity of the water chiller, and can switch the use mode of different systems, so that the refrigeration or heating capacity of the water chiller realizes multiple and independent optional combinations, and is suitable for different use scenarios.

[0006] The technical solution adopted by the present application to solve the problem is:

[0007] A multi-system water chiller is provided, characterized in that it comprises at least:

[0008] A first heat exchange system and a first water system, the first heat exchange system comprising a first heat exchanger, and the first water system comprising a first water tank and a first water pipe;

[0009] A second heat exchange system and a second water system, the second heat exchange system comprising a second heat exchanger, and the second water system comprising a second water tank and a second water pipe;

[0010] The combined heat exchanger comprises at least a first heat exchange section and a second heat exchange section, and the first heat exchange section and the second heat exchange section are arranged alternately in sequence.

[0011] The first heat exchange section and the second heat exchange section are arranged in parallel, so that the first heat exchange system and the first heat exchange section form a first heat exchange circulation loop, and the second heat exchange system and the second heat exchange section form a second heat exchange circulation loop; or the first heat exchange section and the second heat exchange section are arranged in series, so that the first heat exchange system, the first heat exchange section, the second heat exchange system and the second heat exchange section form a third heat exchange circulation loop.

[0012] In one preferred embodiment, the present application provides a technical solution about the specific design of two heat exchange systems.

[0013] In the technical solution, the first heat exchange system and the second heat exchange system further comprise a compressor, a throttling element, a four-way valve and a main valve, the compressor, the throttling element, the four-way valve, the first heat exchanger and the first heat exchange section form a first heat exchange circulation loop, the compressor, the throttling element, the four-way valve, the second heat exchanger and the second heat exchange section form a second heat exchange circulation loop; the main valve is located between the first heat exchanger and the first heat exchange section, and between the second heat exchanger and the second heat exchange section.

[0014] In another preferred embodiment, the present application provides a technical solution about the specific design of two water systems.

[0015] In the technical solution, the first water tank and the second water tank are arranged in parallel, so that the first water system and the first heat exchanger form a first water circulation loop, and the second water system and the second heat exchanger form a second water circulation loop; or the first water tank and the second water tank are arranged in series, so that the first water system, the first heat exchanger, the second water system and the second heat exchanger form a third water circulation loop.

[0016] Further, the first water system and the second water system further comprise a water pump, a water flow switch, an electric heating element and a pressure sensor, the first water pipe and the second water pipe comprise an inlet pipe and an outlet pipe, the inlet pipe is connected with the water outlet of the first water tank and the water inlet of the first heat exchanger, and connected with the water outlet of the second water tank and the water inlet of the second heat exchanger; the outlet pipe is connected with the water outlet of the first heat exchanger and the water outlet of the second heat exchanger; the water pump and the water flow switch are located in the inlet pipe, the electric heating element is located in the outlet pipe, and the pressure sensor is located in the inlet pipe and the outlet pipe.

[0017] Based on the same design idea, the application further provides a multi-system water chiller control method, which is applied to the multi-system water chiller described above, and the control method comprises the following steps:

[0018] detecting a first operating parameter of the multi-system water chiller, starting an operating mode of the multi-system water chiller according to a detection result, and controlling the operation of a first heat exchange system, a second heat exchange system, a first water system and a second water system according to the operating mode;

[0019] The first operating parameter at least comprises the return water temperature of the first water tank and / or the second water tank, the switch state of the water flow switch and the shutdown time of the compressor.

[0020] The operating mode at least comprises a single heating mode, a single cooling mode, a combined heating mode, a combined cooling mode, a step heating mode and a step cooling mode.

[0021] In a preferred scheme, the application further provides a technical scheme about how to start the single heating mode and the single cooling mode and how to operate after starting.

[0022] In the technical scheme, the single heating mode is started when the following conditions are met simultaneously:

[0023] The return water temperature of the first water tank is less than a first preset temperature, the water flow switch of the first water system is closed, and the shutdown time of the compressor is greater than a first preset time; or the return water temperature of the second water tank is less than a second preset temperature, the water flow switch of the second water system is closed, and the shutdown time of the compressor is greater than the first preset time.

[0024] When the single heating mode is started, the first heat exchange system and the first heat exchange section form a first heating circulation loop, and the first water system and the first heat exchanger form a first hot water circulation loop; or the second heat exchange system and the second heat exchange section form a second heating circulation loop, and the second water system and the second heat exchanger form a second hot water circulation loop.

[0025] The single cooling mode is started when the following conditions are met simultaneously:

[0026] the return water temperature of the first water tank is greater than a third preset temperature, the water flow switch of the first water system is closed, and the shutdown time of the compressor is greater than a first preset time; or, the return water temperature of the second water tank is greater than a fourth preset temperature, the water flow switch of the second water system is closed, and the shutdown time of the compressor is greater than the first preset time;

[0027] when the single cooling mode is started, the first heat exchange system and the first heat exchange section constitute a first refrigeration cycle loop, and the first water system and the first heat exchanger constitute a first cold water circulation loop; or, the second heat exchange system and the second heat exchange section constitute a second refrigeration cycle loop, and the second water system and the second heat exchanger constitute a second cold water circulation loop.

[0028] In another preferred scheme, the present application further provides a technical scheme about how the combined heating mode and the combined cooling mode are started and how they run after being started.

[0029] In this technical scheme, the combined heating mode is started when the following conditions are met simultaneously:

[0030] the return water temperature of the first water tank is less than a first preset temperature, the return water temperature of the second water tank is less than a second preset temperature, the water flow switches of the first water system and the second water system are both closed, and the shutdown time of the compressor is greater than a first preset time;

[0031] when the combined heating mode is started, the first heat exchange system and the first heat exchange section constitute a first heating cycle loop, the first water system and the first heat exchanger constitute a first hot water circulation loop; and, the second heat exchange system and the second heat exchange section constitute a second heating cycle loop, the second water system and the second heat exchanger constitute a second hot water circulation loop;

[0032] the combined cooling mode is started when the following conditions are met simultaneously:

[0033] the return water temperature of the first water tank is greater than a third preset temperature, the return water temperature of the second water tank is greater than a fourth preset temperature, the water flow switches of the first water system and the second water system are both closed, and the shutdown time of the compressor is greater than a first preset time;

[0034] when the combined cooling mode is started, the first heat exchange system and the first heat exchange section constitute a first refrigeration cycle loop, and the first water system and the first heat exchanger constitute a first cold water circulation loop; and, the second heat exchange system and the second heat exchange section constitute a second refrigeration cycle loop, and the second water system and the second heat exchanger constitute a second cold water circulation loop.

[0035] In another preferred scheme, the present application further provides a technical scheme about how the combined heating mode and the combined cooling mode are started and how they run after being started.

