A forced circulation phase change cold storage system

Abstract

The utility model relates to the technical field of cold storage, specifically relates to a forced circulation phase change cold storage system, including main circulation loop and vice circulation loop. Main circulation loop is constituted by phase change material storage tank group, circulating pump group and heat exchanger group, and the forced circulation heat exchange of phase change material and heat exchange medium is realized through first branch of main circulation loop, and vice circulation loop forms the internal circulation path of phase change material storage tank group through second branch, and effectively maintains the uniformity of phase change material in main circulation loop, flowmeter and shunt regulating valve are arranged to circulating pump group outlet, realize double loop flow accurate control, adopt parallel type circulating pump group, parallel type heat exchanger group and parallel type phase change material storage tank group and improve reliability and system capacity, configure temperature, pressure, density monitoring instrument and control valve group in each pipeline node to realize multi -parameter regulation and control, and the system is through double loop collaborative operation and intelligent control, and the heat exchange efficiency and operating stability of phase change cold storage system are improved significantly.

Description

Technical Field

[0001] This utility model relates to the field of cold storage technology, specifically to a forced circulation phase change cold storage system. Background Technology

[0002] Existing phase change energy storage devices all utilize a complete phase change process in a static state for heat storage. However, heat transfer is extremely poor in the all-solid state. When the phase change material is fully solidified, its thermal conductivity decreases significantly, leading to a sharp drop in heat transfer efficiency. Current research indicates that a complete phase change in a phase change system not only results in energy losses exceeding 30% but also extends the system response time by 2-3 times. These issues hinder the application of phase change energy storage technology. Therefore, there is an urgent need to develop novel partial phase change operation strategies. By maintaining the phase change material in a solid-liquid mixed state, these strategies can significantly improve heat transfer performance while ensuring energy storage density, thus overcoming the technical limitations of traditional all-phase change systems. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention provides a forced-cycle phase change cold storage system.

[0004] The technical solution of this utility model is as follows: A forced-circulation phase change cold storage system includes a main circulation loop and a secondary circulation loop. The main circulation loop includes a phase change material (PCM) storage tank group, a circulation pump group, and a heat exchanger group. The heat exchanger group is provided with a PCM inlet, a PCM outlet, a heat exchange medium inlet, and a heat exchange medium outlet. The outlet of the PCM storage tank group is connected to the inlet of the circulation pump group. The outlet of the circulation pump group is connected to the PCM inlet of the heat exchanger group via a first branch. The PCM outlet of the heat exchanger group is connected to the inlet of the PCM storage tank group. The heat exchange medium enters from the heat exchange medium inlet of the heat exchanger group, exchanges heat with the PCM entering the heat exchanger, and then flows out from the heat exchange medium outlet. The PCM stored in the PCM storage tank group is in a gel or paste state in a solidified state. The secondary circulation loop includes a PCM storage tank group and a circulation pump group. The outlet of the PCM storage tank group is connected to the inlet of the circulation pump group, and the outlet of the circulation pump group is connected to the inlet of the PCM storage tank group via a second branch. The PCM storage tank group includes at least one PCM storage tank A.

[0005] Furthermore, the circulating pump set includes circulating pump A and circulating pump B, which are connected in parallel.

[0006] Furthermore, the heat exchanger assembly includes heat exchanger A and heat exchanger B, which are connected in parallel.

[0007] Furthermore, the phase change material storage tank group includes phase change material storage tank A and phase change material storage tank B, which are connected in parallel.

[0008] Furthermore, the outlet of the circulating pump unit is connected to the inlet of the flow meter, the outlet of the flow meter is connected to the phase change material inlet of the heat exchanger unit through the first branch, and the outlet of the flow meter is connected to the inlet of the phase change material storage tank unit through the second branch.

[0009] Furthermore, regulating valves are installed on both the first and second branches.

[0010] Furthermore, a control valve assembly is provided on the connecting pipeline between the outlet of the phase change material storage tank group and the inlet of the circulating pump group; and / or, a control valve assembly is provided on the connecting pipeline between the outlet of the phase change material of the heat exchanger group and the inlet of the phase change material storage tank group.

[0011] Furthermore, the control valve assembly includes temperature monitoring instruments, pressure monitoring instruments, and density monitoring instruments.

