A cold storage scheduling method, system and computer readable storage medium

Abstract

The present invention provides a cold storage scheduling method, system and computer-readable storage medium, the method comprising: determining the energy consumption source during the operation of the cold storage and the calculation method of the energy consumption source; dividing the cold storage operation cycle based on differential electricity prices into four stages: high electricity price steady state and high electricity price non-steady state, low electricity price steady state and low electricity price non-steady state, and determining the mathematical model of the cold storage operation energy consumption in each stage, the decision variable of the cold storage operation energy consumption mathematical model is the set temperature of the cold storage, and the parameter variable is the ambient temperature; scheduling the operation of the cold storage based on the mathematical model of the cold storage operation energy consumption. By dividing the operation cycle of the cold storage into four stages through the differential electricity price model and determining the mathematical model of the cold storage operation energy consumption, the operation of the high-energy-consuming cold storage system based on the differential electricity price can be optimized for energy-saving scheduling, thereby improving the energy-saving level and reducing operating costs.

Description

Technical Field

[0001] The present invention relates to the technical field of cold storage scheduling, and in particular to a cold storage scheduling method, system and computer-readable storage medium. Background Art

[0002] How to reduce energy consumption in the cold storage industry has become an urgent problem to be solved.

[0003] There are two ways to solve the problem of reducing cold storage energy consumption: First, rationally plan the layout of facilities in the cold storage. Optimize the installation position of the air cooler, shelves, and the placement of goods, so that the air cooler operating parameters that reach the storage temperature of the goods in the cold storage are at an operating level with better energy-saving effects; second, according to the differential electricity price model unique to each city in my country, adjust the operation of the cold storage to the differential electricity price model of the city, and optimize the cold storage operation scheduling model to improve the energy-saving level and cost reduction level of the cold storage during operation. At present, there are many studies on the optimization of the internal facility layout of cold storage, covering all types and sizes of cold storage, but there are few studies on optimizing the cold storage operation scheduling model for differential electricity prices.

[0004] The prior art lacks a cold storage energy-saving optimization scheduling method based on differential electricity prices.

[0005] The disclosure of the above background technology content is only used to assist in understanding the concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0006] In order to solve the existing problems, the present invention provides a cold storage scheduling method, system and computer-readable storage medium.

[0007] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0008] A cold storage scheduling method comprises the following steps: S1: determining the energy consumption sources during the operation of the cold storage and the calculation method of the energy consumption sources; S2: dividing the cold storage operation cycle based on differential electricity prices into four stages: high electricity price steady state and high electricity price non-steady state, low electricity price steady state and low electricity price non-steady state, and determining the mathematical model of the cold storage operation energy consumption in each stage, wherein the decision variable of the mathematical model of the cold storage operation energy consumption is the set temperature of the cold storage, and the parameter variable is the ambient temperature; S3: scheduling the operation of the cold storage based on the mathematical model of the cold storage operation energy consumption.

[0009] Preferably, the energy consumption of the cold storage during operation is used to bear the cooling load Q in the cold storage.load , including: when the outside temperature is higher than the temperature inside the cold storage, the outside transfers heat Q to the cold storage through the enclosure structure inside the cold storage wall When the goods enter or leave the cold storage, the hot and compressed air from the outside enters the cold storage through the opening and closing of the cold storage door and conducts heat Q door .

[0010] Preferably, based on the following assumptions: the cold storage is a closed natural space for convective heat exchange and the air in the cold storage is incompressible gas, its density remains basically unchanged during the gas change process and conforms to the Boussinesq hypothesis; the influence of the shelves and pipelines in the cold storage on the air flow is ignored; during the pre-cooling process of the cold storage, the air in the cold storage is a non-steady-state flow and the temperature outside the storage remains basically stable, and the heat conducted from the outside through the cold storage enclosure structure during the operation of the cold storage is divided into two states: steady state and non-steady state; the model of the non-steady state is obtained as follows: assuming that the cold storage is at a certain initial temperature T ini Start overcooling and set the temperature to T c <T ini , the cooling power of the cold air machine is W, in order to find the functional relationship between the temperature T in the cold storage and time, take the minimum time period [T, T+dT]. In the small time period, the temperature change in the cold storage is almost 0, and the energy consumption relationship is as follows:

[0011] W dt=-(c p m p +c v m v )dT+λA(T 0 -T)dt+Q 0 dt

[0012] Among them, c p is the specific heat capacity of air at the temperature in the warehouse, c v is the average specific heat capacity of the goods in the cold storage, m p is the mass of the air in the cold storage, m v is the mass of the goods in the cold storage, A is the ratio of the heat exchange area of ​​the insulation material around the cold storage to the thickness of the insulation material, λ is the thermal conductivity of the cold storage enclosure material, T 0 is the ambient temperature outside the cold storage when the cold storage is running, Q 0 It is the average power of the cooling load of other equipment in operation or taking goods during the period;

[0013] By shifting the integral, we get:

[0014]

[0015] Among them, T c is the set temperature of the air cooler for over-storage of cold air, T iniIt is the initial temperature of the cold storage starting a new operation cycle. The steady state is that the cooling fan in the cold storage always runs with the same set temperature, the temperature in the cold storage remains unchanged, and the temperature difference between indoor and outdoor remains unchanged. This steady state model is simplified into a steady heat conduction model for solution. Specifically: the insulation structure of the cold storage includes a fixed material and an insulation material between the fixed materials. The heat transfer coefficient should be the heat transfer coefficient of the three layers of materials connected in series. The insulation coefficient of the insulation structure is approximately equal to the heat transfer coefficient of the insulation material. The heat transfer equation is as follows:

[0016] Q wall =λA(T 0 -T C ).

