Water chilling unit, control method thereof and machine readable storage medium

Abstract

The invention relates to the technical field of air treatment equipment, in particular to a control method of a water chilling unit, a machine readable storage medium and the water chilling unit. The water chilling unit comprises a cooling water balance pipe, a chilled water balance pipe and a heat exchange device; the cooling water balance pipe is suitable for being connected with at least part of the cooling water inlet pipe in parallel, and a first valve and a first pump are arranged on the cooling water balance pipe; the chilled water balance pipe is suitable for being connected with at least part of the chilled water inlet pipe in parallel, and a second valve and a second pump are arranged on the chilled water balance pipe. The control method comprises the steps of obtaining the actual rotating speed of the compressor; when the actual rotating speed is the lowest preset rotating speed, the actual water outlet temperature of the cooling water is obtained and recorded as the first temperature; judging whether the first temperature meets a first preset condition or not; and if yes, it is determined that the compressor has the unloading requirement, and the first valve, the second valve, the first pump and the second pump are started. According to the invention, the water chilling unit has high energy efficiency and high unloading capacity under the working conditions of high temperature difference and low load.

Description

Technical Field

[0001] The present invention relates to the technical field of air handling equipment, and in particular to a control method for a chiller, a machine-readable storage medium, and a chiller. Background Art

[0002] When chillers operate in scenarios with large temperature differences in the chilled water and low user load, they require higher unloading capacity. To improve unloading capacity, the following solution is currently commonly used: a load-balancing line between the evaporator and condenser is opened, allowing the refrigerant to flow from the condenser to the evaporator through the load-balancing line. This method increases unloading capacity by increasing the evaporator pressure. However, this solution sacrifices energy efficiency in exchange for unloading capacity, and the improvement in unloading capacity is limited. Therefore, existing chillers cannot balance energy efficiency and unloading capacity, that is, they cannot increase unloading capacity while maintaining energy efficiency. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide a control method for a chiller, a machine-readable storage medium and a chiller that overcome the above problems or at least partially solve the above problems. The invention aims to solve the problem that the existing chiller cannot balance energy efficiency and unloading capacity under high temperature difference and low load conditions, so that the chiller has high energy efficiency and high unloading capacity under high temperature difference and low load conditions.

[0004] In one aspect, the present invention provides a control method for a chiller, the chiller comprising a chilled water inlet pipe, a cooling water inlet pipe, a cooling water balancing pipe, a chilled water balancing pipe, and a heat exchange device; the cooling water balancing pipe is adapted to be arranged in parallel with at least a portion of the cooling water inlet pipe, and is provided with a first valve and a first pump; the chilled water balancing pipe is adapted to be arranged in parallel with at least a portion of the chilled water inlet pipe, and is provided with a second valve and a second pump; the heat exchange device is adapted to exchange heat between cooling water in the cooling water balancing pipe and chilled water in the chilled water balancing pipe;

[0005] The control method includes:

[0006] Get the actual speed of the compressor;

[0007] When the actual speed is the lowest preset speed, obtaining the actual outlet temperature of the cooling water, which is recorded as the first temperature;

[0008] determining whether the first temperature satisfies a first preset condition;

[0009] If so, it is determined that the compressor has an unloading requirement, and the first valve, the second valve, the first pump, and the second pump are opened.

[0010] Optionally, after opening the first valve, the second valve, the first pump and the second pump, the method further includes: controlling the rotation speeds of the first pump and the second pump according to the first temperature.

[0011] Optionally, the first preset condition includes any one of the following conditions:

[0012] The first temperature is less than a target temperature;

[0013] The first temperature is not less than a target temperature, and a decreasing speed of the first temperature is greater than a first set threshold.

[0014] Optionally, controlling the rotational speeds of the first pump and the second pump according to the first temperature includes:

[0015] When the first temperature is lower than a target temperature, controlling the rotational speeds of the first pump and the second pump according to a temperature difference between the target temperature and the first temperature; and / or

[0016] When the first temperature is not less than a target temperature and a decreasing speed of the first temperature is greater than a first set threshold, the rotational speeds of the first pump and the second pump are controlled according to the decreasing speed.

[0017] Optionally, the temperature difference is positively correlated with the rotational speed;

[0018] The descending speed is positively correlated with the rotational speed.

[0019] Optionally, the first valve and the second valve are ball valves;

[0020] The first pump and the second pump are gear pumps;

[0021] The heat exchange device is a plate heat exchanger.

[0022] Optionally, controlling the rotational speeds of the first pump and the second pump according to the temperature difference between the target temperature and the first temperature includes:

[0023] Obtaining a preset temperature difference range in which the temperature difference lies;

[0024] Obtaining a preset speed corresponding to the preset temperature difference range;

[0025] The first pump and the second pump are controlled to execute the preset speed.

[0026] Optionally, controlling the rotational speeds of the first pump and the second pump according to the temperature difference between the target temperature and the first temperature includes:

[0027] When the temperature difference is within a first preset temperature difference range, controlling the first pump and the second pump to execute a first speed;

[0028] When the temperature difference is within a second preset temperature difference range, controlling the first pump and the second pump to execute a second speed;

[0029] When the temperature difference is within a third preset temperature difference range, controlling the first pump and the second pump to execute a third speed;

[0030] The temperature difference values ​​of the first preset temperature difference interval, the second preset temperature difference interval, and the third preset temperature difference interval increase in sequence; and the first speed, the second speed, and the third speed increase gradually.

