Air conditioner waterway system and mixed flow control method thereof

Abstract

The invention provides an air conditioner waterway system and a mixed flow control method thereof. The air conditioner waterway system comprises a water supply pipe, a water return pipe, a mixed water diverter, a first mixed flow water supplementing pipe, a second mixed flow water supplementing pipe, a flow balance pipe, a conventional circulating waterway and a mixed flow circulating waterway. Return water of the indoor unit and supply water of the outdoor unit are mixed, and the flow of the air conditioner waterway system is regulated and controlled in different states, so that variable water temperature control of the constant water temperature air conditioner system is realized; and therefore, the indoor units in different environments are regulated and controlled in a targeted manner, and the refrigeration effects of the indoor units in the air conditioning system in different environments are guaranteed.

Description

Technical Field

[0001] The present invention belongs to the field of water multi-connected air conditioners, and more specifically, relates to an air conditioning water system and a mixed flow control method thereof. Background Art

[0002] The water multi-split air conditioning system is mainly composed of an outdoor unit and multiple indoor units connected by a water system. In the cooling mode, the chilled water taken by the outdoor unit is driven by a water pump to transport the chilled water to each indoor unit, and then the indoor unit exchanges heat with the indoor air to achieve the purpose of regulating the indoor temperature.

[0003] The water temperature and flow rate of the outdoor unit in a conventional air-conditioning system are relatively constant, while the capacity of each indoor unit, the room orientation, and the activities of people in the environment are different, which leads to large differences in the heat load of each indoor unit. The combination of the two will result in the conventional fixed water temperature air-conditioning system being unable to guarantee the cooling effect of the indoor unit in different environments in the air-conditioning system. Summary of the invention

[0004] The object of the present invention is to provide an air conditioning water system and a mixed flow control method thereof, so as to solve the problem that a conventional fixed water temperature air conditioning system cannot guarantee the refrigeration effect of an indoor unit under different environments in the air conditioning system.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides an air conditioning water system, the air conditioning water system comprising a water supply pipe connected to a water outlet of an outdoor unit, a water return pipe connected to a water inlet of the outdoor unit, and a plurality of conventional circulating water circuits arranged in parallel, each of the conventional circulating water circuits comprising a water inlet branch connected to the water supply pipe and a water inlet of an indoor unit, and a water outlet branch connected to the water return pipe and a water outlet of the indoor unit, and further comprising:

[0007] Mixing water divider;

[0008] A first mixed flow water supply pipe, connected to the water supply pipe and the water inlet of the mixed water divider;

[0009] A second mixed flow water supply pipe is connected to the return water pipe and the water inlet of the mixed water divider;

[0010] Multiple mixed flow circulation water circuits, each of which includes a mixed flow water supply branch connected to the water outlet of the mixing water divider and the water inlet of the indoor unit, and a mixed flow return branch connected to the water inlet of the mixing water divider and the water outlet of the indoor unit. The mixed flow circulation water circuit connected to the same indoor unit is selectively connected to the conventional circulation water circuit.

[0011] Furthermore, it also includes:

[0012] The flow balance pipe is connected to the return pipe and the water outlet of the water mixing diverter.

[0013] Furthermore, a first proportional valve, a second proportional valve and a third proportional valve for adjusting the water flow are respectively installed on the first mixed flow water supply pipe, the second mixed flow water supply pipe and the flow balance pipe.

[0014] Furthermore, the mixed flow return water branches in the plurality of mixed flow circulating water circuits merge to form a mixed flow water inlet main pipeline, and a circulating water pump and a mixed flow water inlet temperature sensor are installed on the mixed flow water inlet main pipeline.

[0015] The present invention also provides a mixed flow control method for the air conditioning water system as described above, comprising:

[0016] Detect the indoor ambient temperature of the environment where each indoor unit is in operation;

[0017] Determine whether the temperature difference between the indoor ambient temperature and the set ambient temperature is less than the set ambient temperature difference value;

[0018] If yes, it is determined that the indoor unit is a steady-state indoor unit, only the mixed flow circulation water circuit where the steady-state indoor unit is located is connected, and the mixed water divider is replenished with water through the first mixed flow replenishment pipe or the second mixed flow replenishment pipe to adjust the water inlet temperature of the steady-state indoor unit;

[0019] If not, it is determined that the indoor unit is a non-steady-state indoor unit, and only the conventional circulating water circuit where the non-steady-state indoor unit is located is connected.

[0020] Furthermore, the method further includes: when there are at least two steady-state indoor units, detecting the outlet water temperature of each steady-state indoor unit, and selecting the steady-state indoor unit with the highest outlet water temperature as the target indoor unit;

[0021] The method of replenishing water to the mixing water divider through the first mixed flow make-up pipe or the second mixed flow make-up pipe to adjust the water inlet temperature of the steady-state indoor unit is: replenishing water to the mixing water divider through the first mixed flow make-up pipe or the second mixed flow make-up pipe until the actual inlet water temperature of the target indoor unit reaches the target inlet water temperature.

[0022] Further, replenishing water to the mixing water divider through the first mixed flow replenishing pipe or the second mixed flow replenishing pipe until the actual inlet water temperature of the target indoor unit reaches the target inlet water temperature includes:

[0023] Detecting the actual inlet water temperature of the target indoor unit;

[0024] Determine whether the temperature difference between the actual water inlet temperature and the rated water supply temperature is greater than a first set water temperature difference value;

[0025] If yes, adjusting the opening of the first proportional valve disposed on the first mixed flow water supply pipe so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is equal to the first set water temperature difference;

[0026] If not, adjust the opening of the second proportional valve on the second mixed-flow water supply pipe so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is equal to the first set water temperature difference.