[0017] Preferably, determining the mathematical model of the cold storage operating energy consumption during each stage of operation includes the following steps: obtaining the electricity price model of the city where the cold storage is located; calculating the cold storage operating energy consumption of each stage based on the electricity price model, and integrating to obtain the energy consumption mathematical model of the cold storage operating cycle.

[0018] Preferably, in the low electricity price non-steady state stage: assuming that the cold storage is at a certain initial temperature T ini Start overcooling and set the temperature to T c <T ini , the cooling power of the cooling air machine under low electricity price non-steady state is W 11 ,In order to find the functional relationship between the temperature T in the cold storage and time, take the minimum time period [T, T+dT]. In the small time period, the temperature change in the cold storage is almost 0. The energy consumption relationship is as follows:

[0019] W 11 dt=-(c p m p +c v m v )dT+λA(T 0 -T)dt+Q 0 dt

[0020] By shifting the integral, we get:

[0021]

[0022] According to the above integral formula, the cold storage operation time t can be obtained during the low electricity price non-steady state process. 11 , and the total time under low electricity price is t 1 , then the difference between the two is the cold storage operation time t under low electricity price steady state 12 ;

[0023] At the same time, after the set temperature is lowered, the overall power of the air cooler is the rated power, and the following is obtained:

[0024] W 11 =EERW 0

[0025] Among them, W 0 is the rated power of the air cooler; EER is the energy efficiency ratio at the rated power of the air cooler;

[0026] In the low electricity price steady state stage:

[0027] W 12 =λA(T 0 -TC)+Q 0 .

[0028] Preferably, for the non-steady-state stage with high electricity price: assuming that the cold storage reaches the set temperature T c <T ini After entering the high electricity price stage, the cooling fan does not work under the non-steady state of high electricity price, so its cooling power is 0. In order to find the functional relationship between the temperature T in the cold storage and time, the minimum time period [T, T+dT] is taken. In the small time period, the temperature change in the cold storage is almost 0. The energy consumption relationship is as follows:

[0029] 0=-(c p m p +c v m v )dT+λA(T 0 -T)dt+Q 0 dt

[0030] By shifting the integral, we get:

[0031]

[0032] According to the above integral formula, the system operation time t can be obtained during the non-steady state of high electricity price. 21 , and the total time under high electricity price is t 2 , then the difference between the two is the system operation time t under high electricity price steady state 22 ;

[0033] For the high electricity price steady-state stage: the cooling fan in the cold storage always runs at the same set temperature, the temperature in the cold storage remains basically unchanged, and the temperature difference between indoor and outdoor remains basically unchanged. This steady-state model can be simplified into a steady-state heat conduction model for solution:

[0034] W 22 =λA(T 0 -T ini )+Q 0 .

[0035] Preferably, the cold storage stores excess cold when operating at low electricity prices, and reduces energy consumption when operating at high electricity prices, and must go through the above four stages to complete a cycle of operation, so the energy consumption objective function of the cold storage in a single cycle is as follows:

[0036] min(power)=(t 11 W 11 +t 12 W 12 )+(t 22 W 22 )

[0037] By adding the differential electricity price model, the energy consumption cost objective function of a single cycle is obtained as follows:

[0038] min(price)=price 1 (t 11 W 11 +t 12 W 12 )+price 2 (t 22 W 22 )

[0039] Furthermore, the following function expression is obtained:

[0040]

[0041]

[0042] From the final expression of the above price objective function, we can see that when the specific usage parameters of the cold storage are determined, the variable of the price objective function is the cold storage set temperature T c The ambient temperature outside the warehouse T 0 .

[0043] Preferably, scheduling the operation of the cold storage based on the mathematical model of the cold storage operation energy consumption includes the following steps: S31: obtaining the ambient temperature of the city where the cold storage is located, and solving the mathematical function model of the cold storage cycle energy consumption based on the ambient temperature and the reading of the specific parameters of the cold storage operation to obtain the set temperature corresponding to the decision variable; S32: adjusting the cold storage based on the set temperature value of the cold storage operation and solving the energy saving level of the cold storage after the operation mode is optimized.

[0044] The present invention also provides a cold storage scheduling method system, comprising a processor and a storage medium for storing a computer program; wherein the processor is used to execute at least any of the above methods when executing the computer program.

[0045] The present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of any of the above methods are implemented.

