Variable-evaporation-temperature-chiller-based refrigeration system and thermal management method

Abstract

A variable-evaporation-temperature-chiller-based refrigeration system and a thermal management method. Disclosed is a variable-evaporation-temperature-chiller-based refrigeration system, comprising: a first low-temperature chiller (100), a first medium-temperature chiller (110), a plurality of cold storage valves (F1-F28), a control module (200), and a first water storage tank (300). The first low-temperature chiller (100) is connected to a low-temperature cold storage inlet and a low-temperature cold storage outlet of the first water storage tank (300) by means of the cold storage valves (F1-F28), respectively. The first medium-temperature chiller (110) is connected to a medium-temperature cold storage inlet and a medium-temperature cold storage outlet of the first water storage tank (300) by means of the cold storage valves (F1-F28), respectively. The control module (200) is used for controlling the opening and closing of the cold storage valves (F1-F28) by measuring the temperatures at the cold storage outlets of the first water storage tank (300).

Description

Variable evaporating temperature type chiller refrigeration system and thermal management method TECHNICAL FIELD

[0001] The present application relates to the technical field of chillers, in particular to a variable evaporating temperature type chiller refrigeration system and thermal management method. BACKGROUND

[0002] With the continuous rise of global temperature and the increasing emphasis on the finiteness of energy resources, the importance of air conditioning systems in the fields of construction and industry is gradually highlighted. The operation of air conditioning systems not only has an important influence on indoor comfort and production efficiency, but also is directly related to energy consumption and environmental impact. Therefore, improving the energy efficiency of air conditioning systems has become an urgent task.

[0003] Air conditioning systems are one of the main components of energy consumption in the fields of construction and industry. According to the data of the International Energy Agency (IEA), more than 40% of global building energy consumption is used for heating, ventilation and air conditioning (HVAC) systems. This proportion is even higher in some hot regions. Therefore, the energy efficiency of air conditioning systems directly affects the efficiency of energy resources and environmental sustainability. The unit energy efficiency of air conditioning systems is greatly affected by the outlet temperature, and traditional chillers use a fixed evaporating temperature to produce chilled water, which continuously keeps the outlet temperature low, affecting the unit energy efficiency. SUMMARY

[0004] The main purpose of the present application is to provide a variable evaporating temperature type chiller refrigeration system and thermal management method, aiming to solve the technical problems of low energy efficiency and high energy consumption of the existing chiller refrigeration system.

[0005] To achieve the above object, the application provides a variable evaporation temperature type cold machine refrigeration system, which comprises a first low-temperature cold machine, a first medium-temperature cold machine, a plurality of cold storage valves, a control module and a first water storage tank; the first water storage tank is used for storing cold storage medium for cold storage, and a low-temperature cold storage outlet, a medium-temperature cold storage outlet, a medium-temperature cold storage inlet and a low-temperature cold storage inlet are sequentially arranged on one side of the first water storage tank from top to bottom; the first low-temperature cold machine is connected with the low-temperature cold storage inlet and the low-temperature cold storage outlet of the first water storage tank through the cold storage valves respectively; the first medium-temperature cold machine is connected with the medium-temperature cold storage inlet and the medium-temperature cold storage outlet of the first water storage tank through the cold storage valves respectively; the first low-temperature cold machine and the first medium-temperature cold machine are used for cold storage of the first water storage tank in a variable evaporation temperature form, wherein the variable evaporation temperature form refers to that the evaporation temperature of each cold machine comprises at least two different temperatures; the control module is used for controlling the on-off of the cold storage valves by detecting the cold storage outlet temperature of the first water storage tank; the control module is further used for controlling the cold storage valves to connect the first medium-temperature cold machine and the first water storage tank in a conducting mode when the first water storage tank is cold stored; the control module is further used for controlling the cold storage valves to disconnect the first medium-temperature cold machine and the first water storage tank in an off mode and to connect the first low-temperature cold machine and the first water storage tank in a conducting mode when the cold storage outlet temperature of the first water storage tank is less than a first preset temperature; and the control module is further used for controlling the cold storage valves to disconnect the first low-temperature cold machine and the first water storage tank in an off mode when the cold storage outlet temperature of the first water storage tank is less than a second preset temperature.

[0006] In an embodiment, the system further comprises a heat exchange device and a plurality of heat exchange valves; a heat exchange inlet and a heat exchange outlet are sequentially arranged on the other side of the first water storage tank from top to bottom; the heat exchange device is connected with the heat exchange inlet and the heat exchange outlet of the first water storage tank through the heat exchange valves respectively; the control module is further used for controlling the on-off of the heat exchange valves by detecting the heat exchange outlet temperature of the first water storage tank; and the control module is further used for controlling the heat exchange valves to connect the heat exchange device and the first water storage tank in a conducting mode when the first water storage tank releases cold.

[0007] In an embodiment, the system further comprises a second low-temperature chiller, a second medium-temperature chiller, a plurality of cooling valves, a low-temperature cooling device, and a medium-temperature cooling device; the second low-temperature chiller is connected to the low-temperature cooling device through each of the cooling valves; the second medium-temperature chiller is connected to the medium-temperature cooling device through each of the cooling valves; the control module is further configured to control the on-off of each of the cooling valves according to the cooling demand; and the control module is further configured to, when the direct-supply medium-low-temperature chilled water is required, control the connection between the second medium-temperature chiller and the medium-temperature cooling device to be conducted through the cooling valves, and control the connection between the second low-temperature chiller and the low-temperature cooling device to be conducted through the cooling valves.

[0008] In an embodiment, the system further comprises a second water storage tank; the second water storage tank has the same specifications as the first water storage tank; the first low-temperature chiller is further connected to the low-temperature storage inlet and the low-temperature storage outlet of the second water storage tank through each of the storage valves; the first medium-temperature chiller is further connected to the medium-temperature storage inlet and the medium-temperature storage outlet of the second water storage tank through each of the storage valves; the heat exchange device is further connected to the heat exchange inlet and the heat exchange outlet of the second water storage tank through each of the heat exchange valves; the control module is further configured to, when the second water storage tank is in the storage mode, control the connection between the first medium-temperature chiller and the second water storage tank to be conducted through the storage valves; the control module is further configured to, when the second water storage tank is in the storage mode, control the connection between the first medium-temperature chiller and the second water storage tank to be interrupted and the connection between the first low-temperature chiller and the second water storage tank to be conducted through the storage valves when the temperature of the storage outlet of the second water storage tank is lower than a first preset temperature; and the control module is further configured to, when the second water storage tank is in the storage mode, control the connection between the first low-temperature chiller and the second water storage tank to be interrupted when the temperature of the storage outlet of the second water storage tank is lower than a second preset temperature.

[0009] In addition, to achieve the above object, the present application further provides a thermal management method, which is applied to the variable-evaporation-temperature chiller system as described above, and the method comprises the following steps: conducting the connection between the first medium-temperature chiller and the first water storage tank; obtaining the temperature of the storage outlet of the first water storage tank; interrupting the connection between the first medium-temperature chiller and the first water storage tank and conducting the connection between the first low-temperature chiller and the first water storage tank when the temperature of the storage outlet is lower than a first preset temperature; and interrupting the connection between the first low-temperature chiller and the first water storage tank when the temperature of the storage outlet is lower than a second preset temperature.

