Ocean thermoelectric power generation synergistic system and operation method thereof
By combining adsorption and heating and step-down systems, the alternating adsorption and desorption design of adsorption beds in the ocean temperature difference power generation system is solved, and the problems of low ocean temperature difference power generation efficiency and deep-sea pipeline management are achieved, achieving efficient power generation efficiency and stable system operation.
Patent Information
- Application Number
- CN202510657304.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-21
- Publication Date
- 2025-07-11
AI Technical Summary
The small temperature difference of ocean temperature difference leads to low thermal efficiency, the need for a deep-sea cold source of condensers leads to high costs, and the design and management of long-distance deep-sea pipelines have not been solved.
Adsorption heating and adsorption pressure reduction systems are adopted, and the adsorption and desorption design is designed through the alternate adsorption and desorption design of the adsorption bed, combined with the four-way reversing valve pipeline structure, to achieve improved working fluid evaporation efficiency and increased turbine pressure difference. The warm seawater and deep-sea cold seawater on the ocean surface are used as heat and cold sources to design porous carbon-based material adsorption beds.
It significantly improves the power generation efficiency of ocean temperature difference power generation, reduces the condenser back pressure, increases the pressure difference between front and rear ends of the turbine unit, achieves the improvement of power generation efficiency, and the system operates continuously and stably.
Smart Images
Figure CN120301253A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of ocean energy utilization, and particularly to an ocean thermal energy conversion (OTEC) power generation efficiency enhancement system and its operation method. Background Art
[0002] Ocean thermal energy conversion power generation is a highly potential renewable energy utilization method that utilizes the temperature difference between the surface and deep layers of seawater for power generation. The potential amount of nearshore ocean energy resources in China is approximately 6.97×10 8 kW, and more than 60% of it is distributed in the South China Sea, among which the technically exploitable amount of temperature difference energy accounts for as high as 34%. This technology not only has the advantages of being clean, stable, and sustainable, but also provides humanity with a brand-new energy option and is expected to play an important role in the future energy system.
[0003] The basic principle of ocean thermal energy conversion power generation is to use warm seawater on the ocean surface to heat certain low-boiling-point working fluids, such as ammonia, to vaporize them, or to vaporize seawater itself by reducing pressure to drive a steam turbine for power generation. At the same time, cold seawater extracted from the seabed is used to condense the exhausted gas after power generation work, making it turn back into a liquid again to form a cycle. In this process, the heat exchanger plays a key role, enabling the working fluid to efficiently transfer heat energy between seawater at different temperatures.
[0004] Currently, some ocean thermal energy conversion power generation test stations have been built in the world, such as the 100-kilowatt shore-based ocean thermal energy conversion power generation test station built by Japan near Okinawa Island. These test stations have not only verified the feasibility of ocean thermal energy conversion power generation, but also provided valuable technology and experience accumulation for its commercial application.
[0005] However, ocean thermal energy conversion power generation also faces some technical problems. The temperature difference in ocean thermal energy conversion power generation generally remains at about 20°C. This small temperature difference condition results in a relatively low thermal efficiency of the working fluid cycle, which is generally between 2% and 3% currently. In addition, to improve the power generation efficiency of the turbine unit, a larger pressure difference is required to provide a lower condensation temperature for the condenser, and the cold water pipe extends deeper into the ocean. The design, manufacture, laying, and management of long-distance deep-sea pipelines have always been the technical difficulties of the OTEC system and also the main cost source. Summary of the Invention
[0006] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide an ocean thermal energy conversion power generation efficiency enhancement system and its operation method.
[0007] The present invention is realized through the following technical solutions: An ocean thermal energy conversion (OTEC) efficiency improvement system, comprising an OTEC system, an adsorption pressure reduction system, and an adsorption temperature increase system; the adsorption temperature increase system includes a first condenser, a first evaporator, and at least two groups of adsorption beds, and the adsorption beds include a first adsorption bed and a second adsorption bed; the OTEC system includes a power generation unit, a second evaporator, and a second condenser connected to the second evaporator; the deep sea cold seawater inlet is respectively connected to the first condenser, the second condenser, and the adsorption pressure reduction system, and the surface warm seawater inlet is respectively connected to the first evaporator, the heat exchange tubes of the adsorption beds, and the adsorption pressure reduction system; the second evaporator is connected to the adsorption pressure reduction system through a group of power generation units, and the second condenser is connected to the adsorption pressure reduction system through another group of power generation units; one end of the first adsorption bed is connected to one end of the second adsorption bed through a second vacuum valve and a first vacuum valve, and the first condenser is connected to the pipeline between the first vacuum valve and the second vacuum valve; the other end of the first adsorption bed is connected to the other end of the second adsorption bed through a fourth vacuum valve and a third vacuum valve, and the first evaporator is connected to the pipeline between the third vacuum valve and the fourth vacuum valve; one end of the first adsorption bed and one end of the second adsorption bed are commonly connected to a first four-way reversing valve, and the first four-way reversing valve is connected to the second evaporator; the other end of the first adsorption bed and the other end of the second adsorption bed are commonly connected to a second four-way reversing valve, and the second four-way reversing valve is respectively connected to the surface warm seawater pipe inlet and the second evaporator.
