Power plant steam extraction driven cold generation and storage integrated system suitable for data center

Abstract

The invention discloses a power plant steam extraction driven cold generation and storage integrated system suitable for a data center. The technical problem that a traditional waste heat utilization mode is difficult to directly meet the cold energy requirement of the data center is solved. The system comprises a steam turbine, an electric refrigeration system, a steam type absorption refrigeration system, a hot water type absorption refrigeration system, a phase change cold storage device and a heat exchanger set. The steam turbine receives high-temperature steam of a power plant steam extraction pipeline to drive the turbine to generate electricity and output electric power and waste heat steam. The electric refrigeration system conducts mechanical refrigeration through electric energy generated by power generation of a steam turbine, the steam type absorption refrigeration system and the hot water type absorption refrigeration system conduct refrigeration through waste heat steam and hot water, and gradient utilization of energy is achieved. The phase change cold storage device is used for storing excess cold energy and surplus cold energy in the low-temperature period at night, and cascade transfer and heat exchange of energy are achieved through the heat exchanger set. Dependence on direct supply of a power grid is reduced, and the dual purposes of energy conservation and stable cooling are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy utilization and refrigeration systems, and in particular to a power plant steam extraction driven integrated cooling system suitable for data centers. Background Art

[0002] Data centers in South China currently face a significant energy consumption challenge. The PUE (Power Usage Effectiveness) of most data centers remains between 1.6 and 1.8, despite national standards requiring a PUE < 1.5 for Level 3 energy efficiency. This is due to the fact that non-IT systems still consume a high proportion of energy, with cooling systems accounting for the highest share of energy consumption among these systems. Field research has revealed several issues with data center cooling systems, including the following:

[0003] (1) Single cooling energy supply model: Survey results show that most data center cooling systems still rely on traditional direct power supply from the grid to achieve mechanical cooling. In this process, the system design does not fully consider the possible impact of surrounding environmental facilities on the cooling effect.

[0004] (2) Impact of computing load fluctuations on the cooling system: The cooling load in the computer room changes due to fluctuations in computing load, causing the load rate of the cooling system to fluctuate, which in turn causes a decrease in system energy efficiency.

[0005] (3) Insufficient utilization of low-temperature resources at night: The energy efficiency of refrigeration units is affected by the ambient temperature. The energy efficiency of refrigeration units is expected to improve in low-temperature environments. However, the existing system fails to effectively utilize low-temperature resources at night to improve overall energy efficiency.

[0006] Traditional waste heat utilization methods (such as combined heat and power generation) cannot directly meet the cooling energy needs of data centers. Therefore, a combined cooling system driven by power plant steam extraction suitable for data centers is urgently needed to achieve cascaded waste heat utilization and dynamic load balancing. Summary of the Invention

[0007] The purpose of the present invention is to provide a power plant steam extraction driven integrated cooling system suitable for data centers, so as to solve the technical problem that traditional waste heat utilization methods are difficult to directly meet the cooling energy needs of data centers.

[0008] To achieve the above objectives, the present invention provides the following technical solutions:

[0009] The present invention provides a power plant extraction steam driven integrated cooling system suitable for data centers, comprising: a steam turbine, an electric refrigeration system, a steam absorption refrigeration system, a hot water absorption refrigeration system, a phase change cooling storage device, and a heat exchanger group; wherein,

[0010] The input end of the steam turbine is connected to the power plant extraction pipeline, and is used to receive high-temperature steam and drive the turbine to generate electricity. The output end of the steam turbine is divided into an electric power output end and a waste heat steam output end;

[0011] The electric refrigeration system includes a compressor, a third evaporator, a condenser and a throttling device, wherein the power input end of the compressor is connected to the power output end of the steam turbine, and the compressor, condenser, throttling device and the third evaporator are sequentially connected through a refrigerant pipeline to form a closed circulation loop;

[0012] The steam absorption refrigeration system includes a first high-pressure generator and a first evaporator, whose input end is connected to the waste heat steam output end of the steam turbine through a steam pipe; the hot water absorption refrigeration system includes a second high-pressure generator and a second evaporator, whose input end is connected to the hot water output end of the steam absorption refrigeration system through a hot water pipe;

[0013] The input end of the phase change cold storage device is connected to the cooling output end of the electric refrigeration system, the steam absorption refrigeration system and the hot water absorption refrigeration system respectively, and is used to store excess cooling and surplus cooling generated during the low temperature period at night;

[0014] The heat exchanger group includes multiple heat exchange units, which are respectively arranged between the steam type absorption refrigeration system and the hot water type absorption refrigeration system, and in the waste heat recovery pipeline of each refrigeration system, for realizing the cascade transfer of energy and heat exchange.

