Cascade organic rankine cycle power generation system coupled to a data center and geothermal energy

Abstract

The application discloses a cascade organic Rankine cycle power generation system coupled with a data center and geothermal energy, and relates to the technical field of thermodynamic cycles, comprising data center waste heat recovery technology, geothermal power generation technology, non-azeotropic working fluid component adjustment technology and organic Rankine power generation technology. The application recovers waste heat of the data center and geothermal energy, and couples with the cascade organic Rankine cycle power generation technology to realize geothermal energy-data center waste heat-air temperature gradient utilization power generation. Meanwhile, by adjusting the components of the heat exchange circulating working fluid in the organic Rankine cycle power generation system, the temperature matching between the working fluid and the heat exchange medium is realized, the irreversible loss of the system in the heat exchange process is effectively reduced, and the thermal efficiency and power generation capacity of each organic Rankine cycle system are improved. The system is an economic, effective and feasible improvement scheme, realizes the utilization of medium and low grade heat energy, improves the performance of the organic Rankine cycle power generation system, and promotes the development of the energy-saving technology of the organic Rankine cycle power generation system product.

Description

Technical Field

[0001] This invention relates to the field of thermal cycle technology, specifically to data center waste heat recovery technology, geothermal power generation technology, non-azeotropic working fluid component adjustment technology, and organic Rankine power generation technology. This system enables the efficient recovery and utilization of thermal energy. Background Technology

[0002] The share of fossil fuel consumption is decreasing year by year, while the share of renewable energy consumption will gradually increase. Geothermal energy, as one of the renewable energy sources, has advantages such as stable supply, large reserves, and wide distribution. However, direct heat utilization is constrained by transmission distance, while geothermal power generation can effectively solve the above problems. How to achieve efficient geothermal power generation is the key to improving the utilization rate of renewable energy.

[0003] Organic Rankine cycle (ORC) power generation systems, as a common type of medium- and low-temperature heat-to-work conversion system, can effectively convert medium- and low-grade thermal energy into electrical energy, thereby improving energy quality. However, currently, due to the performance of actual operating components, the heat exchange temperature difference between the working fluid and the heat source / cold source, and the influence of the working fluid itself, the system efficiency is not high. How to rationally construct the circulation loop is one of the important routes to achieve high operating efficiency of the ORC. Furthermore, in the heat exchange process of the ORC, the heat exchange temperature difference between the working fluid and the heat exchange medium is one of the main factors causing irreversible losses in the system. Compared with pure working fluids, non-azeotropic working fluids, due to their temperature glide characteristics, can potentially reduce irreversible losses in the heat exchange process by rationally adjusting the working fluid composition, especially under operating conditions deviating from the design conditions. The key lies in rationally matching the temperature glide of the non-azeotropic working fluid with the temperature changes of the heat exchange medium.

[0004] Data centers are the physical carriers for information production, computing, storage, and transmission. With the advancement of technology, the digital economy plays a vital role in high-quality development. At the same time, data center energy consumption is increasing daily, with a large portion of the electricity consumed being converted into waste heat, which is low-grade heat energy (temperature below 100℃). Direct release into the atmosphere will cause energy waste and accelerate global warming. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a cascade organic Rankine cycle power generation system that couples data centers and geothermal energy. By recovering and utilizing waste heat from data centers and geothermal energy, and by coupling cascade organic Rankine cycle power generation technology, it achieves tiered utilization of heat energy in different temperature ranges, thereby improving the utilization rate of low- and medium-grade heat energy and reducing the energy consumption of the cycle system. Furthermore, by employing a non-azeotropic organic working fluid, and by adjusting the composition of the organic working fluid during the heat exchange process, temperature matching between the working fluid and the heat exchange medium is achieved, thereby reducing irreversible losses in the system and ultimately improving system performance.

