Control method and equipment of cold storage system and cold storage system

Abstract

The invention provides a control method and equipment of a cold storage system and the cold storage system. The control method comprises the steps that the accumulated cold storage capacity of the cold storage tank in the previous day is obtained; acquiring 24-hour hourly electricity price per day; obtaining a cooling load demand hour-by-hour value in the next 24 hours in the previous day through a prediction technology; and according to the accumulated cold storage capacity of the previous day, the 24-hour hourly electricity price and the cooling load demand hourly value of the next 24 hours, cold release control is carried out on the cold storage tank with the goal of the lowest all-day operation electricity price. The dynamic cold release potential based on different electricity prices can be brought into full play, and the operation cost is saved to the maximum extent.

Description

Technical Field

[0001] The present application relates to the field of refrigeration technology, and in particular to a control method and device for a cold storage system and a cold storage system. Background Art

[0002] The cold storage system includes a chiller and a cold storage tank connected in parallel. The automatic control strategy of the cold storage system involves multiple operating modes, such as the chiller single cooling mode, the cold storage tank single cooling mode, the chiller cold storage mode, the combined cooling mode and other modes. Under different operating modes, the implementation of key control objectives and control strategies is usually determined based on experience. For the cold release mode, once it is turned on, a fixed flow rate is released until the cold release ends, and the peak electricity price is usually discontinuous in time. This method has many non-peak periods of electricity price releases, and there is no cold storage capacity to release in the next peak electricity price period, so the cold release strategy usually cannot achieve the best. Secondly, once the cold storage mode is turned on, it will end only when it is fully stored. In the transition season or when the load required at the air conditioning terminal is small, it is not necessary to fully store the cold storage tank. If the cold storage capacity is too large, it cannot be fully released the next day. The cold water is placed in the cold storage tank for too long, resulting in heat transfer loss and energy waste. When the cold storage capacity is small, the low operating cost advantage brought by the peak-valley electricity price difference cannot be fully utilized.

[0003] Therefore, how to achieve reasonable control of cold release and cold storage modes is the key point that distinguishes the cold storage system from the conventional system. Summary of the invention

[0004] The purpose of the present application is to provide a control method, device and cold storage system for a cold storage system, which can solve at least one of the technical problems mentioned in the above prior art.

[0005] One aspect of the present application provides a control method for a cold storage system. The cold storage system includes a cold storage tank. The control method includes: obtaining the cumulative cold storage capacity of the cold storage tank on the previous day; obtaining the hourly electricity price for 24 hours every day; obtaining the hourly value of the cold load demand for the next 24 hours one day in advance through prediction technology; based on the cumulative cold storage capacity of the previous day, the hourly electricity price for 24 hours and the hourly value of the cold load demand for the next 24 hours, the cold storage tank is controlled to release cold with the goal of minimizing the electricity cost for the whole day.

[0006] Furthermore, the cold storage tank is controlled to release cold according to the cumulative cold storage capacity of the previous day, the hourly electricity price of 24 hours and the hourly value of the cold load demand in the next 24 hours, with the goal of minimizing the electricity cost for the whole day, including: taking the hourly value of the cold load demand for the next 24 hours as the cooling demand, taking the cumulative cold storage capacity of the previous day as the hourly allocable cold release capacity as the constraint condition of the optimization model, taking the lowest electricity cost for the whole day as the optimization goal of the optimization model, obtaining the hourly cold release strategy for the next 24 hours through the closed-loop calculation of the optimization model; and controlling the cold release of the cold storage tank hour by hour according to the hourly cold release strategy for the next 24 hours.

[0007] Furthermore, the hourly cooling release strategy for the next 24 hours includes the cooling release start time and the cooling release stop time of the cold storage tank and the hourly cooling release amount after the cooling release is turned on, wherein the hourly cooling release control of the cold storage tank according to the hourly cooling release strategy for the next 24 hours includes: controlling the cooling release start time of the cold storage tank and the hourly cooling release amount after the cooling release is turned on according to the hourly cooling release strategy for the next 24 hours.

[0008] Furthermore, the cooling release priorities of the hourly cooling release strategy for the next 24 hours are from high to low: cooling release during peak electricity price periods, cooling release during average electricity price periods between peak electricity prices, and cooling release during average electricity price periods, wherein controlling the cooling release start time of the cold storage tank includes: controlling the cooling release start time of the cold storage tank according to the cooling release priority.