[0031] Optionally, controlling the rotational speeds of the first pump and the second pump according to the descending speed includes:

[0032] Obtaining a preset speed range in which the descent speed is located;

[0033] Obtaining a preset speed corresponding to the preset speed range;

[0034] The first pump and the second pump are controlled to execute the preset speed.

[0035] Optionally, controlling the rotational speeds of the first pump and the second pump according to the descending speed includes:

[0036] When the descending speed is within a first preset speed range, controlling the first pump and the second pump to execute a fourth speed;

[0037] When the descending speed is within a second preset speed range, controlling the first pump and the second pump to execute a fifth speed;

[0038] When the descending speed is within a third preset speed range, controlling the first pump and the second pump to execute a sixth speed;

[0039] The speed values ​​of the first preset speed interval, the second preset speed interval, and the third preset speed interval increase in sequence; and the fourth speed, the fifth speed, and the sixth speed gradually increase.

[0040] Optionally, after opening the first valve, the second valve, the first pump, and the second pump, the method further includes:

[0041] Obtain the actual outlet temperature of the cooling water, recorded as the second temperature;

[0042] determining whether the second temperature satisfies a second preset condition;

[0043] If so, the first valve, the second valve, the first pump, and the second pump are closed.

[0044] Optionally, the second preset condition includes any one of the following conditions:

[0045] The second temperature is higher than the target temperature, and the second temperature no longer decreases or the decreasing rate of the second temperature is no greater than a first set threshold;

[0046] The second temperature is lower than the target temperature, and a rising speed of the second temperature is greater than or equal to a second set threshold.

[0047] On the other hand, the present invention further provides a machine-readable storage medium having a machine-executable program stored thereon, wherein the machine-executable program is capable of implementing any of the control methods described above when executed by a processor.

[0048] In another aspect, the present invention further provides a chiller, comprising:

[0049] An evaporator, wherein a chilled water inlet of the evaporator is connected to a chilled water inlet pipe;

[0050] Condenser; the cooling water inlet of the condenser is connected to a cooling water inlet pipe;

[0051] a cooling water balancing pipe, arranged in parallel with at least a portion of the cooling water inlet pipe, and provided with a first valve and a first pump;

[0052] a chilled water balancing pipe, arranged in parallel with at least a portion of the chilled water inlet pipe, and provided with a second valve and a second pump;

[0053] The heat exchange device is used for exchanging heat between the cooling water in the cooling water balance pipe and the chilled water in the chilled water balance pipe.

[0054] Optionally, the chiller further includes a controller, which includes a memory, a processor, and a machine executable program stored in the memory and running on the processor, and when the processor executes the machine executable program, it implements the control method described in any one of the above items.

[0055] In the chiller control method, machine-readable storage medium, and chiller of the present invention, on the one hand, by adding a cooling water balance pipe, a chilled water balance pipe, and a heat exchange device between the chilled water inlet pipe and the cooling water inlet pipe, the cooling water and the chilled water can be heat exchanged, so that the chilled water inlet temperature flowing into the evaporator is increased, and the cooling water inlet temperature flowing into the condenser is reduced, thereby reducing the fluorine side pressure difference and pressure ratio of the condenser and evaporator, thereby improving the unloading capacity of the compressor. On the other hand, the first pump can increase the transmission speed of the cooling water in the cooling water balance pipe, and the second pump can increase the transmission speed of the cooling water in the chilled water balance pipe, thereby making the chilled water inlet temperature flowing into the evaporator higher and the cooling water inlet temperature flowing into the condenser lower, thereby further reducing the fluorine side pressure difference and pressure ratio of the condenser and evaporator, thereby further improving the unloading capacity of the compressor. Therefore, when the actual compressor speed reaches the minimum preset speed and there is still a need for unloading, the chilled water balance pipe and the cooling water balance pipe are opened. The heat exchange device, the first pump, and the second pump can quickly and significantly reduce the temperature difference between the chilled water entering the evaporator and the cooling water entering the condenser, thereby significantly improving the compressor's unloading capacity. Furthermore, compared with existing technologies, the present invention can reduce load losses and improve unit energy efficiency. Therefore, the present invention can enable the chiller to achieve high energy efficiency and high unloading capacity under high temperature difference and low load conditions.

[0056] In addition, the control method of the present invention has the beneficial effect that the control procedure is simple and easy to execute.

[0057] Therefore, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0059] Figure 1 is a schematic flow chart of a chiller control method according to an embodiment of the present invention;

[0060] Figure 2 is a schematic flow chart of a chiller control method according to an embodiment of the present invention;

[0061] Figure 3 is a schematic flow chart of a chiller control method according to an embodiment of the present invention;

[0062] Figure 4 is a schematic flow chart of a chiller control method according to an embodiment of the present invention;

[0063] Figure 5 is a schematic flow chart of a chiller control method according to an embodiment of the present invention;

[0064] Figure 6 is a schematic flow chart of a chiller control method according to an embodiment of the present invention;

[0065] Figure 7 is a schematic flow chart of a chiller control method according to an embodiment of the present invention;

[0066] Figure 8 is a schematic flow chart of a chiller control method according to an embodiment of the present invention;