[0008] This system realizes the cascade utilization of waste heat in the process of OTEC by coupling adsorption temperature increase and adsorption pressure reduction; the design of the alternating adsorption and desorption of the first adsorption bed and the second adsorption bed ensures the continuous operation of the system; the four-way reversing valve pipeline structure effectively isolates the working units in different states, enabling the surface warm seawater to enter the power generation system after being heated by adsorption heat release, significantly improving the evaporation efficiency of the working fluid.
[0009] The OTEC system further includes a first transfer pump and a second transfer pump. The first transfer pump is arranged on the pipeline connecting the second evaporator and the second condenser, and the second transfer pump is arranged on the pipeline between the second evaporator and the first four-way reversing valve; the power generation unit includes a primary power generation unit and a secondary power generation unit. The primary power generation unit includes a primary generator and a primary turbine, and the secondary power generation unit includes a secondary generator and a secondary turbine; the primary generator is connected to the second evaporator through the primary turbine, and the secondary generator is connected to the second condenser through the secondary turbine; the adsorption pressure reduction system is respectively connected to the primary turbine and the secondary turbine; the working fluid of the OTEC system is ammonia.
[0010] The working fluid of the adsorption heating-up system is seawater, and the adsorption materials in the first adsorption bed and the second adsorption bed are silica gel, molecular sieve or carbon-based materials.
[0011] The adsorption materials in the first adsorption bed and the second adsorption bed are porous carbon-based materials.
[0012] The adsorption pressure-reducing system includes at least two groups of adsorption beds and several valves; the adsorption beds include a third adsorption bed and a fourth adsorption bed; the valves include a first valve, a second valve, a third valve, a fourth valve, a fifth valve and a sixth valve; the third adsorption bed and the fourth adsorption bed are arranged in a cross-parallel manner. One end of the third adsorption bed is connected to the first-stage turbine through the second valve, and one end of the fourth adsorption bed is connected to the first-stage turbine through the fifth valve after being connected in parallel. The other end of the third adsorption bed is connected to the second-stage turbine through the third valve, and the other end of the fourth adsorption bed is connected to the second-stage turbine through the sixth valve after being connected in parallel; the first valve is a three-way valve, its first interface is connected to the third adsorption bed, its second interface is connected to the deep-sea cold seawater inlet through a seventh valve, and its third interface is connected to the surface warm seawater inlet through an eighth valve; the fourth valve is a three-way valve, its first interface is connected to the fourth adsorption bed, its second interface is connected to the seventh valve, and its third interface is connected to the eighth valve.
[0013] The adsorption materials in the third adsorption bed and the fourth adsorption bed are porous carbon-based materials.
[0014] The adsorption materials in the third adsorption bed and the fourth adsorption bed are activated carbon.
[0015] The cold source of the first condenser is the cold seawater in the deep ocean, and the heat source of the first evaporator is the warm seawater on the ocean surface.
[0016] The second evaporator is always connected to the adsorption bed in the adsorption stage in the adsorption heating-up system to form an adsorption heating-up pipeline, and the fluid in the adsorption heating-up pipeline is in a closed cycle.