[0009] Furthermore, controlling the hourly cooling amount after cooling release is turned on includes: during the peak electricity price period, controlling the cooling tank to release cooling at the maximum cooling amount; and / or during the average period between the peak electricity price periods, controlling the cooling tank to release cooling evenly on an hourly basis with the remaining cooling amount in the cooling tank.

[0010] Furthermore, the cold storage system includes a second control valve, which is arranged between the cold storage tank and the input end of the air-conditioning terminal, wherein controlling the cold release opening time of the cold storage tank includes: controlling the cold release opening time and cold release closing time of the cold storage tank by controlling the opening and closing of the second control valve.

[0011] Furthermore, the cold storage system includes a chiller, a first pump and a third pump, the cold storage tank is connected in parallel with the chiller, the first pump is arranged in a pipeline between the inlet of the chiller connected to the output end of the air-conditioning terminal and the cold storage tank, and the third pump is arranged in a pipeline between the cold storage tank and the input end of the air-conditioning terminal. Controlling the hourly cold release amount after the cold release is turned on includes: controlling the chiller and the cold storage tank to supply cold in proportion by adjusting the frequency of the first pump and the frequency of the third pump.

[0012] Furthermore, adjusting the frequency of the third pump includes: adjusting the frequency of the third pump by adopting PID control according to the most unfavorable pressure difference between the input end and the output end of the air conditioner terminal.

[0013] Furthermore, adjusting the frequency of the first pump includes: adjusting the frequency of the first pump using PID control according to a system flow value, wherein the system flow value is equal to the flow of the branch where the cold storage tank is located multiplied by the ratio of the hourly cooling capacity of the cold machine to the hourly cooling capacity of the cold storage tank when the cold machine and the cold storage tank jointly provide cooling.

[0014] Furthermore, the control method also includes: calculating the cumulative value of the cooling load demand for the next 24 hours based on the hourly value of the cooling load demand for the next 24 hours; and controlling the cooling storage of the cold storage tank for the previous day based on the cumulative value of the cooling load demand for the next 24 hours.

[0015] Furthermore, the cold storage control of the cold storage tank for the previous day based on the accumulated value of the cold load demand for the next 24 hours includes: when the accumulated value of the cold load demand for the next 24 hours is greater than the maximum capacity of the cold storage tank, controlling the cold storage tank to store cold to the maximum capacity of the cold storage tank during the previous day's electricity price valley period; when the accumulated value of the cold load demand for the next 24 hours is less than the maximum capacity of the cold storage tank, and the current cold storage capacity in the cold storage tank meets the accumulated value of the cold load demand for the next 24 hours, controlling not to store cold in the cold storage tank during the previous day's electricity price valley period; when the accumulated value of the cold load demand for the next 24 hours is less than the maximum capacity of the cold storage tank, and the current cold storage capacity in the cold storage tank does not meet the accumulated value of the cold load demand for the next 24 hours, controlling the cold storage tank to store cold to the accumulated value of the cold load demand for the next 24 hours during the previous day's electricity price valley period.

[0016] Furthermore, the cold storage system also includes a chiller connected in parallel with the cold storage tank, and the control method also includes: controlling the chiller according to the hourly cold storage capacity and hourly cold release capacity of the cold storage tank and the actual hourly value of the cold load.

[0017] Another aspect of the present application provides a control device for a cold storage system. The control device includes a memory, a processor, and a computer program stored in the memory, and the processor executes the computer program to implement the steps of the control method for the cold storage system as described above.

[0018] Another aspect of the present application provides a cold storage system. The cold storage system includes a cold machine, a cooling tower, a cold storage tank, an air conditioning terminal, a first pump, a second pump, a third pump, a first control valve, a second control valve and a control device as described above. The cold machine has a first inlet, a first outlet, a second inlet and a second outlet, wherein the first inlet and the first outlet of the cold machine are respectively connected to the cooling tower, and the second pump is provided in the pipeline between the first inlet of the cold machine and the cooling tower; the second outlet of the cold machine and the first end of the cold storage tank are connected to the input end of the air conditioning terminal through the third pump; the outlet of the air conditioning terminal is connected to the second end of the cold storage tank and connected to the second inlet of the cold machine through the first pump; the first control valve is arranged between the third pump and the input end of the air conditioning terminal, and the second control valve is arranged between the first end of the cold storage tank and the third pump.

[0019] Furthermore, the cold storage system also includes a balancing pipeline, wherein one end of the balancing pipeline is connected between the second control valve and the third pump, and the other end of the balancing pipeline is connected to the second end of the cold storage tank.