[0010] In an embodiment, the step of obtaining the temperature of the cold storage outlet of the first water storage tank comprises: building a water temperature change model of the water storage tank based on the height of the first water storage tank; obtaining the current temperature of the cold storage outlet of the first water storage tank; and obtaining the temperature of the cold storage outlet of the first water storage tank based on the water temperature change model of the water storage tank and the current temperature of the cold storage outlet of the first water storage tank.

[0011] In an embodiment, the step of building the water temperature change model of the water storage tank based on the height of the first water storage tank comprises: layering the first water storage tank according to a preset height based on the height of the first water storage tank; obtaining the net flow of vertical exchange between each layer of the first water storage tank; and building the water temperature change model of the water storage tank based on the net flow.

[0012] In an embodiment, before the step of turning on the connection between the first medium-temperature cold machine and the first water storage tank, the method further comprises: turning on the connection between the first water storage tank and the heat exchange device; obtaining the temperature of the cold release outlet of the first water storage tank; and turning off the connection between the first water storage tank and the heat exchange device when the temperature of the cold release outlet of the first water storage tank is higher than a third preset temperature.

[0013] In addition, to achieve the above-mentioned purpose, the present application also provides a storage medium, which is a computer readable storage medium, and a computer program is stored on the storage medium, and the computer program is executed by a processor to implement the steps of the heat management method as described above.

[0014] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the steps of the heat management method as described above.

[0015] The one or more technical solutions provided by the present application have at least the following technical effects:

[0016] By controlling the temperature of the first water storage tank in real time through the control module, the range of the evaporation temperature of the cold machine is continuously adjusted during the cold storage, and by controlling the valves at different positions to be turned on or turned off through the control module, a method for switching the circulation of cold water between the medium-temperature cold machine and the low-temperature cold machine is designed, so that the water temperature of the first water storage tank is continuously processed, the evaporation temperature of the cold machine outlet is improved, the process of large temperature difference and staged cold storage is realized, the energy efficiency is improved, and the cost is saved. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the specification, serve to explain the principles of the application.

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, for those skilled in the art, the other drawings can also be obtained based on these drawings without any creative work.

[0019] Fig. 1 is a structural block diagram provided by an embodiment of the variable evaporation temperature type chiller refrigeration system of the present application;

[0020] Fig. 2 is a structural block diagram provided by an embodiment of the variable evaporation temperature type chiller refrigeration system of the present application;

[0021] Fig. 3 is a device connection relationship diagram provided by the embodiment two of the variable evaporation temperature type chiller refrigeration system of the present application;

[0022] Fig. 4 is a flow diagram of an embodiment three of the thermal management method provided by the present application;

[0023] Fig. 5 is a stratified model diagram of the water storage tank of an embodiment three of the thermal management method provided by the present application;

[0024] Fig. 6 is a mixing flow model diagram of the stratified model of the water storage tank of an embodiment three of the thermal management method provided by the present application.

[0025] Explanation of reference signs:

[0026] The purpose of the present application, functional features and advantages will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0027] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application, and are not used to limit the present application.

[0028] In order to better understand the technical solutions of the present application, the specific embodiments will be described in detail with reference to the accompanying drawings and the specific embodiments.

[0029] In the prior art, there are several significant disadvantages in the energy efficiency improvement of the traditional chiller unit. First, the traditional chiller adopts a fixed evaporation temperature to produce chilled water, and the outlet temperature is continuously low, which affects the energy efficiency of the unit. At the same time, the existing chiller system energy efficiency improvement method mainly relies on high performance refrigeration equipment, but the energy efficiency improvement of the refrigeration equipment is limited, and the energy efficiency improvement often brings a large increase in the initial investment of the equipment.

[0030] Secondly, in the existing cold storage system, the cold storage mainly relies on the valley price of electricity, and the cold is released during the day peak price of electricity. The temperature of the cold storage water at night is lower than the temperature of the cold release, which causes the unit to have low energy efficiency during the cold storage. The traditional cold storage scheme only uses the price difference to obtain benefits, and does not realize the true sense of improving the system energy efficiency, which has high power consumption.

[0031] Based on this, the application provides a variable-evaporation-temperature cold machine refrigeration system. Referring to FIG. 1, FIG. 1 is a structural block diagram of an embodiment of the variable-evaporation-temperature cold machine refrigeration system.

[0032] In this embodiment, the variable-evaporation-temperature cold machine refrigeration system comprises a first low-temperature cold machine 100, a first medium-temperature cold machine 110, a plurality of cold storage valves, a control module 200 and a first water storage tank 300.

[0033] It should be noted that the first water storage tank 300 is used to store cold storage medium for cold storage, and the cold storage medium is usually water, and other substances with good cold storage performance can also be selected. Further, one side of the first water storage tank 300 is sequentially arranged from top to bottom with a low-temperature cold storage outlet, a medium-temperature cold storage outlet, a medium-temperature cold storage inlet and a low-temperature cold storage inlet.

[0034] It should be noted that the low-temperature cold storage outlet and the medium-temperature cold storage outlet are arranged at the upper part, and the medium-temperature cold storage inlet and the low-temperature cold storage inlet are arranged at the bottom part, and there is a certain distance between the medium-temperature cold storage outlet and the medium-temperature cold storage inlet.

[0035] Among them, the first low-temperature cold machine 100 is connected to the low-temperature cold storage inlet and the low-temperature cold storage outlet of the first water storage tank through each cold storage valve. The first medium-temperature cold machine 110 is connected to the medium-temperature cold storage inlet and the medium-temperature cold storage outlet of the first water storage tank 300 through each cold storage valve.

[0036] It should be noted that the cold storage valve is only named for convenience of description, and its essence is still a valve. Here, it refers to the valve that is controlled in the cold storage link of the variable-evaporation-temperature cold machine refrigeration system.

[0037] It can be understood that such a setting is conducive to the cold storage of the first low-temperature cold machine 100 and the first medium-temperature cold machine 110 to the first water storage tank 300 in the form of variable-evaporation-temperature. Among them, the variable-evaporation-temperature of the first medium-temperature cold machine 110 is set to be higher than the variable-evaporation-temperature of the first low-temperature cold machine 100, and the variable-evaporation-temperature can be connected to realize stepless adjustment without difference.

[0038] It should be noted that the variable evaporation temperature form refers to the operating temperature of the evaporator in the cold machine can be dynamically adjusted according to system requirements or operating conditions, and the variable evaporation temperature form of each cold machine at least includes two different evaporation temperatures. The evaporation temperature is a key parameter in the refrigeration system, which directly affects the refrigeration efficiency, energy consumption and temperature control of the cooled object. For example, the cold machine with two different evaporation temperatures for water tank circulation cooling can be understood as switching or gradually changing between two evaporation temperatures according to the preset circulation strategy. This adjustment may be based on system efficiency, energy consumption, cold storage capacity demand or external environment temperature and other factors. By changing the evaporation temperature, the system can more effectively manage the flow of refrigerant and heat exchange, thereby optimizing the entire circulation process.