[0027] Further, after controlling the temperature difference between the actual water inlet temperature and the rated water supply temperature of the target indoor unit to be equal to the first set water temperature difference, the method further includes:

[0028] After running for a period of time, if the temperature difference between the indoor ambient temperature of the target indoor unit and the set ambient temperature is still less than the set ambient temperature difference value, continue to adjust the first proportional valve opening or the second proportional valve opening so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is equal to the second set water temperature difference value, and the second set water temperature difference value is greater than the first set water temperature difference value.

[0029] Further, while adjusting the opening of the first proportional valve disposed on the first mixed flow water supply pipe, the opening of the third proportional valve disposed on the flow balance pipe is adjusted, and the opening of the third proportional valve is equal to the opening of the first proportional valve;

[0030] Alternatively, while adjusting the opening of the second proportional valve disposed on the second mixed flow water supply pipe, the opening of the third proportional valve disposed on the flow balance pipe is adjusted, and the opening of the third proportional valve is equal to the opening of the second proportional valve.

[0031] Furthermore, it also includes:

[0032] When this indoor unit is determined to be the non-steady-state indoor unit and has been running for a period of time, if the temperature difference between the indoor ambient temperature of this indoor unit and the set ambient temperature is less than the set ambient temperature difference value, at this time, this indoor unit is transformed from the non-steady-state indoor unit to the steady-state indoor unit, then the conventional circulating water circuit where this indoor unit is located is disconnected, and the mixed flow circulating water circuit where this indoor unit is located is connected.

[0033] Compared with the prior art, the air conditioning water system and mixed flow control method provided by the present invention have the following beneficial effects:

[0034] When the mixed flow circulating water circuit where the indoor unit is located is connected, the mixed water divider collects the medium and high temperature chilled water after heat exchange of the indoor unit according to the control requirements, and makes the collected medium and high temperature chilled water mixed with the low temperature chilled water from the first mixed flow make-up water pipe, or with the medium and high temperature chilled water from the second mixed flow make-up water pipe and then flows back to the indoor unit to adjust the inlet water temperature of the indoor unit; in this way, the present invention realizes the variable water temperature control of the fixed water temperature air conditioning system, by increasing the inlet water temperature of the indoor unit, thereby increasing the outlet air temperature of the indoor unit, reducing the dehumidification effect, and more accurately controlling the ambient temperature, reducing ambient temperature fluctuations, and improving comfort. In addition, when the mixed flow circulating water circuit where a part of the indoor units are located is connected and the conventional circulating water circuit where another part of the indoor units are located is connected, the water flow saved when the water temperature of a part of the indoor units is adjusted by the mixed flow circulating water circuit can be directly supplied to the other part of the indoor units by the outdoor unit through the conventional circulating water circuit; in this way, the present invention realizes the improvement of the refrigeration capacity of the indoor units by mobilizing the water flow in the system. Then, the indoor units in different environments can be adjusted in a targeted manner to ensure the cooling effect of the indoor units in different environments in the air-conditioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 A schematic diagram of the air conditioning water system provided by the present invention;

[0037] Figure 2 A schematic diagram of conventional control of the air conditioning water system provided by the present invention;

[0038] Figure 3 A schematic diagram of steady-state control of the air conditioning water system provided by the present invention;

[0039] Figure 4 A schematic diagram of the non-steady-state control of the air conditioning water system provided by the present invention;

[0040] Among them, the main marks of the drawings in the figure are:

[0041] 10. Outdoor unit; 20. Indoor unit;

[0042] 31. Mixing water manifold; 32. First mixed flow water supply pipe; 33. Second mixed flow water supply pipe; 34. Flow balance pipe; 351. Mixed flow water supply branch; 352. Mixed flow return branch; 361. Water supply pipe; 362. Water inlet branch; 363. Water return pipe; 364. Water outlet branch;

[0043] 41. First proportional valve; 42. Second proportional valve; 43. Third proportional valve; 44. First mixed flow electric water valve; 45. Second mixed flow electric water valve; 46. Water supply electric water valve; 47. Water return electric water valve;

[0044] 51. Circulating water pump; 52. Main water pump;

[0045] 61. Mixed flow water inlet temperature sensor; 62. Total water inlet temperature sensor; 63. Water inlet temperature sensor; 64. Total return water temperature sensor; 65. Water outlet temperature sensor;

[0046] 70. Buffer water tank. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0048] The water multi-split air conditioning system is mainly composed of an outdoor unit and multiple indoor units connected by a water system. In the cooling mode, the chilled water taken by the outdoor unit is driven by a water pump to transport the chilled water to each indoor unit, and then the indoor unit exchanges heat with the indoor air, thereby achieving the purpose of regulating the indoor temperature. The water supply temperature and water supply flow of the outdoor unit in the conventional air-conditioning system are relatively constant, while the capacity of each indoor unit, the room orientation of the environment, the activities of people, etc. are different, which leads to large differences in the heat load of each indoor unit. The superposition of the two will cause the conventional fixed water temperature air-conditioning system to be unable to guarantee the cooling effect of the indoor units in different environments in the air-conditioning system. Based on this, the present invention proposes an air-conditioning water system and a mixed flow control method thereof.

[0049] See also Figures 1 to 4 The air conditioning water system proposed in the present invention is used to connect an outdoor unit 10 with multiple indoor units 20. The present invention is described by taking one outdoor unit 10 and five indoor units 20 as an example.