[0067] Figure 9 is a schematic flow chart of a chiller control method according to an embodiment of the present invention;

[0068] Figure 10 is a schematic structural diagram of a machine-readable storage medium according to an embodiment of the present invention;

[0069] Figure 11 is a schematic structural diagram of a water chiller according to an embodiment of the present invention;

[0070] Figure 12 1 is a working principle diagram of a chiller according to an embodiment of the present invention. DETAILED DESCRIPTION

[0071] Refer to the following Figures 1 to 12 The present invention will be described in detail with reference to the chiller control method, machine-readable storage medium, and chiller according to embodiments of the present invention. The terms "front," "rear," "upper," "lower," "top," "bottom," "inner," "outer," and "lateral" are used to indicate positions or relationships based on those shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. These terms do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific position. Therefore, they should not be construed as limiting the present invention.

[0072] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the definition of "first", "second", etc. can explicitly or implicitly include at least one of the features, that is, include one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. When a feature "includes or contains" one or more of the features it covers, unless otherwise specifically described, this indicates that other features are not excluded and may further include other features.

[0073] Unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," "coupled," and the like should be interpreted broadly. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components, unless otherwise specified. A person of ordinary skill in the art should be able to understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0074] Figure 1 is a schematic flow chart of a control method for a chiller 100 according to an embodiment of the present invention, and is combined with Figure 2-9 , the present invention provides a control method for a chiller 100.

[0075] The chiller 100 includes a chilled water inlet pipe 151, a cooling water inlet pipe 121, a cooling water balancing pipe 123, a chilled water balancing pipe 153, and a heat exchanger 140. The cooling water inlet pipe 121 is used to supply cooling water to the condenser 113. The cooling water balancing pipe 123 is adapted to be arranged in parallel with at least a portion of the cooling water inlet pipe 121 and is equipped with a first valve 1231 and a first pump 1232. The chilled water inlet pipe 151 is used to supply chilled water to the evaporator 114. The chilled water balancing pipe 153 is adapted to be arranged in parallel with at least a portion of the chilled water inlet pipe 151 and is equipped with a second valve 1531 and a second pump 1532. The heat exchanger 140 is used to exchange heat between the cooling water in the cooling water balancing pipe 123 and the chilled water in the chilled water balancing pipe 153.

[0076] The control method of the chiller 100 includes the following steps:

[0077] S100, obtaining the actual rotation speed of the compressor 111;

[0078] S200, when the actual speed is the lowest preset speed, obtaining the actual outlet temperature of the chilled water, recorded as a first temperature;

[0079] S300, determining whether the first temperature meets a first preset condition; if so, executing S400;

[0080] S400 , determining that the compressor 111 has an unloading requirement, and opening the first valve 1231 , the second valve 1531 , the first pump 1232 , and the second pump 1532 .

[0081] Specifically, the actual outlet temperature of the chilled water refers to the temperature of the chilled water flowing out of the evaporator 114 .

[0082] In this embodiment, by adding a cooling water balancing pipe 123, a chilled water balancing pipe 153, and a heat exchanger 140 between the chilled water inlet pipe 151 and the cooling water inlet pipe 121, heat exchange can be performed between the cooling water and the chilled water, thereby increasing the chilled water inlet temperature of the evaporator 114 and decreasing the cooling water inlet temperature of the condenser 113. This reduces the pressure difference and pressure ratio on the fluorine side between the condenser 113 and the evaporator 114, thereby improving the unloading capacity of the compressor 111. Furthermore, the first pump 1232 increases the cooling water delivery rate in the cooling water balancing pipe 123, and the second pump 1532 increases the cooling water delivery rate in the chilled water balancing pipe 153. This increases the chilled water inlet temperature of the evaporator 114 and decreases the cooling water inlet temperature of the condenser 113. This further reduces the pressure difference and pressure ratio on the fluorine side between the condenser 113 and the evaporator 114, thereby further improving the unloading capacity of the compressor 111. Therefore, when the actual speed of compressor 111 reaches the minimum preset speed and there is still a need for unloading, the chilled water balance pipe 153 and the cooling water balance pipe 123 are opened. Under the action of heat exchange device 140, first pump 1232, and second pump 1532, the temperature difference between the chilled water entering evaporator 114 and the cooling water entering condenser 113 can be quickly and significantly reduced, thereby significantly improving the unloading capacity of compressor 111. In addition, compared with the prior art, the present invention can reduce load losses and improve the energy efficiency of the unit. Therefore, the present invention can enable the chiller 100 to have high energy efficiency and high unloading capacity under high temperature difference and low load conditions.

[0083] Furthermore, assuming the chilled water outlet temperature is controlled at 7°C and the ambient temperature is 35°C, using the existing load balancing valve solution, the cooling water inlet temperature can only be reduced to 30°C. If the actual unit load is 50% and the terminal load is 20%, an additional loss of 30% is required. In this embodiment, using the chilled cooling water temperature balancing pipeline, the actual unit load can be 45%, and if the terminal load is still 20%, an additional loss of 25% is required.

[0084] In some optional embodiments of the present invention, S400 includes the following steps: opening the first valve 1231 and the second valve 1531; and after a first time, starting the first pump 1232 and the second pump 1532. The first time can be set as needed, for example, the first time is 30 seconds.