[0020] The control method, control device and cold storage system with the control device of one or more embodiments of the present application obtain the cumulative cold storage capacity of the cold storage tank on the previous day and the hourly electricity price for 24 hours each day, and obtain the hourly value of the cold load demand for the next 24 hours one day in advance through prediction technology, and dynamically optimize the cold release of the cold storage tank with the goal of minimizing the electricity cost for the whole day, so as to give full play to the dynamic cold release potential based on different electricity prices and maximize the savings in operating costs.

[0021] In addition, the control method, control device and cold storage system with the control device of one or more embodiments of the present application obtain the hourly value of the cold load demand for the next 24 hours one day in advance through prediction technology, calculate the cumulative value of the cold load demand for the next 24 hours based on the hourly value of the cold load demand for the next 24 hours, and dynamically optimize the cold storage of the cold storage tank based on the cumulative value of the cold load demand for the next 24 hours, so as to avoid energy waste caused by excessive cold storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of a cold storage system according to an embodiment of the present application.

[0023] Figure 2 This is a flow chart of a control method for a cold storage system according to an embodiment of the present application.

[0024] Figure 3 for Figure 2 The flowchart of the cold storage tank release control is shown.

[0025] Figure 4 Schematic diagram of cooling capacity distribution on a typical day in July.

[0026] Figure 5 This is a schematic diagram of the 24-hour hourly electricity price in a certain place.

[0027] Figure 6 Schematic diagram of typical daily and monthly demand for building cooling load.

[0028] Figure 7 This is a flow chart of controlling cold storage in a cold storage tank according to one embodiment of the present application.

[0029] Figure 8 for Figure 7 The flowchart shown is a flow chart for controlling the cold storage tank for the previous day based on the cumulative value of the cold load demand in the next 24 hours. DETAILED DESCRIPTION

[0030] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0031] The control method, device and cold storage system of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0032] Figure 1 The schematic diagram of the structure of a cold storage system 100 according to an embodiment of the present application is disclosed. Figure 1 As shown, a cold storage system 100 of one embodiment of the present application includes a cold machine 110, a cooling tower 120, a cold storage tank 130, an air conditioning terminal 140, a first pump 161, a second pump 162, a third pump 163, a first control valve 171 and a second control valve 172.

[0033] The cold machine 110 has a first inlet, a first outlet, a second inlet and a second outlet. The first inlet and the first outlet of the cold machine 110 are respectively connected to the cooling tower 120, and a first circulation loop is formed between the cold machine 110 and the cooling tower 120. A second pump 162 is provided in the pipeline between the first inlet of the cold machine 110 and the cooling tower 120.

[0034] The second outlet of the cold machine 110 and the first end of the cold storage tank 130 are connected to the input end of the air conditioning terminal 140 through the third pump 163; the outlet of the air conditioning terminal 140 is connected to the second end of the cold storage tank 130 and connected to the second inlet of the cold machine 110 through the first pump 161. A second circulation loop is formed between the cold machine 110 and the air conditioning terminal 140. A third circulation loop is formed between the cold machine 110 and the cold storage tank 130. A fourth circulation loop is formed between the cold storage tank 130 and the air conditioning terminal 140.

[0035] The first control valve 171 is disposed between the third pump 163 and the input end of the air conditioning terminal 140. By controlling the opening and closing of the first control valve 171, the opening and closing of the air conditioning terminal 140 can be controlled.

[0036] The second control valve 172 is disposed between the first end of the cold storage tank 130 and the third pump 163. By controlling the opening and closing of the second control valve 172, the cold release opening and closing of the cold storage tank 130 can be controlled.

[0037] Optionally, the cold storage system 100 of the present application may further include a balancing pipeline 150. One end of the balancing pipeline 150 is connected between the second control valve 172 and the third pump 163, and the other end of the balancing pipeline 150 is connected to the second end of the cold storage tank 130. When the cold amount provided is greater than the cold load demand of the air conditioning terminal 140, a portion of the cold amount can be bypassed to the cold storage tank 130 through the balancing pipeline 150, thereby reducing the cold amount entering the input end of the air conditioning terminal 140.

[0038] The cold storage system 100 of the present application may have a variety of different operating modes. For example, the cold storage system 100 may include a cold machine single cold supply mode, a cold storage tank single cold release mode, a cold machine cold storage mode, and a combined cold supply mode.