[0015] Furthermore, the steam turbine is a turbine unit in a combined cycle power generation unit, and its input steam temperature is 300°C and pressure is 1.6 MPa; the output waste heat steam temperature is 229°C and pressure is 0.8 MPa.

[0016] Furthermore, it also includes a water collector and a water distributor. The input end of the water collector is connected to the chilled water output end of the electric refrigeration system, the steam-type absorption refrigeration system, the hot water absorption refrigeration system and the phase change cold storage device; the output end of the water distributor is connected to the evaporator of the electric refrigeration system, the steam-type absorption refrigeration system and the hot water absorption refrigeration system. The collected chilled water is used to cool the data center. After cooling, the return water is transported to each system through the water distributor for further cooling. The entire cooling process forms a closed circulation loop.

[0017] Furthermore, the system also includes a control module for dynamically adjusting the cooling capacity output of the electric refrigeration system, the steam-type absorption refrigeration system, and the hot water absorption refrigeration system according to the cooling load demand of the data center, and achieving load balancing through the phase change cold storage device; during the low temperature period at night, the cold energy generated by the refrigeration system is preferentially stored in the phase change cold storage device, and during the high temperature period during the day or the peak period of cooling demand, the cold energy stored in the phase change cold storage device is released to assist in cooling.

[0018] Furthermore, the steam-type absorption refrigeration system is a lithium bromide absorption chiller, and the temperature of the first-stage waste heat hot water output by it is 95°C; the hot water-type absorption refrigeration system is a lithium bromide absorption chiller, and the temperature of the second-stage waste heat hot water output by it is 70°C.

[0019] Furthermore, the phase change cold storage device uses a hydrated salt phase change material with a melting point of 8°C, and its cold storage density is more than twice that of cold water.

[0020] Based on the above technical solution, the embodiments of the present invention can produce at least the following technical effects:

[0021] The present invention provides a power plant extraction steam driven integrated cooling and storage system suitable for data centers. The system uses power plant extraction steam to drive a steam turbine to generate electricity, directly powering the electric refrigeration system and reducing dependence on direct power supply from the power grid; at the same time, waste heat steam and hot water are used to drive a two-stage absorption refrigeration system to achieve cascade utilization of energy. According to actual measurements, the overall energy saving efficiency of the system reached 21.3%, significantly reducing the PUE value of the data center and meeting the national standard level 3 energy efficiency requirements. In addition, the waste heat steam output by the steam turbine first drives the steam-type absorption refrigeration system, and the generated 95°C high-temperature hot water further drives the hot water-type absorption refrigeration system to achieve secondary utilization of waste heat. By optimizing the heat exchange process through the heat exchanger group, the comprehensive energy utilization rate is increased by more than 35%, effectively reducing In addition, the system design includes a high-efficiency phase-change cold storage device to store excess cooling capacity and low-temperature surplus cooling capacity at night. This not only helps to regulate the load fluctuations of the refrigeration unit, but also improves the overall energy efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0023] Figure 1 It is a structural diagram of an embodiment of the present invention;

[0024] In the figure: 1. Steam turbine; 2. Electric refrigeration system; 201. Compressor; 202. Third evaporator; 203. Condenser; 204. Throttling device; 3. Steam-type absorption refrigeration system; 301. First high-pressure generator; 302. First evaporator; 4. Hot water-type absorption refrigeration system; 401. Second high-pressure generator; 402. Second evaporator; 5. Phase-change cold storage device; 6. Heat exchanger group; 7. Water collector; 8. Water distributor. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] This embodiment provides a power plant steam extraction driven integrated cooling and storage system suitable for data centers. Figure 1 Described together, the integrated cold storage system includes a steam turbine 1, an electric refrigeration system 2, a steam absorption refrigeration system 3, a hot water absorption refrigeration system 4, a phase change cold storage device 5, a heat exchanger group 6, a water collector 7 and a water distributor 8.

