Data center carbon dioxide transcritical direct cooling chip backboard cooling system

Abstract

The invention provides a data center carbon dioxide transcritical direct cooling chip backboard cooling system, which comprises a carbon dioxide gas cooler configured to generate a coolant; the coolant is carbon dioxide in a liquid state or a gas-liquid coexistence state; a plurality of liquid cooling units, wherein the liquid cooling units are configured to perform refrigeration by gasifying the coolant; and the coolant distribution unit is respectively connected with all the liquid cooling units through independent pipelines, and the coolant distribution unit is configured to perform multi-stage regulation on the refrigerating capacity of all the liquid cooling units according to the regional cooling requirements. Through the system, the problem that an existing data center cooling system cannot achieve multi-stage heat exchange adjustment is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning systems, and in particular to a carbon dioxide transcritical direct cooling chip backplane cooling system for a data center. Background Art

[0002] Amidst the accelerating global digital transformation, data centers, as the core carriers of computing infrastructure, are experiencing exponential growth in both scale and energy consumption. According to statistics, energy consumption in traditional data center cooling systems accounts for 30%-40% of overall operating costs. However, with the advancement of artificial intelligence, 5G, and edge computing technologies, the heat flux generated by high-density server clusters has surpassed the heat dissipation limits of traditional air cooling technology. Furthermore, increasingly stringent international regulations on HFO refrigerants are driving the industry towards green cooling solutions with zero ozone depletion potential and low global warming potential.

[0003] Traditional data center cooling systems rely on a hierarchical heat dissipation architecture using HFO refrigerants, which results in system performance degradation. Computer room-level air cooling leads to over-cooling and energy waste due to the lengthy heat conduction path, and the heat dissipation capacity is unable to meet the heat flux density requirements of high-density chips. Furthermore, the high global warming potential of HFO refrigerants conflicts with environmental regulations.

[0004] In addition, the traditional data center cooling system's management of refrigerant distribution is too simple and cannot achieve multi-level heat exchange regulation. Summary of the Invention

[0005] This application proposes a data center carbon dioxide transcritical direct cooling chip backplane cooling system to solve the problem that existing data center cooling systems cannot achieve multi-stage heat exchange regulation.

[0006] The system comprises:

[0007] A carbon dioxide air cooler, wherein the carbon dioxide air cooler is configured to generate a coolant; the coolant is liquid carbon dioxide or a gas-liquid coexisting state;

[0008] a plurality of liquid cooling units, each configured to generate refrigeration by vaporizing the coolant;

[0009] A coolant distribution unit is connected to all the liquid cooling units through independent pipelines, and the coolant distribution unit is configured to perform multi-stage adjustment on the cooling capacity of all the liquid cooling units according to regional cooling requirements.

[0010] Preferably, the liquid cooling unit comprises:

[0011] A chip cold plate group, the chip cold plate group is arranged on the chip of the data center, the input end of the chip cold plate group is connected to the coolant distribution unit, and the chip cold plate group is configured to perform heat exchange gasification processing on the input coolant;

[0012] A backplate heat exchanger is provided on the chip backplate of the data center, the backplate heat exchanger is connected in parallel with the chip cold plate group, the input end of the backplate heat exchanger is connected to the coolant distribution unit, and the backplate heat exchanger is configured to perform heat exchange and vaporization processing on the input coolant.

[0013] Preferably, the coolant distribution unit comprises:

[0014] A low-pressure circulation component is configured to deliver different volumes of the coolant to the corresponding liquid cooling unit at different flow rates.

[0015] Preferably, the coolant distribution unit further comprises an output pipe assembly, one end of the output pipe assembly is connected to the low-pressure circulation assembly, and the other end of the output pipe assembly is respectively connected to the chip cold plate group and the back plate heat exchanger in the liquid cooling unit, and the output pipe assembly is configured to transport the coolant;

[0016] The low-pressure circulation assembly is further configured to deliver the coolant to the chip cold plate assembly and the back plate heat exchanger through the output pipe assembly.