[0006] The objective of this invention is achieved through the following technical solution: This cascade organic Rankine cycle power generation system coupling data center and geothermal energy includes a first heat exchanger, the cooling side outlet of the first heat exchanger is connected to the inlet of a first gas-liquid separator, the gas phase outlet of the first gas-liquid separator is connected to the inlet of a first steam turbine, the liquid phase outlet of the first gas-liquid separator is connected to the second inlet of a first mixing tank, the outlet of the first steam turbine is connected to the heating side inlet of the first layer of the cascade heat exchanger, the heating side outlet of the first layer of the cascade heat exchanger is connected to the first inlet of the first mixing tank through a first working fluid pump, and the outlet of the first mixing tank is connected to the cooling side inlet of the first heat exchanger.

[0007] The first cooling side inlet of the cascade heat exchanger is connected to the outlet of the data center waste heat utilization module; the first cooling side outlet of the cascade heat exchanger is connected to the cooling side inlet of the second heat exchanger; the heating side inlet of the second heat exchanger is connected to the heating side outlet of the first heat exchanger; the cooling side outlet of the second heat exchanger is connected to the heating side inlet of the second layer of the cascade heat exchanger; and the heating side outlet of the second layer of the cascade heat exchanger is connected to the inlet of the data center waste heat utilization module.

[0008] The cooling side outlet of the second layer of the cascade heat exchanger is connected to the inlet of the second gas-liquid separator, and the gas phase outlet of the second gas-liquid separator is connected to the inlet of the second steam turbine. The liquid phase outlet of the second gas-liquid separator is connected to the second inlet of the second mixing tank, and the outlet of the second steam turbine is connected to the heating side inlet of the third heat exchanger. The heating side outlet of the third heat exchanger is connected to the first inlet of the second mixing tank through the second working fluid pump, and the outlet of the second mixing tank is connected to the cooling side inlet of the second layer of the cascade heat exchanger, thereby completing the entire system cycle.

[0009] As a further technical solution, a first flow regulating valve is installed on the connecting pipeline between the first gas-liquid separator and the first mixing tank.

[0010] As a further technical solution, the circulating working fluid in the first heat exchanger cooling side, the first gas-liquid separator, the first steam turbine, the first flow regulating valve, the first heating side of the cascade heat exchanger, the first working fluid pump, and the first mixing tank is a non-azeotropic organic working fluid, which is a mixture of two organic working fluids with different boiling points.

[0011] As a further technical solution, a second flow regulating valve is installed on the connecting pipeline between the second gas-liquid separator and the second mixing tank.

[0012] As a further technical solution, the circulating working fluid in the second cooling side of the cascade heat exchanger, the second gas-liquid separator, the second steam turbine, the second flow regulating valve, the heating side of the third heat exchanger, the second working fluid pump, and the second mixing tank is a non-azeotropic organic working fluid, which is a mixture of two organic working fluids with different boiling points.

[0013] As a further technical solution, the circulating working fluid in the heating side of the first heat exchanger, the cooling side of the first layer and the heating side of the second layer of the cascade heat exchanger, the second heat exchanger, and the waste heat utilization module of the data center is water.

[0014] As a further technical solution, the cascade heat exchanger is provided with several fins and heat exchange tubes, and is divided into a first layer of circulating flow path and a second layer of circulating flow path by a first partition plate. A first layer of flow path is provided with a first layer of flow divider manifold as a first layer of cooling side inlet on one side and a first layer of flow collector manifold as a first layer of cooling side outlet on the other side. The first layer of circulating flow path is provided with a first layer of heating side outlet connected to a first working fluid pump, and the first layer of circulating flow path is also provided with a first layer of heating side inlet connected to a first steam turbine. A second layer of flow path is provided with a second layer of flow divider manifold as a second layer of heating side inlet on one side and a second layer of flow collector manifold as a second layer of heating side outlet on the other side. The second layer of circulating flow path is provided with a second layer of cooling side outlet connected to a second gas-liquid separator, and the second layer of circulating flow path is also provided with a second layer of cooling side inlet connected to a second mixing tank.