[0027] Steam turbine 1 is the turbine unit in a combined cycle power generation unit. Its input is connected to the power plant's extraction pipeline, receiving high-temperature steam at 300°C and 1.6 MPa to drive the turbine for power generation. The output of steam turbine 1 is divided into an electrical output terminal and a waste heat steam output terminal. The waste heat steam has a temperature of 229°C and a pressure of 0.8 MPa.

[0028] The electric refrigeration system 2 comprises a compressor 201, a condenser 203, a throttling device 204, and a third evaporator 202, forming a closed refrigerant circulation loop through refrigerant piping. The power input of compressor 201 is connected to the power output of steam turbine 1, and the electricity generated by steam turbine 1 drives the refrigeration cycle. After being compressed by the compressor, the refrigerant enters the condenser and condenses into a high-pressure liquid. After being depressurized by the throttling device, it enters the third evaporator 202, where it evaporates and absorbs heat, providing cooling for the data center.

[0029] Steam-type absorption refrigeration system 3 is a lithium bromide absorption chiller, comprising a first high-pressure generator 301 and a first evaporator 302. Its input is connected to the waste heat steam output of steam turbine 1 via a steam pipe, utilizing the waste heat steam to drive the refrigeration cycle. In the first high-pressure generator 301, the lithium bromide solution absorbs heat from the waste heat steam, separating it into refrigerant water vapor. This water vapor condenses in the condenser and then enters the first evaporator 302, evaporating and absorbing heat, thereby outputting cooling capacity. The 95°C hot water generated by the waste heat steam is transported via a hot water pipe to the hot water-type absorption refrigeration system 4.

[0030] Hot water absorption refrigeration system 4 is also a lithium bromide absorption chiller, comprising a second high-pressure generator 401 and a second evaporator 402. Its input is connected to the hot water output of steam absorption refrigeration system 3 via a hot water pipe. 95°C hot water drives second high-pressure generator 401. After releasing heat in second high-pressure generator 401, the hot water cools to 70°C before entering second evaporator 402, where it evaporates further, absorbing heat and delivering a second level of cooling capacity.

[0031] The input of the phase-change cold storage device 5 is connected to the cooling outputs of the electric refrigeration system 2, the steam absorption refrigeration system 3, and the hot water absorption refrigeration system 4. This device utilizes a hydrated salt phase-change material with a melting point of 8°C, such as calcium chloride hexahydrate, which has a cold storage density more than twice that of cold water. During nighttime low temperatures or when there is excess cooling, the cold storage device stores cold energy; during daytime high temperatures or peak cooling demand, it releases this cold energy to assist in cooling.

[0032] Heat exchanger assembly 6 includes multiple heat exchange units, located between steam absorption refrigeration system 3 and hot water absorption refrigeration system 4, as well as in the waste heat recovery pipelines of each refrigeration system. For example, the high-temperature hot water output from steam absorption refrigeration system 3 and the low-temperature return water from hot water absorption refrigeration system 4 undergo heat exchange through the heat exchangers, achieving cascaded utilization of waste heat.

[0033] The input of the water collector 7 is connected to the chilled water output of each refrigeration system and cold storage device. The collected chilled water is distributed to the terminal cooling equipment of the data center through the water distributor 8. The cooled return water is then transported back to the evaporators of each refrigeration system through the water distributor 8, forming a closed circulation loop.

[0034] The control module dynamically adjusts the operating status of each cooling system according to the cooling load demand of the data center. Specifically, it includes:

[0035] During the low-temperature period at night, the cold energy is preferentially stored in the phase-change cold storage device 5; during the high-temperature period during the day, the cold storage device is started to release the cold energy, and the compressor power of the electric refrigeration system 2 is adjusted to match the load; the cold load changes are monitored in real time through sensors, and the waste heat distribution ratio of the steam-type and hot water-type absorption refrigeration systems is optimized.