[0017] Preferably, the output ends of the chip cold plate group and the back plate heat exchanger are both connected to the return flow input end of the low-pressure circulation component.

[0018] Preferably, the reflux output end of the low-pressure circulation component is connected to the carbon dioxide air cooler, and the low-pressure circulation component is further configured as follows:

[0019] delivering the liquid refrigerant and the gaseous refrigerant refluxed from the chip cold plate group and the back plate heat exchanger to the carbon dioxide air cooler;

[0020] The carbon dioxide gas cooler is further configured to re-cool the liquid refrigerant and the gaseous refrigerant transported by the low-pressure circulation component to obtain the coolant.

[0021] Preferably, the coolant distribution unit further comprises a return pipe assembly, wherein the return pipe assembly comprises a return input pipe and a return output pipe;

[0022] One end of the reflux input pipe is connected to the chip cold plate group and the back plate heat exchanger respectively, and the other end of the reflux input pipe is connected to the low-pressure circulation component;

[0023] One end of the reflux output pipeline is connected to the low-pressure circulation component, and the other end of the reflux output pipeline is connected to the carbon dioxide air cooler.

[0024] Preferably, the coolant distribution unit further comprises an input pipe assembly, one end of the input pipe assembly is connected to the low-pressure circulation assembly, and the other end of the input pipe assembly is connected to the carbon dioxide air cooler.

[0025] Preferably, the input pipeline assembly includes an electric throttle valve and a first switching electric stop valve.

[0026] Preferably, the output pipe assembly includes:

[0027] A spare pipeline, the spare pipeline being configured to be connected to the added liquid cooling unit, the spare pipeline and the remaining pipelines of the output pipeline assembly being provided with a carbon dioxide working fluid pump, a pressure sensor, and a first pressure reducing valve;

[0028] The backup pipeline is also provided with a second switching electric stop valve;

[0029] The reflux output pipeline is provided with a carbon dioxide compressor and a second pressure reducing valve.

[0030] As can be seen from the above, this application provides a data center carbon dioxide transcritical direct-cooling chip backplane cooling system, which includes a carbon dioxide gas cooler configured to generate a coolant; the coolant is liquid carbon dioxide; a plurality of liquid cooling units, each configured to perform refrigeration by vaporizing the coolant; and a coolant distribution unit, each connected to each of the liquid cooling units via independent pipelines, configured to perform multi-stage adjustment of the cooling capacity of each of the liquid cooling units based on regional cooling needs. Through the above system, this application solves the problem that existing data center cooling systems cannot achieve multi-stage heat exchange adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 This is a schematic diagram of a data center carbon dioxide transcritical direct cooling chip backplane cooling system for this application. DETAILED DESCRIPTION

[0033] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] It should be noted that the brief descriptions of terms in this application are only for the purpose of facilitating the understanding of the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their ordinary and usual meanings.

[0035] It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0036] Amidst the industrial transformation driven by the deep integration of the digital economy and intelligent technologies, data centers, as the physical carriers supporting cloud computing and artificial intelligence, are experiencing a simultaneous surge in computing power density and energy consumption. With the prevalence of heterogeneous computing architectures and the evolution of chip packaging technologies, single-rack power density has surpassed the 30kW threshold, and heat flow distribution has exhibited significant non-uniformity and dynamic fluctuations. The latest report from the International Energy Agency indicates that data centers account for 2% of global electricity consumption annually. As a key energy consumer, optimizing the energy efficiency of thermal management systems has become a core issue hindering the sustainable development of the industry.

