Ocean temperature difference energy and solar energy combined power generation system and offshore platform
Through the multi-stage Rankine circulation system and supercritical Rankine circulation, the problem of low heat utilization in the combined power generation system of ocean temperature difference energy and solar energy is solved, and efficient seawater heat utilization and power generation capacity are achieved.
Patent Information
- Application Number
- CN202421808249.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-29
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2034-07-29
AI Technical Summary
The existing power generation systems driven by combined ocean temperature difference energy and solar energy have the problem of low heat utilization in seawater.
The multi-stage Rankine circulation system is adopted, and the evaporators of each Rankine circulation system are connected to each other. The heat exchange between the multi-stage evaporator and condenser is achieved through the warm seawater pump and the cold seawater pump. Combined with the supercritical Rankine circulation, the heat of the warm seawater and cold seawater is used to reduce seawater energy consumption.
It improves the utilization rate of seawater heat, reduces the energy consumption of the power generation system, improves the power generation capacity, and ensures the effective utilization of ocean temperature difference energy.
Smart Images
Figure CN223227460U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of comprehensive utilization of ocean temperature difference energy and solar energy, in particular to an ocean temperature difference energy and solar energy combined power generation system and an offshore platform. Background Art
[0002] Ocean thermal energy refers to the thermal energy stored between the warm surface water (heated by solar energy) and the colder deeper water at depths of 800 to 1000 meters. The most common use of this energy is in power generation. The basic principle is to use the warm surface water to heat a low-boiling-point working fluid, vaporizing it to drive an expander, which in turn drives a generator. The working fluid vapor at the expander's outlet condenses through heat exchange with the cold deeper water and is then pumped to the evaporator via a working fluid pump, completing the cycle.
[0003] Compared with traditional thermal power generation, ocean thermal power generation systems suffer from low thermal-to-electricity conversion efficiency and high marine engineering investment, as the temperature difference between the cold and hot sources is only about 20°C. This results in high unit electricity costs, which restricts the industrial development of ocean thermal energy. Therefore, power generation systems that combine ocean thermal energy and solar energy have emerged to combine the advantages of both energy sources.
[0004] However, the existing power generation system driven by the combined power of ocean temperature difference and solar energy has the problem of low utilization rate of heat in seawater, which needs to be solved urgently. Utility Model Content
[0005] The main purpose of the utility model is to propose a combined ocean temperature difference energy and solar energy power generation system, aiming to solve the problem of low utilization rate of heat in seawater in the existing power generation system driven by combined ocean temperature difference energy and solar energy.
[0006] To achieve the above-mentioned objectives, the present invention proposes a combined ocean temperature difference energy and solar energy power generation system comprising N-stage Rankine cycle systems, a warm seawater pump and a power generation device, wherein each Rankine cycle system comprises at least an evaporator and a solar collector, wherein the working fluid outlet of the evaporator is connected to the working fluid inlet of the solar collector; the seawater outlet of the evaporator in the k-1-stage Rankine cycle system is connected to the seawater inlet of the evaporator in the k-stage Rankine cycle system; 2≤k≤N; the warm seawater pump is connected to the seawater inlet of the evaporator of the 1st-stage Rankine cycle system; the power generation device is connected to the working fluid outlet of the solar collector; the evaporator is used to perform heat exchange between the supplied working fluid and the supplied warm seawater; the solar collector is used to heat the supplied working fluid; and the power generation device is used to generate electricity using the internal energy of the supplied working fluid.
[0007] In one embodiment, the power generation system further includes a cold seawater pump; each stage of the Rankine cycle system further includes a condenser; the seawater outlet end of the condenser in the k-th stage Rankine cycle system is connected to the seawater inlet end of the condenser in the k-1-th stage Rankine cycle system; 2≤k≤N; the cold seawater pump is connected to the seawater inlet end of the condenser in the N-th stage Rankine cycle system; the working fluid inlet end of the condenser is connected to the power generation equipment, and the working fluid outlet end of the condenser is connected to the working fluid inlet end of the evaporator; the condenser is used to perform heat exchange between the working fluid used by the power generation equipment during the power generation process and the supplied cold seawater.
