Operation control method of chilled water system and electronic equipment

Abstract

The invention discloses an operation control method of a chilled water system and electronic equipment. The chilled water system comprises N chilled water pumps. The method comprises the following steps: acquiring initial operation frequency intervals of N chilled water pumps; the N chilled water pumps are controlled to operate according to the minimum initial operation frequency in the initial operation frequency interval; according to the relation between the water supply and return pressure difference of the freezing side of the freezing system and a preset water supply and return pressure difference interval, the minimum initial operation frequency is updated, and a target operation frequency interval is obtained; the N chilled water pumps are controlled to operate according to any operation frequency of the target operation frequency interval; determining a target supply and return water temperature difference according to a relation between the supply and return water temperature difference of the freezing side and a preset supply and return water temperature difference interval and a target operation frequency interval; the operation frequency corresponding to the target supply and return water temperature difference is the target operation frequency. The chilled water system is controlled to operate according to the target operation frequency by applying the target supply and return water temperature difference, a cold water pump variable-frequency controller does not need to be installed, variable-frequency control is achieved, and the energy-saving effect is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of chilled water system control, and in particular to an operation control method and electronic equipment of a chilled water system. Background Art

[0002] At present, many chilled water systems are not installed or cannot be installed with chilled water pump variable frequency controllers, or cannot provide frequency adjustment due to safety considerations. This results in only one initial frequency value being set on site for full-load operation, which leads to the problem of large flow and small temperature difference in the chilled water system most of the time, resulting in low refrigeration efficiency and waste of resources.

[0003] In addition, traditional constant pressure difference and constant temperature difference control also have certain limitations, and the reliability and control effect are not ideal. Summary of the invention

[0004] In an exemplary embodiment of the present application, an operation control method and an electronic device of a chilled water system are provided to realize the requirements of variable frequency control without installing a variable frequency controller for a chilled water pump, thereby achieving an energy-saving effect.

[0005] According to a first aspect of an exemplary embodiment, a method for controlling operation of a chilled water system is provided, wherein the chilled water system includes N chilled water pumps; the method includes:

[0006] Obtain the initial operating frequency range of N chilled water pumps;

[0007] Control N chilled water pumps to operate at the minimum initial operating frequency in the initial operating frequency interval;

[0008] According to the relationship between the supply and return water pressure difference on the refrigeration side of the refrigeration system and the preset supply and return water pressure difference range, the minimum initial operating frequency is updated to obtain the target operating frequency range;

[0009] Control N chilled water pumps to operate at any operating frequency within the target operating frequency range;

[0010] The target supply and return water temperature difference is determined based on the relationship between the supply and return water temperature difference on the refrigeration side and the preset supply and return water temperature difference range, as well as the target operating frequency range; wherein the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency.

[0011] The embodiment of the present application can optimize the operating frequency of the chilled water pump through two stages. In the first stage, the preset supply and return water pressure difference is applied for optimization. Specifically, the initial operating frequency interval of N chilled water pumps can be obtained, and then the N chilled water pumps are controlled to operate according to the minimum initial operating frequency in the initial operating frequency interval; according to the relationship between the supply and return water pressure difference on the freezing side of the refrigeration system and the preset supply and return water pressure difference interval, the minimum initial operating frequency is updated to obtain the target operating frequency interval. In the second stage, the preset supply and return water temperature difference is applied for optimization. Specifically, the N chilled water pumps are controlled to operate according to any operating frequency in the target operating frequency interval; according to the relationship between the supply and return water temperature difference on the freezing side and the preset supply and return water temperature difference interval, as well as the target operating frequency interval, the target supply and return water temperature difference is determined. Since there is a corresponding relationship between the supply and return water temperature difference and the operating frequency, the operating frequency corresponding to the target supply and return water temperature difference can be determined as the target operating frequency. By using the target operating frequency to control the operation of the chilled water pump, the requirements of frequency conversion control can be achieved without installing a cold water pump frequency conversion controller, thereby achieving energy-saving effects.

[0012] In an optional implementation, the minimum initial operating frequency is updated according to the relationship between the supply and return water pressure difference on the refrigeration side and the preset supply and return water pressure difference interval to obtain the target operating frequency interval, including:

[0013] If the supply and return water pressure difference on the refrigeration side is greater than the maximum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically reduced; if the supply and return water pressure difference on the refrigeration side is less than the minimum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically increased; until the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference interval, and a new minimum initial operating frequency is determined according to the operating frequency when the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference interval;

[0014] If the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference range, the current operating frequency is used as the new minimum initial operating frequency;

[0015] According to the new minimum initial operating frequency and the maximum initial operating frequency, a target operating frequency range is obtained.

[0016] In the above embodiment, in the process of determining the target operating frequency interval, the supply and return water pressure difference on the freezing side is divided into three situations: the supply and return water pressure difference on the freezing side is greater than the maximum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, less than the minimum preset supply and return water pressure difference, and within the preset supply and return water pressure difference interval. Different methods are used to adjust the minimum initial operating frequency to obtain the target operating frequency interval. This process is the optimization process of the first stage, which realizes the optimization of the initial operating frequency interval.

[0017] In an optional implementation, determining a new minimum initial operating frequency according to the operating frequency when the supply and return water pressure difference on the refrigeration side is within a preset supply and return water pressure difference interval includes:

[0018] If the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is greater than the set frequency, the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is determined as the new minimum initial operating frequency; wherein the set frequency indicates the operating frequency corresponding to the minimum flow on the evaporation side of the chilled water system;

[0019] If the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is less than the set frequency, the operating frequency of the previous cycle of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is determined as the new minimum initial operating frequency.