[0039] In the chiller-only cooling mode, the chiller 110 , the cooling tower 120 , the first pump 161 , the second pump 162 , the third pump 163 and the first control valve 171 are turned on, and the second control valve 172 is turned off.

[0040] In the cold storage tank independent cold release mode, the third pump 163, the first control valve 171 and the second control valve 172 are opened, and the cold machine 110, the cooling tower 120, the first pump 161 and the second pump 162 are closed.

[0041] In the cold storage mode of the chiller, the chiller 110 , the cooling tower 120 , the first pump 161 , the second pump 162 and the second control valve 172 are turned on, and the third pump 163 and the first control valve 171 are turned off.

[0042] In the combined cooling mode, the chiller 110 , the cooling tower 120 , the first pump 161 , the second pump 162 , the third pump 163 , the first control valve 171 and the second control valve 172 are all opened.

[0043] In the related art, the control of the cooling capacity of the cold storage tank 130 is usually to release cooling at the peak of electricity price, and to supplement the insufficient cooling capacity with cooling machine 110. However, the peak, valley and average periods of electricity prices may be different in different cities, and the peak electricity price may also appear intermittently in time. There are also peak electricity price periods in summer and non-summer. The complex distribution of electricity prices makes it difficult to control the cooling time period from a global perspective, and it is even more difficult to control the amount of cooling released.

[0044] To this end, the present application provides a control method for a cold storage system 100 . Figure 2 A flow chart of a control method of a cold storage system 100 according to an embodiment of the present application is disclosed. Figure 2 As shown, a control method of a cold storage system 100 according to an embodiment of the present application may include steps S11 to S14.

[0045] In step S11 , the cumulative cold storage amount of the cold storage tank 130 on the previous day is acquired.

[0046] In step S12, the hourly electricity price for 24 hours a day is obtained.

[0047] In step S13, the hourly value of the cooling load demand for the next 24 hours is obtained one day in advance by using the forecasting technology.

[0048] For example, the hourly value of the cooling load demand for the next 24 hours can be obtained one day in advance through a prediction model based on the actual hourly value of the cooling load for the previous 24 hours.

[0049] The prediction model can adopt the mature LSTM (Long Short-Term Memory) model. With the development of deep machine learning algorithms, the current building cooling load prediction technology is relatively mature. The mature LSTM model can be used to predict future cooling load changes, and satisfactory prediction results can be obtained when the training data quality is good. The present application can predict the hourly value of cooling load demand in the next 24 hours by introducing a prediction model using a deep machine learning algorithm, and apply it to the automatic control of the cold storage system 100 to guide the cold release control of the cold storage system 100, thereby making up for the lack of automatic control of the cold storage system 100.

[0050] In step S14, based on the cumulative cold storage capacity of the previous day obtained in step S11, the hourly electricity price of 24 hours obtained in step S12, and the hourly value of the cold load demand for the next 24 hours obtained in step S13, the cold storage tank 130 is controlled to release cold with the goal of minimizing the electricity cost throughout the day.

[0051] Figure 3 Revealed Figure 2 The flowchart of the cold storage tank 130 is shown in FIG. Figure 3 As shown, in some embodiments, step S14 of controlling the cold storage tank 130 to release cold based on the accumulated cold storage capacity of the previous day, the hourly electricity price of 24 hours and the hourly value of the cold load demand in the next 24 hours with the goal of minimizing the electricity cost for the whole day may include step S141 and step S142.

[0052] In step S141, an hourly cooling release strategy for the next 24 hours is generated through an optimization model according to the cumulative cooling storage capacity of the previous day, the hourly electricity price and the hourly value of the cooling load demand for the next 24 hours.

[0053] For example, the hourly cooling release strategy for the next 24 hours can be generated by taking the lowest electricity cost for the whole day as the optimization goal. An optimization model is established, with the lowest electricity cost for the whole day as the optimization goal of the optimization model, and the adjustable variables are the cooling release on / off time of the cold storage tank 130 and the hourly cooling release after the cooling release is turned on. The accumulated value of the cooling load demand for the next 24 hours is used as the cooling demand, and the accumulated cooling storage capacity of the previous day is used as the hourly allocable cooling release capacity as the restriction condition of the optimization model, and the hourly cooling release strategy for the next 24 hours is obtained through the closed-loop calculation of the optimization model.

[0054] The hourly cooling release strategy for the next 24 hours includes the cooling release start time and the cooling release stop time of the cooling storage tank 130 and the hourly cooling release amount after the cooling release is started.