[0017] An operation method of a system for enhancing ocean thermal energy conversion efficiency, the operation method of the system is as follows:
[0018] Adsorption heating process: Inject seawater as the working fluid into the first evaporator. The seawater is surface warm seawater. Pass the ocean surface warm seawater through the heat exchange tubes of the first evaporator from the surface warm seawater inlet. The working fluid evaporates in a vacuum environment. Control the second four-way reversing valve to pass the ocean surface warm seawater through the heat exchange tubes of the first adsorption bed from the surface warm seawater inlet. Open the fourth vacuum valve between the first evaporator and the first adsorption bed to allow the working fluid vapor to enter the first adsorption bed. Start the second delivery pump in the adsorption heating pipeline. The heat released by adsorption heats the seawater in the heat exchange tubes of the first adsorption bed, and the seawater temperature can be raised from 28 °C to 35 - 40 °C, and then it is passed into the evaporator of the ocean thermal energy conversion system for use; when the adsorption of the first adsorption bed is completed, close the fourth vacuum valve between the first evaporator and the first adsorption bed, and open the second vacuum valve between the first condenser and the first adsorption bed; close the first vacuum valve between the first condenser and the second adsorption bed, and open the third vacuum valve between the first evaporator and the second adsorption bed. Inject the deep-sea low-temperature seawater from the deep-sea cold seawater inlet into the heat exchange tubes of the first condenser. Switch the first four-way reversing valve and the second four-way reversing valve. The seawater after evaporation and cooling in the second evaporator is transported to the second adsorption bed by the second delivery pump to continue the adsorption heating process; inject the surface warm seawater into the heat exchange tubes of the first adsorption bed. Under the action of pressure difference, the working fluid adsorbed and saturated in the first adsorption bed is desorbed into the first condenser and condensed into fresh water. The surface warm seawater used for desorption can be directly discharged into the environment; the first adsorption bed and the second adsorption bed are used in combination. Through the switching of the first four-way reversing valve and the second four-way reversing valve, the fluid after adsorption heating in the first adsorption bed or the second adsorption bed is kept passing into the second evaporator of the ocean, and it is a closed cycle; while other adsorption beds remain in the desorption state to make the system operate continuously and stably;
[0019] Power generation - pressure reduction process: In the ocean thermal energy conversion system, the seawater after adsorption heating heats the working fluid ammonia to vaporize it through the second evaporator, and then transports the high-pressure gas to the first-stage turbine to do work. The first-stage turbine rotates and drives the first-stage generator to generate electricity. The high-pressure gas is transformed into a low-pressure gas working fluid. Open the second valve, close the third valve, and control the first valve to pass the deep-sea cold seawater into the heat exchanger of the third adsorption bed, and pass the low-pressure gas working fluid into the third adsorption bed for adsorption until it is adsorbed and saturated; when the third adsorption bed is adsorbed and saturated, close the second valve, open the third valve, and control the first valve to pass the surface warm seawater into the first adsorption bed to desorb the ammonia working fluid, which enters the second-stage turbine to expand and generate electricity. Finally, the depressurized working fluid vapor enters the second condenser and is condensed by the deep-sea cold seawater, and is transported to the second evaporator through the first delivery pump to achieve circulation; multiple groups of adsorption beds and valves cooperate to make the process of the working fluid vapor generated by the first-stage turbine being adsorbed and the process of the desorption of the adsorbed and saturated adsorption bed driving the second-stage turbine to generate electricity proceed simultaneously.
[0020] Compared with the prior art, the advantages of the present invention are as follows:
[0021] 1. The adsorption heating system can effectively increase the evaporation temperature of the ocean thermal energy conversion system, improve the working fluid steam pressure, thereby enhancing the power generation efficiency. Moreover, both the heat source and the cold source of the adsorption heating system come from the ocean, only requiring a small amount of energy supply equipment without additional energy consumption.
[0022] 2. Compared with the condenser, which can only condense the working fluid steam to the corresponding saturated vapor pressure at a certain temperature, the adsorption bed can reduce the pressure of the working fluid steam to a lower level through adsorption at the same temperature, effectively reducing the back pressure at the rear end of the first-stage turbine, increasing the pressure difference, and improving the power generation efficiency of the turbine.
[0023] 3. The working fluid steam generated by the desorption of the adsorption pressure reduction system is used to drive a two-stage turbine generator for expansion power generation, improving the energy utilization efficiency.
[0024] 4. By coupling the adsorption heating and pressure reduction systems with the thermoelectric power generation system, the effective improvement of the power generation efficiency can be achieved by increasing the power generation evaporation temperature and the pressure difference between the front and rear ends of the turbine unit. Description of the Drawings
[0025] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.
[0026] Meanings of the reference numerals in the drawings: 1. First condenser; 2. Second evaporator; 31. First-stage generator; 32. Second-stage generator; 41. First-stage turbine; 42. Second-stage turbine; 5. Second condenser; 61. First transfer pump; 62. Second transfer pump; 7. Third adsorption bed; 8. Fourth adsorption bed; 9. First adsorption bed; 10. Second adsorption bed; 11. First four-way reversing valve; 12. Second four-way reversing valve; 13. First evaporator; 141. First valve; 142. Second valve; 143. Third valve; 144. Fourth valve; 145. Fifth valve; 146. Sixth valve; 147. Seventh valve; 148. Eighth valve; 151. First vacuum valve; 152. Second vacuum valve; 153. Third vacuum valve; 154. Fourth vacuum valve; 16. Deep-sea cold seawater inlet; 17. First drain port; 18. Surface warm seawater inlet; 19. Second drain port; 20. Circulating working fluid injection port. Detailed Embodiment
[0027] The following further elaborates on the content of the present invention in conjunction with the drawings and detailed embodiments.