[0015] As a further technical solution, the data center waste heat utilization module includes a server room wall. A distribution manifold is installed at the top of the server room wall to connect to the second heating side outlet of the cascade heat exchanger, and a collection manifold is installed at the bottom of the server room wall to connect to the first cooling side inlet of the cascade heat exchanger. Several second partitions are evenly spaced inside the server room wall to form several cooling channels. Several cabinets are spaced apart in each cooling channel. One end of each cooling channel is connected to the distribution manifold, and the other end is connected to the collection manifold.

[0016] As a further technical solution, the circulating working fluid in the cooling side of the third heat exchanger is air. After flowing into the cooling side from the atmosphere, it absorbs heat from the heating side of the third heat exchanger and then flows back into the atmosphere.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. By recovering waste heat and geothermal energy from data centers and coupling them with cascade organic Rankine cycle power generation technology, the power generation can be achieved through the cascade utilization of geothermal energy, waste heat from data centers, and air temperature.

[0019] 2. At the same time, by adjusting the composition of the heat exchange working fluid in the organic Rankine cycle power generation system, temperature matching between the working fluid and the heat exchange medium can be achieved, thereby effectively reducing irreversible losses in the heat exchange process and improving the thermal efficiency and power generation of each organic Rankine cycle system.

[0020] 3. This system is an economical, effective, and feasible improvement solution that enables the utilization of medium- and low-grade thermal energy, effectively improves the performance of organic Rankine cycle power generation systems, and promotes the development of energy-saving technologies for organic Rankine cycle power generation system products. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] Figure 2 This is a schematic diagram of the cascade heat exchanger in this invention.

[0023] Figure 3 This is a schematic diagram of the data center waste heat utilization module in this invention.

[0024] Figure 4 This is a schematic diagram of the working fluid temperature change in the first heat exchanger before adjustment in Example 1.

[0025] Figure 5 This is a schematic diagram showing the change in the working fluid temperature of the first heat exchanger after adjustment in Example 1.

[0026] Figure 6 This is a schematic diagram of the working fluid temperature change in the third heat exchanger before adjustment in Example 2.

[0027] Figure 7 This is a schematic diagram showing the change in the working fluid temperature of the third heat exchanger after adjustment in Example 2.

[0028] Explanation of reference numerals in the attached drawings: First heat exchanger 101, First gas-liquid separator 102, First steam turbine 103, First flow regulating valve 104, Cascade heat exchanger 105, First layer diversion manifold 105-1, First layer collection manifold 105-2, Second layer diversion manifold 105-3, Second layer collection manifold 105-4, Fin 105-5, First baffle 105-6, Heat exchange tube 105-7, First working fluid pump 106, First mixing tank 107, Data center waste heat utilization module 108, Diversion manifold 108-1, Cabinet 108-2, Computer room wall 108-3, Second baffle 108-4, Collection manifold 108-5, Second heat exchanger 109, Second gas-liquid separator 110 111 Second steam turbine, 112 Second flow regulating valve, 113 Third heat exchanger, 114 Second working fluid pump, 115 Second mixing tank, 116 First pipeline, 117 Second pipeline, 118 Third pipeline, 119th pipeline, 12th pipeline, 13th pipeline, 14th pipeline, 15th pipeline, 16th pipeline, 17th pipeline, 18th pipeline, 19th pipeline, 20th pipeline, 21st pipeline, 22nd pipeline, 23rd pipeline, 24th pipeline, 25th pipeline. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings:

[0030] As attached Figures 1-7As shown, this cascade organic Rankine cycle power generation system coupling a data center and geothermal energy includes a first heat exchanger 101, a first gas-liquid separator 102, a first steam turbine 103, a first flow regulating valve 104, a cascade heat exchanger 105, a first-layer distribution manifold 105-1, a first-layer collection manifold 105-2, a second-layer distribution manifold 105-3, a second-layer collection manifold 105-4, fins 105-5, a first baffle 105-6, heat exchange tubes 105-7, a first working fluid pump 106, a first mixing tank 107, a data center waste heat utilization module 108, a distribution manifold 108-1, a cabinet 108-2, a server room wall 108-3, a second baffle 108-4, a collection manifold 108-5, and a second heat exchanger 108-1. 09. Second gas-liquid separator 110. Second steam turbine 111. Second flow regulating valve 112. Third heat exchanger 113. Second working fluid pump 114. Second mixing tank 115. First pipeline 1, Second pipeline 2, Third pipeline 3, Fourth pipeline 4, Fifth pipeline 5, Sixth pipeline 6, Seventh pipeline 7, Eighth pipeline 8, Ninth pipeline 9, Tenth pipeline 10, Eleventh pipeline 11, Twelfth pipeline 12, Thirteenth pipeline 13, Fourteenth pipeline 14, Fifteenth pipeline 15, Sixteenth pipeline 16, Seventeenth pipeline 17, Eighteenth pipeline 18, Nineteenth pipeline 19, Twentieth pipeline 20, Twenty-first pipeline 21, Twenty-second pipeline 22, Twenty-third pipeline 23, Twenty-fourth pipeline 24, and Twenty-fifth pipeline 25.