[0050] The air conditioning water system includes a water supply pipe 361 connected to the water outlet of the outdoor unit 10, a water return pipe 363 connected to the water inlet of the outdoor unit 10, and a plurality of conventional circulating water circuits arranged in parallel, each of which includes a water inlet branch 362 connected to the water supply pipe 361 and the water inlet of the indoor unit 20, and a water outlet branch 364 connected to the water return pipe 363 and the water outlet of the indoor unit 20. In addition, the air conditioning water system also includes:

[0051] Mixing water divider 31;

[0052] The first mixed flow water supply pipe 32 is connected to the water supply pipe 361 and the water inlet of the mixed water divider 31;

[0053] The second mixed flow water supply pipe 33 is connected to the return pipe 363 and the water inlet of the mixed water divider 31;

[0054] Multiple mixed flow circulation water circuits, each mixed flow circulation water circuit includes a mixed flow water supply branch 351 connected to the water outlet of the mixing water divider 31 and the water inlet of the indoor unit 20, and a mixed flow return water branch 352 connected to the water inlet of the mixing water divider 31 and the water outlet of the indoor unit 20. The mixed flow circulation water circuit connected to the same indoor unit 20 is selectively connected to the conventional circulation water circuit.

[0055] The advantage of such a design is that when the mixed flow circulating water circuit where the indoor unit is located is connected, the mixed water divider collects the medium and high temperature chilled water after heat exchange of the indoor unit according to the control requirements, and makes the collected medium and high temperature chilled water mixed with the low temperature chilled water from the first mixed flow make-up water pipe, or with the medium and high temperature chilled water from the second mixed flow make-up water pipe and then flows back to the indoor unit to adjust the inlet water temperature of the indoor unit; in this way, the present invention realizes the variable water temperature control of the fixed water temperature air conditioning system, by increasing the inlet water temperature of the indoor unit, thereby increasing the outlet air temperature of the indoor unit, reducing the dehumidification effect, and more accurately controlling the ambient temperature, reducing ambient temperature fluctuations, and improving comfort. In addition, when the mixed flow circulating water circuit where a part of the indoor units are located is connected and the conventional circulating water circuit where another part of the indoor units are located is connected, the water flow saved when the water temperature of a part of the indoor units is adjusted by the mixed flow circulating water circuit can be directly supplied to the other part of the indoor units by the outdoor unit through the conventional circulating water circuit, so that the present invention realizes the improvement of the refrigeration capacity of the indoor units by mobilizing the water flow in the system. Then, the indoor units in different environments can be adjusted in a targeted manner to ensure the cooling effect of the indoor units in different environments in the air-conditioning system.

[0056] In a preferred embodiment, the air conditioning water system further includes a flow balance pipe 34 connected to the return pipe 363 and the water outlet of the water mixing divider 31 .

[0057] The advantage of this design is that the excess water in the water mixer can be discharged in time through the flow balance pipe, thereby ensuring the hydraulic balance in the system.

[0058] In a preferred embodiment, proportional valves for adjusting the water flow are installed on the first mixed flow water supply pipe 32 , the second mixed flow water supply pipe 33 and the flow balance pipe 34 .

[0059] like Figure 1 As shown, a first proportional valve 41 is installed on the first mixed flow water supply pipe 32 , a second proportional valve 42 is installed on the second mixed flow water supply pipe 33 , and a third proportional valve 43 is installed on the flow balance pipe 34 .

[0060] It should be understood that, during the mixed flow control process of the air conditioning water system, the opening of the third proportional valve 43 is always consistent with the opening of the first proportional valve 41 or the second proportional valve 42. Specifically, the first proportional valve 41 and the second proportional valve 42 are opened one by one. If the first proportional valve 41 is opened, the opening of the third proportional valve 43 is consistent with the opening of the first proportional valve 41; if the second proportional valve 42 is opened, the opening of the third proportional valve 43 is consistent with the opening of the first proportional valve 41.

[0061] The advantage of such a design is that the flow rate of medium and high temperature chilled water entering the mixing water divider 31 is regulated by the first proportional valve 41 (flowing through the first mixed flow feed water pipe 32), and the flow rate of low temperature chilled water entering the mixing water divider 31 is regulated by the second proportional valve 42 (flowing through the second mixed flow feed water pipe 33), thereby flexibly adjusting the inlet water temperature of the indoor unit 20; at the same time, the water flow discharged from the mixing water divider 31 is regulated by the third proportional valve 43 (flowing through the flow balance pipe 34) to ensure the hydraulic balance in the system.

[0062] In a preferred embodiment, each water inlet branch 362, each water outlet branch 364, each mixed flow water supply branch 351 and each mixed flow return water branch 352 is installed with a water valve for controlling the interruption of water flow.

[0063] like Figure 1 As shown, there are five indoor units 20, and each indoor unit 20 is configured with a corresponding water inlet branch 362 and a water outlet branch 364, and each water inlet branch 362 is installed with a water supply electric water valve 46, and each water outlet branch 364 is installed with a water return electric water valve 47. At the same time, each indoor unit 20 is configured with a corresponding mixed flow water supply branch 351 and a mixed flow return water branch 352, and each mixed flow water supply branch 351 is installed with a first mixed flow electric water valve 44, and each mixed flow return water branch 352 is installed with a second mixed flow electric water valve 45.

[0064] In practical applications, the water supply electric water valve 46 , the water return electric water valve 47 , the first mixed flow electric water valve 44 and the second mixed flow electric water valve 45 may be, but are not limited to, solenoid valves.

[0065] The advantage of this design is that the conventional circulating water circuit where the indoor unit is located is automatically connected by opening the water supply electric water valve and the return electric water valve, and the mixed flow circulating water circuit where the indoor unit is located is automatically connected by opening the first mixed flow electric water valve and the second mixed flow electric water valve.

[0066] In a preferred embodiment, the mixed flow return water branches 352 in a plurality of mixed flow circulating water circuits merge to form a mixed flow water inlet main pipeline, and a circulating water pump 51 and a mixed flow water inlet temperature sensor 61 are installed on the mixed flow water inlet main pipeline.