[0036] In the technical solution, the following conditions are met simultaneously, and the step-by-step heating mode is started:

[0037] The return water temperature of the first water tank and the second water tank is less than the fifth preset temperature, the water flow switch of the first water system and the second water system is closed, and the shutdown time of the compressor is greater than the first preset time;

[0038] When the step-by-step heating mode is started, the first heat exchange system, the first heat exchange section, the second heat exchange system and the second heat exchange section form a third heating circulation loop, and the first water system, the first heat exchanger, the second water system and the second heat exchanger form a third hot water circulation loop;

[0039] The following conditions are met simultaneously, and the step-by-step cooling mode is started:

[0040] The return water temperature of the first water tank and the second water tank is greater than the sixth preset temperature, the water flow switch of the first water system and the second water system is closed, and the shutdown time of the compressor is greater than the first preset time;

[0041] When the step-by-step cooling mode is started, the first heat exchange system, the first heat exchange section, the second heat exchange system and the second heat exchange section form a third cooling circulation loop, and the first water system, the first heat exchanger, the second water system and the second heat exchanger form a third cold water circulation loop.

[0042] In another preferred scheme, the application also provides a technical solution about how the auxiliary heating mode is started, closed and run after being started.

[0043] In the technical solution, the control method comprises:

[0044] When the multi-system water chiller runs the single heating mode, the combined heating mode or the step-by-step heating mode, the second operating parameter of the first water system and / or the second water system is detected, and the auxiliary heating mode is started or closed according to the detection result;

[0045] The second operating parameter at least includes the outlet water temperature of the first heat exchanger and / or the second heat exchanger, the return water temperature of the first water tank and / or the second water tank, the inlet water pressure of the inlet water pipeline, the outlet water pressure of the outlet water pipeline and the continuous starting time of the electric heating element.

[0046] Further, the following conditions are met simultaneously, and the auxiliary heating mode is started:

[0047] The outlet water temperature is less than the seventh preset temperature, the inlet water pressure is within the first preset pressure range, and the outlet water pressure is within the second preset pressure range;

[0048] When the auxiliary heating mode is started, the electric heating element works;

[0049] When the following conditions are met simultaneously, the auxiliary heating mode is closed:

[0050] The return water temperature is greater than the eighth preset temperature, and the electric heating continuous start time is greater than the second preset time.

[0051] In summary, the multi-system water chiller and its control method provided by the present application have at least the following technical effects compared to the prior art:

[0052] 1) The multi-system water chiller of the present application includes at least two heat exchange systems and at least two water systems, the heat exchange systems are used to combine to form or separately constitute independent heat exchange circulation loops, and the water systems are used to combine to form or separately constitute independent water circulation loops, so as to increase the heating or cooling capacity when multiple systems work together, and significantly improve the hot water or cold water output capacity.

[0053] 2) The multi-system water chiller of the present application switches and controls different heat exchange circulation loops (including heating circulation loops and cooling circulation loops) by adjusting the refrigerant flow path between the two heat exchange systems and the combined heat exchanger, and switches and controls different water circulation loops (including hot water circulation loops and cold water circulation loops) by adjusting the water medium flow path of the two water systems, so that different operating modes can be selected and switched according to different heat or cooling capacity requirements after the unit is installed, and hot water or cold water of corresponding capacity and temperature can be output, so that the heating or cooling capacity of the unit matches the actual demand, without the need to replace the entire device or part of the elements, with low cost and convenient maintenance.

[0054] 3) The multi-system water chiller control method of the present application automatically performs load control with the actual demand for heating or cooling water of the water system and the current working condition of the heat exchange system as the target, compares the real-time collected operating parameters and target parameters, and switches and controls different operating modes of the unit through the series or parallel state of the combined heat exchanger and the series or parallel state of the water tank, so that the temperature and quantity of the finally output water meet the requirements. Compared to the traditional multi-head series or hybrid design, the multi-system water chiller of the present application does not need to load or unload according to the load demand, or even frequently start and stop the compressor, avoiding the online running compressor running in the low efficiency area (high load to maximum load and low load to minimum load) for a long time, with good stability and high energy efficiency ratio. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 is a schematic diagram of the composition of the multi-system water chiller of the present application;

[0056] Figure 2 is a schematic diagram of the composition of the first heat exchange system, the first heat exchange section and the first water system of the present application;

[0057] Figure 3 The component schematic diagram of the second heat exchange system, the second heat exchange section and the second water system of the application;

[0058] Figure 4 The component schematic diagram of the first water circulation loop of the application;

[0059] Figure 5 The component schematic diagram of the second water circulation loop of the application;

[0060] Figure 6 The component schematic diagram of the third water circulation loop of the application;

[0061] In the drawings, the reference signs have the following meanings:

[0062] 1, first heat exchange system; 11, first heat exchanger; 12, compressor; 13, throttling element; 14, four-way valve; 15, main valve; 16, economizer; 17, separator; 2, second heat exchange system; 21, second heat exchanger; 3, first water system; 31, first water tank; 32, water pump; 33, water flow switch; 34, electric heating element; 4, second water system; 41, second water tank; 5, combined heat exchanger; 51, first heat exchange section; 52, second heat exchange section; 53, first fan; 54, second fan; 6, equipment terminal. DETAILED DESCRIPTION

[0063] In order to better understand and implement, the technical solutions in the embodiments of the application will be clearly and completely described below in conjunction with the drawings in the embodiments of the application.

[0064] In the description of the application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs. The terms used in the specification of the application herein are only for the purpose of describing the specific embodiments and are not intended to limit the application.

[0066] Example 1

[0067] In the first embodiment of the application, a technical solution of specific design of heat exchange system and water system for multi-system water chiller is provided.

[0068] Referring to Figure 1 As shown, according to the embodiment of the present application, the multi-system water chiller comprises at least two heat exchange systems and two water systems, specifically: a first heat exchange system 1 and a second heat exchange system 2, the first heat exchange system 1 comprises a first heat exchanger 11, and the second heat exchange system 2 comprises a second heat exchanger 21; a first water system 3 and a second water system 4, the first water system 3 comprises a first water tank 41 and a first water pipe, and the second water system 4 comprises a second water tank 41 and a second water pipe. Wherein, the first heat exchanger 11 and the second heat exchanger 21 can be used as condensers or evaporators of the heat exchange system, respectively used for heating or cooling demand; the first water tank 31 and the second water tank 41 are used as water storage containers of the water system, and according to the actual water demand, different capacity of hot water or cold water is output through the water pipe.

[0069] Referring to Figure 1 As shown, the multi-system water chiller further comprises a combined heat exchanger 5, the combined heat exchanger 5 comprises at least two heat exchange sections, specifically: a first heat exchange section 51 and a second heat exchange section 52, the first heat exchange section 51 and the second heat exchange section 52 are arranged alternately. Wherein, the first heat exchanger 11 and the second heat exchanger 21 can be used as condensers or evaporators of the heat exchange system, respectively used for heating or cooling demand. In particular, when the first heat exchanger 11 and the second heat exchanger 21 are used as condensers, the first heat exchange section 51 and the second heat exchange section 52 are used as evaporators; when the first heat exchanger 11 and the second heat exchanger 21 are used as evaporators, the first heat exchange section 51 and the second heat exchange section 52 are used as condensers.