[0031] Reference Appendix Figure 1The cooling side outlet of the first heat exchanger 101 is connected to the inlet of the first gas-liquid separator 102. The gas phase outlet of the first gas-liquid separator 102 is connected to the inlet of the first steam turbine 103. The liquid phase outlet of the first gas-liquid separator 102 is connected to the second inlet of the first mixing tank 107 through the first flow regulating valve 104. The outlet of the first steam turbine 103 is connected to the first heating side inlet of the cascade heat exchanger 105. The first heating side outlet of the cascade heat exchanger 105 is connected to the first inlet of the first mixing tank 107 through the first working fluid pump 106. The outlet of the first mixing tank 107 is connected to the cooling side inlet of the first heat exchanger 101. The first cooling side inlet of the cascade heat exchanger 105 is connected to the outlet of the data center waste heat utilization module 108. The first cooling side outlet of the cascade heat exchanger 105 is connected to the cooling side inlet of the second heat exchanger 109. The heating side inlet of the second heat exchanger 109 is connected to the heating side outlet of the first heat exchanger 101. The cooling side outlet of the second heat exchanger 109 is connected to the second heating side inlet of the cascade heat exchanger 105. The second heating side outlet of the cascade heat exchanger 105 is connected to the inlet of the data center waste heat utilization module 108. The cooling side outlet of the second layer of the cascade heat exchanger 105 is connected to the inlet of the second gas-liquid separator 110, and the gas phase outlet of the second gas-liquid separator 110 is connected to the inlet of the second steam turbine 111. The liquid phase outlet of the second gas-liquid separator 110 is connected to the second inlet of the second mixing tank 115 through the second flow regulating valve 112. The outlet of the second steam turbine 111 is connected to the heating side inlet of the third heat exchanger 113. The heating side outlet of the third heat exchanger 113 is connected to the first inlet of the second mixing tank 115 through the second working fluid pump 114. The outlet of the second mixing tank 115 is connected to the cooling side inlet of the second layer of the cascade heat exchanger 105, thereby completing the entire system cycle.

[0032] Preferably, the circulating working fluid in the cooling side of the first heat exchanger 101, the first gas-liquid separator 102, the first steam turbine 103, the first flow regulating valve 104, the first heating side of the cascade heat exchanger 105, the first working fluid pump 106, and the first mixing tank 107 is a non-azeotropic organic working fluid, which is a mixture of an organic working fluid with a higher boiling point and another organic working fluid with a lower boiling point.

[0033] The circulating working fluid in the second cooling side of the cascade heat exchanger 105, the second gas-liquid separator 110, the second steam turbine 111, the second flow regulating valve 112, the heating side of the third heat exchanger 113, the second working fluid pump 114, and the second mixing tank 115 is a non-azeotropic organic working fluid, which is a mixture of one organic working fluid with a higher boiling point and another organic working fluid with a lower boiling point.

[0034] The circulating working fluid in the first heat exchanger 101 (heating side), the first cooling side and the second heating side of the cascade heat exchanger 105, the second heat exchanger 109, and the data center waste heat utilization module 108 is water.