[0085] like Figure 2 As shown, in some optional embodiments of the present invention, after S400, the control method further includes the following steps: S500, controlling the rotation speeds of the first pump 1232 and the second pump 1532 according to the first temperature.

[0086] In this embodiment, controlling the rotational speed of the first pump 1232 and the second pump 1532 according to the first temperature is more conducive to quickly and accurately increasing the chilled water temperature and lowering the cooling water temperature, thereby helping to reduce the pressure between the condenser 113 and the evaporator 114, and further improving the unloading capacity of the compressor 111.

[0087] In some optional embodiments of the present invention, the first preset condition includes any one of the following conditions:

[0088] The first temperature is less than the target temperature;

[0089] The first temperature is not less than the target temperature, and the falling speed of the first temperature is greater than the first set threshold value. In other words, the falling speed of the first temperature is too fast.

[0090] This embodiment provides two conditions for determining whether the compressor 111 has a need to unload. As long as any one of the above conditions is met, it means that the compressor 111 has a need to unload. The above conditions have the advantage of being easy to operate.

[0091] In some optional embodiments of the present invention, S500, the step of controlling the rotational speeds of the first pump 1232 and the second pump 1532 according to the first temperature includes: S501, when the first temperature is lower than the target temperature, controlling the rotational speeds of the first pump 1232 and the second pump 1532 according to the temperature difference between the target temperature and the first temperature.

[0092] In some optional embodiments of the present invention, S500, the step of controlling the rotational speeds of the first pump 1232 and the second pump 1532 according to the first temperature includes: S502, when the first temperature is not less than the target temperature and the decreasing rate of the first temperature is greater than the first set threshold, controlling the rotational speeds of the first pump 1232 and the second pump 1532 according to the decreasing rate.

[0093] like Figure 3 As shown, in some optional embodiments of the present invention, S500, the step of controlling the rotational speeds of the first pump 1232 and the second pump 1532 according to the first temperature includes: S501, when the first temperature is lower than the target temperature, controlling the rotational speeds of the first pump 1232 and the second pump 1532 according to the temperature difference between the target temperature and the first temperature; S502, when the first temperature is not lower than the target temperature and the falling rate of the first temperature is greater than a first set threshold, controlling the rotational speeds of the first pump 1232 and the second pump 1532 according to the falling rate.

[0094] The specific method of controlling the rotational speed of the above embodiment is more conducive to accurately controlling the rotational speeds of the first pump 1232 and the second pump 1532 under different working conditions, thereby further improving the control accuracy and speed of the chilled water temperature and the cooling water temperature.

[0095] In some optional embodiments of the present invention, in the step of controlling the rotational speeds of first pump 1232 and second pump 1532 based on the temperature difference between the target temperature and the first temperature, the temperature difference and the rotational speed are positively correlated. That is, the greater the temperature difference, the greater the rotational speeds of first pump 1232 and second pump 1532; the smaller the temperature difference, the lower the rotational speeds of first pump 1232 and second pump 1532, which is beneficial for energy conservation and emission reduction. Therefore, the above method facilitates further precise raising of the chilled water temperature and lowering of the cooling water temperature, thereby more accurately improving the unloading capacity of compressor 111.

[0096] In some optional embodiments of the present invention, in the step of controlling the rotational speeds of first pump 1232 and second pump 1532 based on the drop rate, the drop rate is positively correlated with the rotational speed. That is, the greater the rate of drop of the first temperature, the greater the rotational speeds of first pump 1232 and second pump 1532; and the slower the rate of drop of the first temperature, the slower the rotational speeds of first pump 1232 and second pump 1532, which is beneficial for energy conservation and emission reduction. Therefore, the above method facilitates further precise raising of the chilled water temperature and lowering of the cooling water temperature, thereby further facilitating precise improvement of the lifting and unloading capacity of compressor 111.

[0097] like Figure 4 As shown, in some optional embodiments of the present invention, S501, controlling the rotation speeds of the first pump 1232 and the second pump 1532 according to the temperature difference between the target temperature and the first temperature, includes the following steps:

[0098] S5011, obtaining the preset temperature difference range in which the temperature difference lies;

[0099] S5012, obtaining a preset speed corresponding to a preset temperature difference range;

[0100] S5013, controlling the first pump 1232 and the second pump 1532 to execute a preset speed.

[0101] This embodiment provides a specific method for controlling the rotation speed of the first pump 1232 and the second pump 1532. Through the above method, the method has the advantage of being easy to operate. In this embodiment, the number and range of the preset temperature difference intervals can be set as needed.

[0102] like Figure 5 As shown, in some optional embodiments of the present invention, S501, controlling the rotation speeds of the first pump 1232 and the second pump 1532 according to the temperature difference between the target temperature and the first temperature, includes the following steps:

[0103] S5014, when the temperature difference is within the first preset temperature difference range, controlling the first pump 1232 and the second pump 1532 to operate at a first speed;

[0104] S5015, when the temperature difference is within the second preset temperature difference range, controlling the first pump 1232 and the second pump 1532 to operate at a second speed;

[0105] S5016, when the temperature difference is within the third preset temperature difference range, controlling the first pump 1232 and the second pump 1532 to operate at a third speed;

[0106] The temperature difference values ​​of the first preset temperature difference interval, the second preset temperature difference interval and the third preset temperature difference interval increase in sequence; and the first speed, the second speed and the third speed increase gradually.