[0020] In the above embodiment, in the process of determining the new minimum initial operating frequency, the operating frequency when the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference interval is greater than the set frequency or less than the set frequency, and different methods are used to determine the new minimum initial operating frequency. Applying the set frequency to optimize the optimization process of the first stage is more in line with the actual operating conditions.

[0021] In an optional embodiment, the method further includes:

[0022] The minimum flow rate on the evaporation side, the rated frequencies and rated flows of N chilled water pumps are determined based on the usage information of the chilled water system, and the set frequency is calculated.

[0023] The set frequency calculated in the above embodiment combines the minimum flow rate on the evaporation side, the rated frequency and the rated flow rate of N chilled water pumps, and the calculation result is more accurate, and thus using it to constrain the optimization process of the first stage is more in line with the actual situation.

[0024] In an optional implementation, the target supply and return water temperature difference is determined according to the relationship between the supply and return water temperature difference on the freezing side and the preset supply and return water temperature difference range, as well as the target operating frequency range, including:

[0025] If the supply and return water temperature difference on the refrigeration side is greater than the maximum preset supply and return water temperature difference of the preset supply and return water temperature difference interval, or less than the minimum preset supply and return water temperature difference of the preset supply and return water temperature difference interval, the current supply and return water temperature difference is adjusted to the set temperature difference; wherein the preset supply and return water temperature difference interval is determined according to the set temperature difference and the set temperature difference fluctuation value;

[0026] When the operating frequency corresponding to the set temperature difference is within the target operating frequency range, the set temperature difference is determined to be the target supply and return water temperature difference;

[0027] When the operating frequency corresponding to the set temperature difference is not within the target operating frequency range, a new set temperature difference is re-determined until the operating frequency corresponding to the new set temperature difference is within the target operating frequency range, and the new set temperature difference is determined as the target supply and return water temperature difference;

[0028] If the supply and return water temperature difference on the refrigeration side is within the preset supply and return water temperature difference range, the current supply and return water temperature difference is determined as the target supply and return water temperature difference.

[0029] The above embodiment is a process of optimizing the target supply and return water temperature difference in the second stage. In this process, the supply and return water temperature difference on the freezing side is greater than the maximum preset supply and return water temperature difference, or less than the minimum preset supply and return water temperature difference, and is located in the preset supply and return water temperature difference range. Different methods are used to determine the target supply and return water temperature difference. In the first two cases, by adjusting the set temperature difference, it is ensured that the determined operating frequency is in the target operating frequency range. Since there is a corresponding relationship between the supply and return water temperature difference and the operating frequency, after determining the target supply and return water temperature difference, the target operating frequency can be determined, and the target operating frequency is used to control the operation of the chilled water pump.

[0030] In an optional implementation, the maximum preset supply and return water temperature difference is the sum of the set temperature difference and the set temperature difference fluctuation value; the minimum preset supply and return water temperature difference is the difference between the set temperature difference and the set temperature difference fluctuation value.

[0031] In the above embodiments, the maximum preset supply and return water temperature difference and the minimum preset supply and return water temperature difference are dynamically adjusted by setting the temperature difference and the set temperature difference fluctuation value, thereby improving the fit with the actual operating conditions.

[0032] In an optional implementation, the supply and return water pressure difference is the pressure difference between the supply water pressure and the return water pressure; the supply and return water temperature difference is the temperature difference between the supply water temperature and the return water temperature.

[0033] In the above embodiments, combined with the characteristics of the chilled water system, the supply and return water temperature difference and the supply and return water temperature difference can both characterize the operating effect of the chilled water pump. Therefore, the supply and return water temperature difference and the supply and return water temperature difference can be used as measurement indicators to evaluate the operating effect of the chilled water pump under different operating frequencies.

[0034] In an optional embodiment, the preset supply and return water pressure difference interval is determined based on the chilled water system only when the most unfavorable equipment is operating; the most unfavorable equipment is a device whose equipment pipeline is at a distance greater than a set distance threshold from the chiller of the chilled water system and whose operating pressure difference is less than a set pressure difference threshold.

[0035] In the above embodiment, considering that the operation condition of the most unfavorable equipment can better reflect the characteristics of the supply and return water pressure difference, the preset supply and return water pressure difference range can be determined when only the most unfavorable equipment is working, thereby improving the accuracy of the optimization process.

[0036] According to a second aspect of an exemplary embodiment, there is provided an electronic device, which is applied to a chilled water system, wherein the chilled water system includes N chilled water pumps; the electronic device includes a processor and a memory;

[0037] Memory, configured to execute:

[0038] Storing the initial operating frequency intervals of N chilled water pumps;

[0039] A processor configured to execute:

[0040] Obtain the initial operating frequency range of N chilled water pumps;

[0041] Control N chilled water pumps to operate at the minimum initial operating frequency in the initial operating frequency interval;

[0042] According to the relationship between the supply and return water pressure difference on the refrigeration side of the refrigeration system and the preset supply and return water pressure difference range, the minimum initial operating frequency is updated to obtain the target operating frequency range;

[0043] Control N chilled water pumps to operate at any operating frequency within the target operating frequency range;

[0044] The target supply and return water temperature difference is determined based on the relationship between the supply and return water temperature difference on the refrigeration side and the preset supply and return water temperature difference range, as well as the target operating frequency range; wherein the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency.