[0039] It should be noted that the different temperature values of the variable evaporation temperature of the cold machine, and the switching strategy can be selected by calibration test to obtain the optimal performance value.

[0040] It should be noted that the control module 200 controls the on-off of each said cold storage valve by detecting the cold storage outlet temperature of the first water tank 300. Among them, the cold storage outlet temperature is used as temperature control because the cold storage outlet at the upper part is the last change of water temperature, which can well measure whether to switch or end the cold storage. Specifically, the control module 200 can be realized by computer with certain algorithm, receiving temperature detection signal, converting into control signal and sending to cold machine and valve to control the temperature of cold machine and the conduction of each said cold storage valve, which is not described here.

[0041] Specifically, the variable evaporation temperature form cold machine refrigeration system first controls the connection of each said cold storage valve to the first medium-temperature cold machine 110 and the first water tank 300 through the control module 200 in the cold storage link, so as to realize the first medium-temperature cold machine 110 to store cold in the first water tank 300 in the form of variable evaporation temperature.

[0042] Further, when the cold storage outlet temperature of the first water tank 300 is less than the first preset temperature, the control module 200 controls each said cold storage valve to disconnect the connection of the first medium-temperature cold machine 110 and the first water tank 300, and controls each said cold storage valve to connect the first low-temperature cold machine 100 and the first water tank 300.

[0043] It can be understood that the first preset temperature is the condition value for the first medium-temperature cold machine 110 to switch to the first low-temperature cold machine 100, which can be obtained by pre-calibration, and when the temperature is less than the first preset temperature, the first medium-temperature cold machine 110 stops cold storage, and the first low-temperature cold machine 100 is used for cold storage.

[0044] Finally, when the cold storage outlet temperature of the first cold storage tank 300 is less than the second preset temperature, the control module 200 controls the cold storage valves to close the connection between the first low-temperature chiller and the first cold storage tank 300.

[0045] It can be understood that the second preset temperature is a condition value for the end of the cold storage link, and can also be obtained by pre-calibration. When the temperature is less than the second preset temperature, the first low-temperature chiller 100 also stops cold storage.

[0046] In this embodiment, the first cold storage tank is measured by the control module in real time, the chiller is continuously adjusted in the cold storage range of the chiller evaporation temperature, the valves at different positions are controlled by the control module to be turned on or turned off, and the medium and low-temperature chiller is designed to switch the cold storage cold water circulation method, so that the first cold storage tank is continuously treated, the chiller outlet evaporation temperature is improved, the large temperature difference and the staged cold storage process are realized, the energy efficiency is improved, and the cost is saved.

[0047] Further, please refer to FIG. 2, which is a structural block diagram of the second embodiment of the variable evaporation temperature type chiller refrigeration system.

[0048] Based on the above embodiment, in this embodiment, in addition to the devices and modules described above, the variable evaporation temperature type chiller refrigeration system further comprises a heat exchange device 400 and a plurality of heat exchange valves.

[0049] It should be noted that the heat exchange device 400 is not limited to a certain device, but can also be a certain heat exchange system, which plays a role in exchanging heat and helps the first cold storage tank 300 to release cold. Therefore, in order to release cold, the first cold storage tank 300 needs to be arranged with a heat exchange inlet and a heat exchange outlet from top to bottom on the other side.

[0050] It can be understood that the heat exchange inlet is arranged at the upper part of the first cold storage tank 300, and the heat exchange outlet is arranged at the bottom of the first cold storage tank 300, which is due to the reason of heat exchange efficiency. There is a certain distance between the heat exchange inlet and the heat exchange outlet.

[0051] It can be understood that the heat exchange device 400 is connected to the heat exchange inlet and the heat exchange outlet of the first cold storage tank through the heat exchange valves.

[0052] It should be noted that the heat exchange valve is named only for the convenience of description, and its essence is still a valve. Here, it refers to the valve that is controlled in the cold release link of the variable evaporation temperature type chiller refrigeration system.

[0053] It should be noted that the control module 200 is also used to control the on-off of each heat exchange valve by detecting the temperature of the heat exchange outlet of the first water tank. Similarly, the temperature of the heat exchange outlet is selected because the temperature at the heat exchange outlet changes last and can be better measured.

[0054] It can be understood that the control module 200 controls each heat exchange valve to conduct the connection of the heat exchange device and the first water tank when the first water tank releases cold. When the temperature of the heat exchange outlet of the first water tank 300 exceeds the preset heat exchange temperature, the heat exchange valve is controlled to be turned off to stop heat release.

[0055] In this embodiment, the system further comprises a second low-temperature refrigerator 500, a second medium-temperature refrigerator 510, a plurality of cold use valves, a low-temperature cold use device 600, and a medium-temperature cold use device 610.

[0056] It should be noted that the low-temperature cold use device 600 and the medium-temperature cold use device 610 refer to devices or systems that directly require a refrigerator to provide cold. Therefore, in order to directly provide cold, a separate second low-temperature refrigerator 500, a second medium-temperature refrigerator 510, and a plurality of cold use valves are added.

[0057] It can be understood that the second low-temperature refrigerator 500 is connected to the low-temperature cold use device 600 through each cold use valve; and the second medium-temperature refrigerator 510 is connected to the medium-temperature cold use device 610 through each cold use valve.

[0058] It should be noted that the cold use valve is named only for ease of description, and its essence is still a valve. Here, it refers to a valve that is controlled in the direct cold supply link of the variable evaporation temperature type refrigerator refrigeration system.

[0059] It should be noted that the control module 200 controls the on-off of each cold use valve through cold use demand; and the control module 200 controls the connection of the second medium-temperature refrigerator 510 and the medium-temperature cold use device 610 through each cold use valve, and controls the connection of the second low-temperature refrigerator 500 and the low-temperature cold use device 600 through each cold use valve when directly supplying low-temperature refrigerated water, so as to control the direct cold supply.

[0060] In addition, the system further comprises a second water tank 310.

[0061] It should be noted that the introduction of the second water tank 310 realizes the grading of cold storage and the grading of cold release, and further realizes that one water tank stores cold while another water tank releases cold, thereby providing more options.

[0062] It can be understood that, in the embodiment, the second water storage tank 310 has the same specifications and openings as the first water storage tank, but is not limited to other possible configurations of the second water storage tank 310, which will not be described here.

[0063] It can be understood that, in terms of connection, the second water storage tank 310 and the first water storage tank are basically the same, and the control means are also basically the same. The first low-temperature chiller 100 is also connected to the low-temperature cold storage inlet and the low-temperature cold storage outlet of the second water storage tank 310 through the respective cold storage valves; the first medium-temperature chiller 110 is connected to the medium-temperature cold storage inlet and the medium-temperature cold storage outlet of the second water storage tank 310 through the respective cold storage valves; the heat exchange equipment 400 is also connected to the heat exchange inlet and the heat exchange outlet of the second water storage tank 310 through the respective heat exchange valves; the control module 200 is also used to control the respective cold storage valves to conduct the connection between the first medium-temperature chiller 110 and the second water storage tank 310 when the second water storage tank 310 is cold storage; the control module 200 is also used to control the respective cold storage valves to cut off the connection between the first medium-temperature chiller 110 and the second water storage tank 310 when the cold storage outlet temperature of the second water storage tank 310 is less than the first preset temperature, and control the respective cold storage valves to conduct the connection between the first low-temperature chiller 100 and the second water storage tank 310; the control module 200 is also used to control the respective cold storage valves to cut off the connection between the first low-temperature chiller 100 and the second water storage tank 310 when the cold storage outlet temperature of the second water storage tank 310 is less than the second preset temperature; and the control module 200 is also used to control the respective heat exchange valves to conduct the connection between the heat exchange equipment 400 and the second water storage tank 310 when the second water storage tank 310 is cold release.