[0107] Specifically, each interval range is not unique and can be set as needed. For example, when 0 < target temperature - first temperature ≤ 0.5°C, first pump 1232 and second pump 1532 operate at a first speed; when 0.5°C < target temperature - first temperature ≤ 1°C, first pump 1232 and second pump 1532 operate at a second speed; and when target temperature - first temperature > 1°C, first pump 1232 and second pump 1532 operate at a third speed.

[0108] like Figure 6 As shown, in some optional embodiments of the invention, S502, controlling the rotation speeds of the first pump 1232 and the second pump 1532 according to the descending speed, includes the following steps:

[0109] S5021, obtaining the preset speed range in which the descent speed is located;

[0110] S5022, obtaining a preset speed corresponding to a preset speed range;

[0111] S5023 , controlling the first pump 1232 and the second pump 1532 to execute a preset rotation speed.

[0112] This embodiment provides a specific method for controlling the rotational speed of the first pump 1232 and the second pump 1532. The method has the advantage of being easy to operate. In this embodiment, the number and range of the preset speed intervals can be set as needed.

[0113] like Figure 7 As shown, in some optional embodiments of the invention, S502, controlling the rotation speeds of the first pump 1232 and the second pump 1532 according to the descending speed, includes the following steps:

[0114] S5024, when the descending speed is within the first preset speed range, controlling the first pump 1232 and the second pump 1532 to operate at a fourth speed;

[0115] S5025, when the descending speed is within the second preset speed range, controlling the first pump 1232 and the second pump 1532 to operate at a fifth speed;

[0116] S5026, when the descending speed is within the third preset speed range, controlling the first pump 1232 and the second pump 1532 to operate at a sixth speed;

[0117] The speed values ​​of the first preset speed interval, the second preset speed interval and the third preset speed interval increase in sequence; and the fourth speed, the fifth speed and the sixth speed gradually increase.

[0118] Specifically, the rate of decrease of the first temperature refers to the rate of change of the water temperature, denoted as D. D = (first temperature before the set time period - current first temperature) / set time period. The set time period is 1s to 60s, preferably 5s. Preferably, the fourth speed is equal to the first speed, the fifth speed is equal to the second speed, and the sixth speed is equal to the third speed.

[0119] like Figure 8 As shown, in some optional embodiments of the present invention, S400, the first valve 1231, the second valve 1531, the first pump 1232 and the second pump 1532 are opened, and then the following steps are further included:

[0120] S600: Obtain the actual outlet temperature of the chilled water, recorded as the second temperature;

[0121] S700, determining whether the second temperature meets a second preset condition; if so, executing S800;

[0122] S800 , close the first valve 1231 , the second valve 1531 , the first pump 1232 , and the second pump 1532 .

[0123] Specifically, the second preset condition is a closing condition of the cooling water balance pipe 123 and the chilled water balance pipe 153 .

[0124] Preferably, in S800 , the first valve 1231 and the second valve 1531 are closed first; and then the first pump 1232 and the second pump 1532 are closed.

[0125] In some optional embodiments of the present invention, the second preset condition includes any one of the following conditions:

[0126] The second temperature is higher than the target temperature, and the second temperature no longer decreases or the rate of decrease of the second temperature is no greater than a first set threshold;

[0127] The second temperature is lower than the target temperature, and a rising speed of the second temperature is greater than or equal to a second set threshold.

[0128] Specifically, the second set threshold value may need to be set. For example, the rising speed is denoted as d, and the second set threshold value is denoted as d1. d = (current second temperature - second temperature before the set time period) / set time period. When d ≥ d1, first pump 1232 and second pump 1532 are first closed, followed by first valve 1231 and second valve 1531. The set time period can range from 1 second to 60 seconds, preferably 5 seconds.

[0129] In some optional embodiments of the present invention, the first valve 1231 and the first valve 1231 are ball valves. Preferably, the first valve 1231 and the first valve 1231 are electric ball valves. In other alternative embodiments, the first valve 1231 and the first valve 1231 can also be stop valves.

[0130] In some alternative embodiments of the present invention, the first pump 1232 and the second pump 1532 are gear pumps. In other alternative embodiments, the first pump 1232 and the second pump 1532 may also be vane pumps.

[0131] In some optional embodiments of the present invention, the heat exchange device 140 is a plate heat exchanger. In other optional embodiments of the present invention, the heat exchange device 140 can also be a heat exchanger with other structures.

[0132] like Figure 9 As shown, in a preferred embodiment of the present invention, the control method of the chiller 100 includes the following steps:

[0133] S1, obtaining the actual speed of the compressor 111;

[0134] S2, when the actual speed is the lowest preset speed, obtain the actual outlet temperature of the chilled water, which is recorded as the first temperature;

[0135] S3, determining whether the first temperature satisfies any one of the following conditions: the first temperature is lower than the target temperature; the first temperature is not lower than the target temperature, and the rate of decrease of the first temperature is greater than a first set threshold. If any of the above conditions is met, proceed to S4.

[0136] S4 , determining that the compressor 111 has an unloading demand, and opening the first valve 1231 , the second valve 1531 , the first pump 1232 , and the second pump 1532 .