[0070] In the technical scheme of this embodiment, by switching the series or parallel connection and the open or closed state of different heat exchange sections in the combined heat exchanger, the switching and selection of different heat exchange circulation loops can be realized, so as to adapt to the actual demand of different scenes.

[0071] This embodiment takes the technical scheme of two heat exchange systems, two water systems and two heat exchange sections as an example, and the working mode and principle of the multi-system water chiller are described as follows:

[0072] 1, when the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are arranged in parallel, the first heat exchange system 1 and the first heat exchange section 51 form a first heat exchange circulation loop, and the second heat exchange system 2 and the second heat exchange section 52 form a second heat exchange circulation loop, at this time:

[0073] 1) Referring to Figure 2 As shown, if the first heat exchange section 51 of the combined heat exchanger 5 is working and the second heat exchange section 52 is not working, the first heat exchanger 11 in the first heat exchange system 1 and the water medium of the first water system 3 are heat exchanged, so that the first water system 3 outputs corresponding hot water or cold water and directly supplies to the equipment terminal 6 such as the coil.

[0074] 2) see Figure 3 As shown, if the second heat exchange section 52 of the combined heat exchanger 5 is working and the first heat exchange section 51 is not working, the second heat exchanger 21 in the second heat exchange system 2 and the water medium in the second water system 4 exchange heat, so that the second water system 4 produces corresponding hot water or cold water and directly supplies the terminal equipment 6 such as the coil.

[0075] 3) see Figure 2 and Figure 3 As shown, if the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 work at the same time, the first heat exchange cycle loop and the second heat exchange cycle loop respectively form two independent refrigerant circulation loops, so that the first water system 3 and the second water system 4 respectively produce corresponding hot water or cold water and directly supply the terminal equipment 6 such as the coil.

[0076] 2, see Figure 1 As shown, when the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are arranged in series, the first heat exchange system 1, the first heat exchange section 51, the second heat exchange system 2 and the second heat exchange section 52 form a third heat exchange cycle loop, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 work at the same time, and the refrigerant flow paths of the first heat exchange system 1 and the second heat exchange system 2 are consistent, so that the first water system 3 and the second water system 4 combine to produce corresponding hot water or cold water. Specifically:

[0077] 1) The third heat exchange cycle loop can be a refrigerant circulation of the first heat exchanger 11-first heat exchange section 51-second heat exchange section 52-second heat exchanger 21. At this time, the hot water or cold water produced by the first water system 3 flows to the second water system 4, and then to the terminal equipment 6 such as the coil after the heat exchange in the second water system 4 is completed.

[0078] 2) The third heat exchange cycle loop can also be a refrigerant circulation of the second heat exchanger 21-second heat exchange section 52-first heat exchange section 51-first heat exchanger 11. At this time, the hot water or cold water produced by the second water system 4 flows to the first water system 3, and then to the terminal equipment 6 such as the coil after the heat exchange in the first water system 3 is completed.

[0079] In particular, the opening or closing state of the first heat exchange section 51 and the second heat exchange section 52 and the series or parallel state between them can be realized by the opening and closing valve in the pipeline or the combination of the opening and closing valve and the one-way valve. Of course, the combined heat exchanger of the present application is not limited to the above two design methods.

[0080] Therefore, the multi-system water chiller of the present application can increase the heating or refrigeration capacity when the multiple systems work together, and significantly improve the hot water or cold water output capacity. Moreover, the present application adjusts the refrigerant flow path between the two heat exchange systems and the combined heat exchanger by controlling the opening and closing state and the series and parallel state of different heat exchange sections, and then switches the control of different heat exchange circulation loops; the present application adjusts the water medium flow path of the two water systems, and then switches the control of different water circulation loops. Through the above design, the present application can select and switch different operation modes according to different heat or cold demand after the water chiller is installed, and output hot water or cold water with corresponding capacity and temperature, so that the heating or refrigeration capacity of the unit matches the actual demand, without the need to replace the entire device or part of the elements, with low cost and convenient maintenance.

[0081] Specifically, the first heat exchanger 11 and the second heat exchanger 21 of the present embodiment can preferably be plate heat exchangers, and the first heat exchange section 51 and the second heat exchange section 52 can preferably adopt finned tube heat exchangers.

[0082] Embodiment 2

[0083] In the second embodiment of the present application, a specific design of the two heat exchange systems is provided on the basis of the first embodiment.

[0084] Referring to Figure 2 and Figure 3 , in the technical solution of this embodiment, the first heat exchange system 1 and the second heat exchange system 2 further include a compressor 12, a throttling element 13 and a four-way valve 14, the compressor 12, the throttling element 13, the four-way valve 14, the first heat exchanger 11 and the first heat exchange section 51 constitute a first heat exchange circulation loop, and the compressor 12, the throttling element 13, the four-way valve 14, the second heat exchanger 21 and the second heat exchange section 52 constitute a second heat exchange circulation loop. The refrigerant flow path of the first heat exchange circulation loop is: the compressor 12-four-way valve 14-first heat exchanger 11-throttling element 13-first heat exchange section 51-four-way valve 14-compressor 12 (at this time, the first water system produces hot water), or: the compressor 12-four-way valve 14-first heat exchange section 51-throttling element 13-first heat exchanger 11-four-way valve 14-compressor 12 (at this time, the first water system produces cold water). Similarly, the refrigerant flow path of the second heat exchange circulation loop is: the compressor 12-four-way valve 14-second heat exchanger 21-throttling element 13-second heat exchange section 52-four-way valve 14-compressor 12 (at this time, the second water system produces hot water), or: the compressor 12-four-way valve 14-second heat exchange section 52-throttling element 13-second heat exchanger 21-four-way valve 14-compressor 12 (at this time, the second water system produces cold water).

[0085] Further, the compressor 12, the throttling element 13, the four-way valve 14, the first heat exchanger 11, the first heat exchange section 51, the second heat exchanger 21 and the second heat exchange section 52 can also constitute a third heat exchange cycle loop, at this time, the refrigerant flow path is (for the sake of distinction, the components in the first heat exchange system are uniformly named with "first" as the prefix, and the components in the second heat exchange system are uniformly named with "second" as the prefix):

[0086] 1) The first compressor 12, the first heat exchanger 11, the first throttling element 13, the first heat exchange section 51, the second compressor 12, the second heat exchanger 21, the second throttling element 13, and the second heat exchange section 52 are sequentially communicated to constitute a third heating cycle loop (at this time, the first waterway system and the second waterway system combine to heat water, and finally output hot water through the second waterway system);

[0087] 2) The second compressor 12-four-way valve 14-second heat exchanger 21-second throttling element 13-second heat exchange section 52-four-way valve 14-first compressor 12-four-way valve 14-first heat exchanger 11-first throttling element 13-first heat exchange section 51-four-way valve 14-second compressor 12 (at this time, the first waterway system and the second waterway system combine to heat water, and finally output hot water through the first waterway system);

[0088] 3) The first compressor 12-four-way valve 14-first heat exchange section 51-first throttling element 13-first heat exchanger 11-four-way valve 14-second compressor 12-four-way valve 14-second heat exchange section 52-second throttling element 13-second heat exchanger 21-four-way valve 14-first compressor 12 (at this time, the first waterway system and the second waterway system combine to heat water, and finally output hot water through the second waterway system);

[0089] 4) The second compressor 12-four-way valve 14-second heat exchange section 52-second throttling element 13-second heat exchanger 21-four-way valve 14-first compressor 12-four-way valve 14-first heat exchange section 51-first throttling element 13-first heat exchanger 11-four-way valve 14-second compressor 12 (at this time, the first waterway system and the second waterway system combine to heat water, and finally output hot water through the first waterway system).