[0028] Embodiment
[0029] Refer to Figure 1, is an ocean thermal energy conversion (OTEC) efficiency enhancement system, including an OTEC system, an adsorption pressure reduction system, and an adsorption temperature increase system; the adsorption temperature increase system includes a first condenser 1, a first evaporator 13, and at least two groups of adsorption beds, and the adsorption beds include a first adsorption bed 9 and a second adsorption bed 10; the OTEC system includes a generator set, a second evaporator 2, and a second condenser 5 connected to the second evaporator 2; the deep - sea cold seawater inlet 16 is respectively connected to the first condenser 1, the second condenser 5, and the adsorption pressure reduction system, and the surface warm seawater inlet 18 is respectively connected to the first evaporator 13, the heat exchange tubes of the adsorption beds, and the adsorption pressure reduction system; the second evaporator 2 is connected to the adsorption pressure reduction system through a group of generator sets, and the second condenser 5 is connected to the adsorption pressure reduction system through another group of generator sets; one end of the first adsorption bed 9 is connected to one end of the second adsorption bed 10 through a second vacuum valve 152 and a first vacuum valve 151, and the first condenser 1 is connected to the pipeline between the first vacuum valve 151 and the second vacuum valve 152; the other end of the first adsorption bed 9 is connected to the other end of the second adsorption bed 10 through a fourth vacuum valve 154 and a third vacuum valve 153, and the first evaporator 13 is connected to the pipeline between the third vacuum valve 153 and the fourth vacuum valve 154; one end of the first adsorption bed 9 and one end of the second adsorption bed 10 are jointly connected to a first four - way reversing valve 11, and the first four - way reversing valve 11 is connected to the second evaporator 2; the other end of the first adsorption bed 9 and the other end of the second adsorption bed 10 are jointly connected to a second four - way reversing valve 12, and the second four - way reversing valve 12 is respectively connected to the surface warm seawater pipe inlet and the second evaporator 2.
[0030] This system realizes the cascade utilization of waste heat in the process of OTEC by coupling adsorption temperature increase and adsorption pressure reduction; the design of the alternating adsorption and desorption of the first adsorption bed 9 and the second adsorption bed 10 ensures the continuous operation of the system; the four - way reversing valve pipeline structure effectively isolates the working units in different states, enabling the surface warm seawater to enter the power generation system after adsorbing heat and increasing in temperature, significantly improving the evaporation efficiency of the working fluid.
[0031] The OTEC system also includes a first transfer pump 61 and a second transfer pump 62. The first transfer pump 61 is arranged on the pipeline connecting the second evaporator 2 and the second condenser 5, and the second transfer pump 62 is arranged on the pipeline between the second evaporator 2 and the first four - way reversing valve 11; the generator set includes a primary power generation unit and a secondary power generation unit. The primary power generation unit includes a primary generator 31 and a primary turbine 41, and the secondary power generation unit includes a secondary generator 32 and a secondary turbine 42; the primary generator 31 is connected to the second evaporator 2 through the primary turbine 41, and the secondary generator 32 is connected to the second condenser 5 through the secondary turbine 42; the adsorption pressure reduction system is respectively connected to the primary turbine 41 and the secondary turbine 42; the working fluid of the OTEC system is ammonia.
[0032] The working medium of the adsorption heating-up system is seawater. The adsorption materials in the first adsorption bed 9 and the second adsorption bed 10 are silica gel, molecular sieve or carbon-based materials, which are energy-saving, environmentally friendly, widely sourced and inexpensive.
[0033] The adsorption materials in the first adsorption bed 9 and the second adsorption bed 10 are porous carbon-based materials, which have a large specific surface area and a large water vapor adsorption capacity, significantly improving the adsorption / desorption cycle efficiency.
[0034] The adsorption pressure-reducing system includes at least two groups of adsorption beds and several valves; the adsorption beds include the third adsorption bed 7 and the fourth adsorption bed 8; the valves include the first valve 141, the second valve 142, the third valve 143, the fourth valve 144, the fifth valve 145 and the sixth valve 146; the third adsorption bed 7 and the fourth adsorption bed 8 are arranged in a cross-parallel manner. One end of the third adsorption bed 7 is connected to the first-stage turbine 41 in parallel through the second valve 142, and one end of the fourth adsorption bed 8 is connected to the first-stage turbine 41 in parallel through the fifth valve 145. The other end of the third adsorption bed 7 is connected to the second-stage turbine 42 in parallel through the third valve 143, and the other end of the fourth adsorption bed 8 is connected to the second-stage turbine 42 in parallel through the sixth valve 146; the first valve 141 is a three-way valve, its first interface is connected to the third adsorption bed 7, its second interface is connected to the deep-sea cold seawater inlet 16 through the seventh valve 147, and its third interface is connected to the surface warm seawater inlet 18 through the eighth valve 148; the fourth valve 144 is a three-way valve, its first interface is connected to the fourth adsorption bed 8, its second interface is connected to the seventh valve 147, and its third interface is connected to the eighth valve 148.