[0137] S5. When the first temperature is lower than the target temperature, the rotational speeds of the first pump 1232 and the second pump 1532 are controlled according to the temperature difference between the target temperature and the first temperature: when the temperature difference is in the first preset temperature difference range, the first pump 1232 and the second pump 1532 are controlled to execute the first rotational speed; when the temperature difference is in the second preset temperature difference range, the first pump 1232 and the second pump 1532 are controlled to execute the second rotational speed; when the temperature difference is in the third preset temperature difference range, the first pump 1232 and the second pump 1532 are controlled to execute the third rotational speed; wherein, the temperature difference values ​​of the first preset temperature difference range, the second preset temperature difference range and the third preset temperature difference range increase sequentially; the first rotational speed, the second rotational speed and the third rotational speed gradually increase.

[0138] S6. When the first temperature is not less than the target temperature and the falling speed of the first temperature is greater than the first set threshold, the rotational speeds of the first pump 1232 and the second pump 1532 are controlled according to the falling speed: when the falling speed is in the first preset speed range, the first pump 1232 and the second pump 1532 are controlled to execute the fourth speed; when the falling speed is in the second preset speed range, the first pump 1232 and the second pump 1532 are controlled to execute the fifth speed; when the falling speed is in the third preset speed range, the first pump 1232 and the second pump 1532 are controlled to execute the sixth speed; wherein, the speed values ​​of the first preset speed range, the second preset speed range and the third preset speed range increase sequentially; the fourth speed, the fifth speed and the sixth speed gradually increase.

[0139] S7, obtaining the actual outlet temperature of the chilled water, recorded as the second temperature;

[0140] S8, determining whether the second temperature satisfies any one of the following conditions:

[0141] The second temperature is higher than the target temperature, and the second temperature no longer decreases or the rate of decrease of the second temperature is no greater than a first set threshold;

[0142] The second temperature is lower than the target temperature, and the rising speed of the second temperature is greater than or equal to the second set threshold. If any of the above conditions is met, S9 is executed.

[0143] S9, close the first valve 1231, the second valve 1531, the first pump 1232 and the second pump 1532.

[0144] In some optional embodiments of the present invention, the control method of the chiller 100 is applicable to the cooling operation mode of the chiller 100 .

[0145] In some optional embodiments of the present invention, the control method of the chiller 100 is applicable to the heating operation mode of the chiller 100 .

[0146] Figure 10is a schematic diagram of a machine-readable storage medium 200 according to an embodiment of the present invention. Figure 10 As shown, an embodiment of the present invention further provides a machine-readable storage medium 200 on which a machine executable program 201 is stored. When the machine executable program 201 is executed by the processor 132, the control method of the chiller 100 according to any of the above embodiments is implemented.

[0147] It should be noted that the logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any machine-readable storage medium 200 for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor 132, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or used in combination with these instruction execution systems, devices or apparatuses.

[0148] For the purposes of the present embodiment, the machine-readable storage medium 200 can be any device that can contain, store, communicate, propagate, or transmit a program for use with an instruction execution system, device, or apparatus, or in conjunction with such an instruction execution system, device, or apparatus. More specific examples (not an exhaustive list) of the machine-readable storage medium 200 include the following: an electrical connection portion having one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory 131 (RAM), read-only memory 131 (ROM), erasable and editable read-only memory 131 (EPROM or flash memory 131), a fiber optic device, and a portable compact disc read-only memory 131 (CDROM). In addition, the machine-readable storage medium 200 can even be paper or other suitable medium on which the program can be printed, as the program can be obtained electronically, for example, by optically scanning the paper or other medium, and then editing, interpreting, or otherwise processing it in a suitable manner as needed, and then stored in the memory 131.

[0149] like Figure 12As shown, an embodiment of the present invention further provides a chiller 100, comprising an evaporator 114, a condenser 113, a cooling water balancing pipe 123, a chilled water balancing pipe 153, and a heat exchange device 140. The chilled water inlet of the evaporator 114 is connected to the chilled water inlet pipe 151, and the chilled water outlet of the evaporator 114 is connected to the chilled water outlet pipe 152. The cooling water inlet of the condenser 113 is connected to the cooling water inlet pipe 121. The cooling water balancing pipe 123 is adapted to be arranged in parallel with at least a portion of the cooling water inlet pipe 121 and is provided with a first valve 1231 and a first pump 1232. The chilled water balancing pipe 153 is adapted to be arranged in parallel with at least a portion of the cooling water inlet pipe 121 and is provided with a second valve 1531 and a second pump 1532. The heat exchange device 140 is configured to exchange heat between the cooling water in the cooling water balancing pipe 123 and the chilled water in the chilled water balancing pipe 153.

[0150] During operation of the chiller 100, when the unloading capacity of the compressor 111 needs to be increased, the cooling water balance pipe 123 and the chilled water balance pipe 153 can be opened, and the heat exchange device 140 can exchange heat between the cooling water and the chilled water. Furthermore, the first pump 1232 can increase the flow rate of cooling water in the cooling water balance pipe 123, and the second pump 1532 can increase the flow rate of cooling water in the chilled water balance pipe 153, further increasing the temperature of the chilled water entering the evaporator 114 and further decreasing the temperature of the cooling water entering the condenser 113. Therefore, under high temperature differential and low load conditions, opening the cooling water balance pipe and the chilled water balance pipe can quickly and significantly reduce the temperature difference between the chilled water entering the evaporator 114 and the cooling water entering the condenser 113, thereby significantly increasing the unloading capacity of the compressor 111. Furthermore, compared to the prior art, the present invention can reduce load losses and improve the unit's energy efficiency. Therefore, the present invention can enable the chiller 100 to have high energy efficiency and high unloading capacity under high temperature differential and low load conditions.