[0046] The beneficial effects of the present invention are: providing a cold storage scheduling method, system and computer-readable storage medium, dividing the operation cycle of the cold storage into four stages through a differential electricity price model, and determining a mathematical model of the cold storage operation energy consumption, which can optimize the energy-saving scheduling of the operation of a high-energy-consuming cold storage system based on differential electricity prices, thereby improving the energy-saving level and reducing operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of a cold storage scheduling method in an embodiment of the present invention.

[0048] Figure 2 Schematic diagram of the source of cold load inside the cold storage in the embodiment of the present invention.

[0049] Figure 3 Schematic diagram of the proportion of cold load inside the cold storage in the embodiment of the present invention.

[0050] Figure 4 It is a schematic diagram of the cold storage insulation structure in an embodiment of the present invention.

[0051] Figure 5 It is a schematic diagram of a method for determining a mathematical model of cold storage operation energy consumption in each stage in an embodiment of the present invention.

[0052] Figure 6 It is a state change diagram within the cold storage operation cycle in an embodiment of the present invention.

[0053] Figure 7 It is a schematic diagram of a method for scheduling the operation of the cold storage based on a mathematical model of the cold storage operation energy consumption in an embodiment of the present invention.

[0054] Figure 8 It is a flow chart of cold storage operation scheduling based on differential electricity prices in an embodiment of the present invention.

[0055] Fig. 9 1 is a comparison chart of monthly setting temperatures of cold storages in Harbin, Shenzhen and Shanghai in an embodiment of the present invention.

[0056] Fig.10 It is a comparison chart of the monthly energy consumption after optimization and the original monthly energy consumption of Harbin cold storage in the embodiment of the present invention.

[0057] Fig.11 It is a comparison chart of the optimized annual energy consumption and the original annual energy consumption of the cold storages in Harbin, Shenzhen and Shanghai in the embodiment of the present invention.

[0058] Fig.12It is a comparison chart of the annual energy consumption after optimization and the original annual energy consumption cost of the cold storages in Harbin, Shenzhen and Shanghai in the embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to make the technical problems, technical solutions and beneficial effects to be solved by the embodiments of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0060] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for both fixing and circuit connection.

[0061] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0062] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0063] like Figure 1 As shown, the present invention provides a cold storage scheduling method, comprising the following steps:

[0064] S1: Determine the energy consumption source during the operation of the cold storage and the calculation method of the energy consumption source;

[0065] S2: Divide the cold storage operation cycle based on differential electricity prices into four stages: high electricity price steady state and high electricity price non-steady state, low electricity price steady state and low electricity price non-steady state, and determine the mathematical model of cold storage operation energy consumption in each stage, the decision variable of the cold storage operation energy consumption mathematical model is the set temperature of the cold storage, and the parameter variable is the ambient temperature;

[0066] S3: Scheduling the operation of the cold storage based on a mathematical model of the cold storage operation energy consumption.

[0067] The present invention divides the operation cycle of the cold storage into four stages through the differential electricity price model and determines the mathematical model of the cold storage operation energy consumption. It can optimize the energy-saving scheduling of the operation of the high-energy-consuming cold storage system based on the differential electricity price, thereby improving the energy-saving level and reducing the operating cost.

[0068] The content of the present invention is described in detail as follows.

[0069] In step S1, the energy consumption sources during the operation of the cold storage and the calculation method of the energy consumption sources are determined, as described in detail below.

[0070] like Figure 2 As shown, in one embodiment of the present invention, more than 80% of the energy consumption of the cold storage refrigeration system is used to bear the cold load in the cold storage, wherein the cold load in the cold storage is Q load The main sources are as follows:

[0071] 1) The outside temperature is usually higher than the temperature inside the cold storage. The outside transfers heat Q to the cold storage through the enclosure structure (roof, wall and ground) inside the cold storage. wall ;

[0072] 2) When goods enter or leave the cold storage, the outside world passes through the opening and closing of the cold storage door, and hot and compressed air enters the cold storage and conducts heat Q door ;

[0073] 3) After the goods enter the cold storage, due to their own high temperature, they will radiate heat Q to the cold storage retr ;

[0074] 4) The heat generated by the lighting equipment and other automation equipment in the cold storage during operation Q elec .

[0075] like Figure 3 As shown in the figure, the cold loads from different sources in the cold storage vary greatly. When the cold storage is in operation, 85% of the cold loads are from 1) and 2) above. Therefore, the calculation will be conducted for the main sources of the cold loads. For the convenience of description, the symbols and meanings used in the energy consumption calculation are first provided in Table 1.

[0076] Table 1 Symbol table of cold storage energy consumption model

[0077]

[0078] As above, the cooling load Q in the cold storage load The first source: The analysis and calculation of heat transfer from the enclosure structure to the cold storage is as follows:

[0079] Choosing a reasonable mathematical model for research modeling now requires making the following series of assumptions:

[0080] The cold storage is a closed natural space for convective heat exchange and the air in the cold storage is incompressible gas. Its density remains basically unchanged during the gas change process and conforms to the Boussineske hypothesis;

[0081] Ignore the impact of shelves and pipes in the cold storage on air flow;

[0082] During the cold storage precooling process, the air in the cold storage flows in a non-steady state and the temperature outside the cold storage remains basically stable.