[0035] The adsorption materials in the third adsorption bed 7 and the fourth adsorption bed 8 are porous carbon-based materials.
[0036] The adsorption materials in the third adsorption bed 7 and the fourth adsorption bed 8 are activated carbon.
[0037] The cold source of the first condenser 1 is the deep-sea cold seawater, and the heat source of the first evaporator 13 is the surface warm seawater.
[0038] The second evaporator 2 is always connected to the adsorption bed in the adsorption stage in the adsorption heating-up system to form an adsorption heating-up pipeline. The fluid in the adsorption heating-up pipeline is a closed cycle, which can reduce heat energy loss. The first condenser 1 uses 2°C deep-sea cold seawater to form a 26°C temperature difference with the surface warm seawater, which can improve the desorption efficiency.
[0039] In this embodiment, in the adsorption pressure reduction system, by switching the valves, the fluid flowing into the third adsorption bed 7 and the fourth adsorption bed 8 can be controlled. When the third adsorption bed 7 is in the adsorption state, by controlling the first valve 141, deep-sea cold seawater (about 2°C) at a depth of about 1000 m is introduced into the heat exchange tubes of the third adsorption bed 7. The second valve 142 is opened, and the third valve 143 is closed. The pressure-reducing working medium vapor discharged after the first-stage turbine 41 does work is introduced into the third adsorption bed 7 for adsorption until adsorption saturation. After the third adsorption bed 7 reaches adsorption saturation, the second valve 142 is closed, the third valve 143 is opened, and by controlling the first valve 141, surface warm seawater (about 28°C) is introduced into the heat exchange tubes of the third adsorption bed 7 to start desorption. The desorbed working medium vapor enters the second-stage turbine 42 to drive and generate electricity. At the same time, deep-sea cold seawater (about 2°C) is introduced into the second condenser 5. The working medium vapor after doing work enters the second condenser 5 and is condensed into a liquid state, which is transported to the second evaporator 2 by the first delivery pump 61 to realize the cycle. While the third adsorption bed 7 is desorbing, the fifth valve 145 can be opened, the sixth valve 146 is closed, and by controlling the fourth valve 144, deep-sea cold seawater (about 2°C) is introduced into the heat exchange tubes of the fourth adsorption bed 8, and the fourth adsorption bed 8 starts to adsorb. The adsorption pressure reduction system is provided with multiple groups of adsorption beds for combined use, which can enable the system to operate continuously and stably.
[0040] In this embodiment, the second evaporator 2 is always kept in communication with the first adsorption bed 9 or the second adsorption bed 10 in the adsorption stage of the adsorption temperature increase system, ensuring that the fluid entering the second evaporator 2 has been heated by adsorption heat release. Through the combined switching of the first four-way reversing valve 11 and the second four-way reversing valve 12, a closed-loop circulation of the fluid in the adsorption temperature increase pipeline can be realized. After the fluid discharged from the second evaporator 2 is cooled, it is circulated and introduced into the other first adsorption bed 9 or second adsorption bed 10 under the drive of the second delivery pump 62 to adsorb and release heat for heating, and then recycled for heating, avoiding energy waste.
[0041] In this embodiment, the evaporation heat source of the first evaporator 13 of the adsorption temperature increase system is surface warm seawater (about 28°C), which is introduced through the surface warm seawater inlet 18. The cold source of the first condenser 1 is deep-sea cold seawater (about 2°C), which is introduced through the deep-sea cold seawater inlet 16. A circulating working medium injection port 20 is provided on the first evaporator 13, and seawater working medium can be quantitatively injected into the interior of the first evaporator 13. A first drain port 17 is provided on the first evaporator 13. After the adsorption temperature increase system operates for a period of time, the seawater working medium inside the first evaporator 13 has an increasing salt content due to continuous evaporation of water. After reaching a certain stage, it needs to be regularly discharged and seawater working medium needs to be replenished. The seawater with a high salt content generated can be used for salinity gradient power generation. The first condenser 1 is provided with a second drain port 19 for discharging the fresh water condensed by the first condenser 1, which can be used for drinking or irrigating domestic water.
[0042] In this embodiment, it has the ability of continuous operation: an alternating working mechanism of four adsorption beds (two for heating + two for pressure reduction), combined with a valve control system, breaks through the intermittent operation bottleneck caused by the mismatch of adsorption / desorption cycles in traditional systems, and can achieve continuous power generation. In the figure, the components without connection markings to other components are all directly discharged. It mainly utilizes the cold seawater or warm seawater extracted from the deep sea or surface seawater, and can be directly discharged into the ocean after use. In the figure, for the deep-sea cold seawater inlet 16, surface warm seawater inlet 18, or some other liquid discharge ports, circulating working fluid injection ports 20, drain ports, etc., valves for individually controlling opening and closing are set according to actual needs, and the description of the reference numerals will not be repeated.