[0067] See also Figure 1, the five mixed flow return water branches 352 corresponding to the five indoor units 20 finally merge to form a mixed flow water inlet main pipeline and then connect to the mixed water divider 31. Preferably, a circulating water pump 51 is installed on the mixed flow water inlet main pipeline. Of course, the circulating water pump 51 can also be installed on the mixed flow water outlet main pipeline (not shown in the figure) of the mixed water divider 31. A mixed flow water inlet temperature sensor 61 is also installed on the mixed flow water inlet main pipeline, and the mixed flow water inlet temperature sensor 61 is located on the side of the circulating water pump 51 away from the mixed water divider 31. The mixed flow water inlet temperature sensor 61 is used to detect the mixed flow water inlet temperature. The mixed flow water inlet temperature sensor 61 can use a temperature sensing bag.

[0068] The advantage of this design is that the circulating water pump 51 provides power for the water circulation in the mixed flow circulating water circuit, ensuring that the water circulates at a set flow rate. At the same time, the mixed flow inlet water temperature sensor 61 detects the mixed flow inlet water temperature, and the inlet water temperature of the indoor unit 20 can be adjusted according to the mixed flow inlet water temperature.

[0069] In a preferred embodiment, an ambient temperature sensor is installed at the return air position of each indoor unit 20 to detect the indoor ambient temperature. The ambient temperature sensor can be a temperature sensing package.

[0070] In a preferred embodiment, if Figure 1 As shown, the main water pump 52 and the total water inlet temperature sensor 62 are installed on the water supply pipe 361, and the water inlet temperature sensor 63 is installed on each water inlet branch 362. The water inlet temperature sensor 63 can adopt a temperature sensing package.

[0071] The advantage of this design is that low-temperature chilled water is delivered from the outdoor unit 10 to the indoor unit 20 via the main water pump 52, and the total water supply temperature and the actual inlet water temperature of the indoor unit 20 are detected respectively via the total inlet water temperature sensor 62 and the inlet water temperature sensor 63, so that the inlet water temperature of the indoor unit 20 can be adjusted according to the total water supply temperature and the actual inlet water temperature.

[0072] In a preferred embodiment, if Figure 1 As shown, a total return water temperature sensor 64 is installed on the return water pipe 363, and an outlet water temperature sensor 65 is installed on each outlet water branch 364. The total return water temperature sensor 64 and the outlet water temperature sensor 65 can adopt a temperature sensing package.

[0073] The advantage of this design is that by respectively detecting the total return water temperature and the outlet water temperature of the indoor unit 20 through the total return water temperature sensor 64 and the outlet water temperature sensor 65, the target indoor unit can be selected according to the total return water temperature and the inlet water temperature, and then the inlet water temperature can be adjusted for the target indoor unit.

[0074] In a preferred embodiment, the air conditioning water system further includes a buffer water tank 70 , which is connected to the return water pipe 363 .

[0075] The advantage of this design is that by adding a buffer water tank, the system water capacity can be increased and the pressure can be balanced.

[0076] Based on the specific structure of the aforementioned air conditioning water system, the mixed flow control method of the air conditioning water system provided by the present invention comprises the following steps:

[0077] Detect the indoor ambient temperature of the environment where each indoor unit is in operation;

[0078] Determine whether the temperature difference between the indoor ambient temperature and the set ambient temperature is less than the set ambient temperature difference value;

[0079] If yes, it is determined that the indoor unit is a steady-state indoor unit, only the mixed flow circulation water circuit where the steady-state indoor unit is located is connected, and the mixed water manifold is replenished with water through the first mixed flow replenishment pipe or the second mixed flow replenishment pipe to adjust the water inlet temperature of the steady-state indoor unit;

[0080] If not, it is determined that the indoor unit is a non-steady-state indoor unit, and only the conventional circulating water circuit where the non-steady-state indoor unit is located is connected.

[0081] The advantage of such a design is that when the mixed flow circulation water circuit where the steady-state indoor unit is located is connected, the mixed water divider collects the medium and high temperature chilled water after heat exchange of the indoor unit according to the control requirements, and makes the collected medium and high temperature chilled water mixed with the low temperature chilled water from the first mixed flow make-up water pipe, or with the medium and high temperature chilled water from the second mixed flow make-up water pipe, and then flows back to the indoor unit to adjust the inlet water temperature of the steady-state indoor unit; in this way, the present invention realizes the variable water temperature control of the fixed water temperature air conditioning system, by increasing the inlet water temperature of the steady-state indoor unit, thereby increasing the outlet air temperature of the steady-state indoor unit, reducing the dehumidification effect, and more accurately controlling the ambient temperature, reducing ambient temperature fluctuations, and improving comfort. In addition, when the mixed flow circulation water circuit where the steady-state indoor unit is located is connected and the conventional circulation water circuit where the unsteady-state indoor unit is located is connected, the water flow saved when the water temperature of the steady-state indoor unit is adjusted by the mixed flow circulation water circuit can be directly supplied to the unsteady-state indoor unit by the outdoor unit through the conventional circulation water circuit, so that the present invention realizes the improvement of the refrigeration capacity of the unsteady-state indoor unit by mobilizing the water flow in the system. Then, the indoor units in different environments can be adjusted in a targeted manner to ensure the cooling effect of the indoor units in different environments in the air-conditioning system.