[0037] The current mainstream cooling system follows a hierarchical heat transfer architecture, forming discrete thermal management loops at the computer room, cabinet, and chip levels. While this progressive cooling model ensures basic thermal safety, it exposes multiple systemic flaws in actual operation. First, the physical segmentation of the heat transfer path results in a lack of coordinated control mechanisms among the heat exchange units at each level. This leads to thermal response lags between the computer room air conditioning system and the internal cooling modules of the servers, necessitating the implementation of a global overcooling strategy to compensate for local hot spots. Second, the phase change cooling system based on HFO refrigerants is constrained by the inherent limitations of a single loop, making it difficult to dynamically allocate refrigerant flow based on real-time heat loads, often resulting in ineffective cooling redundancy under full load conditions. Furthermore, faced with the three-dimensional, non-steady-state thermal field generated by high-density computing equipment, traditional systems lack a cross-level adaptive adjustment mechanism, which can easily lead to the risk of cascading thermal runaway when responding to sudden thermal shocks.

[0038] The existing cooling architecture's piping design lacks multi-fluid compatibility interfaces, and the condenser-evaporator coupling method struggles to support the phase change characteristics of new, environmentally friendly refrigerants, leading to exponentially increasing system retrofit costs. More critically, the current cooling capacity distribution mechanism relies solely on mechanical throttling devices for crude control, lacking precise cooling capabilities based on the spatial distribution of heat sources. This makes it impossible to build a multi-stage heat exchange network that matches the thermal demands of server clusters.

[0039] Existing technologies have fundamental design flaws in the dimension of multi-stage heat exchange regulation. Traditional solutions usually adopt a fixed refrigerant distribution strategy to achieve homogeneous flow supply in the entire circuit through unified pressure drop control. When dealing with the heterogeneous heat dissipation needs of multiple heat sources, this single-point control mode can neither implement zoned cooling according to the differences in heat flux density at the chip level, nor establish a dynamic balance between hot and cold channels at the cabinet level. When high-power computing units coexist with low-load storage devices, the system can only meet peak demand by increasing the overall cooling capacity, resulting in up to 40% ineffective cooling loss. In addition, the temperature gradient of the heat exchange medium between the layers lacks effective connection, and there is a significant heat transfer barrier between the computer room-level chiller and the cabinet-level cooling module, resulting in a cross-level heat exchange efficiency drop of approximately 25%.

[0040] At the level of intelligent control, existing systems have yet to overcome the physical limitations of one-way heat transfer. While some solutions have attempted to incorporate control components such as variable-frequency compressors and electronic expansion valves, their control logic remains at the single-variable feedback level, failing to establish a collaborative decision-making model based on multi-dimensional thermal characteristic parameters. This is particularly true when dealing with multiphase flow coupled heat transfer problems. The lack of coordinated analysis of key parameters such as liquid refrigerant distribution, gaseous working fluid flow rate, and solid interface contact thermal resistance prevents the system from achieving dynamic matching of heat transfer intensity across multiple levels.

[0041] Based on the above problems, the present application provides the following implementation methods.

[0042] Figure 1 This is a schematic diagram of a data center carbon dioxide transcritical direct cooling chip backplane cooling system for this application.

[0043] See also Figure 1 It can be seen that this embodiment provides a data center carbon dioxide transcritical direct cooling chip backplane cooling system, the system comprising:

[0044] The carbon dioxide air cooler 100 is configured to generate a coolant; the coolant is liquid carbon dioxide or a gas-liquid coexisting state.

[0045] Specifically, in this embodiment, the carbon dioxide gas cooler 100 is used to provide the coolant. It can be understood that the carbon dioxide gas cooler 100 is a device for liquefying carbon dioxide gas. The carbon dioxide gas cooler 100 converts gaseous carbon dioxide into liquid carbon dioxide or gas-liquid coexisting carbon dioxide, thereby realizing the subsequent provision of the coolant.