[0012] Furthermore, pressure monitoring instruments are installed on the first branch road; And / or, a temperature monitoring instrument is provided at the heat exchange medium outlet of the heat exchanger assembly.

[0013] The beneficial effects achieved by this utility model are as follows: The forced circulation phase change cold storage system of this invention uses a circulation pump group to force circulation of the phase change material and a heat exchanger group to exchange heat with the phase change material, which can be flexibly adjusted according to the amount of heat exchange. The entire cold storage system uses an excess of phase change material, and through circulation heat exchange, some of the phase change material is converted into solid during the cold storage process, changing the original mode of complete phase change of the cold storage material in the static state, and enhancing the heat transfer efficiency.

[0014] The forced circulation phase change cold storage system of this invention achieves uninterrupted operation of the phase change cold storage system by using multiple phase change material storage tanks arranged in parallel, and can also increase the cold storage capacity of the system.

[0015] The forced circulation phase change cold storage system of this invention is equipped with a secondary circulation loop, which can be flexibly opened and closed in the early stage of system operation or during system operation, effectively maintaining the uniformity of the phase change material in the main circulation loop and reducing solid-liquid separation.

[0016] The forced circulation phase change cold storage system of this invention, by setting up dual circulation pumps and dual heat exchangers, can switch between operation or operate in parallel during system operation, ensuring continuous and reliable operation of the system and effectively increasing system capacity.

[0017] The forced circulation phase change cold storage system of this invention realizes full-process monitoring of the cold storage system through control valve group. By monitoring data such as flow rate, temperature, pressure and density at each node in real time, it continuously optimizes the flow distribution of phase change material and provides early warning of pipeline blockage risk. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the overall structure of Embodiment 1 of this utility model; Figure 2 This is a schematic diagram of the overall structure of Embodiment 2 of this utility model.

[0019] In the diagram, 101 is circulating pump A; 102 is circulating pump B; 201 is heat exchanger A; 202 is heat exchanger B; 301 is phase change material storage tank A; 302 is phase change material storage tank B; and 400 is a flow meter. Detailed Implementation

[0020] To facilitate understanding of this utility model by those skilled in the art, the specific embodiments of this utility model are described below with reference to the accompanying drawings. Example

[0021] Please refer to Figure 1 This invention provides an embodiment of a forced circulation phase change cold storage system, comprising a main circulation loop and a secondary circulation loop; the main circulation loop includes a phase change material storage tank group, a circulation pump group, a heat exchanger group, and a flow meter 400; the phase change material storage tank group includes a phase change material storage tank A 301; the circulation pump group includes circulation pump A 101 and circulation pump B 102, which are connected in parallel; the heat exchanger group includes heat exchanger A 201 and heat exchanger B 202, which are connected in parallel; both heat exchanger A 201 and heat exchanger B 202 are provided with a phase change material inlet, a phase change material outlet, a heat exchange medium inlet, and a heat exchange medium outlet. The outlet of phase change material storage tank A 301 is connected to the inlet of circulating pump A 101 and circulating pump B 102; the outlet of circulating pump A 101 and circulating pump B 102 is connected to the inlet of flow meter 400, and the outlet of flow meter 400 is connected to the phase change material inlet of heat exchanger A 201 and heat exchanger B 202 through the first branch; the phase change material outlet of heat exchanger A 201 and heat exchanger B 202 is connected to the inlet of phase change material storage tank A 301; the heat exchange medium enters from the heat exchange medium inlet of heat exchanger A 201 and heat exchanger B 202, exchanges heat with the phase change material entering heat exchanger A 201 and heat exchanger B 202, and then flows out from the heat exchange medium outlet.

[0022] The secondary circulation loop includes a phase change material (PCM) storage tank group and a circulation pump group. The PCM storage tank group includes a PCM storage tank A 301. The circulation pump group includes circulation pump A 101 and circulation pump B 102, which are connected in parallel. The outlet of the PCM storage tank A 301 is connected to the inlet of circulation pump A 101 and circulation pump B 102. The outlet of circulation pump A 101 and circulation pump B 102 is connected to the inlet of flow meter 400. The outlet of flow meter 400 is connected to the inlet of PCM storage tank A 301 via a second branch. The secondary circulation loop effectively maintains the uniformity of the PCM in the main circulation loop and reduces solid-liquid separation by transporting a portion of the PCM from the pump outlet to the PCM storage tank A 301.