[0035] like Figure 2 As shown, a number of fins 105-5 and heat exchange tubes 105-7 are arranged in the cascade heat exchanger 105, and it is divided into a first layer circulation flow path and a second layer circulation flow path by a first partition 105-6. A first layer diversion manifold 105-1 is arranged on the right side of the first layer circulation flow path as the first layer cooling side inlet (connected to the eleventh pipeline 11), and a first layer collection manifold 105-2 is arranged on the left side of the first layer circulation flow path as the first layer cooling side outlet (connected to the twelfth pipeline 12). The first layer circulation flow path is provided with a first layer heating side outlet (connected to the seventh pipeline 7) and connected to the first working fluid pump 106. The first layer circulation flow path is also provided with a first layer heating side inlet (connected to the sixth pipeline 6) and connected to the first steam turbine 103. The second-layer circulation flow path is provided with a second-layer diversion manifold 105-3 on the left side as the second-layer heating side inlet (connected to the thirteenth pipeline 13), and a second-layer collection manifold 105-4 on the right side as the second-layer heating side outlet (connected to the fourteenth pipeline 14). The second-layer circulation flow path is provided with a second-layer cooling side outlet (connected to the sixteenth pipeline 16) connected to the second gas-liquid separator 110. The second-layer circulation flow path is also provided with a second-layer cooling side inlet (connected to the twenty-third pipeline 23) connected to the second mixing tank 115.

[0036] Reference Appendix Figure 3 The data center waste heat utilization module 108 includes a server room wall 108-3. A distribution manifold 108-1 is installed at the top of the server room wall 108-3, connected to the second heating side outlet of the cascade heat exchanger 105 via a fourteenth pipe 14. A collection manifold 108-5 is installed at the bottom of the server room wall 108-3, connected to the first cooling side inlet of the cascade heat exchanger 105 via an eleventh pipe 11. Several second partitions 108-4 are evenly spaced within the server room wall 108-3, dividing the space into several cooling channels. Several server racks 108-2 are spaced within each cooling channel. One end of each cooling channel connects to the distribution manifold 108-1, and the other end connects to the collection manifold 108-5.

[0037] The working process of this invention:

[0038] like Figure 1 As shown, geothermal water flows into the heating side of the first heat exchanger 101, releases heat to the cooling side (i.e., the side where the second pipe 2 and the third pipe 3 are located in the figure), and then flows from the outlet of the heating side of the first heat exchanger 101 to the heating side of the second heat exchanger 109, releases heat to the cooling side again, and flows out from the fifteenth pipe 15, thus completing the gradient release of geothermal energy.

[0039] After absorbing heat from the geothermal water, the non-azeotropic organic working medium in the cooling side of the first heat exchanger 101 flows into the inlet of the first gas-liquid separator 102, separating the gas phase and the liquid phase. Its outlet flow path is divided into two paths: one path is rich in low-boiling-point gaseous organic working medium, which flows from the gas phase outlet through the third pipeline 3 and the fourth pipeline 4 to the first steam turbine 103, expands and does work externally, and flows into the first heating side of the cascade heat exchanger 105 through the sixth pipeline 6, releasing heat to the first cooling side. After the heat is released, it flows into the inlet of the first working fluid pump 106 via the seventh pipeline 7 for pressurization, and then flows into the first inlet of the first mixing tank 107 via the eighth pipeline 8; another high-boiling-point liquid organic working fluid flows out from the liquid phase outlet through the third pipeline 3 and the fifth pipeline 5, flows through the first flow regulating valve 104, and then flows into the second inlet of the first mixing tank 107 via the ninth pipeline 9. After mixing with the working fluid flowing in from the first inlet, it flows into the cooling side inlet of the first heat exchanger 101 via the tenth pipeline 10 to absorb heat again, thus completing the organic Rankine cycle power generation process.