[0082] In a preferred embodiment, the mixed flow control method further comprises the following steps:

[0083] When there are at least two steady-state indoor units, the outlet water temperature of each steady-state indoor unit is detected, and the steady-state indoor unit with the highest outlet water temperature is selected as the target indoor unit;

[0084] The mixing water divider is replenished with water through the first mixed flow replenishment pipe or the second mixed flow replenishment pipe to adjust the water inlet temperature of the steady-state indoor unit: the mixing water divider is replenished with water through the first mixed flow replenishment pipe or the second mixed flow replenishment pipe until the actual inlet water temperature of the target indoor unit reaches the target inlet water temperature.

[0085] The advantage of this design is that by selecting the target indoor unit according to the outlet water temperature of the steady-state indoor unit, the inlet water temperature can be adjusted for the target indoor unit, simplifying the mixed flow control process.

[0086] In a preferred embodiment, water is replenished to the mixed water manifold through the first mixed flow replenishment pipe or the second mixed flow replenishment pipe until the actual inlet water temperature of the target indoor unit reaches the target inlet water temperature, which is specifically achieved in the following manner:

[0087] Detect the actual inlet water temperature of the target indoor unit;

[0088] Determine whether the temperature difference between the actual inlet water temperature and the rated water supply temperature is greater than a first set water temperature difference value;

[0089] If yes, adjust the opening of the first proportional valve on the first mixed flow water supply pipe so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is equal to the first set water temperature difference;

[0090] If not, adjust the opening of the second proportional valve on the second mixed flow water supply pipe so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is equal to the first set water temperature difference.

[0091] The present invention can set the first set water temperature difference value according to actual application requirements, for example, the first set water temperature difference value is 1°C.

[0092] The advantage of this design is that the opening of the first proportional valve or the second proportional valve is determined based on the temperature difference between the actual inlet water temperature of the target indoor unit and the rated water supply temperature and the first set water temperature difference, and the mixed flow control is simple and convenient and easy to implement.

[0093] In a preferred embodiment, after controlling the temperature difference between the actual inlet water temperature of the target indoor unit and the rated water supply temperature to be equal to the first set water temperature difference, the mixed flow control method further includes the following steps:

[0094] After running for a period of time, if the temperature difference between the indoor ambient temperature of the target indoor unit and the set ambient temperature is still less than the set ambient temperature difference value, continue to adjust the opening of the first proportional valve or the second proportional valve opening so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is equal to the second set water temperature difference value, and the second set water temperature difference value is greater than the first set water temperature difference value.

[0095] The present invention can set the first set water temperature difference and the second set water temperature difference according to actual application requirements, for example, the first set water temperature difference is 1°C, and the second set water temperature difference is 2°C.

[0096] It should be understood that after controlling the temperature difference between the actual inlet water temperature and the rated water supply temperature of the target indoor unit to be equal to the second set water temperature difference, the first proportional valve opening or the second proportional valve opening can continue to be adjusted so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is respectively equal to the third set water temperature difference (for example, 3°C), the fourth set water temperature difference (for example, 4°C), etc., until the target indoor unit is transformed into a non-steady-state indoor unit during the next inlet water temperature adjustment process.

[0097] The advantage of this design is that by gradually increasing the inlet water temperature of the target indoor unit until the cooling capacity of the target indoor unit and the indoor heat load reach a balance, the mixed flow control is simple and convenient and easy to implement.

[0098] In a preferred embodiment, the mixed flow control method further comprises the following steps:

[0099] While adjusting the opening of the first proportional valve disposed on the first mixed flow water supply pipe, the opening of the third proportional valve disposed on the flow balance pipe is adjusted, and the opening of the third proportional valve is equal to the opening of the first proportional valve;

[0100] Alternatively, while adjusting the opening of the second proportional valve disposed on the second mixed flow water supply pipe, the opening of the third proportional valve disposed on the flow balance pipe is adjusted, and the opening of the third proportional valve is equal to the opening of the second proportional valve.

[0101] The advantage of this design is that during the mixed flow control process, the opening of the third proportional valve arranged on the flow balance pipe is always consistent with the opening of the first proportional valve arranged on the first mixed flow water supply pipe or the opening of the second proportional valve arranged on the second mixed flow water supply pipe, which is beneficial to ensure the hydraulic balance within the system.

[0102] In a preferred embodiment, the mixed flow control method further comprises the following steps:

[0103] When this indoor unit is determined to be a non-steady-state indoor unit and has been running for a period of time, if the temperature difference between the indoor ambient temperature of this indoor unit and the set ambient temperature is less than the set ambient temperature difference value, this indoor unit is transformed from a non-steady-state indoor unit to a steady-state indoor unit, then the conventional circulating water circuit where this indoor unit is located is disconnected and the mixed flow circulating water circuit where this indoor unit is located is connected.

[0104] The advantage of such a design is that the present invention takes into account that during the adjustment of the air-conditioning system, there will be a process of transformation from a non-steady-state indoor unit to a steady-state indoor unit. Once the non-steady-state indoor unit is transformed into a steady-state indoor unit, the mixed flow circulating water circuit where the indoor unit is located is promptly connected, and the conventional circulating water circuit where the indoor unit is located is promptly cut off to adjust the water inlet temperature of the indoor unit.

[0105] For ease of understanding, the air conditioning water system and mixed flow control method provided by the present invention are described in more detail below in combination with actual application scenarios:

[0106] like Figure 1 As shown, the air conditioning system includes an outdoor unit 10 and five indoor units 20, and the outdoor unit 10 is connected to the five indoor units 20 through an air conditioning water system.