[0008] In one embodiment, the power generation system further includes a mixing container, wherein a seawater inlet end of the mixing container is respectively connected to the evaporator of the N-stage Rankine cycle system and the condenser of the first-stage Rankine cycle system; the mixing container is used to receive and mix the warm seawater from the evaporator of the N-stage Rankine cycle system and the cold seawater from the condenser of the first-stage Rankine cycle system, and discharge the mixed seawater into the seawater stratosphere.
[0009] In one embodiment, the power generation equipment includes an expander and a generator; the working fluid outlet of the solar collector is connected to the inlet of the expander; the outlet of the expander is connected to the condenser; and the driving end of the expander is transmission-connected to the generator.
[0010] In one embodiment, each stage of the Rankine cycle system further includes a working fluid pump, wherein the inlet end of the working fluid pump is connected to the working fluid outlet end of the condenser, and the outlet end of the working fluid pump is connected to the working fluid inlet end of the evaporator.
[0011] In one embodiment, the interior of the evaporator is filled with a high-pressure liquid working fluid; the evaporator is used to perform heat exchange between the high-pressure liquid working fluid and warm seawater to convert the high-pressure liquid working fluid into a subcritical high-pressure gaseous working fluid, and the subcritical high-pressure gaseous working fluid is transported to a solar collector; the solar collector is used to heat the subcritical high-pressure gaseous working fluid to a supercritical state, and transport the supercritical high-pressure gaseous working fluid to an expander; the expander is used to expand the supercritical high-pressure gaseous working fluid to perform work, thereby driving a generator to generate electricity.
[0012] In one embodiment, a high-pressure gaseous working fluid in a supercritical state is converted into exhaust steam in a subcritical state after expanding and performing work inside an expander; the outlet end of the expander is used to transport the exhaust steam to a condenser of a Rankine cycle system; the condenser is used to perform heat exchange between the exhaust steam and cold seawater to obtain a condensed liquid working fluid; a working fluid pump is used to pressurize the condensed liquid working fluid to obtain a high-pressure liquid working fluid, and the high-pressure liquid working fluid is pumped into an evaporator.
[0013] In one embodiment, the working fluid is an organic working fluid.
[0014] In one embodiment, the number of stages of the N-stage Rankine cycle system is set to 2 or 3.
[0015] The utility model also provides an offshore platform, comprising the above-mentioned ocean temperature difference energy and solar energy combined power generation system.
[0016] The technical solution of the present invention adopts a combined power generation system of ocean temperature difference energy and solar energy, including N-stage Rankine cycle systems, warm seawater pumps and power generation equipment, each stage of the Rankine cycle system includes at least an evaporator and a solar collector, the working fluid outlet end of the evaporator is connected to the working fluid inlet end of the solar collector; the seawater outlet end of the evaporator in the k-1-stage Rankine cycle system is connected to the seawater inlet end of the evaporator in the k-stage Rankine cycle system; 2≤k≤N; the warm seawater pump is connected to the seawater inlet end of the evaporator of the 1st stage Rankine cycle system; the power generation equipment is connected to the working fluid outlet end of the solar collector; the evaporator is used to perform heat exchange between the supplied working fluid and the supplied warm seawater; the solar collector is used to heat the supplied working fluid; and the power generation equipment is used to generate electricity using the internal energy of the supplied working fluid.
[0017] This utility model utilizes a multi-stage Rankine cycle system, with the evaporators of each stage interconnected. Warm seawater from heat exchange in the previous evaporator can be used to heat the working fluid in the next evaporator, further extracting heat from the warm seawater. Because the evaporators of each Rankine cycle are interconnected, a single warm seawater pump is required to pump the multiple evaporators, reducing the energy consumption of extracting seawater. Overall, this utility model's technical solution improves the absorption of heat from seawater, increasing power generation capacity while reducing the energy consumption of extracting surface warm seawater. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] 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.