[0151] like Figure 11 As shown, the chiller 100 further includes a controller 130. The controller 130 includes a memory 131, a processor 132, and a machine executable program 201 stored in the memory 131 and running on the processor 132. When the processor 132 executes the machine executable program 201, the chiller control method according to any of the above embodiments is implemented.

[0152] Specifically, the controller 130 may include a processor 132 adapted to execute stored instructions, and a memory 131 that provides temporary storage for the instructions during operation. The processor 132 may be a single-core processor 132, a multi-core processor 132, a computing cluster, or any number of other configurations. The memory 131 may include random access memory 131 (RAM), read-only memory 131, flash memory, or any other suitable storage system.

[0153] The processor 132 can be connected to an I / O interface (input / output interface) suitable for connecting the chiller 100 to one or more I / O devices (input / output devices) via a system interconnect (e.g., PCI, PCI-Express, etc.). The I / O devices may include, for example, a keyboard and a pointing device, wherein the pointing device may include a touchpad or a touch screen, etc.

[0154] Processor 132 can also be linked to the display interface that is suitable for controller 130 being connected to display device through system interconnection.Display device can comprise the display screen that is built-in component of controller 130.Display device can also comprise the computer monitor, television or projector etc. that are externally connected to chiller 100.In addition, network interface controller (networkinterface controller, NIC) can be suitable for controller 130 being connected to network through system interconnection.In certain embodiments, NIC can use any suitable interface or protocol (such as Internet Small Computer System Interface etc.) to transmit data.Network can be cellular network, radio network, wide area network (WAN)), local area network (LAN) or Internet etc.Remote device can be connected to controller 130 through network.

[0155] like Figure 12 As shown, in some optional embodiments of the present invention, the chiller 100 further includes a compressor 111 and an electronic expansion valve 112. The compressor 111, the condenser 113, and the evaporator 114 are connected in sequence via refrigerant pipelines. The refrigerant pipelines include an exhaust pipeline, a throttling pipeline, and an intake pipeline. The compressor 111 is connected to the condenser 113 via an exhaust pipeline, the condenser 113 is connected to the evaporator 114 via a throttling pipeline, and the evaporator 114 is connected to the compressor 111 via an intake pipeline. A one-way valve 115 is provided on the exhaust pipeline, and an electronic expansion valve 112 is provided on the throttling pipeline. A butterfly valve 116 is provided on the intake pipeline.

[0156] The chilled water outlet of the evaporator 114 is connected to a chilled water outlet pipe 152 for delivering the chilled water discharged from the evaporator 114 to the user side 300. The cooling water outlet of the condenser 113 is connected to a cooling water outlet pipe 122 for discharging the cooling water flowing out of the condenser 113 into the cooling tower 400. During use, the chilled water in the chilled water inlet pipe 151 enters the evaporator 114, exchanges heat with the refrigerant, and is then delivered to the user side 300 through the chilled water outlet pipe 152. The cooling tower delivers cooling water to the condenser 113 via the cooling water inlet pipe 121. After exchanging heat with the refrigerant in the condenser 113, this cooling water returns to the cooling tower 400 through the cooling water outlet pipe 122.

[0157] In some optional embodiments of the present invention, cooling water balancing pipe 123 is configured to be arranged in parallel with a portion of cooling water inlet pipe 121, and chilled water balancing pipe 153 is configured to be arranged in parallel with a portion of chilled water inlet pipe 151. Cooling water flowing through cooling water balancing pipe 123 undergoes heat exchange in heat exchange device 140 and then returns to cooling water inlet pipe 121. Chilled water flowing through chilled water balancing pipe 153 undergoes heat exchange in heat exchange device 140 and then returns to chilled water inlet pipe 151.

[0158] In some optional embodiments of the present invention, a temperature sensor is provided at the chilled water outlet of the evaporator 114 for obtaining the temperature of the chilled water flowing out of the evaporator 114 .

[0159] The flowchart provided in this embodiment is not intended to indicate that the operations of the method will be performed in any particular order, or that all operations of the method are included in all every case. In addition, the method may include additional operations. Within the scope of the technical ideas provided by the method of this embodiment, additional changes can be made to the above method.

[0160] The present invention has a plurality of exemplary embodiments, but, without departing from the spirit and scope of the present invention, many other variations or modifications that are consistent with the principles of the present invention can be directly determined or derived from the content disclosed in the present invention. Therefore, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims

1. A method for controlling a chiller, characterized in that: The chiller includes a chilled water inlet pipe, a cooling water inlet pipe, a cooling water balancing pipe, a chilled water balancing pipe and a heat exchange device; the cooling water balancing pipe is suitable for being arranged in parallel with at least a portion of the cooling water inlet pipe, and the cooling water balancing pipe is provided with a first valve and a first pump; the chilled water balancing pipe is suitable for being arranged in parallel with at least a portion of the chilled water inlet pipe, and the chilled water balancing pipe is provided with a second valve and a second pump; the heat exchange device is used to exchange heat between the cooling water in the cooling water balancing pipe and the chilled water in the chilled water balancing pipe; The control method includes: Get the actual speed of the compressor; When the actual speed is the lowest preset speed, obtaining the actual outlet temperature of the cooling water, which is recorded as the first temperature; determining whether the first temperature satisfies a first preset condition; If so, it is determined that the compressor has an unloading requirement, and the first valve, the second valve, the first pump, and the second pump are opened.