[0055] In step S142 , the cold storage tank 130 is controlled to release cold hourly according to the hourly cold release strategy for the next 24 hours generated in step S141 .

[0056] Specifically, the hourly cold release control of the cold storage tank 130 in step S142 may include step S1421 and step S1422. In step S1421, the cold release opening time of the cold storage tank 130 is controlled. In step S1422, the hourly cold release amount of the cold storage tank 130 after the cold release is opened is controlled.

[0057] In some embodiments, the cooling release priorities of the hourly cooling release strategy for the next 24 hours are from high to low: cooling release during peak electricity price periods, cooling release during average electricity price periods between peak electricity prices, and cooling release during average electricity price periods.

[0058] Controlling the cold-releasing opening time of the cold-storage tank 130 may include controlling the cold-releasing opening time of the cold-storage tank 130 according to the cold-releasing priority.

[0059] Figure 4 The schematic diagram of cooling capacity distribution on a typical day in July is revealed. Figure 5 A schematic diagram showing the hourly electricity price for a certain place over 24 hours. Figure 4 and Figure 5As shown, in some embodiments, during the peak electricity price period (9:00-10:00, 13:00-17:00), the cold storage tank 130 is controlled to release cold at the maximum cooling capacity; and / or, during the average period between the peak electricity price periods (11:00-12:00), the cold storage tank 130 is controlled to release cold evenly by hour with the remaining cold storage capacity in the cold storage tank 130. Thus, the operating cost can be minimized under the premise of the cooling load requirement of the day.

[0060] The cooling load demand is different on different days, so the optimization results of the optimization model of this application are different. The optimization result can be obtained one day in advance, and the control can be carried out according to the optimization result on the next day.

[0061] In some embodiments, the cold storage system 100 of the present application includes a second control valve 172, which can be disposed between the cold storage tank 130 and the input end of the air conditioning terminal 140. The step S1421 of controlling the cold release opening time of the cold storage tank 130 includes: the cold release opening time and the cold release closing time of the cold storage tank 130 can be controlled by controlling the opening and closing of the second control valve 172.

[0062] In some embodiments, the first pump 161 is disposed in a pipeline between the inlet connecting the output end of the cold machine 110 and the air conditioning terminal 140 and the cold storage tank 130, and the third pump 163 is disposed in a pipeline between the cold storage tank 130 and the input end of the air conditioning terminal 140. The hourly cold release amount after the cold release is turned on in step S1422 may include: the cold machine 110 and the cold storage tank 130 may be controlled to supply cold in proportion by adjusting the frequency of the first pump 161 and the frequency of the third pump 163.

[0063] In some embodiments, the frequency of the third pump 163 may be adjusted using PID control according to the most unfavorable pressure difference between the input end and the output end of the air conditioning terminal 140 .

[0064] In some embodiments, the frequency of the first pump 161 can be adjusted by PID control according to the system flow value, wherein the system flow value is equal to the flow F of the branch where the cold storage tank 130 is located multiplied by the ratio Q2 of the hourly cooling capacity Q1 of the cold machine 110 and the hourly cooling capacity Q2 of the cold storage tank 130 when the cold machine 110 and the cold storage tank 130 jointly provide cooling, that is, F×Q1 / Q2. Figure 4 As shown, Q1 is the yellow part, Q2 is the green part, and the system flow value F×Q1 / Q2 is the control target. The system flow value is different at different times and changes dynamically with the results.

[0065] Specifically, the frequency of the first pump 161 can be adjusted by PID control according to the actual value of the system flow value and the theoretical value of the system flow value. The actual value of the flow F of the branch where the cold storage tank 130 is located, the actual value of the hourly cooling capacity Q1 of the cold machine 110 when the cold machine 110 and the cold storage tank 130 jointly provide cooling, and the actual value of the hourly cooling capacity Q2 of the cold storage tank 130 can be obtained by sensor measurement, and then, the actual value of the system flow value can be obtained according to the actual value of the flow F of the branch where the cold storage tank 130 is located, the actual value of the hourly cooling capacity Q1 of the cold machine 110 when the cold machine 110 and the cold storage tank 130 jointly provide cooling, and the actual value of the hourly cooling capacity Q2 of the cold storage tank 130. When the refrigeration machine 110 and the cold storage tank 130 jointly provide cooling, the theoretical value of the hourly cooling capacity Q1 of the refrigeration machine 110 and the theoretical value of the hourly cooling capacity Q2 of the cold storage tank 130 can be calculated by the prediction model, and the theoretical value of the flow rate F of the branch where the cold storage tank 130 is located can be obtained by conversion according to the theoretical value of the hourly cooling capacity Q1 of the refrigeration machine 110 and the theoretical value of the hourly cooling capacity Q2 of the cold storage tank 130. Then, the theoretical value of the system flow value can be obtained according to the theoretical value of the flow rate F of the branch where the cold storage tank 130 is located, the theoretical value of the hourly cooling capacity Q1 of the refrigeration machine 110 and the theoretical value of the hourly cooling capacity Q2 of the cold storage tank 130 when the refrigeration machine 110 and the cold storage tank 130 jointly provide cooling.