[0019] Figure 1 This is a structural schematic diagram of an embodiment of the ocean temperature difference energy and solar energy combined power generation system provided by the present utility model.
[0020] Description of Figure Numbers:
[0021] 1. Rankine cycle system; 11. Evaporator; 12. Solar collector; 13. Condenser; 14. Working fluid pump; 2. Warm seawater pump; 3. Power generation equipment; 31. Expander; 32. Generator; 4. Cold seawater pump.
[0022] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 efforts shall fall within the scope of protection of the present invention.
[0024] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.
[0025] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually 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] Ocean thermal energy refers to the thermal energy stored between the warm surface water (heated by solar energy) and the colder deeper water at depths of 800 to 1000 meters. The most common use of this energy is in power generation. The basic principle is to use the warm surface water to heat a low-boiling-point working fluid, vaporizing it to drive an expander, which in turn drives a generator. The working fluid vapor at the expander's outlet condenses through heat exchange with the cold deeper water and is then pumped to the evaporator via a working fluid pump, completing the cycle.
[0027] Compared with traditional thermal power generation, ocean thermal power generation systems suffer from low thermal-to-electricity conversion efficiency and high marine engineering investment, as the temperature difference between the cold and hot sources is only about 20°C. This results in high unit electricity costs, which restricts the industrial development of ocean thermal energy. Therefore, power generation systems that combine ocean thermal energy and solar energy have emerged to combine the advantages of both energy sources.
[0028] However, the existing power generation system driven by the combined power of ocean temperature difference and solar energy has the problem of low utilization rate of heat in seawater, which needs to be solved urgently.
[0029] In order to solve the above problems, the utility model proposes a combined power generation system using ocean temperature difference energy and solar energy.
[0030] See also Figure 1 In one embodiment of the present invention, the ocean temperature difference energy and solar energy combined power generation system includes N-stage Rankine cycle systems 1, warm seawater pumps 2 and power generation equipment 3; each stage of the Rankine cycle system 1 includes at least an evaporator 11 and a solar collector 12, and the working fluid outlet end of the evaporator 11 is connected to the working fluid inlet end of the solar collector 12; the seawater outlet end of the evaporator 11 in the k-1-stage Rankine cycle system 1 is connected to the seawater inlet end of the evaporator 11 in the k-stage Rankine cycle system 1; 2≤k≤N; the warm seawater pump 2 is connected to the seawater inlet end of the evaporator 11 of the first-stage Rankine cycle system 1; the power generation equipment 3 is connected to the working fluid outlet end of the solar collector 12; the evaporator 11 is used to perform heat exchange between the supplied working fluid and the supplied warm seawater; the solar collector 12 is used to heat the supplied working fluid; and the power generation equipment 3 is used to generate electricity using the internal energy of the supplied working fluid.
[0031] It should be noted that the Rankine cycle is a thermodynamic cycle used to convert thermal energy into mechanical energy, which is then converted into electrical energy through a generator. The Rankine cycle typically includes four major processes: isobaric heating, isentropic expansion, isobaric condensation, and isentropic compression. Compared to the Brayton cycle, the Rankine cycle effectively reduces the energy consumption of working fluid transportation by using a liquid working fluid and lower compression pressure.
[0032] Among them, the connection between each component can be achieved by using an insulated pipe. For example, the warm seawater pump 2 is connected to the evaporator 11 through an insulated pipe, the evaporator 11 is connected to the solar collector 12 through an insulated pipe, and the solar collector 12 is connected to the power generation equipment 3 through an insulated pipe.
[0033] The technical solution of the present invention utilizes a multi-stage Rankine cycle system 1, wherein the evaporators 11 of each stage of the Rankine cycle system 1 are interconnected. Warm seawater after heat exchange in the previous evaporator 11 can be used to heat the working fluid in the next evaporator 11, thereby further extracting heat from the warm seawater. Because the evaporators 11 of each stage of the Rankine cycle system 1 are interconnected, only a single warm seawater pump 2 is required to pump the multiple evaporators 11, reducing the energy consumption of extracting seawater. Overall, the technical solution of the present invention can improve the absorption of heat from seawater, thereby increasing power generation capacity while reducing the energy consumption of extracting surface warm seawater.