2. The control method according to claim 1, characterized in that: After opening the first valve, the second valve, the first pump, and the second pump, the method further includes: controlling the rotational speeds of the first pump and the second pump according to the first temperature.

3. The control method according to claim 1, wherein: The first preset condition includes any one of the following conditions: The first temperature is less than a target temperature; The first temperature is not less than a target temperature, and a decreasing speed of the first temperature is greater than a first set threshold.

4. The control method according to claim 2, characterized in that: The controlling of the rotational speeds of the first pump and the second pump according to the first temperature includes: When the first temperature is lower than a target temperature, controlling the rotational speeds of the first pump and the second pump according to a temperature difference between the target temperature and the first temperature; and / or When the first temperature is not less than a target temperature and a decreasing speed of the first temperature is greater than a first set threshold, the rotational speeds of the first pump and the second pump are controlled according to the decreasing speed.

5. The control method according to claim 4, characterized in that: The temperature difference is positively correlated with the rotational speed; The descending speed is positively correlated with the rotational speed.

6. The control method according to claim 1, characterized in that: The first and second valves are ball valves; The first pump and the second pump are gear pumps; The heat exchange device is a plate heat exchanger.

7. The control method according to claim 4, characterized in that: The controlling of the rotational speeds of the first pump and the second pump according to the temperature difference between the target temperature and the first temperature includes: Obtaining a preset temperature difference range in which the temperature difference lies; Obtaining a preset speed corresponding to the preset temperature difference range; The first pump and the second pump are controlled to execute the preset speed.

8. The control method according to claim 4, characterized in that: The controlling of the rotational speeds of the first pump and the second pump according to the temperature difference between the target temperature and the first temperature includes: When the temperature difference is within a first preset temperature difference range, controlling the first pump and the second pump to execute a first speed; When the temperature difference is within a second preset temperature difference range, controlling the first pump and the second pump to execute a second speed; When the temperature difference is within a third preset temperature difference range, controlling the first pump and the second pump to execute a third speed; The temperature difference values ​​of the first preset temperature difference interval, the second preset temperature difference interval, and the third preset temperature difference interval increase in sequence; and the first speed, the second speed, and the third speed increase gradually.

9. The control method according to claim 4, characterized in that: The controlling of the rotational speeds of the first pump and the second pump according to the descending speed includes: Obtaining a preset speed range in which the descent speed is located; Obtaining a preset speed corresponding to the preset speed range; The first pump and the second pump are controlled to execute the preset speed.

10. The control method according to claim 4, characterized in that: The controlling of the rotational speeds of the first pump and the second pump according to the descending speed includes: When the descending speed is within a first preset speed range, controlling the first pump and the second pump to execute a fourth speed; When the descending speed is within a second preset speed range, controlling the first pump and the second pump to execute a fifth speed; When the descending speed is within a third preset speed range, controlling the first pump and the second pump to execute a sixth speed; The speed values ​​of the first preset speed interval, the second preset speed interval, and the third preset speed interval increase in sequence; and the fourth speed, the fifth speed, and the sixth speed gradually increase.

11. The control method according to claim 1, characterized in that: After opening the first valve, the second valve, the first pump, and the second pump, the method further includes: Obtain the actual outlet temperature of the cooling water, recorded as the second temperature; determining whether the second temperature satisfies a second preset condition; If so, the first valve, the second valve, the first pump, and the second pump are closed.

12. The control method according to claim 11, characterized in that: The second preset condition includes any one of the following conditions: The second temperature is higher than the target temperature, and the second temperature no longer decreases or the decreasing rate of the second temperature is no greater than a first set threshold; The second temperature is lower than the target temperature, and a rising speed of the second temperature is greater than or equal to a second set threshold.

13. A machine-readable storage medium, characterized in that A machine executable program is stored thereon, and when the machine executable program is executed by a processor, the control method according to any one of claims 1 to 12 is implemented.

14. A chiller, characterized in that: include: An evaporator, wherein a chilled water inlet of the evaporator is connected to a chilled water inlet pipe; A condenser, wherein a cooling water inlet of the condenser is connected to a cooling water inlet pipe; a cooling water balancing pipe, arranged in parallel with at least a portion of the cooling water inlet pipe, and provided with a first valve and a first pump; a chilled water balancing pipe, arranged in parallel with at least a portion of the chilled water inlet pipe, and provided with a second valve and a second pump; The heat exchange device is used for exchanging heat between the cooling water in the cooling water balance pipe and the chilled water in the chilled water balance pipe.

15. The chiller according to claim 14, characterized in that: The system further includes a controller, which includes a memory, a processor, and a machine executable program stored in the memory and running on the processor, and when the processor executes the machine executable program, the control method according to any one of claims 1 to 12 is implemented.

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