[0046] It should be noted that the carbon dioxide air cooler 100 is not a single condensing device, but has both air cooling and condensing functions. During transcritical operation, the carbon dioxide air cooler 100 plays an air cooling role, that is, the carbon dioxide gas is cooled to obtain mist-like carbon dioxide; during subcritical operation, the carbon dioxide air cooler 100 plays a condensing role, that is, the carbon dioxide gas is condensed to obtain liquid carbon dioxide.

[0047] The system further comprises:

[0048] A plurality of liquid cooling units 200 are provided, each of which is configured to generate refrigeration by vaporizing the coolant.

[0049] Specifically, in this embodiment, the liquid cooling unit 200 is set on the equipment that needs to be cooled in the data center. The liquid cooling unit 200 exchanges heat with the liquid coolant in the pipeline and the external environment, thereby absorbing heat from the external environment, thereby practically regulating the external environment temperature.

[0050] The system further comprises:

[0051] The coolant distribution unit 300 is connected to all the liquid cooling units 200 through independent pipelines. The coolant distribution unit 300 is configured to perform multi-stage adjustment on the cooling capacity of all the liquid cooling units 200 according to regional cooling requirements.

[0052] Specifically, in this embodiment, considering that different locations in the data center need to be cooled to different degrees, and the cooling equipment of the existing data center generally performs the same degree of cooling on the entire data center, resulting in a waste of cooling resources, the coolant distribution unit 300 is provided, and the coolant distribution unit 300 is connected to the multiple liquid cooling units 200 through independent pipelines, and multi-stage cooling adjustment is performed on all the liquid cooling units 200, so as to maximize the utilization of the refrigerant.

[0053] Furthermore, in some embodiments, the liquid cooling unit 200 includes:

[0054] A chip cold plate assembly 210, which is disposed on a chip in a data center. An input end of the chip cold plate assembly 210 is connected to the coolant distribution unit 300, and the chip cold plate assembly 210 is configured to perform heat exchange and gasification processing on the input coolant;

[0055] The backplate heat exchanger 220 is arranged on the chip backplate of the data center. The backplate heat exchanger 220 is connected in parallel with the chip cold plate group 210. The input end of the backplate heat exchanger 220 is connected to the coolant distribution unit 300. The backplate heat exchanger 220 is configured to perform heat exchange and gasification processing on the input coolant.

[0056] Specifically, in this embodiment, in the temperature regulation of the data center, the chip equipment in the data center is mainly cooled, and the main cooling parts of the chip equipment include the chip body and the backplane of the chip. Therefore, the chip cold plate group 210 is set to cool the chip body. The cooling method is to exchange heat with the external environment and vaporize the liquid coolant, thereby absorbing a large amount of external heat, thereby achieving cooling of the chip body.

[0057] The backplane heat exchanger 220 is provided to cool the chip backplane. The cooling method is also to exchange heat with the external environment and vaporize the liquid coolant to absorb a large amount of external heat, thereby achieving cooling of the chip backplane.

[0058] Furthermore, in some embodiments, the coolant distribution unit 300 includes:

[0059] The low-pressure circulation component 310 is configured to deliver different volumes of the coolant to the corresponding liquid cooling unit 200 at different flow rates.

[0060] Specifically, in this embodiment, the coolant input to the carbon dioxide gas cooler 100 is adjusted by the low-pressure circulation component 310, thereby distributing the coolant to a plurality of the liquid cooling units 200, thereby achieving different cooling treatments at different locations in the data center.

[0061] Furthermore, in some embodiments, the coolant distribution unit 300 further includes an output pipe assembly 320, one end of the output pipe assembly 320 is connected to the low-pressure circulation assembly 310, and the other end of the output pipe assembly 320 is respectively connected to the chip cold plate assembly 210 and the back plate heat exchanger 220 in the liquid cooling unit 200, and the output pipe assembly 320 is configured to transport the coolant;

[0062] The low-pressure circulation component 310 is further configured to deliver the coolant to the chip cold plate assembly 210 and the back plate heat exchanger 220 through the output pipe component 320 .