[0043] An operation method of an ocean thermal energy conversion power generation efficiency enhancement system, and the operation method of the system is as follows:
[0044] Adsorption heating process: Inject seawater as the working fluid into the interior of the first evaporator 13. This seawater is surface warm seawater. Inject the ocean surface warm seawater (about 28 °C) into the heat exchange tubes of the first evaporator 13 through the surface warm seawater inlet 18. The working fluid evaporates in a vacuum environment. Control the second four-way reversing valve 12 to inject the ocean surface warm seawater from the surface warm seawater (about 28 °C) inlet into the heat exchange tubes of the first adsorption bed 9. Open the fourth vacuum valve 154 between the first evaporator 13 and the first adsorption bed 9 to allow the working fluid vapor to enter the first adsorption bed 9. Start the second transfer pump 62 in the adsorption heating pipeline. The heat released by adsorption heats the seawater in the heat exchange tubes of the first adsorption bed 9, and the seawater temperature can be increased from 28 °C to 35 - 40 °C, and then it is introduced into the evaporator of the ocean thermal energy conversion power generation system for use; when the adsorption of the first adsorption bed 9 ends, close the fourth vacuum valve 154 between the first evaporator 13 and the first adsorption bed 9, and open the second vacuum valve 152 between the first condenser 1 and the first adsorption bed 9; close the first vacuum valve 151 between the first condenser 1 and the second adsorption bed 10, and open the third vacuum valve 153 between the first evaporator 13 and the second adsorption bed 10. Inject the deep-sea low-temperature seawater (about 2 °C) from the deep-sea cold seawater inlet 16 into the heat exchange tubes of the first condenser 1. Switch the first four-way reversing valve 11 and the second four-way reversing valve 12, and drive the seawater (about 30 - 35 °C) cooled and reduced in temperature by the second evaporator 2 to the second adsorption bed 10 under the drive of the second transfer pump 62 to continue the adsorption heating process; inject the surface warm seawater into the heat exchange tubes of the first adsorption bed 9. Under the action of the pressure difference, the working fluid adsorbed and saturated in the first adsorption bed 9 is desorbed to the first condenser 1 and condensed into fresh water. The surface warm seawater used for desorption can be directly discharged into the environment; the first adsorption bed 9 and the second adsorption bed 10 are used in cooperation. Through the switching of the first four-way reversing valve 11 and the second four-way reversing valve 12, keep the fluid after adsorption heating of the first adsorption bed 9 or the second adsorption bed 10 introduced into the second evaporator 2 of the ocean, and in a closed cycle; while other adsorption beds remain in the desorption state to make the system operate continuously and stably;
[0045] Power generation - pressure reduction process: In the ocean thermal energy conversion power generation system, the seawater after adsorption and heating is used to heat the working medium ammonia in the second evaporator 2 to vaporize it. Then, the high-pressure gas is transported to the first-stage turbine 41 to do work. The first-stage turbine 41 rotates and drives the first-stage generator 31 to rotate and generate electricity. The high-pressure gas is transformed into a low-pressure gas working medium. Open the second valve 142, close the third valve 143, and control the first valve 141 to introduce deep-sea cold seawater (about 2 °C) into the heat exchanger of the third adsorption bed 7, and introduce the low-pressure gas working medium into the third adsorption bed 7 for adsorption until adsorption saturation; generally, at a certain temperature (about 2 °C), the condenser can only condense the ammonia vapor of the working medium to the corresponding saturated vapor pressure (about 443.7 KPa), while at the same temperature (about 2 °C), through the adsorption effect, the adsorption bed can reduce the pressure of the working medium vapor to the lowest (about 177.48 KPa), reducing the back pressure at the rear end of the first-stage turbine 41. Increasing the pressure difference can effectively increase the power generation efficiency of the first-stage turbine 41; when the third adsorption bed 7 is saturated with adsorption, close the second valve 142, open the third valve 143, and control the first valve 141 to introduce the surface warm seawater into the first adsorption bed 9 to desorb the ammonia working medium, which enters the second-stage turbine 42 for expansion and power generation. Finally, the depressurized working medium steam enters the second condenser 5 and is condensed by the deep-sea cold seawater, and is transported to the second evaporator 2 through the first delivery pump 61 to achieve circulation; the cooperation of multiple adsorption beds and valves enables the process of adsorbing the working medium steam generated by the first-stage turbine 41 and the process of desorbing the adsorption-saturated adsorption bed to drive the second-stage turbine 42 to generate electricity to proceed simultaneously.