[0064] Specifically, please refer to FIG. 3, which is a device connection relationship diagram provided by the second embodiment of the variable evaporation temperature type chiller refrigeration system.

[0065] In addition to the first low-temperature chiller 100, the first medium-temperature chiller 110, the control module 200, the first water storage tank 300, the second water storage tank 310, the second low-temperature chiller 500, and the second medium-temperature chiller 510, the specific selection of the variable evaporation temperature type chiller refrigeration system also includes a heat exchange water pump 401, a plate heat exchanger 402, a low-temperature water distributor 601, a low-temperature water collector 602, a medium-temperature water distributor 611, a medium-temperature water collector 612, a low-temperature primary pump 701, a low-temperature secondary pump 702, a medium-temperature primary pump 711, a medium-temperature secondary pump 712, a cooling tower 801, a cooling water pump 802, and valves F1 to F28.

[0066] It should be noted that, as shown in FIG. 3, the cooling tower 801 is connected to the first low-temperature chiller 100, the first medium-temperature chiller 110, the second low-temperature chiller 500 and the second medium-temperature chiller 510 through the cooling water pump 802, respectively; the first low-temperature chiller 100 is connected to the first water storage tank 300 and the second water storage tank 310 through the low-temperature primary pump 701 through a valve; the first medium-temperature chiller 110 is connected to the first water storage tank 300 and the second water storage tank 310 through the medium-temperature primary pump 711 through a valve; the first low-temperature chiller 100 and the second low-temperature chiller 500 are connected to the low-temperature water distributor 601 through the low-temperature secondary pump 702 through a valve, and are also connected to the low-temperature water collector 602; the first medium-temperature chiller 110 and the second medium-temperature chiller 510 are connected to the medium-temperature water distributor 611 through the medium-temperature secondary pump 712 through a valve, and are also connected to the medium-temperature water collector 612; the first water storage tank 300 and the second water storage tank 310 are also connected to the heat exchange water pump 401 through a valve; and the heat exchange water pump 401 is connected to the plate heat exchanger 402.

[0067] It can be understood that when the system only directly supplies medium and low-temperature chilled water, at this time, only the valve F2, the valve F28, the valve F8, the valve F6, the valve F5, the valve F11, the valve F10 and the valve F24 are opened by the control module 200, and the remaining valves are closed, t2 and t1 temperature chilled water is directly prepared by the medium and low-temperature chiller in one step, and the medium and low-temperature chilled water is directly supplied to the energy consumption area through the medium and low-temperature water distributor at this time, and the medium and low-temperature chiller is started according to the load demand.

[0068] It can be understood that when the system needs direct supply of medium and low temperature chilled water and cold storage at the same time, the control module 200 opens the valve F2, the valve F6, the valve F5, the valve F11, directly makes t2 and t1 temperature chilled water in one step by the second medium temperature cold machine 510 and the second low temperature cold machine 500, and supplies the medium and low temperature chilled water to the energy consumption area through the medium and low temperature distribution water tank; when the first water tank 300 is cold stored, the valve F4, the valve F27, the valve F15 and the valve F13 on the first cold storage water tank 300 are opened, and the first medium temperature cold machine 110 is used to circulate and cool the first cold storage water tank 300 in sequence according to the variable evaporation temperatures t3 and t4; after the first cold storage water tank 300 is lowered to the first preset temperature, the valve F4, the valve F15, the valve F27 and the valve F13 are closed, the valve F9, the valve F12, the valve F3 and the valve F14 are opened, and the first low temperature cold machine 100 is used to circulate and cool the first cold storage water tank 300 in sequence according to the variable evaporation temperatures t5 and t6, until the water tank setting temperature t7 is reached; when the second cold storage water tank 310 is cold stored, the valve F4, the valve F27, the valve F18 and the valve F17 on the second cold storage water tank 310 are opened, and the first medium temperature cold machine 110 is used to circulate and cool the first cold storage water tank 300 in sequence according to the variable evaporation temperatures t3 and t4; after the first cold storage water tank 300 is lowered to the setting temperature, the valve F4, the valve F27, the valve F18 and the valve F17 are closed, the valve F3, the valve F19, the valve F16 and the valve F9 are opened, and the first low temperature cold machine 100 is used to circulate and cool the second cold storage water tank 310 in sequence according to the variable evaporation temperatures t5 and t6, until the water tank setting temperature t7 is reached.

[0069] It can be understood that when the system needs direct supply of medium and low temperature chilled water, cold storage and cold release at the same time, the control module 200 opens the valve F2, the valve F6, directly makes t1 temperature chilled water in one step by the second low temperature cold machine 500, and supplies the low temperature chilled water to the energy consumption area through the low temperature distribution water tank. The valve F5 and the valve F11 are opened, t2 temperature chilled water is directly made in one step by the second medium temperature cold machine 510, and the medium temperature chilled water is supplied to the energy consumption area through the medium temperature distribution water tank; the valve F4 and the valve F27 are opened, the valve F15 and the valve F13 on the first cold storage water tank 300 are opened, the first medium temperature cold machine 110 is used to circulate and cool the first cold storage water tank 300 in sequence according to the variable evaporation temperatures t3 and t4; after the first cold storage water tank 300 is lowered to the setting temperature, the valve F4, the valve F15, the valve F27 and the valve F13 are closed, the valve F9, the valve F12, the valve F3 and the valve F14 are opened, and the first low temperature cold machine 100 is used to circulate and cool the first cold storage water tank 300 in sequence according to the variable evaporation temperatures t5 and t6, until the water tank setting temperature t7 is reached; the valve F23 and the valve F22 on the second cold storage water tank 310 are opened, the heat exchange water pump 401 is started, and the opening degrees of the valve F1, the valve F7, the valve F6, the valve F11, the valve F25, the valve F2, the valve F5 and the valve F26 are adjusted according to the required flow of medium and low temperature water.