[0040] The circulating working fluid cooling water enters the inlet of the data center waste heat utilization module 108 via the fourteenth pipe 14. After flowing to the distribution manifold 108-1, it is divided into multiple streams, which then flow into each cooling channel to absorb heat generated by the server rack 108-2. After heat absorption, the cooling water is collected in the collection manifold 108-5 and flows out from the outlet of the data center waste heat utilization module 108. It then flows through the eleventh pipe 11 to the first cooling side of the cascade heat exchanger 105 to absorb heat from the heating side. Subsequently, it flows through the twelfth pipe 12 into the cooling side inlet of the second heat exchanger 109 to absorb heat energy from the geothermal water again, further improving the energy quality, and then through the thirteenth pipe 13. After completing two heat absorption cycles, the cooling water flows into the second heating side of the cascade heat exchanger 105, releasing heat to the second cooling side. Finally, it flows back into the data center waste heat utilization module 108 via the fourteenth pipe 14, thus completing the entire cooling process.

[0041] After the non-azeotropic organic working fluid in the second-layer cooling side of the cascade heat exchanger 105 absorbs heat from the circulating water of the data center waste heat utilization module 108, it flows into the inlet of the second gas-liquid separator 110 to separate the gas phase and the liquid phase, and its outlet flow path is divided into two branches: one branch of the gas-phase organic working fluid rich in low-boiling point flows from the gas-phase outlet through the sixteenth pipeline 16 and the seventeenth pipeline 17 into the second steam turbine 111, expands to output work externally, then flows through the nineteenth pipeline 19 into the heating side of the third heat exchanger 113, releases heat to the cooling side of the third heat exchanger 113, and after completing heat release, flows through the twentieth pipeline 20 into the inlet of the second working fluid pump 114 for pressurization, and then flows through the twenty-first pipeline 21 into the first inlet of the second mixing tank 115. The other branch of the liquid-phase organic working fluid rich in high-boiling point flows out from the liquid-phase outlet, passes through the sixteenth pipeline 16 and the eighteenth pipeline 18, flows through the second flow regulating valve 112, then flows through the twenty-second pipeline 22 into the second inlet of the second mixing tank 115, mixes with the working fluid flowing in from the first inlet, and then jointly flows through the twenty-third pipeline 23 into the inlet of the second-layer cooling side of the cascade heat exchanger 105 to reabsorb heat, thereby completing the organic Rankine cycle power generation process.

[0042] The circulating working fluid in the cooling side of the third heat exchanger 113 is air. After flowing into the cooling side from the atmosphere through the twenty-fourth pipeline 24, it absorbs heat from the heating side of the third heat exchanger 113, and then flows back into the atmosphere through the twenty-fifth pipeline 25.

[0043] Embodiment 1:

[0044] As shown in Figure 4 , 5 , when the system is initially in operation, the first flow regulating valve 104 is closed, the temperature change of the geothermal water on the heating side of the first heat exchanger 101 (from point a to point b in the figure) is consistent with the temperature change of the non-azeotropic working fluid (from point c to point d in the figure), and the irreversible loss area generated by the first heat exchanger 101 at this time is A1. When the geothermal water is affected by factors such as seasons, the flow rate of the geothermal water increases. On the premise that the heat exchange amount and the pinch point temperature difference remain unchanged, the outlet temperature of the geothermal water rises to point b' in the figure, the temperature difference between the inlet and outlet of the heating side decreases (from point a to point b' in the figure), and the irreversible loss generated in the first heat exchanger 101 increases to A1+A2. At this time, the first flow regulating valve 104 is opened to make part of the separated liquid working fluid flow into the first mixing tank 107 and change the composition of the circulating working fluid on the cooling side of the first heat exchanger 101, thereby changing the temperature change of the non-azeotropic working fluid in the first heat exchanger 101 (from point c to point d' in the figure), so as to improve the matching degree between the temperature change of the non-azeotropic working fluid and the geothermal water, reduce the irreversible loss of the first heat exchanger 101 to make A3<A1+A2, and finally realize the improvement of system performance.

