Cooling system using underground cold

Abstract

To provide a cooling system that eliminates reduced cooling efficiency and high energy consumption in high heat generation devices and achieves stable temperature control at low cost. [Solution] This device is a cooling system that uses underground cold energy, and includes a cabinet 1, an underground cavern facility 5, and a circulating cooling system. The circulating cooling system includes a first heat exchanger 3 installed inside the underground cavern, a second heat exchanger inside the box, a carbon dioxide storage tank 2 for storing liquid carbon dioxide, and a circulation pump, with each heat exchanger and tank connected by pipes to form a circulation pipeline. By using liquid carbon dioxide as the working fluid and indirectly cooling the coolant using the natural cold energy of the underground cavern, this system achieves highly efficient heat dissipation and energy savings even under high-load operation, and provides cooling performance with low noise and a long life.

Description

[Technical Field]

[0001] The present invention relates to a cooling device, and more particularly to a cooling system that utilizes underground cold. [Background technology]

[0002] With the rapid development of modern science and technology, the demand for efficient and reliable cooling systems is increasing in fields such as data centers, high-performance computing equipment, and electric vehicles. In particular, the application of high-power density devices such as GPUs, CPUs, and large-capacity battery modules poses a challenge, as the enormous amount of heat generated by these devices can seriously affect the stable operation and lifespan of the equipment. Traditional air-cooling and water-cooling technologies often face issues such as efficiency limitations, high energy consumption, loud noise, and large installation areas when faced with increasing heat dissipation requirements.

[0003] Existing heat dissipation methods typically rely on external cooling towers, chillers, or air conditioning systems, which not only consume a large amount of energy to operate, but also increase the cooling load due to high outdoor temperatures in some regions. Furthermore, these external cooling systems are susceptible to environmental factors such as outdoor temperature and humidity, which can cause fluctuations in cooling efficiency. In recent years, cooling technologies that utilize natural cold sources have become a focus of research, with the aim of reducing energy consumption and lowering operational costs. Summary of the Invention [Problem to be solved by the invention]

[0004] The technical problem that this invention aims to solve is to provide a cooling system that overcomes the limitations of conventional cooling modes and utilizes the cold source of underground soil to achieve highly efficient heat dissipation. [Means for solving the problem]

[0005] The present invention provides a cooling system that utilizes underground cold energy, including: a cabinet 1, a box 11 within which a module to be cooled and a coolant for immersion cooling the module are provided; an underground cavern facility 5 for supplying natural underground cold energy; a circulation cooling system including a first heat exchanger 3, a carbon dioxide storage tank 2, a circulation pump 25, and a second heat exchanger 12, the first heat exchanger 3 installed within the underground cavern facility 5 to absorb the natural cold energy within the underground cavern facility 5; the second heat exchanger 12 installed within the box 11 to absorb the thermal energy of the coolant; and the carbon dioxide storage tank 2 for storing liquid carbon dioxide. The outlet end of the carbon dioxide storage tank 2 is connected to the first end of the second heat exchanger 12 via a first pipe 24, the second end of the second heat exchanger 12 is connected to the first end of the first heat exchanger 3 via a second pipe 32, and the second end of the first heat exchanger 3 is communicated with the return end of the carbon dioxide storage tank 2 via a third pipe 31, thereby forming a circulation pipe. A circulation pump 25 for driving the flow of liquid carbon dioxide within the circulation pipe is provided on at least one of the first pipe, the second pipe, and the third pipe.

[0006] Furthermore, there are multiple box bodies 11, and the first ends of the second heat exchangers 12 in each box body 11 are combined together and connected to the first pipeline 24, and the second ends of the second heat exchangers 12 in each box body 11 are combined together and connected to the second pipeline 32.

[0007] Furthermore, the circulation pump 25 is a variable frequency circulation pump, and a temperature sensor is provided inside the box.

[0008] Furthermore, the first pipe line, the second pipe line, and the third pipe line are covered on the outside with a heat insulating layer.

[0009] Furthermore, the first heat exchangers 3 are provided in plural numbers and are arranged in parallel with each other.

[0010] Furthermore, a spare circulation pump is provided on the first pipe line, the second pipe line, or the third pipe line.