[0083] From the above, we can see that the cold load dissipated from the outside through the enclosure structure in the cold storage will experience two states: steady state and non-steady state during the operation of the cold storage.

[0084] The non-steady-state state is when the air cooler in the cold storage is pre-cooling or the set temperature of the air cooler changes. At this time, the temperature in the cold storage is constantly changing, causing the temperature difference inside and outside the storage to change continuously. At this time, the method of establishing a differential equation for the temperature change in a very short time can be used to find the function of the change of the cooling load over time to solve it.

[0085] The steady-state state is that the cooling fan in the cold storage always runs at the same set temperature, the temperature in the cold storage remains basically unchanged, and the temperature difference between indoor and outdoor remains basically unchanged. This steady-state model can be simplified into a steady-state heat conduction model for solution.

[0086] The model of the non-steady state is obtained as follows:

[0087] Assume that the cold storage is at a certain initial temperature T ini Start overcooling and set the temperature to T c <T ini , the cooling power of the cold air machine is W, in order to find the functional relationship between the temperature T in the cold storage and time, take the minimum time period [T, T+dT]. In the small time period, the temperature change in the cold storage is almost 0, and the energy consumption relationship is as follows:

[0088] W dt=-(c p m p +c v m v )dT+λA(T 0 -T)dt+Q 0 dt

[0089] Among them, c p is the specific heat capacity of air at the temperature in the warehouse, c v is the average specific heat capacity of the goods in the cold storage, m p is the mass of the air in the cold storage, m v is the mass of the goods in the cold storage, A is the ratio of the heat exchange area of ​​the insulation material around the cold storage to the thickness of the insulation material, λ is the thermal conductivity of the cold storage enclosure material, T0 is the ambient temperature outside the cold storage when the cold storage is running, Q 0 It is the average power of the cooling load of other equipment in operation or taking goods during the period;

[0090] By shifting the integral, we get:

[0091]

[0092] Among them, T c is the set temperature of the air cooler for over-storage of cold air, T ini It is the initial temperature when the cold storage starts a new operation cycle.

[0093] According to the above integral formula, the system operation time in the non-steady-state process can be obtained, and then the functional relationship between the temperature T in the cold storage and time can be found.

[0094] The steady state is that the cooling fan in the cold storage always runs with the same set temperature, the temperature in the cold storage remains unchanged, and the temperature difference between indoor and outdoor remains unchanged. This steady state model is simplified into a steady heat conduction model for solution.

[0095] like Figure 4 As shown, the structure of the cold storage insulation material includes a fixing material 1 and an insulation material 2 between the fixing material 1. The steady-state model is regarded as a heat conduction model, and its heat transfer coefficient should be the heat transfer coefficient of the three layers of materials connected in series. However, since the fixing material is generally made of hard materials with poor insulation effect and thin thickness, the insulation coefficient of the composite material can be approximately equal to the heat transfer coefficient of the insulation material in the middle of the fixing material. The heat transfer equation is as follows:

[0096] Q wall =λA(T 0 -T C )

[0097] From the above, we can see that the heat dissipation power of the enclosure structure into the cold storage during the steady-state and non-steady-state processes in the cold storage operation cycle is always closely related to factors such as the set temperature of the cold storage, the selection of insulation materials, and the temperature difference outside the storage.

[0098] As above, the cooling load Q in the cold storage load The second source: The energy loss caused by hot air seepage when goods enter and leave the cold storage is calculated as follows:

[0099] When goods enter or leave a cold storage, the heat that is transferred by hot pressurized air from the outside into the cold storage through the opening and closing of the cold storage door is usually studied by combining model simulation, empirical formulas and experimental measurements.

[0100] In order to obtain the simulation model results and the input parameters of the empirical formula, it is necessary to simulate the state of the cold storage door when it is opened and closed. Here, the boundary conditions are designed based on the actual working conditions as follows:

[0101] (1) Inlet boundary: The velocity inlet boundary is adopted, the inlet wind speed is 9.3 m / s, and the inlet temperature is set at -18 °C. It is difficult to determine the exact value of the turbulent kinetic energy and kinetic energy dissipation rate in the equation, so the turbulence intensity and characteristic size are used to define the turbulence. The turbulence intensity is set to 5% and the hydraulic diameter is 0.4 m.

[0102] (2) Outlet boundary: Since the wind speed and pressure at the return air outlet are unknown, a free outlet boundary is used.

[0103] (3) Wall: The fan wall material is steel, so select steel. The cold storage wall material is polyurethane foam board, so select custom material properties to set parameters such as density and thermal conductivity. The cold storage wall adopts the first type of boundary conditions, and the initial temperature is set to 26°C. There is a certain amount of leakage on the door wall. There is a heat exchange and it is set to convection heat exchange wall conditions. The heat flux density is 1.27W / m 2 The wall thickness is 0.1m.

[0104] According to the above simulation results, the permeability of the CFD simulation results can be obtained, and the parameters such as air flow temperature and velocity are input into the empirical formula to obtain the results as shown in Table 2 below.