[0045] According to a third aspect of an exemplary embodiment, there is provided an operation control device for a chilled water system, the device being applied to a chilled water system, the chilled water system comprising N chilled water pumps; the device comprising:

[0046] A data transmission unit is used to: obtain the initial operating frequency intervals of N chilled water pumps;

[0047] The data processing unit is used to: control the N chilled water pumps to operate according to the minimum initial operating frequency in the initial operating frequency interval;

[0048] The data processing unit is further used to: update the minimum initial operating frequency according to the relationship between the supply and return water pressure difference on the refrigeration side of the refrigeration system and the preset supply and return water pressure difference interval to obtain the target operating frequency interval;

[0049] The data processing unit is further used to: control the N chilled water pumps to operate at any operating frequency within the target operating frequency range;

[0050] The data processing unit is also used to determine the target supply and return water temperature difference based on the relationship between the supply and return water temperature difference on the refrigeration side and the preset supply and return water temperature difference range, as well as the target operating frequency range; wherein the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency.

[0051] According to a fourth aspect of an exemplary embodiment, a computer storage medium is provided, in which computer program instructions are stored. When the instructions are executed on a computer, the computer executes the operation control method of the chilled water system as in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0053] Figure 1 The schematic diagram of a chilled water system provided by an embodiment of the present application is exemplarily shown;

[0054] Figure 2 The schematic diagram of another chilled water system provided by an embodiment of the present application is exemplarily shown;

[0055] Figure 3 A flow chart of an operation control method of a chilled water system provided by an embodiment of the present application is exemplarily shown;

[0056] Figure 4 A flow chart of a method for determining a target operating frequency range provided by an embodiment of the present application is exemplarily shown;

[0057] Figure 5 An exemplary diagram of a frequency regulation principle for reducing the supply and return water pressure difference provided in an embodiment of the present application is shown;

[0058] Figure 6 An exemplary diagram of a frequency regulation principle when increasing the supply and return water pressure difference provided in an embodiment of the present application is shown;

[0059] Figure 7 A flow chart of a method for determining a target supply and return water temperature difference provided in an embodiment of the present application is exemplarily shown;

[0060] Figure 8 A flow chart of a complete chilled water system operation control method provided by an embodiment of the present application is exemplarily shown;

[0061] Fig. 9 The structural diagram of an operation control device of a chilled water system provided by an embodiment of the present application is exemplarily shown;

[0062] Fig.10 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is exemplarily shown. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0064] In the field of smart building energy conservation, it is necessary to realize refined automatic control of cold source equipment. There are usually three types of solutions in the current industry: ① Install a variable frequency controller in the water supply pipe of the chilled water pump. Due to the cost, accuracy and coverage of the controller, this solution is only suitable for local adjustment and cannot achieve remote control effects. ② Require manufacturers to provide frequency control authority. This solution has security risks and may conflict with the security policy of the manufacturer's equipment under automatic operation. ③ Regular manual on-site control. This solution requires the arrangement of on-site inspections by R&D personnel with energy-saving experience, which is subject to professional requirements and labor costs.

[0065] To this end, an embodiment of the present application provides an operation control method for a chilled water system, in which optimization is performed through two stages. In the first stage, a preset supply and return water pressure difference is applied for optimization. For example, the initial operating frequency interval of N chilled water pumps can be obtained, and then the N chilled water pumps are controlled to operate at the minimum initial operating frequency in the initial operating frequency interval; according to the relationship between the supply and return water pressure difference on the freezing side of the refrigeration system and the preset supply and return water pressure difference interval, the minimum initial operating frequency is updated to obtain a target operating frequency interval. In the second stage, a preset supply and return water temperature difference is applied for optimization. For example, N chilled water pumps are controlled to operate at any one of the operating frequencies in the target operating frequency interval; according to the relationship between the supply and return water temperature difference on the freezing side and the preset supply and return water temperature difference interval, as well as the target operating frequency interval, the target supply and return water temperature difference is determined; wherein the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency. There is no need to install a chilled water pump variable frequency controller to achieve the requirements of variable frequency control and achieve energy-saving effects.

[0066] After introducing the design ideas of the embodiments of the present application, the following briefly introduces the application scenarios to which the technical solutions of the embodiments of the present application can be applied. It should be noted that the application scenarios introduced below are only used to illustrate the embodiments of the present application and are not limited. In specific implementation, the technical solutions provided by the embodiments of the present application can be flexibly applied according to actual needs.

[0067] refer to Figure 1 , shows a schematic diagram of a chilled water system, Figure 2 A schematic diagram of another chilled water system provided in an embodiment of the present application. Figure 1 and Figure 2 The above is only used as an example and does not constitute a specific limitation. The embodiment of the present application mainly focuses on the control of the operating frequency of the refrigeration pump.

[0068] To further illustrate the technical solution provided by the embodiment of the present application, this is described in detail below in conjunction with the accompanying drawings and specific implementation methods. Although the embodiment of the present application provides the method operation steps shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on routine or no creative labor. In the steps where there is no necessary causal relationship logically, the execution order of these steps is not limited to the execution order provided in the embodiment of the present application.

[0069] Combine the following Figure 1 and Figure 2 The application scenario shown is shown in Figure 3 A flow chart of an operation control method of a chilled water system is shown to illustrate the technical solution provided in an embodiment of the present application.