[0011] Furthermore, an emergency shutoff valve is provided on the first pipeline, the second pipeline, or the third pipeline.

[0012] Furthermore, the module to be cooled is an electronic or electrical heat-generating component.

[0013] Furthermore, the electronic and electrical heat-generating component is a battery, a GPU, a CPU, or a rectifier-inverter power module. [Effects of the Invention]

[0014] The cooling system of this invention utilizes the natural cold of underground caverns as a permanent, stable, and free cold source, completely eliminating the need for traditional air conditioning or compressor-driven cooling systems, significantly reducing the system's operating energy consumption and achieving truly green cooling. Liquid carbon dioxide, with its excellent environmental and physical properties, is used as the circulating working fluid, absorbing heat within the second heat exchanger and providing powerful cooling capacity to the enclosure. By combining the highly efficient temperature uniformity of immersion cooling with the powerful heat dissipation capabilities of active liquid cooling, immersion cooling directly and quickly transfers heat from the heat-generating component to the coolant, which then efficiently transports the heat to the underground cavern via the carbon dioxide circulation system and dissipates it, forming a highly efficient heat conduction path from the electronic heat-generating component to the natural cold source, achieving heat dissipation efficiency far superior to that of traditional air or liquid cooling. [Brief explanation of the drawings]

[0015] [Figure 1] This is a structural diagram of the cooling system that utilizes underground cold energy according to this invention. [Figure 2] The figure shows the piping of the cooling system that utilizes underground cold energy according to this invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2, the cooling system utilizing underground cold energy according to the present invention includes a cabinet 1, an underground cavern facility 5, and a circulating cooling system. Cabinet 1 is provided with a number of boxes 11, each of which contains a module to be cooled. The module to be cooled is a functional module, such as an electronic or electrical heat-generating component, such as a battery, a GPU, a CPU, a hard disk, or a rectifier / inverter power module. That is, cabinet 1 may be a power storage cabinet, a data center, or an intelligent computing center. The boxes 11 are filled with a coolant, which is used to immerse and cool the module to be cooled.

[0017] The underground cavern facility 5 supplies natural underground cold energy, a renewable natural resource derived primarily from the natural cooling of the soil. This energy is uniformly distributed, less susceptible to the effects of external climates, and a reliable source of cold. Applying this underground cold energy to cooling systems makes full use of natural resources, reduces energy consumption, lowers costs, reduces reliance on traditional cooling methods, and curbs carbon dioxide emissions.

[0018] The circulating cooling system is used to transfer underground cold energy into the box 11, cool the coolant inside the box 11, and ultimately cool the modules to be cooled. The circulating cooling system includes a first heat exchanger 3, a carbon dioxide storage tank 2, a circulation pump 25, and a second heat exchanger 12. The first heat exchanger 3 is installed inside the underground cavern facility 5 and absorbs the natural cold energy inside the underground cavern facility 5. The second heat exchanger 12 is installed inside the box 11 and absorbs the thermal energy of the coolant. The carbon dioxide storage tank 2 stores liquid carbon dioxide. The outlet end of the carbon dioxide storage tank 2 is connected to the first end of the second heat exchanger 12 via a first pipe 24. The second end of the second heat exchanger 12 is connected to the first end of the first heat exchanger 3 via a second pipe 32. The second end of the first heat exchanger 3 is connected to the return end of the carbon dioxide storage tank 2 via a third pipe 31, thereby forming a circulation pipe. A circulation pump 25 is provided on at least one of the first, second and third pipelines, and this circulation pump 25 drives the flow of liquid carbon dioxide within the circulation pipeline, thereby realizing heat transfer within the circulation pipeline.