[0105] Table 2 Comparison of energy consumption of cold storage air infiltration

[0106]

[0107] In step S2, a mathematical model of the cold storage operation energy consumption in each stage is first determined, wherein the decision variable of the mathematical model of the cold storage operation energy consumption is the set temperature of the cold storage, and the parameter variable is the ambient temperature, as described in detail below.

[0108] like Figure 5 As shown, in one embodiment of the present invention, determining a mathematical model for the cold storage operation energy consumption during operation at each stage includes the following steps:

[0109] Obtain an electricity price model for the city where the cold storage is located;

[0110] The energy consumption of the cold storage operation in each stage is calculated based on the electricity price model, and then the energy consumption mathematical model of the cold storage operation cycle is obtained through integration.

[0111] The off-peak electricity price in Shenzhen is one-fourth of the peak electricity price, so the high-energy consumption cold storage will over-store cold when the off-peak electricity price is running, and reduce energy consumption when the peak electricity price is running. This operation scheduling mode can reduce the overall energy consumption cost of the cold storage operation, and because the off-peak electricity price usually corresponds to the period of time when the temperature is lower every day, the energy caused by excessive cold storage can also be greatly reduced. From the simulation results, it can be seen that the pre-cooling time of the cold storage is usually between 40-45 minutes, and the cold storage time of lowering the set temperature will be shorter than this period, and the peak and valley time period of industrial electricity consumption is usually longer than 120 minutes. Therefore, the cold storage will over-store cold when the electricity price is low and reduce energy consumption when the electricity price is high. It will definitely experience the steady-state and non-steady-state stages at low electricity prices and the steady-state and non-steady-state stages at high electricity prices, such as Figure 6 shown.

[0112] Based on the electricity price model, the energy consumption of the cold storage operation in each stage is obtained respectively, and the energy consumption mathematical model of the cold storage operation cycle is integrated as follows:

[0113] In the non-steady-state phase of low electricity prices:

[0114] Assume that the cold storage is at a certain initial temperature T ini Start overcooling and set the temperature to T c <T ini , the cooling power of the cooling air machine under low electricity price non-steady state is W 11 ,In order to find the functional relationship between the temperature T in the cold storage and time, take the minimum time period [T, T+dT]. In the small time period, the temperature change in the cold storage is almost 0. The energy consumption relationship is as follows:

[0115] W 11 dt=-(c p m p +c v m v )dT+λA(T 0 -T)dt+Q 0 dt

[0116] Among them, Q 0 It represents the average power of other cooling loads in this time period (lighting equipment, taking goods, etc.), which can be obtained by simulation and empirical formula method. The integral is shifted to get:

[0117]

[0118] According to the above integral formula, the cold storage operation time t can be obtained during the low electricity price non-steady state process. 11 , and the total time under low electricity price is t 1 , then the difference between the two is the cold storage operation time t under low electricity price steady state 12 ;

[0119] At the same time, after the set temperature is lowered, the overall power of the air cooler is the rated power, and the following is obtained:

[0120] W 11 =EERW 0

[0121] Among them, W 0 is the rated power of the air cooler; EER is the energy efficiency ratio at the rated power of the air cooler;

[0122] In the low electricity price steady state stage:

[0123] W 12 =λA(T 0 -T C )+Q 0

[0124] For the non-steady-state phase with high electricity prices:

[0125] Assume that the cold storage reaches the set temperature T c <T ini After entering the high electricity price stage, the cooling fan does not work under the non-steady state of high electricity price, so its cooling power is 0. In order to find the functional relationship between the temperature T in the cold storage and time, the minimum time period [T, T+dT] is taken. In the small time period, the temperature change in the cold storage is almost 0. The energy consumption relationship is as follows:

[0126] 0=-(c p m p +c v m v )dT+λA(T 0 -T)dt+Q 0 dt

[0127] By shifting the integral, we get:

[0128]

[0129] According to the above integral formula, the system operation time t can be obtained during the non-steady state of high electricity price. 21 , and the total time under high electricity price is t 2 , then the difference between the two is the system operation time t under high electricity price steady state 22 ;

[0130] For the high electricity price steady state stage:

[0131] The cooling fan in the cold storage always runs at the same set temperature, the temperature in the cold storage remains basically unchanged, and the temperature difference between indoor and outdoor remains basically unchanged. This steady-state model can be simplified into a steady-state heat conduction model for solution:

[0132] W 22=λA(T 0 -T ini )+Q 0

[0133] The cold storage stores excessive cold when operating at low electricity prices, and reduces energy consumption when operating at high electricity prices. It must go through the above four stages to complete a cycle of operation, so the energy consumption objective function of the cold storage in a single cycle is as follows:

[0134] min(power)=(t 11 W 11 +t 12 W 12 )+(t 22 W 22 )

[0135] By adding the differential electricity price model, the energy consumption cost objective function of a single cycle is obtained as follows:

[0136] min(price)=price 1 (t 11 W 11 +t 12 W 12 )+price 2 (t 22 W 22 )

[0137] Combining the equations of the above four stages, we get the following function expression equation:

[0138]

[0139]

[0140] From the final expression of the above price objective function, it can be seen that when the specific usage parameters of the cold storage (cold storage structure, selection of insulation materials, cargo storage frequency, specific parameters of the air cooler, etc.) are determined, the variable of the price objective function is the cold storage set temperature T c The ambient temperature outside the warehouse T 0 It should be noted that the set temperature should not exceed the lowest set temperature of the air cooler, and the wind speed and humidity in the cold storage should also be kept within an appropriate range to ensure that the storage conditions of frozen food are met.