[0045] Embodiment 2:

[0046] As shown in Figure 6 , 7 as shown in the figure, when the system is initially in operation, the second flow control valve 112 is closed, the temperature change of air in the cooling side of the third heat exchanger 113 (from point a to point b in the figure) is consistent with the temperature change of the non-azeotropic working fluid (from point c to point d in the figure), and the irreversible loss area generated by the third heat exchanger 113 at this time is A1+A2. When the air is affected by factors such as seasons, the air flow rate increases. On the premise that the heat exchange amount and the pinch point temperature difference remain unchanged, the outlet temperature of the air rises to point b' in the figure, and the temperature difference between the inlet and outlet of the cooling side decreases. Under the constraint of the pinch point temperature difference, the condensing pressure of the non-azeotropic working fluid rises, the condensing temperature continuously increases from point c' to point d' in the figure, and the irreversible loss generated in the third heat exchanger 113 increases to A1+A3. At this time, the second flow control valve 112 is opened, so that part of the separated liquid working fluid flows into the second mixing tank 115 and changes the composition of the circulating working fluid on the heating side of the third heat exchanger 113, thereby changing the temperature change of the non-azeotropic working fluid in the third heat exchanger 113 from point c to point d'' in the figure, so as to improve the matching degree between the temperature change of the non-azeotropic working fluid and the air, reduce the irreversible loss of the third heat exchanger 113 such that A4<A1+A3, and finally realize the improvement of system performance.

[0047] In summary, the geothermal power generation technology, data center waste heat utilization technology, organic Rankine cycle power generation technology and non-azeotropic working fluid composition regulation technology in the present invention are of great significance for improving the energy utilization rate of renewable energy and medium-low grade thermal energy. These several parts complement and match each other, and have huge application potential for the recovery and utilization of medium-low grade energy, which mainly includes two aspects: first, a cascaded organic Rankine cycle is constructed according to three different thermal energy grades, namely geothermal temperature, data center waste heat temperature and ambient temperature, to utilize the thermal energy of each part in a cascade manner, so as to reduce the irreversible loss of the system; second, according to the changes of geothermal energy and ambient working conditions, the composition of the non-azeotropic working fluid is adjusted to match the temperature change of the non-azeotropic working fluid with geothermal energy or the environment in real time, expand the adjustability of the system, and further reduce the irreversible loss of the system, so as to efficiently recover geothermal energy and data center waste heat, and realize the improvement of system operation efficiency.

[0048] It can be understood that, for those skilled in the art, equivalent substitutions or modifications made to the technical solution and inventive concept of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A cascade organic Rankine cycle power generation system coupling data center and geothermal energy, characterized in that: The system includes a first heat exchanger (101), the cooling side outlet of the first heat exchanger (101) is connected to the inlet of the first gas-liquid separator (102), the gas phase outlet of the first gas-liquid separator (102) is connected to the inlet of the first steam turbine (103), the liquid phase outlet of the first gas-liquid separator (102) is connected to the second inlet of the first mixing tank (107), the outlet of the first steam turbine (103) is connected to the first heating side inlet of the cascade heat exchanger (105), the first heating side outlet of the cascade heat exchanger (105) is connected to the first inlet of the first mixing tank (107) through the first working fluid pump (106), and the outlet of the first mixing tank (107) is connected to the cooling side inlet of the first heat exchanger (101). The first cooling side inlet of the cascade heat exchanger (105) is connected to the outlet of the data center waste heat utilization module (108), the first cooling side outlet of the cascade heat exchanger (105) is connected to the cooling side inlet of the second heat exchanger (109), the heating side inlet of the second heat exchanger (109) is connected to the heating side outlet of the first heat exchanger (101), the cooling side outlet of the second heat exchanger (109) is connected to the second heating side inlet of the cascade heat exchanger (105), and the second heating side outlet of the cascade heat exchanger (105) is connected to the inlet of the data center waste heat utilization module (108). The second cooling side outlet of the cascade heat exchanger (105) is connected to the inlet of the second gas-liquid separator (110), and the gas phase outlet of the second gas-liquid separator (110) is connected to the inlet of the second steam turbine (111). The liquid phase outlet of the second gas-liquid separator (110) is connected to the second inlet of the second mixing tank (115), and the outlet of the second steam turbine (111) is connected to the heating side inlet of the third heat exchanger (113). The heating side outlet of the third heat exchanger (113) is connected to the first inlet of the second mixing tank (115) through the second working fluid pump (114). The outlet of the second mixing tank (115) is connected to the second cooling side inlet of the cascade heat exchanger (105), thereby completing the entire system cycle. The circulating working fluid on the heating side of the first heat exchanger (101) is geothermal water.

