Ice storage ice melting rate control method

Abstract

The invention relates to the technical field of air conditioner energy storage, and discloses an ice storage ice melting rate control method which comprises the following steps: S1, aiming at each unit in an ice storage air conditioner system, constructing basic data models of all units including a refrigerating unit and an ice making unit at different load rates, the basic data is based on quantity adjustment of the unit at different water supply temperatures under different cooling water temperatures; s2, in combination with outdoor weather forecast, constructing a system cooling load demand model at a t moment; s3, constructing a system comprehensive efficiency model according to the refrigeration / ice-making efficiency and the economic efficiency of the unit; and S4, constructing an ice melting rate model, and predicting the ice melting amount of the ice storage device at the t moment in order to meet the cold load demand of the system and maximize the comprehensive efficiency of the system. By accurately controlling the ice melting rate and performing optimal adjustment based on the basic data model, the comprehensive efficiency of the system can be maximized, the energy consumption can be reduced, and the operation cost of the system can be reduced, so that the energy-saving property and the economical efficiency of the system can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of air conditioning energy storage, and in particular to an ice storage and ice melting rate control method. Background Art

[0002] In order to truly achieve peak shifting and valley filling, ice storage systems pursue a higher ice melting rate in order to fully release cooling capacity during peak power periods. However, the problem that follows is that if the ice melting rate is not controlled, the ice storage device will melt ice at the fastest speed, resulting in a waste of cooling capacity and having to use more refrigeration units during peak power periods; or too much cooling capacity is reserved so that there is still a lot of remaining cooling capacity at the end of the peak power period. Therefore, ice storage air conditioners require the automatic control system to control the ice melting rate so that it can track the load conditions and meet the system's requirements for cooling capacity. The basic requirement is that in addition to reserving for peak power periods, it can also use ice melting for cooling when the efficiency of the chiller decreases due to low load.

[0003] The operator needs to have an understanding of the hourly load of the day in order to formulate an operation strategy. If the strategy is inappropriate, the above problems will occur. In other words, the prediction of hourly load is of great significance to the melting rate of ice storage air conditioning systems. However, it is quite difficult to achieve hourly load prediction. On the one hand, this is because there are too many factors that affect the hourly load, and more importantly, it is a requirement for historical operation data. At present, most methods for predicting hourly loads are inseparable from the historical data of system operation. Therefore, obtaining and maintaining a complete historical database becomes a prerequisite for realizing hourly load prediction, which is obviously difficult in operation. To make the prediction function of hourly load feasible, on the one hand, it is necessary to have a prediction method that does not rely on a historical database, and on the other hand, it is necessary to have a simpler and more feasible means of maintaining and establishing a historical database.

[0004] During the system design phase, the system operation strategy is usually formulated by the designer under the design load conditions of 25%, 50%, 75%, and 100%. The operation strategy generally meets the system's cooling load requirements, the ice storage is exhausted within one ice storage and melting cycle, and the ice melting conditions appear as much as possible during peak power periods. However, when formulating the operation strategy, the designers only rigidly meet the system's cooling load requirements, lack the support of basic unit data, and do not fully consider the unit's refrigeration / ice-making efficiency under different conditions, resulting in a problem of high system energy consumption; the operation strategy only selects individual typical conditions, and the selection of conditions is relatively extensive; at the same time, the formulation of the operation strategy is ultimately for energy and money saving, and in addition to system energy consumption, the system's economy should also be considered. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides an ice storage and ice melting rate control method to solve the problem that when designers formulate operation strategies, they only rigidly meet the system cooling load requirements, lack basic unit data support, and do not fully consider the unit refrigeration / ice-making efficiency under different working conditions, resulting in high system energy consumption.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for controlling ice melting rate of ice storage, comprising the following steps:

[0007] S1. For each unit in the ice storage air conditioning system, a basic data model of all units including refrigeration units and ice-making units at different load rates is constructed. The basic data is based on the quantity adjustment of the units at different cooling water temperatures and different water supply temperatures, that is, the units change the refrigeration / ice-making capacity of the units at different cooling water temperatures by adjusting the water supply temperature or the circulating water flow rate;

[0008] S2. Combined with the outdoor weather forecast, a system cooling load demand model at time t is constructed;

[0009] S3. Construct a comprehensive system efficiency model based on the cooling / icing efficiency and economic efficiency of the unit;

[0010] S4. Construct an ice melting rate model to meet the system cooling load demand and maximize the system comprehensive efficiency, and predict the ice melting amount of the ice storage device at time t.