[0141] In step S3, the operation of the cold storage is scheduled based on the mathematical model of the cold storage operation energy consumption as described below.

[0142] like Figure 7 As shown, in one embodiment of the present invention, scheduling the operation of the cold storage based on the mathematical model of the cold storage operation energy consumption includes the following steps:

[0143] S31: Obtaining the ambient temperature of the city where the cold storage is located, solving the mathematical function model of the cold storage cycle energy consumption based on the ambient temperature and the reading of the specific operating parameters of the cold storage, and obtaining the set temperature corresponding to the decision variable;

[0144] S32: adjusting the cold storage based on the set temperature value of the cold storage operation and solving the energy saving level after the cold storage operation mode is optimized.

[0145] Based on the mathematical function expression of the cold storage energy consumption model, the specific operating parameters of the cold storage (cold storage structure, selection of insulation materials, cargo storage frequency, specific parameters of the cold air blower, etc.) and the external ambient temperature T can be determined. 0 After determination, the variable of the objective function is the cold storage set temperature T c According to the characteristics of the cold storage that the set temperature can be adjusted periodically with the change of differential electricity prices, the following cold storage operation flow chart can be obtained. Figure 8 shown.

[0146] Continue as Figure 8 As shown in the figure, when the cold storage operation scheduling process starts, it should be as follows Figure 8 Set the initial temperature T of the cold storage operation ini The setting of this initial temperature ensures that the cold storage can quickly drop from the empty room temperature state to the refrigeration state for storing goods at rated power, thereby ensuring that the temperature in the cold storage is always kept below the storage temperature required for storing goods during the adjustment process.

[0147] Input the specific operating parameters of the cold storage (cold storage structure, selection of insulation materials, cargo storage frequency, specific parameters of the air cooler, etc.) and the ambient temperature T outside the cold storage at this moment. 0 The above-mentioned specific parameters of the cold storage and the ambient temperature parameters affect the energy consumption cost level function of the cold storage, thereby affecting the operation scheduling of the cold storage. The ambient temperature should be read in real time to improve the fine adjustment of the model.

[0148] Enter the cold storage set temperature T c The set temperature comes from the solution of the mathematical model of the cold storage cycle energy consumption. When the specific operating parameters and ambient temperature parameters of the cold storage are determined, the set temperature can also be determined accordingly. It can be seen that the set temperature will also change in real time with the change of ambient temperature.

[0149] The temperature inside the cold storage and the set temperature are judged in real time. When the temperature inside the cold storage is lower than the set temperature, the refrigeration system of the cold storage stops working; when the temperature inside the cold storage is higher than the set temperature, the refrigeration system of the cold storage determines whether excessive cold storage is needed.

[0150] The electricity price model for this electricity price determination is derived from the peak and valley electricity price model of the city where the cold storage is located. If this is a low electricity price period, the refrigeration system determines that the cold storage is over-storing during this period. The sign of the end of over-storing is that the temperature inside the cold storage reaches the set temperature. At this time, the cold storage maintains this set temperature until entering a high electricity price period. Since this is a high electricity price period, the cold storage only needs to keep the temperature inside the cold storage below the storage temperature of the goods. If the temperature inside the cold storage is significantly lower than this temperature, the cold storage refrigeration system will stop working immediately.

[0151] Since the cold storage regulation has a certain hysteresis, the time interval for real-time reading of the specific parameters of the cold storage operation and the ambient temperature parameters outside the cold storage should not be too long. Too long will lead to the hysteresis of the cold storage regulation, so that the temperature of the cold storage in some time periods is higher than the storage temperature of the goods, which will affect the quality of the stored goods. The reading of the cold storage value here adopts the method of reading once every minute, so the cycle is one day, and the maximum value of M is 1440. The selection of its value can also be changed according to the specific characteristics of different cold storages.

[0152] Since Harbin is located in northern China, the temperature difference between day and night is large, and the temperature difference between day and night as an important variable in this model will have a great impact on the calculation results. Therefore, Harbin in northern China, Shanghai in eastern China, and Shenzhen in southern China were selected as comparison objects.

[0153] like Fig. 9 As shown, according to the method of the present invention, the annual monthly average day and night temperature difference of Harbin, Shenzhen and Shanghai is input into the energy consumption cost model of the three cities to solve the optimal set temperature of the three cities in each month in 2018.

[0154] like Fig.10 As shown in the figure, the energy consumption is optimized by adjusting the set temperature on a monthly basis. The optimal set temperature model is input into the Harbin energy consumption function model and the energy consumption cost model to obtain a before-and-after comparison chart of Harbin's monthly average energy consumption in 2018.