[0019] This underground cooling system utilizes the natural cold of underground caverns as a permanent, stable, and free cold source, completely eliminating the need for traditional air conditioning or compressor-driven cooling systems. It significantly reduces the system's operating energy consumption and achieves truly green cooling. Liquid carbon dioxide (LCC) is used as the circulating working fluid, boasting excellent environmental and physical properties. It absorbs heat within the second heat exchanger, providing powerful cooling capacity for the enclosure. Combining the highly efficient temperature uniformity of immersion cooling with the powerful heat dissipation capabilities of active liquid cooling, immersion cooling directly and quickly transfers heat from the battery cells to the coolant. The carbon dioxide circulation system then efficiently transports and dissipates the heat into the underground cavern, forming a highly efficient heat conduction path from the battery cells to the natural cold source. Its heat dissipation efficiency far exceeds that of traditional air or liquid cooling. The outside of the first, second and third pipelines are coated with an insulating layer, and insulating the pipelines minimizes the loss of cold during the carbon dioxide transport process, prevents condensation on the pipe walls, and efficiently transfers the cold from the underground cavern to the box body, improving the energy utilization efficiency of the entire system.

[0020] In this application, the number of boxes 11 may be one or more. When there are more than one, the first ends of the second heat exchangers 12 in each box 11 are combined together and connected to the first pipe 24, and the second ends of the second heat exchangers 12 in each box 11 are combined together and connected to the second pipe 32. By adopting a manifold system, it is ensured that all boxes are cooled by the same cooling system, which helps maintain the temperature uniformity of each box and prevents differences in the lifespan of internal modules caused by uneven cooling.

[0021] In this embodiment, the circulation pump 25 is a variable frequency circulation pump. The variable frequency pump allows the flow rate and speed of carbon dioxide to be intelligently adjusted according to the actual heat load. A temperature sensor is installed inside the enclosure to detect the internal temperature. The pump speed is reduced during low loads, further reducing the pump's energy consumption and reducing wear and noise. This achieves precise temperature control, energy savings, and quiet operation.

[0022] In this embodiment, there are multiple first heat exchangers 3, which are arranged in parallel with each other. Installing multiple parallel first heat exchangers in the underground cavern increases the contact area with the underground cold source, improving heat exchange efficiency. At the same time, this design also provides a certain degree of redundancy. Even if a problem occurs with one of the heat exchangers, the system can still maintain partial cooling capacity, improving cooling capacity and reliability.

[0023] To enhance operational safety, a backup circulating pump is provided on the first, second, or third pipeline. An emergency shut-off valve is also provided on the first, second, or third pipeline. In the event of a failure in the main circulating pump, the backup pump immediately takes over, preventing interruptions to the cooling system and significantly improving the operational reliability and availability of the system. This meets the high demands for continuous operation in industrial energy storage, data centers, or intelligent computing centers. In the event of a pipeline leak or other system emergency, the failed section can be quickly isolated, preventing the leakage of large amounts of carbon dioxide and ensuring the safety of equipment and personnel. This is an important safety protection measure.

[0024] During operation, cryogenic liquid carbon dioxide is pressurized by a circulating pump and transported through a sealed piping system to the second heat exchanger (coil) inside the box. During this process, the liquid carbon dioxide exchanges heat thoroughly with the immersion liquid, absorbing a large amount of heat and increasing in temperature. The liquid carbon dioxide is then transported through a thermally insulated piping system to a pre-constructed underground cavern storage facility. Within the underground cavern, the naturally low temperature environment and excellent thermal insulation of the earth's formations further cool the liquid carbon dioxide, maintaining it in a stable liquid state. Finally, after these cooling processes, the cryogenic liquid carbon dioxide is returned to the aboveground storage tank through a return piping system, completing the entire circulating cooling process. The entire system is fully sealed to ensure no carbon dioxide leaks, and a precise temperature control system maintains the optimal operating temperature at each stage.

[0025] To enhance the reliability of the system, multiple redundant mechanisms have been designed, including a standby pump group, emergency shut-off valves, and independent power supply units, to respond to unexpected situations. These measures not only enhance the cabinet's protection capability in extreme situations, but also facilitate subsequent fault diagnosis and maintenance.

[0026] The cooling system design takes into full consideration the actual needs of industrial and commercial applications, optimizing the piping layout and improving heat exchange efficiency to further enhance overall system performance. In actual operation, the cooling coil layout is determined through precise calculations to ensure that liquid carbon dioxide evenly covers the heat source area of ​​each battery cell, achieving highly efficient heat transfer.