[0090] Further, referring to Figure 2 and Figure 3As shown, the first heat exchange system 1 and the second heat exchange system 2 further comprise a main valve 15, which is located between the first heat exchanger 11 and the first heat exchange section 51, and between the second heat exchanger 21 and the second heat exchange section 51. The main valve 15 is used to control the on-off of the refrigerant flow path between the first heat exchanger 11 and the first heat exchange section 51, and between the second heat exchanger 21 and the second heat exchange section 52. Specifically, when the first heat exchange section 51 and the second heat exchange section 52 are connected in series, or the first heat exchange section 51 and the second heat exchange section 52 are connected in parallel and the first heat exchange section 51 is working, the main valve 15 of the first heat exchange system 1 is opened, and the third heat exchange circulation loop or the first heat exchange circulation loop can be formed, respectively. Similarly, when the first heat exchange section 51 and the second heat exchange section 52 are connected in series, or the first heat exchange section 51 and the second heat exchange section 52 are connected in parallel and the second heat exchange section 52 is working, the main valve 15 of the second heat exchange system 2 is opened, and the third heat exchange circulation loop or the second heat exchange circulation loop can be formed, respectively.

[0091] Referring to Figure 2 and Figure 3 As shown, in an optional solution of the embodiment, the first heat exchange system 1 and the second heat exchange system 2 further comprise an economizer 16, which is connected with the outlet of the first heat exchanger 11, the outlet of the first heat exchange section 51, the outlet of the second heat exchanger 21 or the outlet of the second heat exchange section 52. The economizer 16 is essentially a heat exchanger, which is used to supercool the refrigerant flowing through it, so as to improve the efficiency and performance of the refrigeration system. Taking the first heat exchange circulation loop for heating function as an example, the first heat exchanger 11 is a condenser, and the economizer 16 is connected with the outlet of the first heat exchanger 11; taking the first heat exchange circulation loop for refrigeration function as an example, the first heat exchange section 51 is a condenser, and the economizer 16 is connected with the outlet of the first heat exchange section 51. The design idea of the remaining circulation loops is the same, which will not be described here.

[0092] Referring to Figure 2 and Figure 3 As shown, in another optional solution of the embodiment, the first heat exchange system 1 and the second heat exchange system 2 further comprise a separator 17, which is connected with the inlet of the compressor 12 of the first heat exchange system 1 and the second heat exchange system 2, respectively. The separator 17 is used to separate the refrigerant before entering the compressor 12, so as to prevent the compressor 12 from being damaged by liquid hammer.

[0093] To avoid ambiguity, it needs to be particularly pointed out that the compressor 12, the throttling element 13, the four-way valve 14, the main valve 15, the economizer 16 and the separator 17 described in the present application are at least one in the first heat exchange system 1 and the second heat exchange system 2. For example, the compressor 12 in the first heat exchange system 1 at least comprises a first compressor, the compressor 12 in the second heat exchange system 2 at least comprises a second compressor, and so on.

[0094] Embodiment 3

[0095] In the third embodiment of the present application, a specific design of two water systems is provided on the basis of the first embodiment.

[0096] In the technical solution of this embodiment, by the series or parallel state of the water tank, switching and selection of different water circulation loops can be realized, so as to adapt to the actual needs of different scenes.

[0097] This embodiment takes the technical solution of two heat exchange systems, two water systems and two heat exchange sections as an example to describe the working mode and principle of the multi-system water chiller as follows

[0098] 1. When the first water tank 31 and the second water tank 41 are connected in parallel, the first water system 3 and the first heat exchanger 11 form a first water circulation loop, and the second water system 4 and the second heat exchanger 21 form a second water circulation loop, at this time:

[0099] 1) Referring to FIG. 1, if the first heat exchange circulation loop works and the second heat exchange circulation loop does not work, the first water circulation loop works (the first water tank 31-the first heat exchanger 11-the equipment terminal 6-the first water tank 31), that is, the first water system 3 outputs corresponding hot water or cold water and directly supplies to the equipment terminal 6 such as the coil. Figure 4 2) Referring to FIG. 2, if the second heat exchange circulation loop works and the first heat exchange circulation loop does not work, the second water circulation loop works (the second water tank 41-the second heat exchanger 21-the equipment terminal 6-the second water tank 41), that is, the second water system 4 outputs corresponding hot water or cold water and directly supplies to the equipment terminal 6 such as the coil.

[0100] Figure 5 3) Referring to FIG. 3 and FIG. 4, if the first heat exchange circulation loop and the second heat exchange circulation loop work at the same time, the first water circulation loop and the second water circulation loop work at the same time, and the first water system 3 and the second water system 4 output corresponding hot water or cold water and supply to the equipment terminal 6 respectively.

[0101] 2. Referring to FIG. 5, when the first water tank 31 and the second water tank 41 are connected in series, the first water system 3, the first heat exchanger 11, the second water system 4 and the second heat exchanger 21 form a third water circulation loop, according to the different refrigerant flow paths of the third heat exchange circulation loop, it can be divided into: Figure 4 Figure 5

[0102] 2. Referring to FIG. 5, when the first water tank 31 and the second water tank 41 are connected in series, the first water system 3, the first heat exchanger 11, the second water system 4 and the second heat exchanger 21 form a third water circulation loop, according to the different refrigerant flow paths of the third heat exchange circulation loop, it can be divided into: Figure 6

[0103] ​​​​1) The first water tank 31, the first heat exchanger 11, the second water tank 41, the second heat exchanger 21 and the equipment terminal 6 are sequentially connected to form a third hot water circulation loop. At this time, the hot water or cold water produced by the first water system 3 flows to the second water system 4, and then flows to the equipment terminal 6 such as a coil after the heat exchange in the second water system 4.

[0104] 2) The second water tank 41, the second heat exchanger 21, the first water tank 31, the first heat exchanger 11, the equipment terminal 6 and the second water tank 41. At this time, the hot water or cold water produced by the second water system 4 flows to the first water system 3, and then flows to the equipment terminal 6 such as a coil after the heat exchange in the first water system 3.