[0023] Circulating pump A 101 and circulating pump B 102 are connected in parallel. When circulating pump A 101 stops unexpectedly due to mechanical failure, electrical problems or other reasons, circulating pump B 102 can be switched on immediately to avoid system interruption and ensure the continuity of the cold storage / release process. In addition, in some systems, circulating pump B 102 can also participate in flow regulation, and the two circulating pumps can operate simultaneously to meet peak load demands.

[0024] Heat exchangers A 201 and B 202 are connected in parallel. As the solid content of the phase change material gradually increases, ice blockage may occur in a single heat exchanger. Switching between heat exchangers A 201 and B 202 can effectively alleviate ice blockage and prevent system shutdown. In addition, the two heat exchangers can also operate simultaneously to increase system capacity.

[0025] The phase change material selected for this system is gel-like or paste-like in the solidified state. This type of phase change material still has a certain fluidity in the solidified state and can be forced to circulate through a circulation pump group; the phase change material can circulate in the main circulation loop and the secondary circulation loop.

[0026] Both the first and second branches are equipped with regulating valves, which can adjust the flow rate of phase change material entering the first and second branches respectively during actual operation.

[0027] A control valve assembly is installed on the connecting pipeline between the outlet of the phase change material storage tank A 301 and the inlet of the circulating pump group. This control valve assembly includes temperature monitoring instruments, pressure monitoring instruments, and density monitoring instruments; it monitors the temperature, pressure, and density of the phase change material at the outlet of the phase change material storage tank A 301 and the inlet of the circulating pump group in real time.

[0028] A control valve assembly is installed on the connecting pipeline between the phase change material outlet of the heat exchanger group and the inlet of the phase change material storage tank A 301. This control valve assembly includes temperature monitoring instruments, pressure monitoring instruments, and density monitoring instruments; it monitors the temperature, pressure, and density of the phase change material at the heat exchanger group's phase change material outlet / phase change material storage tank A 301 in real time.

[0029] The first branch is equipped with a pressure monitoring instrument to monitor the pressure of the phase change material at the inlet of the heat exchanger in real time, thus preventing pipeline blockage.

[0030] Temperature monitoring instruments are installed at the outlet of the heat exchange medium of the heat exchanger group to monitor the temperature of the heat exchange medium at the outlet of the heat exchanger in real time and verify the heat exchange efficiency of the system.

[0031] Specifically, the working mode of this system is as follows: Cold Storage Mode: Liquid phase change material (PCM) flows out of the PCM storage tank assembly outlet, is pressurized by the circulating pump assembly, and enters the flow meter 400. The flow meter 400 monitors the PCM flow rate at the circulating pump assembly outlet in real time. The PCM from the flow meter 400 outlet enters the heat exchanger assembly through the first branch of the main circulation loop and the PCM storage tank assembly through the second branch of the secondary circulation loop. The regulating valves on the first and second branches dynamically adjust the PCM flow rates. The liquid PCM entering the heat exchanger assembly through the first branch exchanges heat with the heat exchange medium within the heat exchanger assembly. Part of the PCM solidifies, and the liquid PCM is converted into a liquid-solid mixed state PCM, which enters the PCM storage tank assembly for storage. The heat exchange medium absorbs heat from the PCM and is discharged from the heat exchange medium outlet of the heat exchanger. The secondary circulation loop is dynamically opened and closed according to the state of the PCM, with two main operating states: 1) running synchronously with the heat exchanger throughout the entire process; 2) intermittent operation.