[0034] For ease of understanding, illustratively, the N-stage Rankine cycle system 1 can be set as a three-stage Rankine cycle system 1. In the process of pumping warm seawater, the warm seawater pump 2 sequentially pumps the warm seawater from the ocean surface to the evaporator 11 of the first-stage Rankine cycle system 1, the evaporator 11 of the second-stage Rankine cycle system 1, and the evaporator 11 of the third-stage Rankine cycle system 1, so that the warm seawater sequentially exchanges heat with the working medium inside the evaporator 11 of each stage of the Rankine cycle system 1, thereby improving the utilization rate of the heat of the warm seawater.
[0035] As a preferred embodiment, the N-stage Rankine cycle system 1 can be configured as a two-stage Rankine cycle system 1 or a three-stage Rankine cycle system 1. This fully utilizes the heat in the warm seawater while avoiding the problem of reduced heating effect on the working medium after the warm seawater undergoes heat exchange with the working medium in the multi-stage evaporator 11, thereby ensuring heating efficiency. Of course, the N-stage Rankine cycle system 1 can also be configured as a Rankine cycle system 1 with a greater number of stages, and the number of stages of the Rankine cycle system 1 is not limited herein.
[0036] Furthermore, the existing power generation system combining ocean temperature difference energy and solar energy has a low utilization rate not only for the heat of warm seawater but also for the coldness of cold seawater. Figure 1 The power generation system further includes a cold seawater pump 4; each stage of the Rankine cycle system 1 further includes a condenser 13; the seawater outlet end of the condenser 13 in the k-th stage Rankine cycle system 1 is connected to the seawater inlet end of the condenser 13 in the k-1-th stage Rankine cycle system 1; 2≤k≤N; the cold seawater pump 4 is connected to the seawater inlet end of the condenser 13 in the N-th stage Rankine cycle system 1; the working fluid inlet end of the condenser 13 is connected to the power generation equipment 3, and the working fluid outlet end of the condenser 13 is connected to the working fluid inlet end of the evaporator 11; the condenser 13 is used to perform heat exchange between the working fluid used by the power generation equipment 3 during the power generation process and the supplied cold seawater.
[0037] Thus, in this embodiment, by connecting the condensers 13 of each stage of the Rankine cycle system 1 to each other, the cold seawater after heat exchange in the condenser 13 of the k-th stage Rankine cycle system 1 can be used to condense the working medium in the condenser 13 of the k-1-th stage Rankine cycle system 1, thereby further extracting the cold seawater; because the condensers 13 of each stage of the Rankine cycle system 1 are connected to each other, only a single cold seawater pump 4 is required to achieve the pumping effect of the multi-stage evaporator 11, thereby reducing the energy consumption of extracting seawater.
[0038] Similarly, for ease of understanding, the above example of the N-stage Rankine cycle system 1 being set as a three-stage Rankine cycle system 1 is continued for explanation: in the process of pumping cold seawater, the cold seawater pump 4 sequentially pumps the cold seawater from the ocean surface to the condenser 13 of the third-stage Rankine cycle system 1, the condenser 13 of the second-stage Rankine cycle system 1, and the condenser 13 of the first-stage Rankine cycle system 1, so that the cold seawater sequentially exchanges heat with the working medium inside the condenser 13 of each stage of the Rankine cycle system 1, thereby improving the utilization rate of the heat of the cold seawater.