[0105] Preferably, the first water pipe and the second water pipe include a water inlet pipe and a water outlet pipe. The water inlet pipe is used to connect the water outlet of the first water tank 31 and the water inlet of the first heat exchanger 11, and connect the water outlet of the second water tank 31 and the water inlet of the second heat exchanger 21. The water outlet pipe is connected with the water outlet of the first heat exchanger 11 and the water outlet of the second heat exchanger 21.

[0106] Thus, as shown in FIG. 1, the first water circulation loop formed by the first water tank 31 and the first heat exchanger 11 is: the first water tank 31-the water inlet pipe-the first heat exchanger 11-the water outlet pipe-the equipment terminal 6-the first water tank 31. Figure 4 As shown in FIG. 2, the second water circulation loop formed by the second water tank 41 and the second heat exchanger 21 is: the second water tank 41-the water inlet pipe-the second heat exchanger 21-the water outlet pipe-the equipment terminal 6-the second water tank 41.

[0107] Figure 5 As shown in FIG. 3, the third water circulation loop formed by the first water tank 31, the first heat exchanger 11, the second water tank 41 and the second heat exchanger is: the first water tank 31-the water inlet pipe-the first heat exchanger 11-the water outlet pipe-the second water tank 41-the second heat exchanger 21-the equipment terminal 6-the first water tank 31; or: the second water tank 41-the water inlet pipe-the second heat exchanger 21-the water outlet pipe-the first water tank 31-the first heat exchanger 11-the equipment terminal 6-the second water tank 41.

[0108] Further, as shown in FIG. 4 and FIG. 5, the first water system 3 and the second water system 4 further include a water pump 32 and a water flow switch 33, which are located in the water inlet pipe. The water pump 32 is used to provide power for the water medium flow of the first water circulation loop, the second water circulation loop and the third water circulation loop, and the water flow switch 33 is used to control the water flow of the water system according to the environmental signal, so as to realize the switching control of different water circulation loops. Figure 6

[0109] Figure 2 Figure 3 ​​​​​

[0110] Further, referring to Figure 2 and Figure 3 As shown, the first water system 3 and the second water system 4 further comprise an electric heating element 34 located in the outlet water pipe and a pressure sensor (not shown in the figure) located in the inlet water pipe and the outlet water pipe. Specifically, the electric heating element 34 is used to start when the water system is in the heating mode and when the heating capacity of the first heat exchanger 11 or the second heat exchanger 21 is insufficient, to increase the outlet water temperature of the water system. The pressure sensor is used to monitor the pressure value of the water system in real time, to ensure stable circulation of the water system.

[0111] Embodiment 4

[0112] Based on the same design idea, the application further provides an embodiment of a control method for a multi-system water chiller, which is applied to the multi-system water chiller described in the above embodiments.

[0113] In the technical solution of this embodiment, the control method comprises:

[0114] Step 1. Detecting a first operating parameter of the multi-system water chiller;

[0115] Step 2. Starting an operating mode of the multi-system water chiller according to the detection result;

[0116] Step 3. Controlling the operation of the first heat exchange system 1, the second heat exchange system 2, the first water system 3 and the second water system 4 according to the operating mode.

[0117] Wherein, the first operating parameter at least comprises the return water temperature of the first water tank 31 and / or the second water tank 41, the switch state of the water flow switch 33, and the downtime of the first compressor 12 and / or the second compressor 12. The operating mode at least comprises a single heating mode, a single cooling mode, a combined heating mode, a combined cooling mode, a step heating mode, and a step cooling mode.

[0118] The control method of this embodiment automatically performs load control with the actual demand for heating or cooling water of the water system and the current working condition of the heat exchange system as the target, compares the real-time acquired operating parameters and target parameters, and thus switches the series or parallel state of the combined heat exchanger 5 and the series or parallel state of the water tank to control different operating modes of the unit, so that the finally output water temperature and water quantity meet the requirements. Compared with the traditional multi-head series or hybrid design, this embodiment does not need to load or unload according to the load demand, or even frequently start and stop the compressor 12, avoids that the online running compressor 12 runs in the low efficiency area (high load to maximum load and low load to minimum load) for a long time, has good stability and high energy efficiency ratio.

[0119] Specifically, in single heating or single cooling mode, any heat exchange system and any water circuit system of the chiller unit can be activated according to the actual external heat or cooling demand, thereby producing hot or cold water of the preset temperature and capacity to supply the equipment terminal 6. In combined heating or combined cooling mode, different heat exchange systems and different water circuit systems can be activated according to the actual external heat or cooling demand, producing hot or cold water of the preset temperature and capacity respectively, and then supplying it to different equipment terminals 6. In stepped heating or stepped cooling mode, different heat exchange systems and water circuit systems can be connected in series according to the actual external heat or cooling demand, so that the cold or hot water in the water tank undergoes stepped heating or cooling in stages, ultimately outputting high-temperature and large-capacity hot or cold water.

[0120] Example 5

[0121] In the fifth embodiment of the present invention, based on the fourth embodiment, a technical solution is provided regarding how to start the single-heat mode and the single-cool mode and how to operate after starting them.

[0122] In the technical solution of this embodiment, the operable single-heat mode includes a first single-heat mode and a second single-heat mode.

[0123] See Figure 2 and Figure 4 As shown, multiple chiller units will simultaneously start the first single-heat mode when the following conditions are met:

[0124] The return water temperature of the first water tank 31 is lower than the first preset temperature, the water flow switch 33 of the first water circuit system 3 is closed, and the shutdown time of the first compressor 12 is longer than the first preset time. At this time, the equipment terminal 6 corresponding to the first water tank 31 is in a hot water demand state, and the operating conditions of the first water circuit system 3 and the first heat exchange system 1 are in a stable state, so the first compressor 12 of the first heat exchange system 1 and the water pump 32 of the first water circuit system 3 can be turned on.

[0125] When the first single-heat mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are connected in parallel. The first heat exchange system 1 and the first heat exchange section 51 form the first heating circulation loop, and the first water system 3 and the first heat exchanger 1 form the first hot water circulation loop, so that the first water system 3 produces the corresponding hot water and supplies it directly to the equipment terminal 6.

[0126] See Figure 3 and Figure 5 As shown, the multi-system chiller unit will start the second single-heat mode when the following conditions are met simultaneously:

[0127] The return water temperature of the second water tank 41 is lower than the second preset temperature, and the water flow switch 33 of the second water circuit system 4 is closed, while the shutdown time of the second compressor 12 is longer than the first preset time. At this time, the equipment terminal 6 corresponding to the second water tank 41 is in a hot water demand state, and the operating conditions of the second water circuit system 4 and the first heat exchange system 2 are in a stable state, so the second compressor 12 of the first heat exchange system 2 and the water pump 32 of the second water circuit system 4 can be turned on.