[0046] In this embodiment, the evaporator heats the low-boiling-point liquid working medium and vaporizes and pressurizes it, driving the first-stage turbine 41 to rotate and driving the first-stage generator 31 to generate electricity. The high-pressure gas working medium is transformed into a low-pressure gas and then adsorbed and recovered by the adsorption pressure reduction system. Subsequently, the surface warm seawater of the ocean is used to remove the working medium in the adsorption bed, generating working medium steam that enters the second-stage turbine 42 to drive the second-stage generator 32 to generate electricity, and finally enters the condenser and is condensed by the deep-sea cold seawater. The adsorption heating system uses the heat released during the adsorption process of the first adsorption bed 9 and the second adsorption bed 10 to increase the temperature of the surface warm seawater and is connected to the second evaporator 2 of the ocean thermal energy conversion power generation system to increase the evaporation temperature of the power generation system.
[0047] The above detailed description is a specific description of the feasible embodiments of the present invention. These embodiments are not intended to limit the patent scope of the present invention. Any equivalent implementation or modification without departing from the present invention shall be included in the patent scope of this case.
Claims
1. An ocean thermal energy conversion efficiency enhancement system, characterized in that: It includes an ocean thermal energy conversion system, an adsorption pressure reduction system and an adsorption temperature increase system; the adsorption temperature increase system includes a first condenser, a first evaporator and at least two groups of adsorption beds, and the adsorption beds include a first adsorption bed and a second adsorption bed; the ocean thermal energy conversion system includes a generator set, a second evaporator and a second condenser connected to the second evaporator; the deep sea cold seawater inlet is respectively connected to the first condenser, the second condenser and the adsorption pressure reduction system, and the surface warm seawater inlet is respectively connected to the first evaporator, the heat exchange tubes of the adsorption beds and the adsorption pressure reduction system; the second evaporator is connected to the adsorption pressure reduction system through a group of generator sets, and the second condenser is connected to the adsorption pressure reduction system through another group of generator sets; one end of the first adsorption bed is connected to one end of the second adsorption bed through a second vacuum valve and a first vacuum valve, and the first condenser is connected to the pipeline between the first vacuum valve and the second vacuum valve; the other end of the first adsorption bed is connected to the other end of the second adsorption bed through a fourth vacuum valve and a third vacuum valve, and the first evaporator is connected to the pipeline between the third vacuum valve and the fourth vacuum valve; one end of the first adsorption bed and one end of the second adsorption bed are jointly connected to a first four-way reversing valve, and the first four-way reversing valve is connected to the second evaporator; the other end of the first adsorption bed and the other end of the second adsorption bed are jointly connected to a second four-way reversing valve, and the second four-way reversing valve is respectively connected to the surface warm seawater pipe inlet and the second evaporator.
2. The ocean thermal energy conversion power generation efficiency enhancement system according to claim 1, wherein: The ocean thermal energy conversion system further includes a first delivery pump and a second delivery pump. The first delivery pump is arranged on the pipeline connecting the second evaporator and the second condenser, and the second delivery pump is arranged on the pipeline between the second evaporator and the first four-way reversing valve; the generator set includes a primary power generation unit and a secondary power generation unit. The primary power generation unit includes a primary generator and a primary turbine, and the secondary power generation unit includes a secondary generator and a secondary turbine; the primary generator is connected to the second evaporator through the primary turbine, and the secondary generator is connected to the second condenser through the secondary turbine; the adsorption pressure reduction system is respectively connected to the primary turbine and the secondary turbine; the working medium of the ocean thermal energy conversion system is ammonia.
3. The ocean thermal energy conversion power generation efficiency enhancement system according to claim 1, wherein: The working medium of the adsorption temperature increase system is seawater, and the adsorption materials in the first adsorption bed and the second adsorption bed are silica gel, molecular sieve or carbon-based materials.
4. The ocean thermal energy conversion power generation efficiency enhancement system according to claim 3, wherein: The adsorption materials in the first adsorption bed and the second adsorption bed are porous carbon-based materials.
5. The ocean thermal energy conversion power generation efficiency enhancement system according to claim 2, wherein: The adsorption pressure reduction system includes at least two groups of adsorption beds and several valves; the adsorption beds include a third adsorption bed and a fourth adsorption bed; the valves include a first valve, a second valve, a third valve, a fourth valve, a fifth valve and a sixth valve; the third adsorption bed and the fourth adsorption bed are arranged in a cross-parallel manner, one end of the third adsorption bed is connected to the first-stage turbine through the second valve, and one end of the fourth adsorption bed is connected to the first-stage turbine through the fifth valve after being connected in parallel; the other end of the third adsorption bed is connected to the second-stage turbine through the third valve, and the other end of the fourth adsorption bed is connected to the second-stage turbine through the sixth valve after being connected in parallel; the first valve is a three-way valve, its first interface is connected to the third adsorption bed, its second interface is connected to the deep-sea cold seawater inlet through the seventh valve, and its third interface is connected to the surface warm seawater inlet through the eighth valve; the fourth valve is a three-way valve, its first interface is connected to the fourth adsorption bed, its second interface is connected to the seventh valve, and its third interface is connected to the eighth valve.