[0070] S301: Obtaining initial operating frequency intervals of N chilled water pumps.

[0071] S302: Control N chilled water pumps to operate at the minimum initial operating frequency in the initial operating frequency interval.

[0072] S303: According to the relationship between the supply and return water pressure difference on the refrigeration side of the refrigeration system and the preset supply and return water pressure difference range, the minimum initial operating frequency is updated to obtain the target operating frequency range.

[0073] S304: Control the N chilled water pumps to operate at any operating frequency within the target operating frequency range.

[0074] S305: Determine a target supply and return water temperature difference according to the relationship between the supply and return water temperature difference on the freezing side and the preset supply and return water temperature difference range, as well as the target operating frequency range.

[0075] Among them, the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency.

[0076] The embodiment of the present application can optimize the operating frequency of the chilled water pump through two stages. In the first stage, the preset supply and return water pressure difference is applied for optimization. Specifically, the initial operating frequency interval of N chilled water pumps can be obtained, and then the N chilled water pumps are controlled to operate according to the minimum initial operating frequency in the initial operating frequency interval; according to the relationship between the supply and return water pressure difference on the freezing side of the refrigeration system and the preset supply and return water pressure difference interval, the minimum initial operating frequency is updated to obtain the target operating frequency interval. In the second stage, the preset supply and return water temperature difference is applied for optimization. Specifically, the N chilled water pumps are controlled to operate according to any operating frequency in the target operating frequency interval; according to the relationship between the supply and return water temperature difference on the freezing side and the preset supply and return water temperature difference interval, as well as the target operating frequency interval, the target supply and return water temperature difference is determined. Since there is a corresponding relationship between the supply and return water temperature difference and the operating frequency, the operating frequency corresponding to the target supply and return water temperature difference can be determined as the target operating frequency. By using the target operating frequency to control the operation of the chilled water pump, the requirements of frequency conversion control can be achieved without installing a cold water pump frequency conversion controller, thereby achieving energy-saving effects.

[0077] In S301, assuming that there are N chilled water pumps in the chilled water system, usually, the initial operating frequency intervals of the N chilled water pumps are the same. If the initial operating frequency intervals of different chilled water pumps are different, the initial operating frequency interval of each chilled water pump can also be optimized separately. In the embodiment of the present application, the optimization process of the operating frequency is described for an initial operating frequency interval.

[0078] For example, the minimum initial operating frequency of the initial operating frequency interval may be 40 Hz, and the maximum initial operating frequency of the initial operating frequency interval may be the same as the rated frequency, for example, 50 Hz. Therefore, the initial operating frequency interval is (40 Hz, 50 Hz).

[0079] In S302, N chilled water pumps are controlled to operate at a minimum initial operating frequency in an initial operating frequency interval, for example, at 40 Hz for two days.

[0080] In S303, after a period of operation at 40Hz, the supply water pressure and return water pressure on the refrigeration side are detected in real time, and the difference between the two is calculated as the supply and return water pressure difference. According to the relationship between the supply and return water pressure difference on the refrigeration side of the refrigeration system and the preset supply and return water pressure difference range, the minimum initial operating frequency is updated to obtain the target operating frequency range.

[0081] Specifically, refer to Figure 4 , Figure 4 A flow chart of a method for determining a target operating frequency range provided in an embodiment of the present application. Figure 4 At least the following steps are included:

[0082] S401: Determine a new minimum initial operating frequency.

[0083] Among them, when determining the new minimum initial operating frequency, the preset supply and return water pressure difference interval is applied. The preset supply and return water pressure difference interval is determined based on the chilled water system only when the most unfavorable equipment is working. The most unfavorable equipment is the equipment whose equipment pipeline is greater than the set distance threshold from the chiller of the chilled water system and the operating pressure difference is less than the set pressure difference threshold. For example, the preset supply and return water pressure difference can be set to 5-10 meters of water column, that is, 0.05Mpa-0.1Mpa.

[0084] Optionally, there are three main cases for determining the new minimum initial operating frequency:

[0085] Case A1: If the supply and return water pressure difference on the refrigeration side is greater than the maximum preset supply and return water pressure difference in the preset supply and return water pressure difference range, the current operating frequency is periodically reduced.

[0086] For example, if the detected supply and return water pressure difference is greater than 0.1Mpa, the frequency can be reduced by 2Hz, that is, the chilled water pump can be controlled to operate at 38Hz. Figure 5 A frequency regulation principle diagram for reducing the supply and return water pressure difference provided in an embodiment of the present application.

[0087] Case A2: If the supply and return water pressure difference on the refrigeration side is less than the minimum preset supply and return water pressure difference in the preset supply and return water pressure difference range, the current operation frequency is periodically increased.

[0088] For example, if the detected supply and return water pressure difference is less than 0.05Mpa, the frequency can be increased by 2Hz, that is, the chilled water pump can be controlled to operate at 42Hz. Figure 6 A frequency regulation principle diagram for increasing the supply and return water pressure difference provided in an embodiment of the present application.

[0089] In both cases A1 and A2, the operation of periodically adjusting the frequency is to stop adjusting the frequency until the supply and return water pressure difference on the freezing side is within a preset supply and return water pressure difference range.

[0090] For example, after one adjustment, if the supply and return water pressure difference is still greater than 0.1Mpa or still less than 0.05Mpa, continue to adjust in the same way. The operating frequency when the frequency adjustment operation is stopped can be 32Hz or 36Hz.