[0128] When the second single-heat mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are connected in parallel. The second heat exchange system 2 and the second heat exchange section 52 constitute the second heating circulation loop, and the second water system 4 and the second heat exchanger 2 constitute the second hot water circulation loop, so that the second water system 4 produces the corresponding hot water and supplies it directly to the equipment terminal 6.

[0129] See Figure 2 and Figure 4 As shown, the multi-system chiller unit will start the first single-cooling mode when the following conditions are met simultaneously:

[0130] The return water temperature of the first water tank 31 is higher than the third preset temperature, and the water flow switch 33 of the first water circuit system 3 is closed, and the shutdown time of the first compressor 12 is longer than the first preset time. At this time, the equipment terminal 6 corresponding to the first water tank 31 is in a cold water demand state, and the operating conditions of the first water circuit system 3 and the first heat exchange system 1 are in a stable state, so the first compressor 12 of the first heat exchange system 1 and the water pump 32 of the first water circuit system 3 can be turned on.

[0131] When the first single-cooling mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are set in parallel. The first heat exchange system 1 and the first heat exchange section 51 form the first refrigeration cycle loop, and the first water system 3 and the first heat exchanger 11 form the first cold water cycle loop, so that the first water system 3 produces corresponding cold water and supplies it directly to the equipment terminal 6.

[0132] See Figure 3 and Figure 5 As shown, the multi-system chiller unit will start the second single-cooling mode when the following conditions are met simultaneously:

[0133] The return water temperature of the second water tank 41 is higher than the fourth preset temperature, the water flow switch of the second water circuit system 4 is closed, and the shutdown time of the second compressor 12 is longer than the first preset time. At this time, the equipment terminal 6 corresponding to the second water tank 41 is in a cold water demand state, and the operating conditions of the second water circuit system 4 and the first heat exchange system 2 are in a stable state, so the second compressor 12 of the first heat exchange system 2 and the water pump 32 of the second water circuit system 4 can be turned on.

[0134] When the second single cold mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are arranged in parallel, the second heat exchange system 4 and the second heat exchange section 52 form a second refrigeration cycle loop, and the second waterway system 4 and the second heat exchanger 22 form a second cold water circulation loop, so that the second waterway system 4 outputs corresponding cold water and directly supplies the equipment terminal 6.

[0135] Specifically, the first preset temperature in the embodiment is less than the second preset temperature, and the first preset temperature and the second preferred temperature are preferably 10-35℃, and can be set and adjusted according to the heat or cold demand required by the specific equipment terminal 6. The first preset time is preferably 5 minutes, and can be preferably 3 minutes if the cold water unit is powered on for the first time.

[0136] Embodiment 6

[0137] In the sixth embodiment of the present application, a technical solution about how to start and run the combined heating mode and the combined refrigeration mode is provided on the basis of the fourth embodiment.

[0138] In the technical solution of the embodiment, the combined heating mode and the combined refrigeration mode are used to output hot water or cold water of required temperature and capacity for the corresponding equipment terminal 6 through the respective waterway systems.

[0139] Referring to Figures 2-5 When the following conditions are met, the multi-system cold water unit starts the combined heating mode:

[0140] The return water temperature of the first water tank 31 is less than the first preset temperature, and the return water temperature of the second water tank 31 is less than the second preset temperature, and the water flow switches 33 of the first waterway system 3 and the second waterway system 4 are both closed, and the shutdown time of the first compressor 12 and the second compressor 12 is greater than the first preset time. At this time, the equipment terminal 6 corresponding to the first water tank 31 and the second water tank 41 is in a hot water demand state, and the working conditions of the two heat exchange systems and the two waterway systems are in a stable state, and the compressors 12 of the two heat exchange systems and the water pumps 32 of the two waterway systems can be started.

[0141] When the combined heating mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are arranged in parallel, the first water tank 31 and the second water tank 41 are arranged in parallel, the first heat exchange system 1 and the first heat exchange section 51 form a first heating cycle loop, and the first waterway system 3 and the first heat exchanger 11 form a first hot water circulation loop. And, the second heat exchange system 2 and the second heat exchange section 52 form a second heating cycle loop, and the second waterway system 4 and the second heat exchanger 21 form a second hot water circulation loop. Thus, the first waterway system 3 and the second waterway system 4 output corresponding hot water and supply the corresponding equipment terminal 6, respectively.

[0142] Referring toFigures 2-5 As shown in FIG. 1 and FIG. 2, when the following conditions are met, the multi-system water chiller starts the combined refrigeration mode:

[0143] As shown in FIG. 1 and FIG. 2, when the following conditions are met, the multi-system water chiller starts the combined refrigeration mode:

[0144] When the combined refrigeration mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are connected in parallel, the first water tank 31 and the second water tank 41 are connected in parallel, the first heat exchange system 1 and the first heat exchange section 51 form a first refrigeration cycle loop, and the first water system 3 and the first heat exchanger 11 form a first cold water circulation loop. In addition, the second heat exchange system 1 and the second heat exchange section 52 form a second refrigeration cycle loop, and the second water system 4 and the second heat exchanger 2 form a second cold water circulation loop. Thus, the first water system 3 and the second water system 4 produce corresponding cold water and supply it to the corresponding equipment terminal 6, respectively.

[0145] Specifically, in the embodiment, the first preset temperature is less than the second preset temperature, and the first preset temperature and the second preset temperature are preferably 10-35℃, and can be set and adjusted according to the heat or cold demand of the specific equipment terminal 6. The first preset time is preferably 5 minutes, and can be preferably 3 minutes if the water chiller is powered on for the first time.

[0146] Embodiment 7

[0147] In the seventh embodiment of the present application, on the basis of the fourth embodiment, a technical solution is provided for how the step-by-step heating mode and the step-by-step refrigeration mode are started and how they run after being started.

[0148] In the technical solution of this embodiment, the step-by-step heating mode and the step-by-step refrigeration mode are used to realize the production of hot water or cold water with high / low temperature demand and large capacity demand for one of the corresponding equipment terminals 6 through the cooperation of multiple water systems.

[0149] Referring to FIG. 1 and FIG. 2, when the following conditions are met, the multi-system water chiller starts the step-by-step heating mode: Figure 1 Figure 6 Referring to FIG. 1 and FIG. 2, when the following conditions are met, the multi-system water chiller starts the step-by-step heating mode:

[0150] ​The return water temperature of the first water tank 31 and the second water tank 41 is less than the fifth preset temperature, the water flow switch 33 of the first water system 3 and the second water system 4 is closed, and the shutdown time of the first compressor 12 and the second compressor 12 is greater than the first preset time. At this time, only one equipment terminal 6 is in hot water demand state (corresponding to any one of the first water tank 31 and the second water tank 41), and the hot water temperature or capacity demand is large, and the working conditions of the two heat exchange systems and the two water systems are in a stable state, and the compressor 12 of the two heat exchange systems and the water pump 32 of the water system can be started.