[0107] Specifically, the air conditioning water system includes a water supply pipe 361 connected to the water outlet of the indoor unit 20, a water return pipe 363 connected to the water inlet of the indoor unit 20, five water inlet branches 362 arranged in parallel and connected to the water supply pipe 361 and the water inlet of the indoor unit 20, and five water outlet branches 364 arranged in parallel and connected to the water return pipe 363 and the water outlet of the indoor unit 20. The main water pump 52 and the total water inlet temperature sensor 62 are installed on the water supply pipe 361, the total water return temperature sensor 64 is installed on the water return pipe 363, the water supply electric water valve 46 and the water inlet temperature sensor 63 are installed on the water inlet branch 362, and the water return electric water valve 47 and the water outlet temperature sensor 65 are installed on the water outlet branch 364. In addition, five mixed flow water supply branches 351 and five mixed flow return branches 352 are arranged between the mixing water divider 31 and the five indoor units 20. The five mixed flow return branches 352 finally merge to form a mixed flow water inlet main pipeline and are connected to the mixing water divider 31. A circulating water pump 51 and a mixed flow water inlet temperature sensor 61 are installed on the mixed flow water inlet main pipeline, a first mixed flow electric water valve 44 is installed on the mixed flow water supply branch 351, and a second mixed flow electric water valve 45 is installed on the mixed flow return branch 352. In addition, the first mixed flow water supply pipe 32 is connected to the water supply pipe 361 and the water inlet of the mixing water divider 31, the second mixed flow water supply pipe 33 is connected to the return pipe 363 and the water inlet of the mixing water divider 31, and the flow balance pipe 34 is connected to the mixed water divider outlet and the return pipe 363. The first mixed flow water supply pipe 32 is provided with a first proportional valve 41 , the second mixed flow water supply pipe 33 is provided with a second proportional valve 42 , and the flow balance pipe 34 is provided with a third proportional valve 43 . In addition, the return pipe 363 is also connected to the buffer water tank 70 .

[0108] The air conditioning water system control process is as follows:

[0109] When the air conditioning system is turned off, the first proportional valve 41, the second proportional valve 42, the third proportional valve 43, the first mixed flow electric water valve 44, the second mixed flow electric water valve 45, the water supply electric water valve 46 and the return water electric water valve 47 are all in a closed state.

[0110] like Figure 2As shown, when the air-conditioning system starts to operate in cooling mode, the main water pump 52 is turned on according to the rated flow rate, the water supply electric water valve 46 and the return electric water valve 47 corresponding to the running indoor unit 20 are opened, the air-conditioning system enters the normal working state, and the outdoor unit 10 provides chilled water to the indoor unit 20 in the system according to the rated water supply temperature.

[0111] After the air conditioning system has been running stably for a certain period of time, it starts to detect the number n of the indoor units 20 that are turned on, and the indoor ambient temperature of the environment where each turned-on indoor unit 20 is located. If the temperature difference between the indoor ambient temperature and the set ambient temperature is ≤1°C, the indoor unit 20 is recorded as a steady-state indoor unit, and the number is recorded as n1. If the temperature difference between the indoor ambient temperature and the set ambient temperature is greater than 1°C, the indoor unit 20 is recorded as a non-steady-state indoor unit, and the number is recorded as n2, where n=n1+n2.

[0112] According to the status of the indoor unit 20 in the air conditioning system, the air conditioning water system is divided into the following three control schemes:

[0113] like Figure 3 As shown, under the steady-state control scheme, all indoor units 20 are steady-state indoor units.

[0114] The purpose is to achieve variable water temperature control in the fixed water temperature air-conditioning system. The steady-state indoor unit uses medium-temperature water to supply water, which increases the steady-state indoor unit outlet air temperature, reduces the dehumidification effect, and can more accurately control the ambient temperature, reduce ambient temperature fluctuations, and improve comfort. At the same time, as the flow of the main water pump decreases, the energy consumption of the main water pump can be reduced, which has a certain energy-saving effect.

[0115] If the number of steady-state indoor units n1=n, it indicates that the operation state of the indoor units 20 in the air-conditioning system is stable, and the capacity ratio of the indoor and outdoor units is in a balanced state.

[0116] At this time, the first mixed flow electric water valve 44 and the second mixed flow electric water valve 45 corresponding to the steady-state indoor unit are opened, the circulating water pump 51 is opened (the circulating water pump 51 operates according to the rated total flow of the steady-state indoor unit to meet the stable operation of the small cycle of the steady-state indoor unit and the mixing water divider 31), the water supply electric water valve 46 and the water return electric water valve 47 corresponding to the steady-state indoor unit are closed, and the air conditioning system starts mixed flow operation. The outlet water temperature of each steady-state indoor unit is detected, and the steady-state indoor unit with the highest outlet water temperature is selected as the target indoor unit.

[0117] The first proportional valve 41 and the third proportional valve 43 are opened to detect the actual inlet water temperature of the target indoor unit in real time. If the temperature difference between the actual inlet water temperature of the target indoor unit and the rated water supply temperature is ≥1°C, the opening of the first proportional valve 41 is adjusted so that the temperature difference between the actual inlet water temperature of the target indoor unit and the rated water supply temperature is 1°C; if the temperature difference between the actual inlet water temperature of the target indoor unit and the rated water supply temperature is <1°C, the first proportional valve 41 is closed, the second proportional valve 42 is opened, and the opening of the second proportional valve 42 is adjusted so that the temperature difference between the actual inlet water temperature of the target indoor unit and the rated water supply temperature is 1°C. During the air conditioning system adjustment process, the opening of the third proportional valve 43 is always consistent with the opening of the first proportional valve 41 or the second proportional valve 42.