[0070] It can be understood that when the system needs direct supply of medium and low temperature chilled water and cold release at the same time, the control module 200 opens the valve F2 and the valve F6, directly prepares the t1 temperature chilled water in one step by the second low temperature chiller 500, and directly supplies the low temperature chilled water to the energy using area through the low temperature distribution header. The valve F5 and the valve F11 are opened, the t2 temperature chilled water is directly prepared in one step by the second medium temperature chiller 510, and the medium and low temperature chilled water is directly supplied to the energy using area through the medium temperature distribution header; when the first water storage tank 300 releases cold, the valve F20 and the valve F21 on the first water storage tank 300 are opened, the heat exchange water pump is started, and the opening degrees of the valve F1, the valve F7, the valve F6, the valve F11, the valve F25, the valve F2, the valve F5 and the valve F26 are adjusted according to the required flow of the medium and low temperature water; when the second water storage tank 310 releases cold, the valve F23 and the valve F22 on the second water storage tank 310 are opened, the heat exchange water pump is started, and the opening degrees of the valve F1, the valve F7, the valve F6, the valve F11, the valve F25, the valve F2, the valve F5 and the valve F26 are adjusted according to the required flow of the medium and low temperature water.

[0071] It can be understood that when the system needs cold storage and cold release at the same time, the control module 200 opens the valve F4, the valve F24, the valve F27, the valve F10, the valve F15 and the valve F13 on the first water storage tank 300, and the two medium temperature chillers are sequentially circulated at the variable evaporation temperatures t3 and t4 to circulate the water tank of the first cold storage; after the first water tank is lowered to the set temperature, the valve F4, the valve F24, the valve F27, the valve F10, the valve F15 and the valve F13 are closed, the valve F8, the valve F9, the valve F3, the valve F28, the valve F12 and the valve F14 are opened, and the two low temperature chillers are sequentially circulated at the variable evaporation temperatures t5 and t6 to circulate the first water storage tank 300, until the set temperature t7 of the water tank is reached; when the second water storage tank 310 releases cold, the valve F23 and the valve F22 on the second water storage tank 310 are opened, the heat exchange water pump is started, and the valve F7, the valve F1, the valve F25 and the valve F26 are opened.

[0072] It can be understood that when the system only needs cold release, when the first water storage tank 300 releases cold, the control module 200 opens the valve F20 and the valve F21 on the first water storage tank 300, starts the heat exchange water pump, and opens the valve F1, the valve F7, the valve F25 and the valve F26; when the second water storage tank 310 releases cold, the valve F23 and the valve F22 on the second water storage tank 310 are opened, the heat exchange water pump is started, and the valve F1, the valve F7, the valve F25 and the valve F26 are opened.

[0073] The following is an example, the medium and low temperature chillers are adjustable evaporation temperature chillers, the required low temperature chilled water temperature of the energy using area is 7℃, the return water temperature is 14℃, the medium temperature chilled water temperature is 14℃, and the return water temperature is 21℃. The volumes of the two cold storage water tanks are both 1500m 3, height 18 m, diameter 10.3 m, two kinds of working conditions are given.

[0074] The first working condition: control by night valley price electricity storage and release of cold quantity in daytime peak price:

[0075] The night part of the cold machine directly supplies medium and low temperature chilled water, and the remaining cold machine is used for cold storage of the cold storage water tank. Open valve F2 and valve F6, and directly make 7℃ temperature chilled water by the second low temperature cold machine 500 in one step, which is directly supplied to the energy using area through the low temperature distribution header. Open valve F5 and valve F11, and directly make 14℃ temperature chilled water by the second medium temperature cold machine 510 in one step, which is directly supplied to the energy using area through the medium temperature distribution header.

[0076] When the first cold storage tank 300 is cold stored, open valve F4, valve F27, valve F15 and valve F13 on the first cold storage tank 300, and the first medium temperature cold machine circulates in sequence according to variable evaporation temperatures 17℃ and 14℃ to circulate the first cold storage tank 300 to be cooled; after the first cold storage tank 300 is cooled to the first preset temperature, close valve F4, valve F15, valve F27 and valve F13, open valve F9, valve F12, valve F3 and valve F14, and open the first low temperature cold machine to circulate in sequence according to variable evaporation temperatures 11℃ and 6℃ to circulate the first cold storage tank 300 to be cooled, until the set temperature 6℃ of the water tank is reached.

[0077] When the second cold storage tank 310 is cold stored, open valve F4, valve F27, valve F18 and valve F17 on the second cold storage tank 310, and the first medium temperature cold machine 110 circulates in sequence according to variable evaporation temperatures 17℃ and 14℃ to circulate the second cold storage tank 310 to be cooled; after the second cold storage tank 310 is cooled to the first preset temperature, close valve F4, valve F27, valve F18 and valve F17, open valve F9, valve F16, valve F3 and valve F19, and open the first low temperature cold machine 100 to circulate in sequence according to variable evaporation temperatures 11℃ and 6℃ to circulate the first cold storage tank 300 to be cooled, until the set temperature 6℃ of the water tank is reached.

[0078] According to the calculation formula Q=C*M*△T, wherein the water density is 1000 kg / m 3, the specific heat capacity of water is C = 4.2 * 10^3 J / (kg·℃), the total cold storage capacity of the pool is 49000kW·h. During the charging, the variable evaporation temperature refrigeration is used, and the COP is 8.1, 7.5, 6.0 and 5.6 respectively in four stages, that is, the pool charging consumes 7206kW·h. The water storage system completes the charging and discharging process once a day, and has 15 days of system maintenance per year, that is, the reference operation days per year is 350 days, the peak operation is 280 days, and the peak electricity price is 60 days. The electricity price during charging is 0.2214 yuan / kW·h, that is, the pool charging consumes 558393 yuan.

[0079] Through the conventional low-temperature system, the charging efficiency of the water storage system is calculated as 95%, the cold capacity of the water storage system is 46550kW·h during discharging; the normal COP of the medium-temperature system is calculated as 7.5, and the COP of the low-temperature system is calculated as 5.6. The required power is 7107kW·h; without water storage, the normal medium-temperature system operates at a peak electricity price of 0.6004 yuan / kW·h, and operates for 290 days, and the peak electricity price is 0.7014 yuan / kW·h, and operates for 60 days. The refrigeration cost of the normal medium-temperature system is 1536533 yuan.

[0080] According to the above calculation information, each water cooling system charging and discharging cycle can save electricity: Q2 = normal medium-temperature system refrigeration cost - pool charging cost = 1536533 - 558393 = 978140 yuan.

[0081] The second working condition: the water tank circulates continuously during the day and releases cold, and completes two water tank circulation charging and discharging processes in 3 hours. From 8am to 8pm, a total of 4 cycles are calculated. The medium-temperature chiller directly supplies medium-temperature chilled water during the day, and needs to be charged and discharged:

[0082] When the first water tank 300 is charged and the second water tank 310 is discharged, the valve F2 and the valve F6 are opened, and the 7℃ temperature chilled water is directly prepared by the second low-temperature chiller 500 in one step, and is directly supplied to the low-temperature chilled water distribution tank. The valve F5 and the valve F11 are opened, and the 14℃ temperature chilled water is directly prepared by the second medium-temperature chiller 510 in one step, and is directly supplied to the medium-temperature chilled water distribution tank.