[0155] like Fig.11 and Fig.12 As shown in the figure, the energy consumption is optimized by adjusting the set temperature seasonally. The optimal set temperature models of the three cities are input into the energy consumption function models and energy consumption cost function models of the three cities. The energy consumption and energy consumption cost of the cold storage in the three cities are compared with the energy consumption and energy consumption cost of the original strategy under the over-cold storage model based on differential electricity prices.

[0156] Further, as shown in Table 3, it is the annual energy consumption analysis of Harbin, Shanghai and Shenzhen.

[0157] Table 3 Annual energy consumption analysis of Harbin, Shanghai and Shenzhen

[0158]

[0159] An embodiment of the present application also provides a control device, including a processor and a storage medium for storing a computer program; wherein the processor is used to execute at least the method described above when executing the computer program.

[0160] An embodiment of the present application also provides a storage medium for storing a computer program, which at least performs the method described above when executed.

[0161] An embodiment of the present application further provides a processor, which executes a computer program and at least performs the method described above.

[0162] The storage medium may be implemented by any type of volatile or non-volatile storage device, or a combination thereof. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a ferromagnetic random access memory, a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); the magnetic surface memory may be a disk memory or a tape memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAMEnhanced Synchronous Dynamic Random Access Memory), synchronous link dynamic random access memory (SLDRAM), direct memory bus random access memory (DRRAM). The storage media described in the embodiments of the present invention are intended to include, but are not limited to, these and any other suitable types of memory.

[0163] In the several embodiments provided in the present application, it should be understood that the disclosed systems and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored, or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0164] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0165] In addition, all functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0166] Those skilled in the art can understand that: all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), disks or optical disks, etc. Various media that can store program codes.

[0167] Alternatively, if the above-mentioned integrated unit of the present invention is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present invention can be essentially or partly reflected in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, RAM, magnetic disks or optical disks.

[0168] The methods disclosed in several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0169] The features disclosed in several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0170] The features disclosed in several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0171] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art of the present invention, several equivalent substitutions or obvious variations can be made without departing from the concept of the present invention, and the performance or use is the same, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A cold storage scheduling method, characterized in that: The steps include: S1: Determine the energy consumption source during the operation of the cold storage and the calculation method of the energy consumption source; S2: Divide the cold storage operation cycle based on differential electricity prices into four stages: high electricity price steady state and high electricity price non-steady state, low electricity price steady state and low electricity price non-steady state, and determine the mathematical model of cold storage operation energy consumption in each stage, the decision variable of the cold storage operation energy consumption mathematical model is the set temperature of the cold storage, and the parameter variable is the ambient temperature; S3: Scheduling the operation of the cold storage based on a mathematical model of the cold storage operation energy consumption; Scheduling the operation of the cold storage based on the mathematical model of the cold storage operation energy consumption comprises the following steps: S31: Obtaining the ambient temperature of the city where the cold storage is located, solving the mathematical function model of the cold storage cycle energy consumption based on the ambient temperature and the reading of the specific operating parameters of the cold storage, and obtaining the set temperature corresponding to the decision variable; S32: adjusting the cold storage based on the set temperature value of the cold storage operation and solving the energy saving level after the cold storage operation mode is optimized; Wherein, the energy consumption mathematical function model is: min(power)=(t 11 W 11 +t 12 W 12 )+(t 22 W 22 ) Among them, t 11 is the cold storage operation time during the non-steady state process with low electricity price, W 11 is the cooling power of the air conditioner under low electricity price and non-steady state, t 12 is the cold storage operation time under low electricity price steady state, W 12 is the cooling power of the air conditioner under low electricity price steady state, t 22 is the system operation time under high electricity price steady state, W 22 The cooling power of the air cooler under high electricity price steady state; By adding the differential electricity price model, the energy consumption cost objective function of a single cycle is obtained as follows: min(price)=price1(t 11 W 11 +t 12 W 12 )+price2(t 22 W 22 ) Among them, price1 and price2 are the electricity prices under low electricity price and high electricity price respectively; Furthermore, the following function expression is obtained: Among them, T c T is the set temperature of the air cooler for over-storage of cold air. ini is the initial temperature of the cold storage at the beginning of a new operation cycle, λ is the thermal conductivity of the cold storage enclosure material, A is the ratio of the heat exchange area of ​​the insulation material around the cold storage to the thickness of the insulation material, T0 is the ambient temperature outside the cold storage when the cold storage is running, T is the temperature inside the cold storage, Q0 is the average power of the cold load of other equipment running or taking goods during this period, EER is the energy efficiency ratio at the rated power of the air cooler, W0 is the rated power of the air cooler, c p is the specific heat capacity of air at the temperature in the cold storage, m p is the quality of the air in the cold storage, c v is the average specific heat capacity of the goods in the cold storage, m v is the mass of goods in the cold storage, t1 is the total time at low electricity price, and t2 is the total time at high electricity price; From the final expression of the energy consumption cost objective function, it can be seen that when the specific usage parameters of the cold storage are determined, the variable of the energy consumption cost objective function is the cold storage set temperature T c And the ambient temperature outside the warehouse T0.