[0036] The working principle of each link of the system of the present invention will be explained in detail below:

[0037] 1. Steam type and hot water type lithium bromide absorption refrigeration system:

[0038] A lithium bromide absorption chiller uses lithium bromide solution as the absorbent and water as the refrigerant, achieving refrigeration by evaporating water under a high vacuum and absorbing heat. To ensure a continuous refrigeration process, the evaporated refrigerant water vapor is absorbed by the lithium bromide solution, diluting the solution. This process occurs in the absorber. Then, using thermal energy as a driving force, the solution is heated to separate the water, concentrating the solution. This process occurs in the generator. The generator is filled with lithium bromide solution at a low pressure. When slightly heated, water evaporates from the lithium bromide solution (water evaporates more readily than lithium bromide). The evaporated water vapor condenses in the condenser, becoming refrigerant water. This evaporated water vapor then passes through a throttle valve and evaporates in the evaporator. This evaporated water vapor, removing heat from the chamber, is then absorbed by the lithium bromide solution in the absorber (lithium bromide solution particularly absorbs water vapor). This solution is then heated and evaporated in the generator, repeating this cycle continuously, completing the refrigeration cycle. The steam from the generator condenses into water in the condenser, which, after throttling, is sent to the evaporator for evaporation. This cycle achieves the purpose of continuous refrigeration.

[0039] A two-stage refrigeration system is used here. The high-temperature steam is first cooled by the steam absorption refrigeration system. Then the low-temperature waste heat generated in the generator part flows through the hot water absorption refrigeration system for cooling, so as to achieve the cascade utilization and efficient utilization of energy and reduce damage.

[0040] 2. Working principle of steam turbine:

[0041] Superheated steam extracted from the power plant enters the turbine, where it expands and generates work, rotating the blades and driving the generator. Unlike traditional waste heat utilization methods, which achieve combined heat and power through heat exchangers and other devices, this system aims to achieve efficient cooling in data centers, thus utilizing waste heat to generate cooling energy.

[0042] Here, the high-temperature steam generated by the power plant is used to generate electricity in a steam turbine, the electricity generated is used for mechanical refrigeration, and the by-product waste heat steam is used for absorption refrigeration, thereby achieving efficient utilization of the energy carried by the steam and realizing efficient refrigeration.

[0043] 3. Electric refrigeration system

[0044] The electric refrigeration system uses a large temperature difference centrifugal chiller, which is a steam compression refrigeration. The low-temperature and low-pressure refrigerant gas enters the compressor and becomes a high-temperature and high-pressure gas after compression. After being discharged from the compressor, it enters the condenser and exchanges heat with the cooling water in the condenser. The high-pressure refrigerant liquid condensed in the condenser enters the evaporator after throttling, reducing the pressure and temperature through the expansion valve. The refrigerant evaporates in the evaporator and uses the latent heat of evaporation to reduce the temperature of the chilled water and supply it to the end of the system. The refrigerant gas then enters the compressor to continue the next cycle.

[0045] This system uses a large temperature differential cooling method, which effectively reduces pump and fan energy consumption while also improving the cold storage efficiency of the downstream cold storage device. Although lowering the chilled water outlet temperature will reduce the system's COP, it will improve the system's overall energy efficiency.

[0046] 4. High-efficiency phase change cold storage device

[0047] The main function of this device is to ensure the stable operation of the data center's cooling system; at the same time, it can reduce the overall configuration capacity of the system (achieved by the cold storage device and the refrigeration system jointly providing cooling during peak periods); further, it can also store the excess cooling generated during low temperatures at night in the cold storage device, and release it to provide cooling during high temperatures during the day to improve energy efficiency (the cooling efficiency of the refrigeration system is related to the external ambient temperature; the higher the ambient temperature, the higher the cooling efficiency).

[0048] The entire system operates under variable operating conditions. When the data center's cooling load is less than the cooling capacity supplied, the excess cooling is stored in the cold storage device. When the cooling system's cooling load exceeds the cooling capacity supplied, the cold storage device's cooling capacity is used for supplementary cooling to balance the cooling system's load. Building on this basic cooling principle, the system further implements cold storage during low-temperature nighttime hours and cooling during high-temperature daytime hours, while also maximizing the use of stored cooling capacity daily to maximize cooling efficiency.