[0083] The valve F4, the valve F27, the valve F15 on the first water storage tank 300 and the valve F13 are opened, and the first medium-temperature cold machine is sequentially circulated at variable evaporation temperatures of 17℃ and 14℃ to circulate the first water storage tank 300 to be cooled; after the first water storage tank 300 is cooled to a first preset temperature, the valve F4, the valve F15, the valve F27 and the valve F13 are closed, the valve F9, the valve F12, the valve F3 and the valve F14 are opened, and the first low-temperature cold machine is sequentially circulated at variable evaporation temperatures of 11℃ and 6℃ to circulate the first water storage tank 300 to be cooled until the water tank reaches a set temperature of 6℃. The valve F23 and the valve F22 on the second water storage tank 310 are opened, and the heat exchange water pump 401 is started, and the opening degrees of the valve F1, the valve F7, the valve F25 and the valve F26 are adjusted according to the required flow of medium and low temperature water.

[0084] When the first water storage tank 300 is completed and the second water storage tank 310 is completed, the first water storage tank 300 is switched to be cooled and the second water storage tank 310 is switched to be cooled, the valve F4, the valve F27, the valve F18 on the second water storage tank 310 and the valve F17 are opened, and the first medium-temperature cold machine 110 is sequentially circulated at variable evaporation temperatures of 17℃ and 14℃ to circulate the second water storage tank 310 to be cooled; after the second water storage tank 310 is cooled to a first preset temperature, the valve F4, the valve F27, the valve F18 and the valve F17 are closed, the valve F9, the valve F16, the valve F3 and the valve F19 are opened, and the first low-temperature cold machine 100 is sequentially circulated at variable evaporation temperatures of 11℃ and 6℃ to circulate the first water storage tank 300 to be cooled until the water tank reaches a set temperature of 6℃; the valve F20 and the valve F21 on the first water storage tank 300 are opened, the heat exchange water pump 401 is started, and the opening degrees of the valve F1, the valve F7, the valve F25 and the valve F26 are adjusted according to the required flow of medium and low temperature water.

[0085] According to the calculation formula Q=C*M*△T, wherein the water density is 1000 kg / m 3 , the specific heat capacity of water is C=4.2*10^3 J / (kg·℃), the total water storage capacity of the pool is 3000 m3*4.2*10^3 J / (kg·℃)*1000 kg / m3*14℃=49000 kW·h. During the storage, variable evaporation temperature refrigeration is adopted, which is divided into four stages, and the COP of each stage is 8.1, 7.5, 6.0 and 5.6 respectively, that is, the power consumption of the pool during the storage is 49000*4 / (8.1+7.5+6.0+5.6)=7206 kW·h.

[0086] The water storage system completes four charging and discharging processes during the day, and has 15 days of system maintenance per year. The system is stopped, that is, the reference number of operating days per year is 350 days, the peak operation is 280 days, and the peak electricity price is 60 days.

[0087] The electricity cost during the cold storage is 0.6004 yuan / kW·h during the peak period, and the operation is 290 days; the peak electricity price is 0.7014 yuan / kW·h, and the operation is 60 days, that is, the water pool cold storage consumption cost = 7206 * (0.6004 * 290 + 0.7014 * 60) * 4 = 6231749 yuan;

[0088] Through the conventional medium and low temperature system cold storage, due to the continuous operation of daytime charging and discharging, the cold storage efficiency of the water cold storage system is calculated as 98%, the cold capacity of the water cold storage system during discharging is 49000*98% = 48020 kW·h; the required power is calculated as 48020*2*4 / (7.5+5.6) = 29325 kW·h, the normal COP of the medium temperature system is calculated as 7.5, and the COP of the low temperature system is calculated as 5.6; without using water cold storage, the conventional medium and low temperature system is operated at the peak period of 0.6004 yuan / kW·h, and the operation is 290 days; the peak electricity price is 0.7014 yuan / kW·h, and the operation is 60 days. The refrigeration cost of the normal medium and low temperature system is 293252*0.6004*290+0.7014*293252*60 = 6340108 yuan.

[0089] According to the above calculation information, the daytime charging and discharging can save electricity cost: Q3 = normal medium and low temperature system refrigeration cost - water pool cold storage consumption cost = 6340108-6231749 = 108359 yuan. In summary, the annual operation cost can be saved: Q = Q2+Q3 = 978140+108359 = 1086499 yuan.

[0090] In the embodiment, since the technical solutions of the above embodiments are adopted, at least all the beneficial effects brought by the technical solutions of the above embodiments are achieved. In addition, the variable evaporation temperature type cold machine refrigeration system further introduces a heat exchange device, a second low temperature cold machine, a second medium temperature cold machine, a cold using device and a second water tank, and realizes water tank cold release and cold machine direct cold supply on the basis of these devices, further improves the energy utilization rate, and saves the cost.

[0091] Based on the above embodiment, in Embodiment Three of the present application, the same or similar contents as the above embodiments can be referred to the above introduction, and will not be described in detail. Please refer to FIG. 4, which is a flowchart of Embodiment Three of the heat management method provided by the present application. The heat management method is applied to the variable evaporation temperature type cold machine refrigeration system described above, and the method comprises steps S10 to S40:

[0092] Step S10, turn on the connection between the first medium temperature cold machine and the first water tank.

[0093] It should be noted that the variable evaporation temperature type cold machine refrigeration system needs to pay attention to whether the water tank needs to store cold and whether it is in the cold release state discrimination method, and the switching strategy as a thermal management method to achieve the storage and release cycle of the water tank to improve the energy utilization rate.

[0094] It can be understood that the connection between the first medium-temperature cold machine and the first water storage tank is cooled by the first medium-temperature cold machine with variable evaporation temperature, which is the first step in the storage and release cycle.

[0095] Step S20, obtaining the temperature of the cold storage outlet in the first water storage tank.

[0096] It can be understood that the temperature of the cold storage outlet in the first water storage tank is the final position of the water tank temperature in the cold storage link, so this part can be detected as a sign of whether the first-stage cold storage is achieved. In addition, in order to measure more accurately, the temperatures of different positions of the cold storage outlet can be collected and averaged to reduce errors.

[0097] In a possible implementation, the step of obtaining the temperature of the cold storage outlet in the first water storage tank can include: based on the height of the first water storage tank, building a water storage tank layered water temperature change model; obtaining the current temperature of the cold storage outlet of the first water storage tank; based on the water storage tank layered water temperature change model and the current temperature of the cold storage outlet of the first water storage tank, obtaining the temperature of the cold storage outlet in the first water storage tank.

[0098] It should be noted that since the water storage tank usually has a certain height, the liquid in the water storage tank will have a difference between different layers, so it is necessary to build a water storage tank layered water temperature change model based on the height of the first water storage tank, so as to judge the temperature change of different layers of the water tank and better confirm the temperature of the cold storage outlet in the water tank.

[0099] It should be noted that the step of building a water storage tank layered water temperature change model usually includes: based on the height of the first water storage tank, layering the first water storage tank according to a preset height; obtaining the net flow exchanged in the vertical direction between each layer of the first water storage tank; based on the net flow, building a water storage tank layered water temperature change model.

[0100] It should be noted that the water tank can be evenly set with a thermometer every 600mm-1000mm in the direction of the height of the water tank for real-time measurement of the temperature of each layer of water in the water tank. Specifically, please refer to FIG. 5, which is a schematic diagram of a layered model of the cold storage water tank according to Embodiment Three of the heat management method provided by the present application. The spacing between each layer can be obtained by different water tank heights in an accurate and convenient calculation direction, and can be calibrated by experiments. In addition, temperature measuring points T1, T2, T3, T4, T5 and T6 are set at the low-temperature cold storage outlet, the medium-temperature cold storage outlet, the medium-temperature cold storage inlet, the low-temperature cold storage inlet, the heat exchange inlet and the heat exchange outlet of the water tank, so as to establish a layered water temperature change model of the cold storage water tank.