[0032] Cooling mode: The solid-liquid mixed phase change material flows out from the outlet of the phase change material storage tank group, is pressurized by the circulating pump group, and enters the flow meter 400. The flow meter 400 monitors the phase change material flow data at the outlet of the circulating pump group in real time. The phase change material at the outlet of the flow meter 400 enters the heat exchanger group through the first branch of the main circulation loop and enters the phase change material storage tank group through the second branch of the secondary circulation loop. The regulating valves on the first and second branches dynamically adjust the phase change material flow in the first and second branches. The solid-liquid mixed phase change material entering the heat exchanger group through the first branch exchanges heat with the heat exchange medium in the heat exchanger group. After absorbing the heat from the heat exchange medium, the solid phase change material converts into a liquid state. The solid-liquid mixed phase change material enters the phase change material storage tank group for storage. After exchanging heat with the phase change material, the heat exchange medium is discharged from the heat exchange medium outlet of the heat exchanger group. The secondary circulation loop is dynamically opened and closed according to the state of the phase change material, and has two main working states: 1) running synchronously with the heat exchanger throughout the entire process; 2) intermittent operation. Example

[0033] Please refer to Figure 2This is another embodiment of the present invention, differing from Embodiment 1 in that the phase change material (PCM) storage tank group in this embodiment includes PCM storage tank A 301 and PCM storage tank B 302. When PCM storage tank A 301 reaches its upper limit of cold storage capacity, the inlet and outlet of PCM storage tank A 301 can be closed, while the inlet and outlet of PCM storage tank B 302 can be opened, allowing PCM storage tank B 302 to perform cold storage. During cold release, PCM storage tanks A 301 and B 302 can also operate alternately. By connecting PCM storage tanks A 301 and B 302 in parallel, the phase change cold storage system can operate uninterruptedly and can increase the system's cold storage capacity. Depending on the needs, three or more PCM storage tanks can also be configured.

[0034] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A forced-circulation phase change cold storage system, characterized in that: Includes the main loop and the secondary loop; The main circulation loop includes a phase change material (PCM) storage tank group, a circulation pump group, and a heat exchanger group. The heat exchanger group is provided with a PCM inlet, a PCM outlet, a heat exchange medium inlet, and a heat exchange medium outlet. The outlet of the PCM storage tank group is connected to the inlet of the circulation pump group. The outlet of the circulation pump group is connected to the PCM inlet of the heat exchanger group through a first branch. The PCM outlet of the heat exchanger group is connected to the inlet of the PCM storage tank group. The heat exchange medium enters from the heat exchange medium inlet of the heat exchanger group, exchanges heat with the PCM entering the heat exchanger, and then flows out from the heat exchange medium outlet. The PCM stored in the PCM storage tank group is in a gel or paste state in its solidified state. The secondary circulation loop includes a phase change material storage tank group and a circulation pump group. The outlet of the phase change material storage tank group is connected to the inlet of the circulation pump group, and the outlet of the circulation pump group is connected to the inlet of the phase change material storage tank group through a second branch. The phase change material storage tank group includes at least one phase change material storage tank A (301).

2. The forced-cycle phase change cold storage system according to claim 1, characterized in that: The circulating pump group includes circulating pump A (101) and circulating pump B (102), which are connected in parallel.

3. The forced-cycle phase change cold storage system according to claim 1, characterized in that: The heat exchanger group includes heat exchanger A (201) and heat exchanger B (202), which are connected in parallel.

4. The forced-cycle phase change cold storage system according to claim 1, characterized in that: The phase change material storage tank group includes phase change material storage tank A (301) and phase change material storage tank B (302), which are connected in parallel.

5. A forced-cycle phase change cold storage system according to claim 1, characterized in that: The outlet of the circulating pump group is connected to the inlet of the flow meter (400), the outlet of the flow meter (400) is connected to the phase change material inlet of the heat exchanger group through the first branch, and the outlet of the flow meter (400) is connected to the inlet of the phase change material storage tank group through the second branch.

6. The forced-cycle phase change cold storage system according to claim 1, characterized in that: Both the first branch and the second branch are equipped with regulating valves.

7. The forced-cycle phase change cold storage system according to claim 1, characterized in that: A control valve group is installed on the connecting pipeline between the outlet of the phase change material storage tank group and the inlet of the circulating pump group. And / or, a control valve group is provided on the connecting pipeline between the phase change material outlet of the heat exchanger group and the inlet of the phase change material storage tank group.

8. A forced-cycle phase change cold storage system according to claim 7, characterized in that: The control valve group includes temperature monitoring instruments, pressure monitoring instruments, and density monitoring instruments.

9. A forced-cycle phase change cold storage system according to claim 1, characterized in that: Pressure monitoring instruments are installed on the first branch; And / or, a temperature monitoring instrument is provided at the heat exchange medium outlet of the heat exchanger assembly.

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