[0091] Thereafter, a new minimum initial operating frequency is determined according to the operating frequency when the supply and return water pressure difference on the refrigeration side is within a preset supply and return water pressure difference interval. Optionally, the process of determining the new minimum initial operating frequency can be implemented as follows:

[0092] Case A12-1: If the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is greater than the set frequency, the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is determined as the new minimum initial operating frequency.

[0093] Among them, the set frequency indicates the operating frequency corresponding to the minimum flow on the evaporation side of the chilled water system. The set frequency is calculated in the following way: according to the usage information of the chilled water system (such as the information in the chiller equipment manual), the minimum flow on the evaporation side, the rated frequency and rated flow of N chilled water pumps are determined, and the set frequency is calculated.

[0094] For example, the set frequency can be calculated by the following formula:

[0095]

[0096] Among them, N Z To set the frequency, Q Z is the minimum flow rate on the evaporation side, N e ' is the rated frequency of N chilled water pumps, Q e ' is the rated flow rate of N chilled water pumps. The rated flow rate and rated frequency can be determined from the equipment manual or nameplate. For example, the rated frequency can be 50 Hz. The calculated set frequency can be 35 Hz, for example.

[0097] For example, the operating frequency when the frequency adjustment operation is stopped may be 36 Hz, which is greater than the set frequency of 35 Hz. Then 36 Hz may be determined as the new minimum initial operating frequency.

[0098] Case A12-1: If the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference range is less than the set frequency, the operating frequency of the previous cycle of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference range is determined as the new minimum initial operating frequency.

[0099] For example, the operating frequency when the frequency adjustment operation is stopped may be 34 Hz, which is less than the set frequency of 35 Hz. Then, 36 Hz of the previous cycle may be determined as the new minimum initial operating frequency.

[0100] Case A3: If the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference range, the current operating frequency is used as the new minimum initial operating frequency;

[0101] S402: Obtain a target operating frequency range according to the new minimum initial operating frequency and the maximum initial operating frequency.

[0102] Still taking the above example, the target operating frequency can be determined to be (36 Hz, 50 Hz).

[0103] In S304, N chilled water pumps are controlled to operate at any operating frequency in the target operating frequency range. For example, any operating frequency is 44 Hz.

[0104] In S305, after controlling N chilled water pumps to operate at any operating frequency (for example, 44 Hz) in the target operating frequency range for a period of time, the supply water temperature and return water temperature of the chilled water side are detected in real time, and the difference between the two is calculated as the supply and return water temperature. According to the relationship between the supply and return water temperature difference of the chilled water side and the preset supply and return water temperature difference range, as well as the target operating frequency range, the target supply and return water temperature difference is determined.

[0105] Specifically, refer to Figure 7 , Figure 7 A flow chart of a method for determining a target supply and return water temperature difference provided in an embodiment of the present application. Figure 7 At least the following steps are included:

[0106] S701: If the supply and return water temperature difference on the refrigeration side is greater than the maximum preset supply and return water temperature difference in the preset supply and return water temperature difference interval, or less than the minimum preset supply and return water temperature difference in the preset supply and return water temperature difference interval, the current supply and return water temperature difference is adjusted to the set temperature difference.

[0107] Among them, the preset supply and return water temperature difference interval is determined based on the set temperature difference and the set temperature difference fluctuation value. Optionally, the maximum preset supply and return water temperature difference is the sum of the set temperature difference and the set temperature difference fluctuation value; the minimum preset supply and return water temperature difference is the difference between the set temperature difference and the set temperature difference fluctuation value. For example, the set temperature difference is represented by Tset (for example, 4°C), the set temperature difference fluctuation value is represented by Tconst (for example, 0.1°C), and the preset supply and return water interval is (Tset-Tconst, Tset+Tconst), which can be (3.9°C, 4.1°C). The value of the set temperature difference can be determined based on the cold source data of the chilled water system after automatic tuning through machine learning. The set temperature difference fluctuation value can be determined by on-site debugging of the equipment of the chilled water system.

[0108] In this step, if the detected supply and return water temperature difference on the refrigeration side is greater than 4.1°C or less than 3.9°C, the current supply and return water temperature difference can be adjusted to the current Tset value of 4°C.

[0109] S702: When the operating frequency corresponding to the set temperature difference is within the target operating frequency range, the set temperature difference is determined to be the target supply and return water temperature difference.

[0110] Among them, according to the algorithm configured inside the chilled water system, an operating frequency can be calculated according to the set temperature difference. For example, when the operating frequency calculated according to 4°C is within the target operating frequency range (36Hz, 50Hz), the target supply and return water temperature difference can be determined to be 4°C.

[0111] S703: When the operating frequency corresponding to the set temperature difference is not within the target operating frequency range, a new set temperature difference is re-determined until the operating frequency corresponding to the new set temperature difference is within the target operating frequency range, and the new set temperature difference is determined as the target supply and return water temperature difference;

[0112] Among them, an operating frequency can be calculated according to the set temperature difference. For example, when the operating frequency calculated according to 4°C is within the target operating frequency range (36Hz, 50Hz), the new set temperature difference can be re-determined and recalculated. The new set temperature difference will calculate the corresponding new operating frequency until the new operating frequency corresponding to the calculated new set temperature difference is within the target operating frequency range. The new set temperature difference is determined as the target supply and return water temperature difference. Since there is a corresponding relationship between the supply and return water temperature difference and the operating frequency (which can be realized based on the proportional integral controller and flow control principle), the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency.