[0101] It should be noted that when calculating the water temperature change of a certain layer of the heat storage water tank, the net flow exchanged in the vertical direction between two nodes in the water tank needs to be calculated. This amount depends on the cold machine provided cold and the mass flow rate of the radiator, as well as the values of the two control functions (and) at that instant.

[0102] Specifically, please refer to FIG. 6, which is a schematic diagram of a mixing flow model of the layered model of the cold storage water tank according to Embodiment Three of the heat management method provided by the present application. The net flow from the i-1th node to the ith node can be represented by the mixing flow m mi , which only considers the exchange in the vertical direction and does not consider the flow directly entering the node from the cold machine or the radiator.

[0103] It can be understood that m m1 = 0, m mi = 0.

[0104] From the above mixing flow and control function equation, the energy balance equation of node k can be obtained:

[0105] wherein, it should be noted that m c is the mass flow rate of the cold machine into and out of the water tank, m L is the mass flow rate of the heat exchanger; T c,0 is the temperature from the medium-temperature and low-temperature cold machine, T L,r is the temperature into the heat exchanger, T s,k is the temperature of node k, U is the convective heat transfer coefficient, A is the surface area of the node corresponding to the water tank; Ta is the ambient temperature; and are constant-pressure specific heat capacities; and are control functions, both of which are 0 or 1, and can be determined according to the numerical value of the node temperature and the cold machine temperature or the node temperature and the heat exchanger temperature.

[0106] M1 takes the value of:

[0107] If m mk > 0

[0108] If m m,k+1 > 0

[0109] In the formula, water enters the water tank layer corresponding to its water temperature in calculation, and the formula can be considered as The above formula is simplified as:

[0110] M2 takes the value of:

[0111] m mk (T s,k -T s,k-1 ), if m mk > 0

[0112] m mk+1 (T s,k+1 -T s,k ), if m m,k+1 > 0

[0113] In the above formula, the first term on the right represents the cold provided by the low-temperature cold machine; the second term represents the cold extracted by the load; the third term represents the cold loss of the node to the surrounding environment; the upper formula represents the net exchange of cold between the previous node and the current node due to vertical mixing, and the lower formula represents the net exchange of cold between the next node and the current node due to mixing.

[0114] It can be understood that the mixing flow model of the stratified water tank model is input into the control module, and the control module can obtain the temperature change of the net flow according to the mixing flow model of the stratified water tank model, and combine the current outlet measured temperature, that is, a stratified water temperature change model of the water tank is built. The control module can output the final changed temperature of the current stop of cold storage or cold release by inputting the outlet measured temperature into the stratified water temperature change model of the water tank.

[0115] Step S30, when the temperature of the cold storage outlet is lower than the first preset temperature, the connection between the first medium-temperature cold machine and the first water tank is turned off, and the connection between the first low-temperature cold machine and the first water tank is turned on.

[0116] Step S40, when the temperature of the cold storage outlet is lower than the second preset temperature, the connection between the first low-temperature cold machine and the first water tank is turned off.

[0117] It should be noted that the first preset temperature and the second preset temperature are threshold values of the two variable evaporation temperature cold machines, the former means that the cold machine needs to be switched to the next cold storage level at this time, and the latter means that the target value has been reached at this time, and the cold storage needs to be stopped. Since the switching time and the cold storage stopping time need to be considered comprehensively, the switching is smooth and the cold storage target value is accurate under the premise of hierarchical cold storage, therefore the first preset temperature and the second preset temperature can be obtained through multiple experimental calibration, in the present scheme, the average value of the temperatures of the upper three layers of the water storage tank can be taken as the temperature of the cold storage outlet; the average value of the temperatures of the lower two layers of the water storage tank can be taken as the temperature of the heat exchange outlet.

[0118] In addition, before step S10, it also includes: turning on the connection between the first water storage tank and the heat exchange device; obtaining the temperature of the cold release outlet of the first water storage tank; when the temperature of the cold release outlet of the first water storage tank is higher than the third preset temperature, turning off the connection between the first water storage tank and the heat exchange device.

[0119] Similarly, the third preset temperature means the cold release end time, so the third preset temperature can be obtained through multiple experimental calibration.

[0120] In addition, the second water storage tank should also be applicable to the water tank layered water temperature change model described above, and also applicable to the control method described above.

[0121] In the present embodiment, since the technical solutions of the above embodiments are adopted, at least all the beneficial effects brought by the technical solutions of the above embodiments are achieved. In addition, by constructing the cold storage water tank temperature layering model, the water tank temperature layering precalculation is carried out through numerical iteration, the actual measurement of the measuring point and the layering calculation provide basis for the system control such as cold storage and cold release start and stop, the water tank whether needs to be cold stored and whether is in the cold release state discrimination method is proposed, and the reliable operation of the system is realized.

[0122] It should be noted that the above examples are only used for understanding the present application and do not constitute a limitation on the heat management method of the present application, and more forms of simple transformation based on this technical concept are within the protection scope of the present application.

[0123] The present application provides a computer readable storage medium having computer readable program instructions (i.e. computer programs) stored thereon, the computer readable program instructions being used to execute the heat management method in the above embodiments.

[0124] The computer readable storage medium provided by the present application may, for example, be a U disk, but is not limited to an electric, magnetic, optical, electromagnetic, infrared, or semiconductor system, system, or device, or any combination of the above. More specific examples of the computer readable storage medium can include, but are not limited to, an electric connection with one or more conductive wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present embodiment, the computer readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer readable storage medium can be transmitted in any suitable medium, including but not limited to an electric wire, an optical cable, an RF (Radio Frequency), etc., or any suitable combination of the above.

[0125] Computer program code for carrying out operations of the present application can be written in one or more programming languages or combinations of languages including object oriented programming languages such as Java, Smalltalk, C++ or conventional procedural programming languages such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0126] The flow and block diagrams in the drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flow and block diagrams can represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently or the blocks may be executed in the reverse order, depending on the functionality involved. It will also be noted that each block of the block diagrams and / or flowchart illustrations, and combinations thereof, can be implemented by special purpose hardware-based systems that perform the specified functions or operations, or combinations of special purpose hardware and computer instructions.

[0127] The modules involved in the embodiments of the present application can be implemented in software or in hardware. In some cases, the names of the modules do not limit the modules themselves.

[0128] The readable storage medium provided by the present application is a computer readable storage medium, which stores computer readable program instructions (i.e. computer programs) for executing the above-mentioned heat management method, and can solve the technical problems of low energy efficiency and high energy consumption of the cold machine refrigeration system in the prior art. Compared with the prior art, the computer readable storage medium provided by the present application has the same beneficial effects as the heat management method provided by the above-mentioned embodiments, which will not be repeated here.