[0063] Specifically, in this embodiment, since the coolant distribution unit 300 needs to perform multi-stage temperature reduction regulation on multiple liquid cooling units 200, it is necessary to set the output pipe assembly 320 that is connected to all the liquid cooling units 200 respectively. When the low-pressure circulation assembly 310 needs to deliver the coolant to the corresponding liquid cooling unit 200, it is only necessary to adjust the opening of the corresponding pipe in the output pipe assembly 320, the size of the valve opening and the rate of delivering the coolant to achieve the distribution of the coolant to different liquid cooling units 200 according to different needs. Among them, the heat exchange capacity of the chip cold plate group 210 and the backplate heat exchanger 220 in the same liquid cooling unit 200 can also be adjusted by setting corresponding valves on their respective pipes, that is, the heat exchange capacity of different liquid cooling units 200 can be adjusted, and the heat exchange capacity of the chip cold plate group 210 and the backplate heat exchanger 220 in the same liquid cooling unit 200 can also be adjusted.

[0064] Furthermore, in some embodiments, the output ends of the chip cold plate assembly 210 and the back plate heat exchanger 220 are both connected to the return input end of the low-pressure circulation component 310 .

[0065] Specifically, in this embodiment, after the coolant in the chip cold plate group 210 and the back plate heat exchanger 220 completes a cycle of cooling, it flows back to the low-pressure circulation component 310, so that the coolant after heat exchange can be reused to avoid waste of the coolant.

[0066] Furthermore, in some embodiments, the reflux output end of the low-pressure circulation component 310 is connected to the carbon dioxide gas cooler 100, and the low-pressure circulation component 310 is further configured as follows:

[0067] The liquid refrigerant and the gaseous refrigerant refluxed from the chip cold plate assembly 210 and the back plate heat exchanger 220 are delivered to the carbon dioxide air cooler 100;

[0068] The carbon dioxide gas cooler 100 is further configured to re-cool the liquid refrigerant and the gaseous refrigerant delivered by the low-pressure circulation component 310 to obtain the coolant.

[0069] Specifically, in this embodiment, when the chip cold plate group 210 and the backplate heat exchanger 220 input the liquid refrigerant and the gaseous refrigerant that have completed heat exchange into the low-pressure circulation component 310, the low-pressure circulation component 310 transports the liquid refrigerant and the gaseous refrigerant to the carbon dioxide air cooler 100 for condensation processing, thereby realizing the secondary utilization of the coolant.

[0070] Furthermore, in some embodiments, the coolant distribution unit 300 further includes a return pipe assembly 330 , wherein the return pipe assembly 330 includes a return input pipe 331 and a return output pipe 332 ;

[0071] One end of the return input pipe 331 is connected to the chip cold plate assembly 210 and the back plate heat exchanger 220 respectively, and the other end of the return input pipe 331 is connected to the low-pressure circulation component 310;

[0072] One end of the reflux output pipe 332 is connected to the low-pressure circulation component 310 , and the other end of the reflux output pipe 332 is connected to the carbon dioxide air cooler 100 .

[0073] Specifically, in this embodiment, since the chip cold plate group 210 and the back plate heat exchanger 220 need to transport the working medium that has completed heat exchange back to the carbon dioxide air cooler 100 through the low-pressure circulation component 310, corresponding pipelines are required to complete the transportation of the working medium. Therefore, the return pipe component 330 is set, and the chip cold plate group 210 and the back plate heat exchanger 220 are respectively connected to the low-pressure circulation component 310 through the return input pipe 331 in the return pipe component 330, and the low-pressure circulation component 310 is connected to the carbon dioxide air cooler 100 through the return output pipe 332; when the return working medium is transported to the low-pressure circulation component 310, the return working medium is pressure-configured by the low-pressure circulation component 310 so that it returns to the carbon dioxide air cooler 100 through the return output pipe 332 for re-cooling treatment.