[0113] S704: If the supply and return water temperature difference on the refrigeration side is within the preset supply and return water temperature difference range, the current supply and return water temperature difference is determined as the target supply and return water temperature difference.

[0114] In this case, the current supply and return water temperature difference can be directly determined as the target supply and return water temperature difference, and the corresponding operating frequency is the target operating frequency.

[0115] The embodiment of the present application realizes the indirect adjustment method of the chilled water pump frequency by monitoring the real-time supply and return water pressure difference and supply and return water temperature difference of the chilled water pump based on the proportional integral controller and flow control principle, and solves the reliability and hysteresis problems of the constant pressure difference and constant temperature difference, effectively and automatically controls the energy-saving operation of the chiller, and finally achieves the effect of energy saving and consumption reduction. In addition, without increasing the cost, combined with the safety consideration of the frequency operation of the host group chilled water pump, the dynamic adjustment and optimization of the operating frequency is realized; thereby meeting the requirements of automatic frequency conversion control and achieving a better energy-saving effect.

[0116] It should be noted that, since the methods based on temperature-pressure difference and water supply temperature and pressure adjustment all use temperature control and flow control to affect changes in flow and frequency, the above-mentioned freezing side can be replaced by the evaporation side.

[0117] Figure 8 A flow chart of a complete chilled water system operation control method provided in an embodiment of the present application, Figure 8 The implementation method of each step in can refer to the above embodiment and will not be repeated here.

[0118] like Fig. 9As shown, based on the same inventive concept, an embodiment of the present application provides an operation control device for a chilled water system, which is applied to a chilled water system including N chilled water pumps; the device includes a data transmission unit 91 and a data processing unit 92.

[0119] The data transmission unit 91 is used to: obtain the initial operating frequency intervals of N chilled water pumps;

[0120] The data processing unit 92 is used to: control the N chilled water pumps to operate according to the minimum initial operating frequency in the initial operating frequency interval;

[0121] The data processing unit 92 is further used to: update the minimum initial operating frequency according to the relationship between the supply and return water pressure difference on the refrigeration side of the refrigeration system and the preset supply and return water pressure difference interval to obtain the target operating frequency interval;

[0122] The data processing unit 92 is further used to: control the N chilled water pumps to operate at any operating frequency within the target operating frequency range;

[0123] The data processing unit 92 is also used to determine the target supply and return water temperature difference based on the relationship between the supply and return water temperature difference on the refrigeration side and the preset supply and return water temperature difference range, as well as the target operating frequency range; wherein the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency.

[0124] In an optional implementation, the data processing unit 92 is specifically configured to:

[0125] If the supply and return water pressure difference on the refrigeration side is greater than the maximum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically reduced; if the supply and return water pressure difference on the refrigeration side is less than the minimum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically increased; until the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference interval, and a new minimum initial operating frequency is determined according to the operating frequency when the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference interval;

[0126] If the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference range, the current operating frequency is used as the new minimum initial operating frequency;

[0127] According to the new minimum initial operating frequency and the maximum initial operating frequency, a target operating frequency range is obtained.

[0128] In an optional implementation, the data processing unit 92 is specifically configured to:

[0129] If the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is greater than the set frequency, the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is determined as the new minimum initial operating frequency; wherein the set frequency indicates the operating frequency corresponding to the minimum flow on the evaporation side of the chilled water system;

[0130] If the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is less than the set frequency, the operating frequency of the previous cycle of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is determined as the new minimum initial operating frequency.

[0131] In an optional implementation, the data processing unit 92 is further configured to:

[0132] The minimum flow rate on the evaporation side, the rated frequencies and rated flows of N chilled water pumps are determined based on the usage information of the chilled water system, and the set frequency is calculated.

[0133] In an optional implementation, the data processing unit 92 is specifically configured to:

[0134] If the supply and return water temperature difference on the refrigeration side is greater than the maximum preset supply and return water temperature difference of the preset supply and return water temperature difference interval, or less than the minimum preset supply and return water temperature difference of the preset supply and return water temperature difference interval, the current supply and return water temperature difference is adjusted to the set temperature difference; wherein the preset supply and return water temperature difference interval is determined according to the set temperature difference and the set temperature difference fluctuation value;

[0135] When the operating frequency corresponding to the set temperature difference is within the target operating frequency range, the set temperature difference is determined to be the target supply and return water temperature difference;

[0136] When the operating frequency corresponding to the set temperature difference is not within the target operating frequency range, a new set temperature difference is re-determined until the operating frequency corresponding to the new set temperature difference is within the target operating frequency range, and the new set temperature difference is determined as the target supply and return water temperature difference;

[0137] If the supply and return water temperature difference on the refrigeration side is within the preset supply and return water temperature difference range, the current supply and return water temperature difference is determined as the target supply and return water temperature difference.

[0138] In an optional implementation, the maximum preset supply and return water temperature difference is the sum of the set temperature difference and the set temperature difference fluctuation value; the minimum preset supply and return water temperature difference is the difference between the set temperature difference and the set temperature difference fluctuation value.

[0139] In an optional implementation, the supply and return water pressure difference is the pressure difference between the supply water pressure and the return water pressure; the supply and return water temperature difference is the temperature difference between the supply water temperature and the return water temperature.