[0066] Figure 6 A schematic diagram showing typical daily and monthly demand for building cooling load is revealed. Figure 6 In the calculation, the cumulative cooling load demand of a typical day is selected every month. Figure 6 As shown in the figure, the cumulative cooling load demand is large in summer (June-September), while the cumulative cooling load demand is low in winter (November-February). The cooling capacity of a conventional cold storage tank is 30% of the peak (August). The traditional cold storage control is to store cold until the maximum capacity of the cold storage tank is reached at night. However, for months with low cold load demand (such as November-February), the cold storage tank only needs to release part of the cold the next day to meet the demand, and the excess cold is stored in the cold storage tank. This is repeated every day, resulting in waste of heat transfer losses.

[0067] To this end, the control method of the cold storage system 100 of the present application also provides cold storage control of the cold storage tank. Figure 7 A flow chart of controlling the cold storage tank according to an embodiment of the present application is disclosed. Figure 7 As shown, in some embodiments, the control method of the cold storage system 100 of the present application may further include step S21 and step S22.

[0068] In step S21, the cumulative value of the cooling load demand for the next 24 hours may be calculated based on the hourly value of the cooling load demand for the next 24 hours predicted in step S13.

[0069] In step S22, the cold storage tank may be controlled for the previous day according to the cumulative value of the cold load demand for the next 24 hours obtained in step S21.

[0070] Figure 8 Revealed Figure 7 The flowchart shown in FIG. 1 is a flow chart of controlling the cold storage tank 130 for the previous day based on the accumulated value of the cold load demand for the next 24 hours. Figure 8 As shown, in some embodiments, step S22 of controlling the cold storage tank 130 for the previous day according to the accumulated value of the cold load demand in the next 24 hours may further include steps S221 to S225.

[0071] In step S221, it is determined whether the accumulated value of the cooling load demand in the next 24 hours is greater than the maximum capacity of the cold storage tank 130. When the result of the determination is "yes", the process proceeds to step S222.

[0072] In step S222 , when the accumulated cooling load demand value in the next 24 hours is greater than the maximum capacity of the cold storage tank 130 , the cold storage tank 130 is controlled to store cold to the maximum capacity of the cold storage tank 130 during the electricity price valley period of the previous day.

[0073] When the result of the judgment in step S221 is "No", the process proceeds to step S223. In step S223, it is further judged whether the current cold storage capacity in the cold storage tank 130 can meet the cumulative value of the cold load demand in the next 24 hours. When the result of the judgment is "Yes", the process proceeds to step S224. Otherwise, the process proceeds to step S225.

[0074] In step S224, when the accumulated value of the cooling load demand in the next 24 hours is less than the maximum capacity of the cold storage tank 130, and the current cold storage capacity in the cold storage tank 130 can meet the accumulated value of the cooling load demand in the next 24 hours, the cold storage tank 130 is controlled not to store cold during the valley period of electricity price on the previous day.

[0075] In step S225, when the accumulated value of the cooling load demand for the next 24 hours is less than the maximum capacity of the cold storage tank 130, and the current cold storage capacity in the cold storage tank 130 cannot meet the accumulated value of the cooling load demand for the next 24 hours, the cold storage tank 130 is controlled to store cold to the accumulated value of the cooling load demand for the next 24 hours during the valley period of electricity price on the previous day.

[0076] The control method of the cold storage system 100 of the present application can predict the hourly value of the cold load demand in the next 24 hours by introducing a prediction model, calculate the cumulative value of the cold load demand in the next 24 hours based on the hourly value of the cold load demand in the next 24 hours, and further guide the cold storage control of the cold storage system 100 on the previous day based on the cumulative value of the cold load demand in the next 24 hours, so as to ensure that the cold storage capacity in the cold storage tank 130 is used up as much as possible while meeting the cold load demand of the next day, thereby avoiding energy waste.