2. The cascade organic Rankine cycle power generation system coupling data center and geothermal energy according to claim 1, characterized in that: A first flow regulating valve (104) is installed on the connecting pipeline between the first gas-liquid separator (102) and the first mixing tank (107).

3. The cascade organic Rankine cycle power generation system coupling data center and geothermal energy according to claim 2, characterized in that: The circulating working fluid in the first heat exchanger (101) cooling side, the first gas-liquid separator (102), the first steam turbine (103), the first flow regulating valve (104), the first heating side of the cascade heat exchanger (105), the first working fluid pump (106), and the first mixing tank (107) is a non-azeotropic organic working fluid, which is a mixture of two organic working fluids with different boiling points.

4. The cascade organic Rankine cycle power generation system coupling data center and geothermal energy according to claim 1, characterized in that: A second flow regulating valve (112) is installed on the connecting pipeline between the second gas-liquid separator (110) and the second mixing tank (115).

5. The cascade organic Rankine cycle power generation system coupling data center and geothermal energy according to claim 4, characterized in that: The circulating working fluid in the second cooling side of the cascade heat exchanger (105), the second gas-liquid separator (110), the second steam turbine (111), the second flow regulating valve (112), the heating side of the third heat exchanger (113), the second working fluid pump (114), and the second mixing tank (115) is a non-azeotropic organic working fluid, which is a mixture of two organic working fluids with different boiling points.

6. The cascade organic Rankine cycle power generation system coupling data center and geothermal energy according to claim 1, characterized in that: The circulating working fluid in the first cooling side and the second heating side of the cascade heat exchanger (105), the second heat exchanger (109), and the data center waste heat utilization module (108) is water.

7. The cascade organic Rankine cycle power generation system coupling data center and geothermal energy according to claim 1, characterized in that: The cascade heat exchanger (105) is provided with several fins (105-5) and heat exchange tubes (105-7), and is divided into a first layer circulation flow path and a second layer circulation flow path by a first partition (105-6). A first layer split manifold (105-1) is provided on one side of the first layer circulation flow path as the first layer cooling side inlet, and a first layer collector manifold (105-2) is provided on the other side of the first layer circulation flow path as the first layer cooling side outlet. The first layer circulation flow path has a first layer heating side outlet connected to the first working fluid pump (106). The first layer circulation path is also provided with a first layer heating side inlet connected to the first steam turbine (103); a second layer diversion manifold (105-3) is provided on one side of the second layer circulation path as a second layer heating side inlet, a second layer collection manifold (105-4) is provided on the other side of the second layer circulation path as a second layer heating side outlet, a second layer cooling side outlet is provided in the second layer circulation path connected to the second gas-liquid separator (110), and a second layer cooling side inlet is provided in the second layer circulation path connected to the second mixing tank (115).

8. The cascade organic Rankine cycle power generation system coupling data center and geothermal energy according to claim 1, characterized in that: The data center waste heat utilization module (108) includes a computer room wall (108-3), a distribution manifold (108-1) at the top of the computer room wall (108-3) for connecting the second heating side outlet of the cascade heat exchanger (105), and a collection manifold (108-5) at the bottom of the computer room wall (108-3) for connecting the first cooling side inlet of the cascade heat exchanger (105). Several second partitions (108-4) are evenly spaced inside the computer room wall (108-3) to form several cooling channels. Several cabinets (108-2) are spaced apart in each cooling channel. One end of the cooling channel is connected to the distribution manifold (108-1), and the other end is connected to the collection manifold (108-5).

9. The cascade organic Rankine cycle power generation system coupling data center and geothermal energy according to claim 1, characterized in that: The circulating working fluid in the cooling side of the third heat exchanger (113) is air. After flowing into the cooling side from the atmosphere, it absorbs heat from the heating side of the third heat exchanger (113) and then flows back into the atmosphere.

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