[0074] Furthermore, in some embodiments, the coolant distribution unit 300 further includes an input pipe assembly 340 , one end of which is connected to the low-pressure circulation assembly 310 , and the other end of which is connected to the carbon dioxide air cooler 100 .

[0075] Specifically, in this embodiment, since the carbon dioxide air cooler 100 also needs to use a pipeline to transport the coolant waiting for heat exchange to the low-pressure circulation component 310, the input pipeline component 340 is provided to connect the carbon dioxide air cooler 100 and the low-pressure circulation component 310, thereby constructing a pipeline path for transporting the coolant from the carbon dioxide air cooler 100 to the low-pressure circulation component 310.

[0076] Furthermore, in some embodiments, the input pipeline assembly 340 includes an electric throttle valve 341 and a first switch electric stop valve 342;

[0077] The output pipeline component 320 includes:

[0078] A spare pipeline 321, which is configured to be connected to the added liquid cooling unit 200. The spare pipeline 321 and the remaining pipelines of the output pipeline assembly 320 are all provided with a carbon dioxide working medium pump 322, a pressure sensor 323, and a first pressure reducing valve 324;

[0079] The backup pipeline 321 is further provided with a second switching electric stop valve 325;

[0080] The reflux output pipe 332 is provided with a carbon dioxide compressor 333 and a second pressure reducing valve 334 .

[0081] Specifically, in this embodiment, since the coolant needs to be pressure-adjusted during transportation in the pipeline so that it can be transported smoothly, the above-mentioned valve is required to adjust the delivery pressure of each pipeline, and the pressure inside the pipeline is detected by the pressure sensor 323, so as to realize real-time monitoring of the condition of each pipeline.

[0082] This embodiment has the following advantages:

[0083] It uses pure CO2 refrigerant, which has a zero ozone depletion potential of 0 and a global warming potential of 1, and is naturally pollution-free. The system uses a 120bar high-pressure and 80bar low-pressure transcritical cycle design, combined with a microchannel cold plate to directly cool the chip, to achieve ultra-low heat exchange temperature difference. Compared with other refrigeration systems, it has higher heat exchange efficiency and higher heat exchange sensitivity, allowing the cooling system to quickly respond to chip power changes, which is more conducive to the heat dissipation needs of high-power and high-heat-generating chips, while realizing source-load-following and dynamic operation.

[0084] Through multi-stage heat exchange adjustment, the utilization efficiency of refrigerant is greatly improved and the waste of refrigerant is reduced.

[0085] For ease of explanation, the above description has been made in conjunction with specific embodiments. However, the above discussion of some embodiments is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations can be obtained. The above embodiments are selected and described to better explain the content of this disclosure, thereby enabling those skilled in the art to better use the embodiments.

Claims

1. A data center carbon dioxide transcritical direct cooling chip backplane cooling system, characterized in that: The system comprises: A carbon dioxide air cooler (100), the carbon dioxide air cooler (100) being configured to generate a coolant; the coolant being liquid carbon dioxide or a gas-liquid coexisting state; a plurality of liquid cooling units (200), wherein the liquid cooling units (200) are configured to perform cooling by gasifying the coolant; A coolant distribution unit (300) is connected to all the liquid cooling units (200) through independent pipelines, and the coolant distribution unit (300) is configured to perform multi-stage adjustment on the cooling capacity of all the liquid cooling units (200) according to regional cooling requirements.

2. A data center carbon dioxide transcritical direct cooling chip backplane cooling system according to claim 1, characterized in that: The liquid cooling unit (200) comprises: A chip cold plate group (210), the chip cold plate group (210) is arranged on a chip in a data center, an input end of the chip cold plate group (210) is connected to the coolant distribution unit (300), and the chip cold plate group (210) is configured to perform heat exchange gasification processing on the input coolant; A backplate heat exchanger (220) is provided on a chip backplate of a data center, the backplate heat exchanger (220) is connected in parallel with the chip cold plate group (210), an input end of the backplate heat exchanger (220) is connected to the coolant distribution unit (300), and the backplate heat exchanger (220) is configured to perform heat exchange and gasification processing on the input coolant.