2. The cold storage scheduling method according to claim 1, characterized in that: The energy consumption during the operation of the cold storage is used to bear the cooling load Q in the cold storage. load ,include: When the outside temperature is higher than the temperature inside the cold storage, the outside transfers heat Q to the cold storage through the enclosure structure inside the cold storage. wall ; When the goods enter or leave the cold storage, the hot and compressed air from the outside enters the cold storage through the opening and closing of the cold storage door and conducts heat Q door .

3. The cold storage scheduling method according to claim 2, characterized in that: Based on the following assumptions: The cold storage is a closed natural space for convective heat exchange and the air in the cold storage is incompressible gas. Its density remains basically unchanged during the gas change process and conforms to the Boussineske hypothesis; Ignore the impact of the shelves and pipes in the cold storage on the air flow; During the cold storage precooling process, the air in the cold storage flows in a non-steady state and the temperature outside the cold storage remains basically stable; The heat conducted from the outside through the cold storage enclosure structure is divided into two states: steady state and unsteady state during the operation of the cold storage; The model of the non-steady state is obtained as follows: Assume that the cold storage is at a certain initial temperature T ini Start overcooling and set the temperature to T c <T ini , the cooling power of the cold air machine is W, in order to find the functional relationship between the temperature T in the cold storage and time, take the minimum time period [T, T+dT]. In the small time period, the temperature change in the cold storage is almost 0, and the energy consumption relationship is as follows: Wdt=-(c p m p +c v m v )dT+λA(T0-T)dt+Q0dt By shifting the integral, we get: The steady state is that the cooling fan in the cold storage always runs at the same set temperature, the temperature in the cold storage remains unchanged, and the temperature difference between indoor and outdoor remains unchanged. This steady state model is simplified into a steady state heat conduction model for solution. Specifically: The insulation structure of the cold storage includes a fixed material and an insulation material between the fixed materials. The heat transfer coefficient should be the heat transfer coefficient of the three layers of materials in series. The insulation coefficient of the insulation structure is approximately equal to the heat transfer coefficient of the insulation material. The heat transfer equation is as follows: Q wall =λA(T0-T C )。 4. The cold storage scheduling method according to claim 3, characterized in that: The mathematical model for determining the energy consumption of cold storage during each stage of operation includes the following steps: Obtain an electricity price model for the city where the cold storage is located; The energy consumption of the cold storage operation in each stage is calculated based on the electricity price model, and then the energy consumption mathematical model of the cold storage operation cycle is obtained through integration.

5. The cold storage scheduling method according to claim 4, characterized in that: In the non-steady-state phase of low electricity prices: Assume that the cold storage is at a certain initial temperature T ini Start overcooling and set the temperature to T c <T ini , the cooling power of the cooling air machine under low electricity price non-steady state is W 11 ,To find the functional relationship between the temperature T in the cold storage and time, take the minimum time period [T, T+dT]. In the small time period, the temperature change in the cold storage is almost 0. The energy consumption relationship is as follows: W 11 dt=-(c p m p +c v m v )dT+λA(T0-T)dt+Q0dt By shifting the integral, we get: According to the above integral formula, the cold storage operation time t can be obtained during the low electricity price non-steady state process. 11 , and the total time under low electricity price is t1, then the difference between the two is the cold storage operation time t under low electricity price steady state 12 ; At the same time, after the set temperature is lowered, the overall power of the air cooler is the rated power, and the following is obtained: IN 11 =EERW0 In the low electricity price steady state stage: W 12 =λA(T0-T C )+Q0。 6. The cold storage scheduling method according to claim 5, characterized in that: For the non-steady-state phase with high electricity prices: Assume that the cold storage reaches the set temperature T c <T ini After entering the high electricity price stage, the cooling fan does not work under the non-steady state of high electricity price, so its cooling power is 0. In order to find the functional relationship between the temperature T in the cold storage and time, the minimum time period [T, T+dT} is taken. In the small time period, the temperature change in the cold storage is almost 0. The energy consumption relationship is as follows: 0=-(c p m p +c v m v )dT+λA(T0-T)dt+Q0dt By shifting the integral, we get: According to the above integral formula, the system operation time t can be obtained during the non-steady state of high electricity price. 21 , and the total time under high electricity price is t2, then the difference between the two gives the system operation time t under high electricity price steady state 22 ; For the high electricity price steady state stage: The cooling fan in the cold storage always runs at the same set temperature, the temperature in the cold storage remains basically unchanged, and the temperature difference between indoor and outdoor remains basically unchanged. This steady-state model can be simplified into a steady-state heat conduction model for solution: W 22 =λA(T0-T ini )+Q0。 7. The cold storage scheduling method according to claim 6, characterized in that: The cold storage stores excessive cold when operating at low electricity prices, and reduces energy consumption when operating at high electricity prices, and must go through the above four stages to complete a cycle of operation.

8. A cold storage scheduling method system, characterized in that: It comprises a processor and a storage medium for storing a computer program; wherein the processor is used to execute at least any method according to claims 1-7 when executing the computer program.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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