[0049] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A power plant steam extraction driven integrated cooling system suitable for data centers, characterized by: include: A steam turbine (1), an electric refrigeration system (2), a steam absorption refrigeration system (3), a hot water absorption refrigeration system (4), a phase change cold storage device (5), and a heat exchanger group (6); wherein, The input end of the steam turbine (1) is connected to the power plant extraction pipeline, and is used to receive high-temperature steam and drive the turbine to generate electricity. The output end of the steam turbine (1) is divided into an electric power output end and a waste heat steam output end; The electric refrigeration system (2) comprises a compressor (201), a third evaporator (202), a condenser (203) and a throttling device (204); the power input end of the compressor (201) is connected to the power output end of the steam turbine (1); the compressor (201), the condenser (203), the throttling device (204) and the third evaporator (202) form a closed circulation loop in sequence through a refrigerant pipeline; The steam-type absorption refrigeration system (3) comprises a first high-pressure generator (301) and a first evaporator (302), the input end of which is connected to the waste heat steam output end of the steam turbine (1) via a steam pipe; the hot water-type absorption refrigeration system (4) comprises a second high-pressure generator (401) and a second evaporator (402), the input end of which is connected to the hot water output end of the steam-type absorption refrigeration system (3) via a hot water pipe; The input end of the phase-change cold storage device (5) is respectively connected to the cold output ends of the electric refrigeration system (2), the steam absorption refrigeration system (3) and the hot water absorption refrigeration system (4), and is used to store excess cold and surplus cold generated during the low-temperature period at night; The heat exchanger group (6) includes a plurality of heat exchange units, which are respectively arranged between the steam absorption refrigeration system (3) and the hot water absorption refrigeration system (4), and in the waste heat recovery pipelines of each refrigeration system, for realizing step-by-step energy transfer and heat exchange.

2. The integrated cooling system driven by power plant steam extraction and suitable for data centers according to claim 1 is characterized in that: The steam turbine (1) is a turbine unit in a combined cycle power generation unit, the input steam temperature of which is 300° C. and the pressure of which is 1.6 MPa; the output waste heat steam temperature of which is 229° C. and the pressure of which is 0.8 MPa.

3. The integrated cooling system driven by power plant steam extraction and suitable for data centers according to claim 1 is characterized in that: The system further comprises a water collector (7) and a water distributor (8), wherein the input end of the water collector (7) is connected to the chilled water output ends of the electric refrigeration system (2), the steam absorption refrigeration system (3), the hot water absorption refrigeration system (4) and the phase change cold storage device (5); the output end of the water distributor (8) is connected to the evaporators of the electric refrigeration system (2), the steam absorption refrigeration system (3) and the hot water absorption refrigeration system (4); the collected chilled water is used for cooling the data center; after cooling, the return water is transported to each system through the water distributor (8) for further cooling, and the entire cooling process forms a closed circulation loop.

4. The integrated cooling system driven by power plant steam extraction and suitable for data centers according to claim 1 is characterized in that: The system further comprises a control module for dynamically adjusting the cooling output of the electric refrigeration system (2), the steam absorption refrigeration system (3), and the hot water absorption refrigeration system (4) according to the cooling load demand of the data center, and achieving load balancing through the phase change cold storage device (5); during the low temperature period at night, the cold generated by the refrigeration system is preferentially stored in the phase change cold storage device (5); during the high temperature period during the day or during the peak period of cooling demand, the cold stored in the phase change cold storage device (5) is released to assist in cooling.

5. The integrated cooling system driven by power plant steam extraction and suitable for data centers according to claim 1 is characterized in that: The steam-type absorption refrigeration system (3) is a lithium bromide absorption chiller, and the temperature of the first-stage waste heat hot water outputted by it is 95°C; the hot water-type absorption refrigeration system (4) is a lithium bromide absorption chiller, and the temperature of the second-stage waste heat hot water outputted by it is 70°C.

6. The integrated cooling system driven by power plant steam extraction and suitable for data centers according to claim 1, characterized in that: The phase-change cold storage device (5) uses a hydrated salt phase-change material with a melting point of 8° C., and its cold storage density is more than twice that of cold water.

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