[0118] After the air conditioning system runs in this state for a period of time, it detects whether there is an unsteady-state indoor unit in the air conditioning system. If there is an unsteady-state indoor unit among the running indoor units 20 in the air conditioning system, the air conditioning system runs in the original state; if all the running indoor units 20 in the air conditioning system are steady-state indoor units, then the temperature difference between the actual inlet water temperature of the target indoor unit and the rated water supply temperature is controlled to 2°C. After the air conditioning system runs in this state for a period of time, it detects whether there is an unsteady-state indoor unit in the air conditioning system. If there is an unsteady-state indoor unit among the running indoor units 20 in the air conditioning system, the air conditioning system runs in the previous state; if all the running indoor units 20 in the air conditioning system are steady-state indoor units, then the temperature difference between the actual inlet water temperature of the target indoor unit and the rated water supply temperature is controlled to 3°C. And so on, until there is an unsteady-state indoor unit in the air conditioning system, the air conditioning system runs stably in the previous state.

[0119] The opening adjustment of the first proportional valve 41 can be calculated based on the total water supply temperature, the mixed flow water inlet temperature and the target water inlet temperature of the target indoor unit. Alternatively, the opening of the first proportional valve 41 can be given first, and then the actual water inlet temperature of the indoor unit 20 is compared with the target water inlet temperature, and then the trend of increasing or decreasing the opening of the first water valve is confirmed, so that the actual water inlet temperature of the indoor unit 20 gradually approaches the target water inlet temperature. The opening adjustment of the second proportional valve 42 is similar.

[0120] For example, there are 5 indoor units 20 in operation in the air conditioning system, the rated water supply temperature of the air conditioner is 7°C, and the set ambient temperature of each indoor unit 20 is 26°C. After a period of operation, the indoor ambient temperature of each indoor unit 20 is 26.5°C, 26.2°C, 26.1°C, 26.4°C, and 26.6°C, respectively, and each indoor unit 20 is a steady-state indoor unit. At present, the outlet water temperature of each indoor unit 20 is 11.8°C, 11.2°C, 11.1°C, 11.5°C, and 11.9°C, respectively, and the fifth indoor unit 20 is selected as the target indoor unit. Then, by adjusting the opening of the first proportional valve 41 or the second proportional valve 42, the actual inlet water temperature of the target indoor unit is controlled to 8°C. After running for a period of time, if the indoor ambient temperature of the fifth indoor unit 20 is still lower than 27°C, the actual inlet water temperature of the target indoor unit is controlled to 9°C by continuing to adjust the opening of the first proportional valve 41 or the second proportional valve 42; after running for a period of time, if the indoor ambient temperature of the fifth indoor unit 20 is still lower than 27°C, the actual inlet water temperature of the target indoor unit is controlled to 10°C, and so on. If the indoor ambient temperature of the fifth indoor unit 20 is greater than 27°C when the actual inlet water temperature is 10°C, the air conditioning system operates stably according to the inlet water temperature of the fifth indoor unit being 9°C.

[0121] like Figure 4 As shown, under the non-steady-state control scheme, some indoor units 20 are non-steady-state indoor units.

[0122] The purpose is to increase the water supply flow of the rated water temperature of the non-steady-state indoor unit while increasing the actual inlet water temperature of the steady-state indoor unit when the capacity ratio of the internal and external units is unbalanced or the environmental heat load of some indoor units 20 is large, thereby increasing the cooling capacity of the non-steady-state indoor unit.

[0123] If the number of non-steady-state indoor units in the air-conditioning system n>n2≥1, it indicates that the heat load of the environment where some indoor units 20 in the air-conditioning system are located is relatively large or the capacity ratio of the indoor and outdoor units is in an unbalanced state.

[0124] At this time, the first mixed flow electric water valve 44 and the second mixed flow electric water valve 45 corresponding to the steady-state indoor unit are opened, the circulating water pump 51 is turned on, the water supply electric water valve 46 and the water return electric water valve 47 corresponding to the steady-state indoor unit are closed, and the air-conditioning system starts semi-mixed flow operation. The water supply electric water valve 46 and the water return electric water valve 47 corresponding to the non-steady-state indoor unit remain opened, and the corresponding first mixed flow electric water valve 44 and the second mixed flow electric water valve 45 are closed.

[0125] The steady-state indoor unit in the air-conditioning system gradually increases the actual inlet water temperature of the steady-state indoor unit according to the steady-state control scheme until the cooling capacity of the steady-state indoor unit reaches a balance with the indoor heat load. After running for a period of time, the indoor ambient temperature of the non-steady-state indoor unit is detected. If the temperature difference between the indoor ambient temperature and the set ambient temperature is ≤1°C, the non-steady-state indoor unit has become a steady-state indoor unit. If all the indoor units 20 running in the air-conditioning system are steady-state indoor units, the air-conditioning system operates according to the steady-state control scheme, that is, the first mixed-flow electric water valve 44 and the second mixed-flow electric water valve 45 corresponding to all steady-state indoor units are opened, and the water supply electric water valve 46 and the return electric water valve 47 are closed; if there are still non-steady-state indoor units in the air-conditioning system at this time, the air-conditioning system continues to operate according to the non-steady-state control scheme.

[0126] Under the out-of-control control scheme, all indoor units 20 are non-steady-state indoor units.

[0127] If the number of non-steady-state indoor units in the air-conditioning system n2=n, it indicates that the total cooling demand of the indoor units 20 in the air-conditioning system is far greater than the cooling capacity of the outdoor unit 10. The air-conditioning system maintains a normal working state and issues feedback to the user that the capacity ratio of the air-conditioning system is unbalanced.

[0128] The present invention achieves variable water temperature control of a fixed water temperature air conditioning system by mixing the return water of the indoor unit with the water supply of the outdoor unit and regulating the flow of the air conditioning water system under different conditions. In addition, the indoor units under different environments are regulated in a targeted manner to ensure the cooling effect of the indoor units under different environments in the air conditioning system. This solution is not only applicable to conventional multi-connected air conditioning systems, but also to large air conditioning water systems, and its effect will be more obvious in large air conditioning water systems.