[0011] Preferably, in step S1, for all units in the ice storage air conditioning system, a constraint model including unit refrigeration / ice-making efficiency, unit refrigeration / ice-making economic efficiency, and refrigeration capacity of each unit is constructed as follows:

[0012]

[0013]

[0014] Q i、min ≤Q i ≤Q i、max

[0015] Among them, COP i、j％ : Refrigeration / ice-making efficiency of the i-th unit at j% load rate, kW / kW, j% is 0% to 100% load rate, when the data curve is fitted by the least squares method, j% can select discrete load rate values ​​in 5% increments;

[0016] Q i、j％ : Refrigeration / ice-making capacity of the i-th unit at j% load rate, kW;

[0017] E i、j％ : Power consumption of the i-th unit at j% load rate, kW;

[0018] ECF i、j％、t : Refrigeration / ice-making economic efficiency of the i-th unit at j% load rate and time t, yuan / kWh;

[0019] ECO i , t : The electricity price of the i-th unit at time t is RMB / kWh, based on the energy storage time-of-use electricity price and non-residential electricity price at the project location;

[0020] Q i、min and Q i、max : The lower and upper limits of the cooling capacity when the i-th unit is turned on, kW.

[0021] Preferably, in step S2, according to the outdoor weather forecast of the project location, the outdoor calculated temperature of the air conditioner in summer, and the indoor design parameters of the air conditioner, the system cooling load demand model at time t is constructed as follows:

[0022]

[0023] Among them, LX t : System cooling load demand at time t, kW;

[0024] Q s : Design cooling load, kW;

[0025] t n : Indoor design temperature, ℃;

[0026] T w、t : The outdoor temperature at time t, ℃, is based on the outdoor weather forecast of the project location; 34.8℃ is the calculated outdoor temperature for air conditioning in summer in Nanjing, and other areas are similar.

[0027] Preferably, in step S3, the comprehensive efficiency of the ice storage air conditioning system at time t is constructed by combining the refrigeration / ice-making efficiency and economic efficiency of the unit;

[0028]

[0029] Among them, ENF t : The overall system efficiency at time t. The energy consumption of the refrigeration system water pump is relatively small compared with the energy consumption of the unit. To simplify the calculation, the overall efficiency of the ice storage air conditioning system only considers the refrigeration / ice-making efficiency and economic efficiency of each unit under the premise of meeting the cooling load demand of the ice storage air conditioning system.

[0030] N: Number of units, units.

[0031] Preferably, in the step S4, the following steps S401 to S403 are performed for the working condition of the ice storage device and the ice melting rate of the ice storage device, and the operating condition of the ice storage device is evaluated and the predicted ice melting rate is obtained under the premise of ignoring the cold capacity loss of the ice storage device and 100% exhaustion of the cold capacity in the ice storage device within one ice storage and melting cycle;

[0032] Step S401: According to step S2, the cooling load demand in a 24-hour ice storage and melting cycle and the designed ice storage capacity of the ice storage device are obtained, and whether the ice storage device is put into operation is determined according to the following formula:

[0033]

[0034]

[0035]

[0036]

[0037] Wherein, LX: system cooling load demand within a 24-hour ice storage and melting cycle, kWh;

[0038] XB: ice storage capacity of the ice storage device within a 24-hour ice storage and melting cycle, kWh;

[0039] RB t : The amount of ice melted by the ice storage device at time t, kWh;

[0040] XB s : Designed ice storage capacity of the ice storage device, kWh;

[0041] n: the number of units participating in ice-making operation at time t, units;

[0042] When the system cooling load demand LX ≤ the designed ice storage capacity XB s When the ice storage device is put into operation, it is assumed that the ice storage device is put into operation, and the process proceeds to step S402. By comparing the system comprehensive efficiency of the ice storage device being put into operation and the ice storage device not being put into operation in an ice storage and melting cycle, it is determined whether the ice storage device is put into operation; if the ice storage device is put into operation, the process proceeds to step S403 to obtain the ice melting rate of the ice storage device; otherwise, the ice storage device is not put into operation; when the system cooling load demand LX> the designed ice storage capacity XB s When the ice storage device is put into operation, the process goes to step S402;