[0027] This application incorporates an innovative design for the cooling system, eliminating the traditional built-in liquid cooling unit in favor of a more efficient, space-optimized solution. This improvement significantly improves the utilization of the cabinet's internal space and makes the overall structure simpler and more compact. By simplifying the mechanical structure of the cooling system, it effectively reduces the manufacturing costs of the device and reduces the complexity of later-stage maintenance. Furthermore, this new cooling method ensures heat dissipation performance while avoiding the risk of liquid leakage that may exist in traditional liquid cooling systems, further enhancing the safety and reliability of the system. This design optimization meets the stringent space utilization requirements of industrial and commercial applications while achieving the dual goals of cost control and performance assurance.

[0028] After sufficient heat exchange with the immersion liquid, the low-temperature liquid carbon dioxide absorbs a large amount of heat and its temperature rises. It is then transported through piping to the underground cavern. The natural low-temperature environment and excellent insulation of the formation further cool the liquid, maintaining it in a stable liquid state. A dedicated pump group and storage tank are installed outside the cabinet, and a high-efficiency circulation pump delivers the liquid carbon dioxide to a cooling coil network between each box unit. This design fully utilizes the excellent thermodynamic properties of carbon dioxide, allowing its liquid form to efficiently absorb the heat in the immersion liquid during the circulation process, achieving a rapid cooling effect. The heated liquid carbon dioxide is then safely transported to the pre-constructed underground cavern through a specially designed insulated piping system under strictly controlled pressure and flow rate. The natural low-temperature characteristics of the deep underground rock formations, combined with the insulating barrier formed by the special geological structure and the artificially reinforced insulation layer, allow the transported liquid carbon dioxide to continuously and steadily release heat, gradually lowering its temperature to an ideal level before finally returning to the storage tank.

[0029] It should be noted that the above is only a preferred embodiment of the present invention. Those skilled in the art can make various improvements and modifications without departing from the technical principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A cooling system that utilizes underground cold energy, Equipped with cabinets, underground cavern facilities, and a circulating cooling system, a box is provided within the cabinet, and a module to be cooled and a cooling liquid for immersing and cooling the module to be cooled are provided within the box; The underground cavern facility provides natural underground cooling and heating, the circulating cooling system includes a first heat exchanger, a carbon dioxide storage tank, a circulating pump, and a second heat exchanger; The first heat exchanger is installed in the underground cavern facility and absorbs natural cold energy in the underground cavern facility; the second heat exchanger is installed in the box and absorbs thermal energy of the cooling liquid; the carbon dioxide storage tank stores liquid carbon dioxide, and a liquid outlet of the carbon dioxide storage tank is connected to a first end of the second heat exchanger through a first pipe; a second end of the second heat exchanger is connected to a first end of the first heat exchanger through a second pipe, and the second end of the first heat exchanger is connected to a return end of the carbon dioxide storage tank through a third pipe, thereby forming a circulation pipe; A cooling system that utilizes underground cold energy, characterized in that a circulation pump that drives the flow of liquid carbon dioxide within the circulation pipeline is provided on at least one of the first pipeline, the second pipeline, and the third pipeline.

2. 2. The cooling system according to claim 1, wherein the box body is one or more, and first ends of the second heat exchangers in each box body are joined together and connected to the first pipe line, and second ends of the second heat exchangers in each box body are joined together and connected to the second pipe line.

3. The cooling system of claim 1 , wherein the circulation pump is a variable frequency circulation pump.

4. 2. The cooling system according to claim 1, wherein the first heat exchanger is a plurality of first heat exchangers arranged in parallel with each other.

5. 2. The cooling system according to claim 1, wherein a spare circulation pump is provided in any one of the first pipe line, the second pipe line, and the third pipe line.

6. The cooling system according to claim 1 , wherein an emergency shutoff valve is provided in any one of the first pipe line, the second pipe line, and the third pipe line.

7. 2. The cooling system according to claim 1, wherein the module to be cooled is an electronic or electrical heat-generating component.

8. The cooling system of claim 7, wherein the electronic or electrical heat-generating component is a battery, a GPU, a CPU, or a rectifier / inverter power module.

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