6. The ocean thermal energy conversion power generation efficiency enhancement system according to claim 5, wherein: The adsorption materials in the third adsorption bed and the fourth adsorption bed are porous carbon-based materials.
7. The ocean thermal energy conversion power generation efficiency enhancement system according to claim 6, wherein: The adsorption materials in the third adsorption bed and the fourth adsorption bed are activated carbon.
8. The ocean thermal energy conversion efficiency enhancement system according to claim 1, characterized in that: The cold source of the first condenser is the cold seawater in the deep ocean, and the heat source of the first evaporator is the warm seawater on the ocean surface.
9. The ocean thermal energy conversion power generation efficiency enhancement system according to claim 1, wherein: The second evaporator is always connected to the adsorption bed in the adsorption stage in the adsorption temperature-raising system to form an adsorption temperature-raising pipeline, and the fluid in the adsorption temperature-raising pipeline is in a closed cycle.
10. A method for operating the ocean thermal energy conversion efficiency enhancement system according to claim 1, characterized in that: The operation method of the system is as follows: Adsorption heating process: Inject seawater as the working fluid into the first evaporator. The seawater is surface warm seawater. Feed the ocean surface warm seawater into the heat exchange tubes of the first evaporator through the surface warm seawater inlet. The working fluid evaporates in a vacuum environment. Control the second four-way reversing valve, and feed the ocean surface warm seawater into the heat exchange tubes of the first adsorption bed through the surface warm seawater inlet. Open the fourth vacuum valve between the first evaporator and the first adsorption bed to allow the working fluid vapor to enter the first adsorption bed. Start the second delivery pump in the adsorption heating pipeline. The heat released by adsorption heats the seawater in the heat exchange tubes of the first adsorption bed, and the seawater temperature can be increased from 28°C to 35 - 40°C, and then it is fed into the evaporator of the ocean thermal energy conversion system for use; when the adsorption of the first adsorption bed is completed, close the fourth vacuum valve between the first evaporator and the first adsorption bed, and open the second vacuum valve between the first condenser and the first adsorption bed; close the first vacuum valve between the first condenser and the second adsorption bed, and open the third vacuum valve between the first evaporator and the second adsorption bed. Inject deep-sea low-temperature seawater into the heat exchange tubes of the first condenser through the deep-sea cold seawater inlet. Switch the first four-way reversing valve and the second four-way reversing valve. The seawater after evaporation and cooling in the second evaporator is transported to the second adsorption bed under the drive of the second delivery pump to continue the adsorption heating process; inject the surface warm seawater into the heat exchange tubes of the first adsorption bed. Under the action of pressure difference, the working fluid adsorbed and saturated in the first adsorption bed is desorbed into the first condenser and condensed into fresh water. The surface warm seawater used for desorption can be directly discharged into the environment; the first adsorption bed and the second adsorption bed are used in combination. Through the switching of the first four-way reversing valve and the second four-way reversing valve, the fluid after adsorption heating in the first adsorption bed or the second adsorption bed is kept fed into the second evaporator of the ocean, and it is a closed cycle; while other adsorption beds remain in the desorption state to make the system operate continuously and stably; Power generation - pressure reduction process: In the ocean thermal energy conversion system, the seawater after adsorption heating heats the working fluid ammonia to gasify it through the second evaporator, and then transports the high-pressure gas to the first-stage turbine to do work. The first-stage turbine rotates and drives the first-stage generator to generate electricity. The high-pressure gas is transformed into a low-pressure gas working fluid. Open the second valve, close the third valve, and control the first valve to feed deep-sea cold seawater into the heat exchanger of the third adsorption bed, and feed the low-pressure gas working fluid into the third adsorption bed for adsorption until it is adsorption-saturated; when the third adsorption bed is adsorption-saturated, close the second valve, open the third valve, and control the first valve to feed the surface warm seawater into the first adsorption bed to desorb the ammonia working fluid, which enters the second-stage turbine to expand and generate electricity. Finally, the pressure-reduced working fluid vapor enters the second condenser and is condensed by the deep-sea cold seawater, and is transported to the second evaporator through the first delivery pump to achieve circulation; multiple groups of adsorption beds and valves cooperate to make the process that the working fluid vapor generated by the first-stage turbine is adsorbed, and the process that the adsorption-saturated adsorption bed desorbs to drive the second-stage turbine to generate electricity proceed simultaneously.