[0043] S402: According to the system cooling load demand obtained in step S2 and the refrigeration constraint of each unit obtained in step S1, it is determined whether the ice storage device enters the ice melting state at time t:

[0044] The system cooling load demand at time t or LX t<min[Q i、min , i∈[1,N]], the ice storage device must enter the ice melting state and enter step S403;

[0045] The system cooling load demand at time t According to the system comprehensive efficiency at time t, it is determined whether the ice storage device has entered the ice melting condition. Assuming that the ice storage device has entered the ice melting condition, the process proceeds to step S403.

[0046] S403. According to the cooling load demand obtained in step S2 and the system comprehensive efficiency combining energy efficiency and economic efficiency, the ice melting rate of the ice storage device at time t is obtained as follows:

[0047] When the system cooling load demand LX ≤ the designed ice storage capacity XB s When the system cooling load demand LX> designed ice storage capacity XB s And LX t <min[Q i、min , i∈[1,N]], RB t According to the following formula:

[0048] RB t =LX t

[0049] When the system cooling load demand LX> designed ice storage capacity XB s and When RB t According to the following formula:

[0050]

[0051] When the system cooling load demand When RB t According to the following formula:

[0052]

[0053]

[0054]

[0055] The present invention provides an ice storage and ice melting rate control method, which has the following beneficial effects:

[0056] 1. The present invention can maximize the overall efficiency of the system, reduce energy consumption, and lower system operating costs by accurately controlling the ice melting rate and optimizing the adjustment based on the basic data model, thereby effectively improving the energy saving and economy of the system.

[0057] 2. The present invention obtains a basic database through least squares fitting and accurately predicts the system's cooling load demand, ensuring a more reasonable application of the ice storage device, reducing cooling waste, and achieving accurate control and optimal utilization of the system.

[0058] 3. By constructing an hourly cooling load demand model, the system can adjust the ice melting rate in real time according to outdoor meteorological conditions and load changes, effectively reducing energy waste and equipment loss caused by frequent start and stop of the refrigeration unit.

[0059] 4. The present invention realizes peak shifting and valley filling by adopting the strategy of storing ice during valley power periods and releasing cold during peak power periods, thereby reducing the dependence on refrigeration units during peak periods, thereby reducing electricity costs and operating expenses during peak power periods. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A schematic diagram of a flow chart of a method for controlling ice storage and ice melting rate designed for the present invention;

[0061] Figure 2 The present invention is a schematic diagram for implementing the logic judgment method for predicting the ice melting rate of ice storage. DETAILED DESCRIPTION

[0062] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] Please see attached Figure 1 -Attached Figure 2 The embodiment of the present invention provides an ice storage melting rate control method, comprising the following steps:

[0064] S1. For each unit in the ice storage air conditioning system, a basic data model of all units including refrigeration units and ice-making units at different load rates is constructed. The basic data is based on the quantity adjustment of the units at different cooling water temperatures and different water supply temperatures, that is, the units change the refrigeration / ice-making capacity of the units at different cooling water temperatures by adjusting the water supply temperature or the circulating water flow rate;

[0065] S2. Combined with the outdoor weather forecast, a system cooling load demand model at time t is constructed;

[0066] S3. Construct a comprehensive system efficiency model based on the cooling / icing efficiency and economic efficiency of the unit;

[0067] S4. Construct an ice melting rate model to meet the system cooling load demand and maximize the system comprehensive efficiency, and predict the ice melting amount of the ice storage device at time t.

[0068] In the step S1, for all units in the ice storage air conditioning system, a constraint model including unit refrigeration / ice-making efficiency, unit refrigeration / ice-making economic efficiency, and refrigeration capacity of each unit is constructed as follows:

[0069]

[0070]

[0071] Q i、min ≤Q i ≤Q i、max

[0072] Among them, COP i、j％ : Refrigeration / ice-making efficiency of the i-th unit at j% load rate, kW / kW, j% is 0% to 100% load rate, when the data curve is fitted by the least squares method, j% can select discrete load rate values ​​in 5% increments;

[0073] Q i、j％ : Refrigeration / ice-making capacity of the i-th unit at j% load rate, kW;

[0074] E i、j％ : Power consumption of the i-th unit at j% load rate, kW;

[0075] ECF i、j％、t : Refrigeration / ice-making economic efficiency of the i-th unit at j% load rate and time t, yuan / kWh;

[0076] ECO i , t : The electricity price of the i-th unit at time t is RMB / kWh, based on the energy storage time-of-use electricity price and non-residential electricity price at the project location;

[0077] Q i、min and Q i、max : The lower and upper limits of the cooling capacity when the i-th unit is turned on, kW.