[0077] In some embodiments, in combination Figure 4 As shown, the control method of the cold storage system 100 of the present application may further include: controlling the refrigeration of the chiller 110 according to the hourly cold storage capacity and hourly cold release capacity of the cold storage tank 130 and the actual hourly value of the cold load.

[0078] The present application also provides a control device for a cold storage system 100. The control device includes a memory, a processor, and a computer program stored in the memory. When the processor executes the computer program, the steps of the control method for the cold storage system 100 described above can be implemented.

[0079] The cold storage system 100 of the present application may further include the control device.

[0080] The control method and control device of the cold storage system 100 of the present application, and the cold storage system 100 with the control device obtain the cumulative cold storage capacity of the cold storage tank on the previous day and the hourly electricity price for 24 hours each day, and obtain the hourly value of the cold load demand for the next 24 hours one day in advance through prediction technology, and dynamically optimize the cold release of the cold storage tank with the goal of minimizing the electricity cost for the whole day, which can give full play to the dynamic cold release potential based on different electricity prices and maximize the savings in operating costs.

[0081] In addition, the control method and control device of the cold storage system 100 of the present application, and the cold storage system 100 with the control device obtain the hourly value of the cold load demand for the next 24 hours one day in advance through prediction technology, and calculate the cumulative value of the cold load demand for the next 24 hours based on the hourly value of the cold load demand for the next 24 hours. The cold storage tank is dynamically optimized and controlled based on the cumulative value of the cold load demand for the next 24 hours, which can avoid energy waste caused by excessive cold storage.

[0082] The control method, device and cold storage system of the cold storage system provided in the embodiment of the present application are introduced in detail above. Specific examples are used herein to illustrate the control method, device and cold storage system of the cold storage system of the embodiment of the present application. The description of the above embodiments is only used to help understand the core idea of ​​the present application and is not intended to limit the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made to the present application without departing from the spirit and principles of the present application, and these improvements and modifications should also fall within the scope of protection of the claims attached to the present application.

Claims

1. A control method for a cold storage system, the cold storage system comprising a cold storage tank, characterized in that: The control method comprises: Obtain the cumulative cold storage capacity of the cold storage tank on the previous day; Get the hourly electricity price for 24 hours a day; Obtain the hourly value of cooling load demand for the next 24 hours one day in advance through forecasting technology; According to the accumulated cold storage capacity of the previous day, the hourly electricity price of 24 hours and the hourly value of the cold load demand of the next 24 hours, the cold storage tank is controlled to release cold with the goal of minimizing the electricity cost for the whole day.

2. The control method according to claim 1, characterized in that: The cold storage tank is controlled to release cold based on the cumulative cold storage capacity of the previous day, the hourly electricity price of 24 hours and the hourly value of the cold load demand of the next 24 hours with the goal of minimizing the electricity fee for the whole day, including: The hourly value of the cooling load demand for the next 24 hours is used as the cooling demand, the accumulated cooling storage capacity of the previous day is used as the hourly distributable cooling capacity as the restriction condition of the optimization model, the lowest electricity fee for the whole day is used as the optimization target of the optimization model, and the hourly cooling release strategy for the next 24 hours is obtained through the closed-loop calculation of the optimization model; The cold storage tank is controlled to release cold hourly according to the hourly cold release strategy for the next 24 hours.

3. The control method according to claim 2, characterized in that: The hourly cooling release strategy for the next 24 hours includes the cooling release start time and the cooling release stop time of the cooling storage tank and the hourly cooling release amount after the cooling release is turned on. The hourly cooling release control of the cooling storage tank according to the hourly cooling release strategy for the next 24 hours includes: The cold release start time of the cold storage tank and the hourly cold release amount after the cold release is started are controlled according to the hourly cold release strategy for the next 24 hours.

4. The control method according to claim 3, characterized in that: The priority of the hourly cooling release strategy for the next 24 hours is from high to low: cooling release during the peak electricity price period, cooling release during the average electricity price period between the peak electricity prices, and cooling release during the average electricity price period. The control of the cooling release start time of the cold storage tank includes: The cold release opening time of the cold storage tank is controlled according to the cold release priority.

5. The control method according to claim 4, characterized in that: The hourly cooling capacity after the controlled cooling is turned on includes: During the peak electricity price period, the cold storage tanks are controlled to release cold at the maximum cooling capacity; and / or During the average period between the peak periods of electricity prices, the cold storage tank is controlled to release cold evenly on an hourly basis according to the remaining cold storage capacity in the cold storage tank.