[0151] When the step heating mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are arranged in series, the first water tank 31 and the second water tank 41 are arranged in series, the first heat exchange system 1, the first heat exchange section 51, the second heat exchange system 2 and the second heat exchange section 52 form a third heating cycle (as described in Embodiment 2), and the first water system 3, the first heat exchanger 11, the second water system 4 and the second heat exchanger 21 form a third hot water cycle (as described in Embodiment 3). Thus, the first water system 3 or the second water system 4 finally produces hot water with high temperature and large capacity, and supplies it to the corresponding equipment terminal 6.

[0152] When the step heating mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are arranged in series, the first water tank 31 and the second water tank 41 are arranged in series, the first heat exchange system 1, the first heat exchange section 51, the second heat exchange system 2 and the second heat exchange section 52 form a third heating cycle (as described in Embodiment 2), and the first water system 3, the first heat exchanger 11, the second water system 4 and the second heat exchanger 21 form a third hot water cycle (as described in Embodiment 3). Thus, the first water system 3 or the second water system 4 finally produces hot water with high temperature and large capacity, and supplies it to the corresponding equipment terminal 6. Figure 1 Figure 6 When the step heating mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are arranged in series, the first water tank 31 and the second water tank 41 are arranged in series, the first heat exchange system 1, the first heat exchange section 51, the second heat exchange system 2 and the second heat exchange section 52 form a third heating cycle (as described in Embodiment 2), and the first water system 3, the first heat exchanger 11, the second water system 4 and the second heat exchanger 21 form a third hot water cycle (as described in Embodiment 3). Thus, the first water system 3 or the second water system 4 finally produces hot water with high temperature and large capacity, and supplies it to the corresponding equipment terminal 6.

[0153] The return water temperature of the first water tank 31 and the second water tank 41 is greater than the sixth preset temperature, the water flow switch 33 of the first water system 3 and the second water system 4 is closed, and the shutdown time of the first compressor 12 and the second compressor 12 is greater than the first preset time. At this time, only one equipment terminal 6 is in cold water demand state (corresponding to any one of the first water tank 31 and the second water tank 41), and the cold water temperature demand is low or the capacity demand is large, and the working conditions of the two heat exchange systems and the two water systems are in a stable state, and the compressor 12 of the two heat exchange systems and the water pump 32 of the water system can be started.

[0154] When the step heating mode is started, the first heat exchange section 51 and the second heat exchange section 52 of the combined heat exchanger 5 are arranged in series, the first water tank 31 and the second water tank 41 are arranged in series, the first heat exchange system 1, the first heat exchange section 51, the second heat exchange system 2 and the second heat exchange section 52 form a third heating cycle (as described in Embodiment 2), and the first water system 3, the first heat exchanger 11, the second water system 4 and the second heat exchanger 21 form a third hot water cycle (as described in Embodiment 3). Thus, the first water system 3 or the second water system 4 finally produces hot water with high temperature and large capacity, and supplies it to the corresponding equipment terminal 6.

[0155] ​Specifically, the fifth preset temperature in the embodiment is less than the sixth preset temperature, and the fifth preset temperature and the sixth preset temperature are preferably 5-40℃, and can be set and adjusted according to the heat or cold demand of the specific equipment terminal 6. The first preset time is preferably 5 minutes, and can be preferably 3 minutes if the water chiller is powered on for the first time.

[0156] Embodiment 8

[0157] In the eighth embodiment of the application, a technical solution is provided on the basis of the fourth embodiment about how the auxiliary heating mode is started, stopped and operated after being started.

[0158] In the technical solution of this embodiment, the control method comprises:

[0159] Step 1. When the multi-system water chiller operates in the single heating mode, the combined heating mode or the step heating mode, the second operating parameter of the first water system 3 and / or the second water system 4 is detected.

[0160] Step 2. The auxiliary heating mode is started or stopped according to the detection result.

[0161] The second operating parameter at least includes the outlet water temperature of the first heat exchanger 11 and / or the second heat exchanger 21, the return water temperature of the first water tank 31 and / or the second water tank 41, the inlet water pressure of the inlet water pipeline, the outlet water pressure of the outlet water pipeline and the continuous starting time of the electric heating element 34.

[0162] Referring to FIGS. 1, 2 and 3, Figure 2 and Figure 3 In one preferred scheme of this embodiment, the multi-system water chiller starts the auxiliary heating mode when the following conditions are met simultaneously:

[0163] The outlet water temperature is less than the seventh preset temperature, and the inlet water pressure is within the first preset pressure range, and the outlet water pressure is within the second preset pressure range. At this time, the hot water temperature produced by the water system cannot reach the preset temperature, and the working condition of the water system is in a stable state, and the auxiliary heating mode can be started to improve the outlet water temperature. When the auxiliary heating mode is started, the electric heating element 34 works.

[0164] The auxiliary heating mode is stopped when the following conditions are met simultaneously:

[0165] When the return water temperature is greater than the eighth preset temperature, and the continuous starting time of the electric heating is greater than the second preset time. At this time, the return water temperature of the water system after heat exchange is higher than the preset value, indicating that the outlet water temperature of the water system has reached the heat demand of the equipment terminal 6, and the multi-system water chiller does not need to continue to start the auxiliary heating mode.

[0166] Specifically, the seventh preset temperature is greater than the eighth preset temperature in the embodiment, and the seventh preset temperature and the eighth preset temperature are preferably 10-35℃. The first preset pressure range is preferably 1-2 bar, and the second preset pressure range is preferably 1-2 bar. The second preset time is preferably 2 minutes.

[0167] The technical means disclosed in the present application scheme is not limited to the technical means disclosed in the above-mentioned embodiments, but also includes the technical scheme composed of any combination of the above technical features. It should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, a number of improvements and refinements can also be considered as the protection scope of the present application.