[0078] In step S2, according to the outdoor weather forecast of the project location, the outdoor calculated temperature of the air conditioner in summer, and the indoor design parameters of the air conditioner, the system cooling load demand model at time t is constructed as follows:

[0079]

[0080] Among them, LX t : System cooling load demand at time t, kW;

[0081] Q s : Design cooling load, kW;

[0082] tn : Indoor design temperature, ℃;

[0083] T w、t : The outdoor temperature at time t, ℃, is based on the outdoor weather forecast of the project location; 34.8℃ is the calculated outdoor temperature for air conditioning in summer in Nanjing, and other areas are similar.

[0084] In the step S3, the comprehensive efficiency of the ice storage air conditioning system at time t is constructed by combining the refrigeration / ice-making efficiency and economic efficiency of the unit;

[0085]

[0086] Among them, ENF t : The overall system efficiency at time t. The energy consumption of the refrigeration system water pump is relatively small compared with the energy consumption of the unit. To simplify the calculation, the overall efficiency of the ice storage air conditioning system only considers the refrigeration / ice-making efficiency and economic efficiency of each unit under the premise of meeting the cooling load demand of the ice storage air conditioning system.

[0087] N: Number of units, units.

[0088] In the step S4, the operating condition of the ice storage device and the ice melting rate of the ice storage device are evaluated by performing the following steps S401 to S403, ignoring the cold capacity loss of the ice storage device and the 100% exhaustion of the cold capacity in the ice storage device within one ice storage and melting cycle, and obtaining the predicted ice melting rate;

[0089] Step S401: According to step S2, the cooling load demand in a 24-hour ice storage and melting cycle and the designed ice storage capacity of the ice storage device are obtained, and whether the ice storage device is put into operation is determined according to the following formula:

[0090]

[0091]

[0092]

[0093]

[0094] Wherein, LX: system cooling load demand within a 24-hour ice storage and melting cycle, kWh;

[0095] XB: ice storage capacity of the ice storage device within a 24-hour ice storage and melting cycle, kWh;

[0096] RB t : The amount of ice melted by the ice storage device at time t, kWh;

[0097] XB s : Designed ice storage capacity of the ice storage device, kWh;

[0098] n: the number of units participating in ice-making operation at time t, units;

[0099] When the system cooling load demand LX ≤ the designed ice storage capacity XB s When the ice storage device is put into operation, it is assumed that the ice storage device is put into operation, and the process proceeds to step S402. By comparing the system comprehensive efficiency of the ice storage device being put into operation and the ice storage device not being put into operation in an ice storage and melting cycle, it is determined whether the ice storage device is put into operation; if the ice storage device is put into operation, the process proceeds to step S403 to obtain the ice melting rate of the ice storage device; otherwise, the ice storage device is not put into operation; when the system cooling load demand LX> the designed ice storage capacity XB s When the ice storage device is put into operation, the process goes to step S402;

[0100] S402: According to the system cooling load demand obtained in step S2 and the refrigeration constraint of each unit obtained in step S1, it is determined whether the ice storage device enters the ice melting state at time t:

[0101] The system cooling load demand at time t or LX t <min[Q i、min , i∈[1,N]], the ice storage device must enter the ice melting state and enter step S403;

[0102] The system cooling load demand at time t According to the system comprehensive efficiency at time t, it is determined whether the ice storage device has entered the ice melting condition. Assuming that the ice storage device has entered the ice melting condition, the process proceeds to step S403.