[0129] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An air conditioning water system, comprising a water supply pipe connected to a water outlet of an outdoor unit, a water return pipe connected to a water inlet of the outdoor unit, and a plurality of conventional circulating water circuits arranged in parallel, each of the conventional circulating water circuits comprising a water inlet branch connected to the water supply pipe and a water inlet of an indoor unit, and a water outlet branch connected to the water return pipe and a water outlet of the indoor unit, It is characterized in that Also includes: Mixing water divider; A first mixed flow water supply pipe, connected to the water supply pipe and the water inlet of the mixed water divider; A second mixed flow water supply pipe is connected to the return water pipe and the water inlet of the mixed water divider; Multiple mixed flow circulation water circuits, each of which includes a mixed flow water supply branch connected to the water outlet of the mixing water divider and the water inlet of the indoor unit, and a mixed flow return branch connected to the water inlet of the mixing water divider and the water outlet of the indoor unit. The mixed flow circulation water circuit connected to the same indoor unit is selectively connected to the conventional circulation water circuit.

2. The air conditioning water system according to claim 1, It is characterized in that Also includes: The flow balance pipe is connected to the return pipe and the water outlet of the water mixing diverter.

3. The air conditioning water system according to claim 2, It is characterized in that The first mixed flow water supply pipe, the second mixed flow water supply pipe and the flow balance pipe are respectively installed with a first proportional valve, a second proportional valve and a third proportional valve for adjusting the water flow.

4. The air conditioning water system according to claim 1, It is characterized in that The mixed flow return water branches in the plurality of mixed flow circulating water circuits merge to form a mixed flow water inlet main pipeline, and a circulating water pump and a mixed flow water inlet temperature sensor are installed on the mixed flow water inlet main pipeline.

5. A mixed flow control method for an air conditioning water system according to any one of claims 1 to 4, It is characterized in that include: Detect the indoor ambient temperature of the environment where each indoor unit is in operation; Determine whether the temperature difference between the indoor ambient temperature and the set ambient temperature is less than the set ambient temperature difference value; If yes, it is determined that the indoor unit is a steady-state indoor unit, only the mixed flow circulation water circuit where the steady-state indoor unit is located is connected, and the mixed water divider is replenished with water through the first mixed flow replenishment pipe or the second mixed flow replenishment pipe to adjust the water inlet temperature of the steady-state indoor unit; If not, it is determined that the indoor unit is a non-steady-state indoor unit, and only the conventional circulating water circuit where the non-steady-state indoor unit is located is connected.

6. The mixed flow control method of the air conditioning water system according to claim 5, It is characterized in that Also includes: When there are at least two steady-state indoor units, the outlet water temperature of each steady-state indoor unit is detected, and the steady-state indoor unit with the highest outlet water temperature is selected as the target indoor unit; The method of replenishing water to the mixing water divider through the first mixed flow make-up pipe or the second mixed flow make-up pipe to adjust the water inlet temperature of the steady-state indoor unit is: replenishing water to the mixing water divider through the first mixed flow make-up pipe or the second mixed flow make-up pipe until the actual inlet water temperature of the target indoor unit reaches the target inlet water temperature.

7. The mixed flow control method of the air conditioning water system according to claim 6, It is characterized in that The step of replenishing water to the mixing water divider through the first mixed flow replenishing pipe or the second mixed flow replenishing pipe until the actual inlet water temperature of the target indoor unit reaches the target inlet water temperature includes: Detecting the actual inlet water temperature of the target indoor unit; Determine whether the temperature difference between the actual inlet water temperature and the rated water supply temperature is greater than a first set water temperature difference value; If yes, adjusting the opening of the first proportional valve disposed on the first mixed flow water supply pipe so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is equal to the first set water temperature difference; If not, adjust the opening of the second proportional valve on the second mixed-flow water supply pipe so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is equal to the first set water temperature difference.

8. The mixed flow control method of the air conditioning water system according to claim 7, It is characterized in that After controlling the temperature difference between the actual water inlet temperature and the rated water supply temperature of the target indoor unit to be equal to the first set water temperature difference, the method further includes: After running for a period of time, if the temperature difference between the indoor ambient temperature of the target indoor unit and the set ambient temperature is still less than the set ambient temperature difference value, continue to adjust the first proportional valve opening or the second proportional valve opening so that the temperature difference between the actual inlet water temperature and the rated water supply temperature is equal to the second set water temperature difference value, and the second set water temperature difference value is greater than the first set water temperature difference value.

9. The mixed flow control method for the air conditioning water system according to claim 7 or 8, It is characterized in that While adjusting the opening of the first proportional valve disposed on the first mixed flow water supply pipe, the opening of the third proportional valve disposed on the flow balance pipe is adjusted, and the opening of the third proportional valve is equal to the opening of the first proportional valve; Alternatively, while adjusting the opening of the second proportional valve disposed on the second mixed flow water supply pipe, the opening of the third proportional valve disposed on the flow balance pipe is adjusted, and the opening of the third proportional valve is equal to the opening of the second proportional valve.

10. The mixed flow control method of the air conditioning water system according to claim 5, It is characterized in that Also includes: When this indoor unit is determined to be the non-steady-state indoor unit and has been running for a period of time, if the temperature difference between the indoor ambient temperature of this indoor unit and the set ambient temperature is less than the set ambient temperature difference value, at this time, this indoor unit is transformed from the non-steady-state indoor unit to the steady-state indoor unit, then the conventional circulating water circuit where this indoor unit is located is disconnected, and the mixed flow circulating water circuit where this indoor unit is located is connected.

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