[0129] The present application also provides a computer program product comprising a computer program, which, when executed by a processor, implements the steps of the heat management method as described above.

[0130] The computer program product provided by the present application can solve the technical problems of low energy efficiency and high energy consumption of the cold machine refrigeration system in the prior art. Compared with the prior art, the computer program product provided by the present application has the same beneficial effects as the heat management method provided by the above-mentioned embodiments, which will not be repeated here.

[0131] The above only describes some embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made by using the contents of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A variable evaporating temperature engine-driven refrigeration system, characterized by, The system comprises a first low-temperature chiller, a first medium-temperature chiller, a plurality of cold storage valves, a control module and a first water storage tank. The first water storage tank is used for storing cold storage medium for cold storage, and one side of the first water storage tank is sequentially arranged from top to bottom with a low-temperature cold storage outlet, a medium-temperature cold storage outlet, a medium-temperature cold storage inlet and a low-temperature cold storage inlet. The first low-temperature chiller is connected to the low-temperature cold storage inlet and the low-temperature cold storage outlet of the first water storage tank through the cold storage valves respectively; and the first medium-temperature chiller is connected to the medium-temperature cold storage inlet and the medium-temperature cold storage outlet of the first water storage tank through the cold storage valves respectively. The first low-temperature chiller and the first medium-temperature chiller are used for cold storage of the first water storage tank in a variable evaporation temperature mode, wherein the evaporation temperature of each chiller comprises at least two different temperatures. The control module is used for controlling the on-off of the cold storage valves by detecting the cold storage outlet temperature of the first water storage tank. The control module is further used for controlling the cold storage valves to connect the first medium-temperature chiller and the first water storage tank when the first water storage tank is in cold storage. The control module is further used for controlling the cold storage valves to disconnect the first medium-temperature chiller and the first water storage tank when the cold storage outlet temperature of the first water storage tank is less than a first preset temperature, and controlling the cold storage valves to connect the first low-temperature chiller and the first water storage tank. The control module is further used for controlling the cold storage valves to disconnect the first low-temperature chiller and the first water storage tank when the cold storage outlet temperature of the first water storage tank is less than a second preset temperature.

2. The variable evaporation temperature chiller system of claim 1, wherein, The system further comprises a heat exchange device and a plurality of heat exchange valves. The other side of the first water storage tank is sequentially arranged from top to bottom with a heat exchange inlet and a heat exchange outlet. The heat exchange device is connected to the heat exchange inlet and the heat exchange outlet of the first water storage tank through the heat exchange valves respectively. The control module is further used for controlling the on-off of the heat exchange valves by detecting the heat exchange outlet temperature of the first water storage tank. The control module is further used for controlling the heat exchange valves to connect the heat exchange device and the first water storage tank when the first water storage tank is in cold release.

3. The variable evaporation temperature chiller system of claim 2, wherein, The system further comprises a second low-temperature chiller, a second medium-temperature chiller, a plurality of cold utilization valves, a low-temperature cold utilization device and a medium-temperature cold utilization device. The second low-temperature chiller is connected to the low-temperature cold utilization device through the cold utilization valves. The second medium-temperature chiller is connected to the medium-temperature cold utilization device through the cold utilization valves. The control module is further used for controlling the on-off of the cold utilization valves according to cold utilization demand. The control module is further used for controlling the cold utilization valves to connect the second medium-temperature chiller and the medium-temperature cold utilization device, and controlling the cold utilization valves to connect the second low-temperature chiller and the low-temperature cold utilization device when direct supply of medium-low-temperature chilled water is needed.

4. The variable evaporation temperature chiller system of claim 3, wherein, The system further comprises a second water storage tank. The second water storage tank has the same specifications as the first water storage tank. The first low-temperature chiller is further connected to the low-temperature cold storage inlet and the low-temperature cold storage outlet of the second cold storage tank through the cold storage valves respectively; and the first medium-temperature chiller is connected to the medium-temperature cold storage inlet and the medium-temperature cold storage outlet of the second cold storage tank through the cold storage valves respectively. The heat exchange device is further connected to the heat exchange inlet and the heat exchange outlet of the second cold storage tank through the heat exchange valves respectively. The control module is further configured to, when the second cold storage tank is in cold storage, control the cold storage valves to connect the first medium-temperature chiller and the second cold storage tank. The control module is further configured to, when the second cold storage tank is in cold storage, control the cold storage valves to disconnect the first medium-temperature chiller and the second cold storage tank when the temperature of the cold storage outlet of the second cold storage tank is lower than a first preset temperature, and control the cold storage valves to connect the first low-temperature chiller and the second cold storage tank. The control module is further configured to, when the second cold storage tank is in cold storage, control the cold storage valves to disconnect the first low-temperature chiller and the second cold storage tank when the temperature of the cold storage outlet of the second cold storage tank is lower than a second preset temperature. The control module is further configured to, when the second cold storage tank is in cold storage, control the heat exchange valves to connect the heat exchange device and the second cold storage tank.

5. A thermal management method, characterized by, The application of the variable evaporation temperature type chiller refrigeration system according to any one of claims 1 to 4, the method comprises: connecting the first medium-temperature chiller and the first cold storage tank; obtaining the temperature of the cold storage outlet of the first cold storage tank; when the temperature of the cold storage outlet is lower than a first preset temperature, disconnecting the first medium-temperature chiller and the first cold storage tank, and connecting the first low-temperature chiller and the first cold storage tank; when the temperature of the cold storage outlet is lower than a second preset temperature, disconnecting the first low-temperature chiller and the first cold storage tank.

6. The method of claim 5, wherein, The step of obtaining the temperature of the cold storage outlet of the first cold storage tank comprises: based on the height of the first cold storage tank, building a cold storage tank layered water temperature change model; obtaining the current temperature of the cold storage outlet of the first cold storage tank; based on the cold storage tank layered water temperature change model and the current temperature of the cold storage outlet of the first cold storage tank, obtaining the temperature of the cold storage outlet of the first cold storage tank.

7. The method of claim 6, wherein, The step of building the cold storage tank layered water temperature change model based on the height of the first cold storage tank comprises: based on the height of the first cold storage tank, layering the first cold storage tank according to a preset height; obtaining the net flow exchanged in the vertical direction between each layer of the first cold storage tank; based on the net flow, building the cold storage tank layered water temperature change model.

8. The method of claim 6, wherein, The step of connecting the first medium-temperature chiller and the first cold storage tank further comprises: connecting the first cold storage tank and the heat exchange device; obtaining the temperature of the cold storage outlet of the first cold storage tank; when the temperature of the cold storage outlet of the first cold storage tank is higher than a third preset temperature, disconnecting the first cold storage tank and the heat exchange device.

9. A storage medium, characterized by The storage medium is a computer readable storage medium, and the storage medium stores a computer program. When the computer program is executed by the processor, the steps of the heat management method according to any one of claims 5 to 8 are realized.

10. A computer program product, characterised in that, The computer program product comprises a computer program which, when executed by a processor, implements the steps of the thermal management method according to any one of claims 5 to 8. The computer program product comprises a computer program which, when executed by a processor, implements the steps of the thermal management method according to any one of claims 5 to 8.

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