[0103] S403. According to the cooling load demand obtained in step S2 and the system comprehensive efficiency combining energy efficiency and economic efficiency, the ice melting rate of the ice storage device at time t is obtained as follows:

[0104] When the system cooling load demand LX ≤ the designed ice storage capacity XB s When the system cooling load demand LX> designed ice storage capacity XB s And LX t <min[Q i、min , i∈[1,N]], RB t According to the following formula:

[0105] RB t =LX t

[0106] When the system cooling load demand LX> designed ice storage capacity XB s and When RB t According to the following formula:

[0107]

[0108] When the system cooling load demand When RB t According to the following formula:

[0109]

[0110]

[0111]

[0112] Specifically, when the above design scheme is applied in practice, the precise control of ice melting rate depends on the system cooling load demand LX at time t. t ENF t accurate calculation of .

[0113] Since the system cooling load demand LX t It is not only determined by outdoor meteorological parameters, but also by the thermal physical properties of building materials, air conditioning usage habits in buildings, occupancy rates, etc., which have an impact on the cooling load demand of the system. t Considering that the water temperature in the pipeline has a large inertia and water has a large specific heat capacity, combined with the existing system hourly cooling load and historical meteorological data, the system cooling load demand LX is calculated through the energy meter data at time t-1 on the air conditioning main pipe in the refrigeration room and the outdoor weather forecast at time t. t The calculation model is modified to obtain more accurate data. This process requires the support of a large amount of historical data.

[0114]

[0115] Among them, ft w、t :Outdoor temperature at time t w The system cooling load demand delay correction factor at time .

[0116] Due to the variety of system equipment configurations, in order to simplify the calculation during the design phase, the power consumption of the cooling tower fan, water pump, etc. was ignored without affecting the system comprehensive efficiency ENF comparison, and only the power consumption of the unit was considered. If the power consumption of the auxiliary equipment is taken into account, the system comprehensive efficiency ENF t The calculation of can be optimized as follows.

[0117]

[0118] Among them, FS i、t : The power consumption of the auxiliary equipment corresponding to the i-th unit at time t, including the power consumption of the cooling tower fan, water pump, etc. corresponding to the i-th unit, kWh;

[0119] RBSB t : Power consumption of ice melting equipment at time t, kWh;

[0120] ECO t : The electricity price implemented at time t is RMB / kWh, which is based on the energy storage time-of-use electricity price at the project location.

[0121] In actual use, the system can monitor the data on site, and the power consumption equipment can be further monitored by the power meter. t The calculated value is corrected.

[0122] The ice storage melting rate control method designed in the above technical solution is based on the basic data model including the refrigeration / ice-making efficiency and economic efficiency of each unit in the ice storage air-conditioning system, and uses the least squares method to fit the basic data curve to build a basic database for subsequent automatic control. Based on the basic database, combined with the predicted value of the system's cold load demand, and taking the maximization of the system's comprehensive efficiency as the principle of ice melting rate control, on the premise of meeting various changes in the system's cold load as the basic requirement, it can ensure a more adequate and reasonable application of the ice storage device and more accurate control of the system's energy saving and economy.

[0123] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for controlling ice melting rate of ice storage, characterized in that: The following steps are involved: S1. For each unit in the ice storage air conditioning system, a basic data model of all units including refrigeration units and ice-making units at different load rates is constructed. The basic data is based on the quantity adjustment of the units at different cooling water temperatures and different water supply temperatures, that is, the units change the refrigeration / ice-making capacity of the units at different cooling water temperatures by adjusting the water supply temperature or the circulating water flow rate; S2. Combined with the outdoor weather forecast, a system cooling load demand model at time t is constructed; S3. Construct a comprehensive system efficiency model based on the refrigeration / ice-making efficiency and economic efficiency of the unit; S4. Construct an ice melting rate model to meet the system cooling load demand and maximize the system comprehensive efficiency, and predict the ice melting amount of the ice storage device at time t.

2. The ice storage melting rate control method according to claim 1, characterized in that: In the step S1, for all units in the ice storage air conditioning system, a constraint model including unit refrigeration / ice-making efficiency, unit refrigeration / ice-making economic efficiency, and refrigeration capacity of each unit is constructed as follows: Q i、min ≤Q i ≤Q i、max Among them, COP i、j％ : Refrigeration / ice-making efficiency of the i-th unit at j% load rate, kW / kW, j% is 0% to 100% load rate, when the data curve is fitted by the least squares method, j% can select discrete load rate values ​​in 5% increments; Q i、j％ : Refrigeration / ice-making capacity of the i-th unit at j% load rate, kW; E i、j％ : Power consumption of the i-th unit at j% load rate, kW; ECF i、j％、t : Refrigeration / ice-making economic efficiency of the i-th unit at j% load rate and time t, yuan / kWh; ECO i , t : The electricity price of the i-th unit at time t is RMB / kWh, based on the energy storage time-of-use electricity price and non-residential electricity price at the project location; Q i、min and Q i、max : The lower and upper limits of the cooling capacity when the i-th unit is turned on, kW.