[0140] In an optional embodiment, the preset supply and return water pressure difference interval is determined based on the chilled water system only when the most unfavorable equipment is operating; the most unfavorable equipment is a device whose equipment pipeline is at a distance greater than a set distance threshold from the chiller of the chilled water system and whose operating pressure difference is less than a set pressure difference threshold.

[0141] Since the device is the device in the method in the embodiment of the present application, and the principle of solving the problem by the device is similar to that of the method, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0142] like Fig.10 As shown, based on the same inventive concept, an embodiment of the present application provides an electronic device, which is applied to a chilled water system, and the chilled water system includes N chilled water pumps; the electronic device includes a processor 101 and a memory 102;

[0143] The memory 102 is configured to execute:

[0144] Storing the initial operating frequency intervals of N chilled water pumps;

[0145] A processor configured to execute:

[0146] Obtain the initial operating frequency range of N chilled water pumps;

[0147] Control N chilled water pumps to operate at the minimum initial operating frequency in the initial operating frequency interval;

[0148] According to the relationship between the supply and return water pressure difference on the refrigeration side of the refrigeration system and the preset supply and return water pressure difference range, the minimum initial operating frequency is updated to obtain the target operating frequency range;

[0149] Control N chilled water pumps to operate at any operating frequency within the target operating frequency range;

[0150] The target supply and return water temperature difference is determined based on the relationship between the supply and return water temperature difference on the refrigeration side and the preset supply and return water temperature difference range, as well as the target operating frequency range; wherein the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency.

[0151] In an optional implementation, the processor 101 is specifically configured to execute:

[0152] If the supply and return water pressure difference on the refrigeration side is greater than the maximum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically reduced; if the supply and return water pressure difference on the refrigeration side is less than the minimum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically increased; until the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference interval, and a new minimum initial operating frequency is determined according to the operating frequency when the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference interval;

[0153] If the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference range, the current operating frequency is used as the new minimum initial operating frequency;

[0154] According to the new minimum initial operating frequency and the maximum initial operating frequency, a target operating frequency range is obtained.

[0155] In an optional implementation manner, the processor 101 is specifically configured to:

[0156] If the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is greater than the set frequency, the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is determined as the new minimum initial operating frequency; wherein the set frequency indicates the operating frequency corresponding to the minimum flow on the evaporation side of the chilled water system;

[0157] If the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is less than the set frequency, the operating frequency of the previous cycle of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is determined as the new minimum initial operating frequency.

[0158] In an optional implementation, the processor 101 is further configured to:

[0159] The minimum flow rate on the evaporation side, the rated frequencies and rated flows of N chilled water pumps are determined based on the usage information of the chilled water system, and the set frequency is calculated.

[0160] In an optional implementation manner, the processor 101 is specifically configured to:

[0161] If the supply and return water temperature difference on the refrigeration side is greater than the maximum preset supply and return water temperature difference of the preset supply and return water temperature difference interval, or less than the minimum preset supply and return water temperature difference of the preset supply and return water temperature difference interval, the current supply and return water temperature difference is adjusted to the set temperature difference; wherein the preset supply and return water temperature difference interval is determined according to the set temperature difference and the set temperature difference fluctuation value;

[0162] When the operating frequency corresponding to the set temperature difference is within the target operating frequency range, the set temperature difference is determined to be the target supply and return water temperature difference;

[0163] When the operating frequency corresponding to the set temperature difference is not within the target operating frequency range, a new set temperature difference is re-determined until the operating frequency corresponding to the new set temperature difference is within the target operating frequency range, and the new set temperature difference is determined as the target supply and return water temperature difference;

[0164] If the supply and return water temperature difference on the refrigeration side is within the preset supply and return water temperature difference range, the current supply and return water temperature difference is determined as the target supply and return water temperature difference.

[0165] In an optional implementation, the maximum preset supply and return water temperature difference is the sum of the set temperature difference and the set temperature difference fluctuation value; the minimum preset supply and return water temperature difference is the difference between the set temperature difference and the set temperature difference fluctuation value.

[0166] In an optional implementation, the supply and return water pressure difference is the pressure difference between the supply water pressure and the return water pressure; the supply and return water temperature difference is the temperature difference between the supply water temperature and the return water temperature.

[0167] In an optional embodiment, the preset supply and return water pressure difference interval is determined based on the chilled water system only when the most unfavorable equipment is operating; the most unfavorable equipment is a device whose equipment pipeline is at a distance greater than a set distance threshold from the chiller of the chilled water system and whose operating pressure difference is less than a set pressure difference threshold.

[0168] The embodiment of the present application further provides a computer storage medium, in which computer program instructions are stored. When the instructions are executed on a computer, the computer executes the steps of the above-mentioned operation control method of the chilled water system.

[0169] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0170] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0171] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0172] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0173] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for controlling the operation of a chilled water system, characterized in that: The chilled water system includes N chilled water pumps; the method includes: Obtaining the initial operating frequency intervals of the N chilled water pumps; Controlling the N chilled water pumps to operate at the minimum initial operating frequency in the initial operating frequency interval; According to the relationship between the supply and return water pressure difference on the freezing side of the freezing system and the preset supply and return water pressure difference interval, the minimum initial operating frequency is updated to obtain a target operating frequency interval; Controlling the N chilled water pumps to operate at any operating frequency within the target operating frequency range; The target supply and return water temperature difference is determined based on the relationship between the supply and return water temperature difference on the refrigeration side and the preset supply and return water temperature difference range, as well as the target operating frequency range; wherein the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency.