3. The data center carbon dioxide transcritical direct cooling chip backplane cooling system according to claim 2, characterized in that: The coolant distribution unit (300) comprises: A low-pressure circulation component (310) is configured to deliver different volumes of the coolant to the corresponding liquid cooling unit (200) at different flow rates.

4. The data center carbon dioxide transcritical direct cooling chip backplane cooling system according to claim 3 is characterized in that: The coolant distribution unit (300) further comprises an output pipe assembly (320), one end of the output pipe assembly (320) being connected to the low-pressure circulation assembly (310), and the other end of the output pipe assembly (320) being respectively connected to the chip cold plate group (210) and the back plate heat exchanger (220) in the coolant cooling unit (200), and the output pipe assembly (320) being configured to transport the coolant; The low-pressure circulation component (310) is further configured to deliver the coolant to the chip cold plate assembly (210) and the back plate heat exchanger (220) through the output pipe component (320).

5. The data center carbon dioxide transcritical direct cooling chip backplane cooling system according to claim 4, characterized in that: The output ends of the chip cold plate group (210) and the back plate heat exchanger (220) are both connected to the return flow input end of the low-pressure circulation component (310).

6. A data center carbon dioxide transcritical direct cooling chip backplane cooling system according to claim 5, characterized in that: The reflux output end of the low-pressure circulation component (310) is connected to the carbon dioxide air cooler (100), and the low-pressure circulation component (310) is further configured as follows: delivering the liquid refrigerant and the gaseous refrigerant refluxed from the chip cold plate group (210) and the back plate heat exchanger (220) to the carbon dioxide air cooler (100); The carbon dioxide gas cooler (100) is further configured to re-cool the liquid refrigerant and the gaseous refrigerant transported by the low-pressure circulation component (310) to obtain the coolant.

7. The data center carbon dioxide transcritical direct cooling chip backplane cooling system according to claim 6, characterized in that: The coolant distribution unit (300) further includes a return pipe assembly (330), wherein the return pipe assembly (330) includes a return input pipe (331) and a return output pipe (332); One end of the reflux input pipe (331) is connected to the chip cold plate group (210) and the back plate heat exchanger (220), respectively, and the other end of the reflux input pipe (331) is connected to the low-pressure circulation component (310); One end of the reflux output pipe (332) is connected to the low-pressure circulation component (310), and the other end of the reflux output pipe (332) is connected to the carbon dioxide air cooler (100).

8. The data center carbon dioxide transcritical direct cooling chip backplane cooling system according to claim 7, characterized in that: The coolant distribution unit (300) further comprises an input pipe assembly (340), one end of the input pipe assembly (340) being connected to the low-pressure circulation assembly (310), and the other end of the input pipe assembly (340) being connected to the carbon dioxide air cooler (100).

9. The data center carbon dioxide transcritical direct cooling chip backplane cooling system according to claim 8, characterized in that: The input pipeline assembly (340) includes an electric throttle valve (341) and a first switching electric stop valve (342).

10. The data center carbon dioxide transcritical direct cooling chip backplane cooling system according to claim 8, characterized in that: The output pipe assembly (320) includes: A spare pipeline (321), the spare pipeline (321) is configured to be connected to the added liquid cooling unit (200), and the spare pipeline (321) and the remaining pipelines of the output pipeline assembly (320) are all provided with a carbon dioxide working medium pump (322), a pressure sensor (323) and a first pressure reducing valve (324); The standby pipeline (321) is further provided with a second switching electric stop valve (325); The reflux output pipeline (332) is provided with a carbon dioxide compressor (333) and a second pressure reducing valve (334).

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