3. The ice storage melting rate control method according to claim 1, characterized in that: In step S2, according to the outdoor weather forecast of the project location, the outdoor calculated temperature of the air conditioner in summer, and the indoor design parameters of the air conditioner, the system cooling load demand model at time t is constructed as follows: Among them, LX t : System cooling load demand at time t, kW; Q s : Design cooling load, kW; t n : Indoor design temperature, ℃; T w、t : The outdoor temperature at time t, ℃, is based on the outdoor weather forecast of the project location; 34.8℃ is the calculated outdoor temperature for air conditioning in summer in Nanjing, and other areas are similar.

4. The ice storage melting rate control method according to claim 1, characterized in that: In the step S3, the comprehensive efficiency of the ice storage air conditioning system at time t is constructed by combining the refrigeration / ice-making efficiency and economic efficiency of the unit; Among them, ENF t : The overall efficiency of the system at time t. The energy consumption of the refrigeration system water pump is relatively small compared with the energy consumption of the unit. To simplify the calculation, the overall efficiency of the ice storage air conditioning system only considers the refrigeration / ice-making efficiency and economic efficiency of each unit under the premise of meeting the cooling load demand of the ice storage air conditioning system. N: Number of units, units.

5. The ice storage melting rate control method according to claim 1, characterized in that: In the step S4, the operating condition of the ice storage device and the ice melting rate of the ice storage device are evaluated by performing the following steps S401 to S403, ignoring the cold capacity loss of the ice storage device and the 100% exhaustion of the cold capacity in the ice storage device within one ice storage and melting cycle, and obtaining the predicted ice melting rate; Step S401: According to step S2, the cooling load demand in a 24-hour ice storage and melting cycle and the designed ice storage capacity of the ice storage device are obtained, and whether the ice storage device is put into operation is determined according to the following formula: Wherein, LX: system cooling load demand within a 24-hour ice storage and melting cycle, kWh; XB: ice storage capacity of the ice storage device within a 24-hour ice storage and melting cycle, kWh; RB t : The amount of ice melted by the ice storage device at time t, kWh; XB s : Designed ice storage capacity of the ice storage device, kWh; n: the number of units participating in ice-making operation at time t, units; When the system cooling load demand LX ≤ the designed ice storage capacity XB s When the ice storage device is put into operation, it is assumed that the ice storage device is put into operation, and the process proceeds to step S402. By comparing the system comprehensive efficiency of the ice storage device being put into operation and the ice storage device not being put into operation in an ice storage and melting cycle, it is determined whether the ice storage device is put into operation; if the ice storage device is put into operation, the process proceeds to step S403 to obtain the ice melting rate of the ice storage device; otherwise, the ice storage device is not put into operation; when the system cooling load demand LX> the designed ice storage capacity XB s When the ice storage device is put into operation, the process goes to step S402; S402: According to the system cooling load demand obtained in step S2 and the refrigeration constraint of each unit obtained in step S1, it is determined whether the ice storage device enters the ice melting state at time t: The system cooling load demand at time t or LX t <min[Q i、min , i∈[1,N]], the ice storage device must enter the ice melting state and enter step S403; The system cooling load demand at time t According to the system comprehensive efficiency at time t, it is determined whether the ice storage device has entered the ice melting condition. Assuming that the ice storage device has entered the ice melting condition, the process proceeds to step S403. S403. According to the cooling load demand obtained in step S2 and the system comprehensive efficiency combining energy efficiency and economic efficiency, the ice melting rate of the ice storage device at time t is obtained as follows: When the system cooling load demand LX ≤ the designed ice storage capacity XB s When the system cooling load demand LX> designed ice storage capacity XB s And LX t <min[Q i、min , i∈[1,N]], RB t According to the following formula: RB t =LX t When the system cooling load demand LX> designed ice storage capacity XB s and When RB t According to the following formula: When the system cooling load demand When RB t According to the following formula:

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