6. The control method according to claim 3, characterized in that: The cold storage system includes a second control valve, which is arranged between the cold storage tank and the input end of the air conditioner terminal, wherein controlling the cold release opening time of the cold storage tank includes: The cold release opening time and the cold release closing time of the cold storage tank are controlled by controlling the opening and closing of the second control valve.

7. The control method according to claim 3, characterized in that: The cold storage system includes a cold machine, a first pump and a third pump, the cold storage tank is connected in parallel with the cold machine, the first pump is arranged in a pipeline between the inlet of the cold machine connected to the output end of the air conditioner terminal and the cold storage tank, and the third pump is arranged in a pipeline between the cold storage tank and the input end of the air conditioner terminal, and the hourly cold release amount after the cold release is turned on is controlled. The cooling machine and the cold storage tank are controlled to supply cold in proportion by adjusting the frequency of the first pump and the frequency of the third pump.

8. The control method according to claim 7, characterized in that: Adjusting the frequency of the third pump comprises: The frequency of the third pump is adjusted by adopting PID control according to the most unfavorable pressure difference between the input end and the output end of the air conditioning terminal.

9. The control method according to claim 7, characterized in that: Adjusting the frequency of the first pump comprises: PID control is used to adjust the frequency of the first pump according to the system flow value, wherein the system flow value is equal to the flow of the branch where the cold storage tank is located multiplied by the ratio of the hourly cooling capacity of the cold machine to the hourly cooling capacity of the cold storage tank when the cold machine and the cold storage tank jointly provide cooling.

10. The control method according to any one of claims 1 to 9, characterized in that: Also includes: The cumulative value of the cooling load demand for the next 24 hours is calculated based on the hourly value of the cooling load demand for the next 24 hours; The cold storage tank is controlled for the previous day according to the accumulated value of the cold load demand in the next 24 hours.

11. The control method according to claim 10, characterized in that: The cooling storage control of the previous day according to the accumulated value of cooling load demand in the next 24 hours includes: When the accumulated value of the cooling load demand in the next 24 hours is greater than the maximum capacity of the cold storage tank, the cold storage tank is controlled to store cold to the maximum capacity of the cold storage tank during the valley period of electricity price on the previous day; When the accumulated value of the cooling load demand in the next 24 hours is less than the maximum capacity of the cold storage tank, and the current cold storage capacity in the cold storage tank meets the accumulated value of the cooling load demand in the next 24 hours, the cold storage tank is controlled not to be stored during the electricity price valley period of the previous day; When the accumulated value of the cooling load demand for the next 24 hours is less than the maximum capacity of the cold storage tank, and the current cold storage capacity in the cold storage tank does not meet the accumulated value of the cooling load demand for the next 24 hours, the cold storage tank is controlled to store cold to the accumulated value of the cooling load demand for the next 24 hours during the valley period of electricity price on the previous day.

12. The control method according to claim 11, characterized in that: The cold storage system further includes a cold machine connected in parallel with the cold storage tank, and the control method further includes: The refrigeration machine is controlled according to the hourly cold storage capacity and hourly cold release capacity of the cold storage tank and in combination with the actual hourly value of the cold load.

13. A control device for a cold storage system, comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the control method of the cold storage system according to any one of claims 1 to 12.

14. A cold storage system, characterized in that: The invention comprises a chiller, a cooling tower, a cold storage tank, an air conditioning terminal, a first pump, a second pump, a third pump, a first control valve, a second control valve and a control device as claimed in claim 13, wherein the chiller has a first inlet, a first outlet, a second inlet and a second outlet, wherein: The first inlet and the first outlet of the refrigerator are respectively connected to the cooling tower, and the second pump is provided in the pipeline between the first inlet of the refrigerator and the cooling tower; The second outlet of the cold machine and the first end of the cold storage tank are connected to the input end of the air conditioner terminal through the third pump; The outlet of the air conditioner terminal is connected to the second end of the cold storage tank and connected to the second inlet of the cold machine through the first pump; The first control valve is arranged between the third pump and the input end of the air conditioner terminal, and the second control valve is arranged between the first end of the cold storage tank and the third pump.

15. The cold storage system according to claim 14, characterized in that: It also includes a balancing line, in which: One end of the balancing pipeline is connected between the second control valve and the third pump, and the other end of the balancing pipeline is connected to the second end of the cold storage tank.

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