Claims

1. A multi-system water chiller characterized by, At least comprising: A first heat exchange system comprising a first heat exchanger, and a first water system comprising a first water tank and a first water pipe; A second heat exchange system comprising a second heat exchanger, and a second water system comprising a second water tank and a second water pipe; A combined heat exchanger comprising at least a first heat exchange section and a second heat exchange section, which are arranged alternately in sequence; Wherein, the first heat exchange section and the second heat exchange section are arranged in parallel, so that the first heat exchange system and the first heat exchange section form a first heat exchange circulation loop, and the second heat exchange system and the second heat exchange section form a second heat exchange circulation loop; or, the first heat exchange section and the second heat exchange section are arranged in series, so that the first heat exchange system, the first heat exchange section, the second heat exchange system and the second heat exchange section form a third heat exchange circulation loop; The first heat exchange system and the second heat exchange system each comprise a compressor, a throttling element, a four-way valve and a main valve, a first compressor, a first throttling element, a first four-way valve, the first heat exchanger and the first heat exchange section form a first heat exchange circulation loop, a second compressor, a second throttling element, a second four-way valve, the second heat exchanger and the second heat exchange section form a second heat exchange circulation loop; a first main valve is located between the first heat exchanger and the first heat exchange section, and a second main valve is located between the second heat exchanger and the second heat exchange section; The first water tank and the second water tank are arranged in parallel, so that the first water system and the first heat exchanger form a first water circulation loop, and the second water system and the second heat exchanger form a second water circulation loop; or, the first water tank and the second water tank are arranged in series, so that the first water system, the first heat exchanger, the second water system and the second heat exchanger form a third water circulation loop; When starting the combined heating mode, the first heat exchange system and the first heat exchange section form a first heating circulation loop, the first water system and the first heat exchanger form a first hot water circulation loop; and the second heat exchange system and the second heat exchange section form a second heating circulation loop, and the second water system and the second heat exchanger form a second hot water circulation loop; When starting the step heating mode, the first heat exchange system, the first heat exchange section, the second heat exchange system and the second heat exchange section form a third heating circulation loop, and the first water system, the first heat exchanger, the second water system and the second heat exchanger form a third hot water circulation loop; The first compressor, the first heat exchanger, the first throttling element, the first heat exchange section, the second compressor, the second heat exchanger, the second throttling element and the second heat exchange section are sequentially connected to form a third heating circulation loop; the first water tank, the first heat exchanger, the second water tank, the second heat exchanger and the equipment terminal are sequentially connected to form a third hot water circulation loop.

2. The multiple system water chiller of claim 1, wherein The first water system and the second water system each comprise a water pump, a water flow switch, an electric heating element and a pressure sensor, the first water pipe and the second water pipe comprise an inlet water pipe and an outlet water pipe, the inlet water pipe is connected to the water outlet of the first water tank and the water inlet of the first heat exchanger, and is connected to the water outlet of the second water tank and the water inlet of the second heat exchanger; the outlet water pipe is connected to the water outlet of the first heat exchanger and the water outlet of the second heat exchanger; the water pump and the water flow switch are located in the inlet water pipe, the electric heating element is located in the outlet water pipe, and the pressure sensor is located in the inlet water pipe and the outlet water pipe.

3. A method of controlling a multi-system water chiller, applied to the multi-system water chiller according to any one of claims 1-2, characterized in that, The control method comprises: detecting a first operating parameter of the multi-system water chiller unit, starting an operating mode of the multi-system water chiller unit according to the detection result, and controlling the operation of the first heat exchange system, the second heat exchange system, the first water system and the second water system according to the operating mode; the first operating parameter at least includes the return water temperature of the first water tank and / or the second water tank, the switch state of the water flow switch, and the shutdown time of the compressor; the operating mode at least includes a single heating mode, a single cooling mode, a combined heating mode, a combined cooling mode, a step heating mode and a step cooling mode.

4. The multi-system water chiller control method of claim 3, wherein, When the following conditions are met simultaneously, the single heating mode is started: the return water temperature of the first water tank is less than a first preset temperature, the water flow switch of the first water system is closed, and the shutdown time of the compressor is greater than a first preset time; or, the return water temperature of the second water tank is less than a second preset temperature, the water flow switch of the second water system is closed, and the shutdown time of the compressor is greater than the first preset time; When the single heating mode is started, the first heat exchange system and the first heat exchange section form a first heating circulation loop, and the first water system and the first heat exchanger form a first hot water circulation loop; or, the second heat exchange system and the second heat exchange section form a second heating circulation loop, and the second water system and the second heat exchanger form a second hot water circulation loop; When the following conditions are met simultaneously, the single cooling mode is started: the return water temperature of the first water tank is greater than a third preset temperature, the water flow switch of the first water system is closed, and the shutdown time of the compressor is greater than the first preset time; or, the return water temperature of the second water tank is greater than a fourth preset temperature, the water flow switch of the second water system is closed, and the shutdown time of the compressor is greater than the first preset time; When the single cooling mode is started, the first heat exchange system and the first heat exchange section form a first refrigeration circulation loop, and the first water system and the first heat exchanger form a first cold water circulation loop; or, the second heat exchange system and the second heat exchange section form a second refrigeration circulation loop, and the second water system and the second heat exchanger form a second cold water circulation loop.

5. The multi-system water chiller control method of claim 3, wherein, When the following conditions are met simultaneously, the combined heating mode is started: the return water temperature of the first water tank is less than the first preset temperature, the return water temperature of the second water tank is less than the second preset temperature, the water flow switches of the first water system and the second water system are both closed, and the shutdown time of the compressor is greater than the first preset time; When the following conditions are met simultaneously, the combined cooling mode is started: the return water temperature of the first water tank is greater than a third preset temperature, the return water temperature of the second water tank is greater than a fourth preset temperature, the water flow switches of the first water system and the second water system are both closed, and the shutdown time of the compressor is greater than a first preset time; when the combined heating mode is started, the first heat exchange system and the first heat exchange section form a first refrigeration cycle loop, and the first water system and the first heat exchanger form a first cold water circulation loop; and the second heat exchange system and the second heat exchange section form a second refrigeration cycle loop, and the second water system and the second heat exchanger form a second cold water circulation loop.

6. The multi-system water chiller control method of claim 3, wherein, When the following conditions are met simultaneously, the step-by-step heating mode is started: the return water temperatures of the first water tank and the second water tank are both less than a fifth preset temperature, the water flow switches of the first water system and the second water system are both closed, and the shutdown time of the compressor is greater than a first preset time; When the following conditions are met simultaneously, the step-by-step heating mode is started: the return water temperatures of the first water tank and the second water tank are both greater than a sixth preset temperature, the water flow switches of the first water system and the second water system are both closed, and the shutdown time of the compressor is greater than a first preset time; When the step-by-step heating mode is started, the first heat exchange system, the first heat exchange section, the second heat exchange system, and the second heat exchange section form a third refrigeration cycle loop, and the first water system, the first heat exchanger, the second water system, and the second heat exchanger form a third cold water circulation loop.

7. The multi-system water chiller control method of claim 3, wherein, The control method further comprises: when the multi-system water chiller operates the single heating mode, the combined heating mode, or the step-by-step heating mode, detecting a second operating parameter of the first water system and / or the second water system, and starting or closing the auxiliary heating mode according to the detection result; the second operating parameter at least includes the outlet water temperature of the first heat exchanger and / or the second heat exchanger, the return water temperature of the first water tank and / or the second water tank, the inlet water pressure of the inlet water pipeline, the outlet water pressure of the outlet water pipeline, and the continuous starting time of the electric heating element.

8. The multi-system water chiller control method according to claim 7, wherein, When the following conditions are met simultaneously, the auxiliary heating mode is started: the outlet water temperature is less than a seventh preset temperature, the inlet water pressure is within a first preset pressure range, and the outlet water pressure is within a second preset pressure range; When the auxiliary heating mode is started, the electric heating element works; When the following conditions are met simultaneously, the auxiliary heating mode is closed: the return water temperature is greater than an eighth preset temperature, and the continuous starting time of the electric heating is greater than a second preset time.

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