2. The method according to claim 1, characterized in that: The updating of the minimum initial operating frequency according to the relationship between the supply and return water pressure difference on the refrigeration side and the preset supply and return water pressure difference interval to obtain the target operating frequency interval includes: If the supply and return water pressure difference on the refrigeration side is greater than the maximum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically reduced; if the supply and return water pressure difference on the refrigeration side is less than the minimum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically increased; until the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference interval, and a new minimum initial operating frequency is determined according to the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval; If the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference range, the current operating frequency is used as the new minimum initial operating frequency; A target operating frequency range is obtained according to the new minimum initial operating frequency and the maximum initial operating frequency.

3. The method according to claim 2, characterized in that The determining of a new minimum initial operating frequency according to the operating frequency of the supply and return water pressure difference of the refrigeration side in the preset supply and return water pressure difference range includes: If the operating frequency of the supply and return water pressure difference of the refrigeration side in the preset supply and return water pressure difference interval is greater than the set frequency, the operating frequency of the supply and return water pressure difference of the refrigeration side in the preset supply and return water pressure difference interval is determined as the new minimum initial operating frequency; wherein the set frequency indicates the operating frequency corresponding to the minimum flow rate on the evaporation side of the chilled water system; If the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval is less than the set frequency, the operating frequency of the supply and return water pressure difference on the refrigeration side in the previous cycle in the preset supply and return water pressure difference interval is determined as the new minimum initial operating frequency.

4. The method according to claim 3, characterized in that: The method further comprises: The minimum flow rate on the evaporation side, the rated frequencies and rated flows of the N chilled water pumps are determined according to the usage information of the chilled water system, and the set frequency is calculated.

5. The method according to claim 1, characterized in that: The determining of the target supply and return water temperature difference according to the relationship between the supply and return water temperature difference of the refrigeration side and the preset supply and return water temperature difference interval, and the target operation frequency interval, comprises: If the supply and return water temperature difference on the refrigeration side is greater than the maximum preset supply and return water temperature difference in the preset supply and return water temperature difference interval, or less than the minimum preset supply and return water temperature difference in the preset supply and return water temperature difference interval, the current supply and return water temperature difference is adjusted to the set temperature difference; wherein the preset supply and return water temperature difference interval is determined according to the set temperature difference and the set temperature difference fluctuation value; When the operating frequency corresponding to the set temperature difference is within the target operating frequency range, the set temperature difference is determined to be the target supply and return water temperature difference; When the operating frequency corresponding to the set temperature difference is not within the target operating frequency range, a new set temperature difference is re-determined until the operating frequency corresponding to the new set temperature difference is within the target operating frequency range, and the new set temperature difference is determined as the target supply and return water temperature difference; If the supply and return water temperature difference on the refrigeration side is within the preset supply and return water temperature difference range, the current supply and return water temperature difference is determined as the target supply and return water temperature difference.

6. The method according to claim 5, characterized in that The maximum preset supply and return water temperature difference is the sum of the set temperature difference and the set temperature difference fluctuation value; the minimum preset supply and return water temperature difference is the difference between the set temperature difference and the set temperature difference fluctuation value.

7. The method according to any one of claims 1 to 6, characterized in that: The supply and return water pressure difference is the pressure difference between the supply water pressure and the return water pressure; the supply and return water temperature difference is the temperature difference between the supply water temperature and the return water temperature.

8. The method according to any one of claims 1 to 6, characterized in that: The preset supply and return water pressure difference range is determined based on the fact that the chilled water system only operates in the most unfavorable equipment; the most unfavorable equipment is a device whose equipment pipeline is at a distance greater than a set distance threshold from the chiller of the chilled water system and whose operating pressure difference is less than a set pressure difference threshold.

9. An electronic device, characterized in that: Applied to a chilled water system, the chilled water system comprising N chilled water pumps; the electronic device comprising a processor and a memory; The memory is configured to execute: Storing the initial operating frequency intervals of N chilled water pumps; The processor is configured to execute: Obtaining the initial operating frequency intervals of the N chilled water pumps; Controlling the N chilled water pumps to operate at the minimum initial operating frequency in the initial operating frequency interval; According to the relationship between the supply and return water pressure difference on the freezing side of the freezing system and the preset supply and return water pressure difference interval, the minimum initial operating frequency is updated to obtain a target operating frequency interval; Controlling the N chilled water pumps to operate at any operating frequency within the target operating frequency range; The target supply and return water temperature difference is determined based on the relationship between the supply and return water temperature difference on the refrigeration side and the preset supply and return water temperature difference range, as well as the target operating frequency range; wherein the operating frequency corresponding to the target supply and return water temperature difference is the target operating frequency.

10. The electronic device according to claim 9, characterized in that: The processor is specifically configured to execute: If the supply and return water pressure difference on the refrigeration side is greater than the maximum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically reduced; if the supply and return water pressure difference on the refrigeration side is less than the minimum preset supply and return water pressure difference in the preset supply and return water pressure difference interval, the current operating frequency is periodically increased; until the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference interval, and a new minimum initial operating frequency is determined according to the operating frequency of the supply and return water pressure difference on the refrigeration side in the preset supply and return water pressure difference interval; If the supply and return water pressure difference on the refrigeration side is within the preset supply and return water pressure difference range, the current operating frequency is used as the new minimum initial operating frequency; A target operating frequency range is obtained according to the new minimum initial operating frequency and the maximum initial operating frequency.

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