[0039] Furthermore, in order to avoid the problem that the warm seawater after heat exchange and the cold seawater after cold exchange are directly discharged without treatment, which affects the current seawater temperature and leads to the inability to effectively utilize the ocean temperature difference energy, in an embodiment of the present invention, the power generation system also includes a mixing container, and the seawater inlet end of the mixing container is respectively connected to the evaporator 11 of the N-stage Rankine cycle system 1 and the condenser 13 of the first-stage Rankine cycle system 1; the mixing container is used to receive and mix the warm seawater from the evaporator 11 of the N-stage Rankine cycle system 1 and the cold seawater from the condenser 13 of the first-stage Rankine cycle system 1, and discharge the mixed seawater into the seawater stratosphere.
[0040] It should be noted that the stratosphere refers to the layer of seawater with the same temperature as the mixed seawater. Seawater layers at different depths have different temperatures due to the varying levels of solar radiation they receive. Generally, the deeper the seawater, the lower its temperature. Therefore, discharging the mixed seawater into the stratosphere effectively prevents the discharged seawater from affecting the temperature of that layer, ensuring the effective extraction of ocean temperature gradient energy.
[0041] In this way, by providing a mixing container, the warm seawater from the evaporator 11 of the Nth-stage Rankine cycle system 1 and the cold seawater from the condenser 13 of the first-stage Rankine cycle system 1 are received and mixed with a mixed solution, and the mixed seawater is discharged into the seawater stratosphere, thereby avoiding the discharged seawater from affecting the temperature of a small sea area, and further avoiding the discharged seawater from affecting the temperature of the extracted warm seawater / cold seawater, thereby preventing the utilization of the ocean temperature difference energy from being affected.
[0042] Further, in the embodiments of the present invention, please refer to Figure 1The power generation equipment 3 includes an expander 31 and a generator 32; the working medium outlet of the solar collector 12 is connected to the inlet of the expander 31; the outlet of the expander 31 is connected to the condenser 13; the driving end of the expander 31 is connected to the generator 32. For further information, please refer to Figure 1 Each stage of the Rankine cycle system 1 further includes a working fluid pump 14 , the inlet end of the working fluid pump 14 is connected to the working fluid outlet end of the condenser 13 , and the outlet end of the working fluid pump 14 is connected to the working fluid inlet end of the evaporator 11 .
[0043] As mentioned above, the Rankine cycle typically includes four major processes: isobaric heating, isentropic expansion, isobaric condensation, and isentropic compression. In this embodiment, the working fluid first undergoes heat exchange in the evaporator 11 and solar collector 12, completing the isobaric heating process. The working fluid then expands and performs work in the expander 31, completing the isentropic expansion process. The working fluid then undergoes heat exchange in the condenser 13, completing the isobaric condensation process. Finally, the working fluid is transported and compressed by the working fluid pump 14, completing the isentropic compression process. Thus, the power generation system combining ocean temperature difference energy and solar energy of the present invention realizes a complete Rankine cycle.
[0044] Furthermore, in an embodiment of the present invention, the evaporator 11 is filled with a high-pressure liquid working medium; the evaporator 11 is used to perform heat exchange between the high-pressure liquid working medium and the warm seawater, so that the high-pressure liquid working medium is converted into a high-pressure gaseous working medium in a subcritical state, and the high-pressure gaseous working medium in the subcritical state is transported to the solar collector 12; the solar collector 12 is used to heat the high-pressure gaseous working medium in the subcritical state to a supercritical state, and transport the high-pressure gaseous working medium in the supercritical state to the expander 31; the expander 31 is used to expand the high-pressure gaseous working medium in the supercritical state to perform work, so as to drive the generator 32 to generate electricity.
[0045] In this embodiment, secondary heating via the evaporator 11 and solar collector 12 transforms the original high-pressure liquid working fluid into a supercritical, high-pressure gaseous working fluid, thereby achieving a supercritical Rankine cycle. Compared to existing subcritical Rankine cycles, the supercritical Rankine cycle of the present invention achieves a good temperature match between the warm seawater (heat source) and the solar collector 12 because its evaporation heat exchange process does not pass through a two-phase region. Through the supercritical Rankine cycle, heat exchange losses between the warm seawater and the working fluid, and between the solar collector 12 and the working fluid, are reduced, thermoelectric conversion efficiency is improved, and the amount of seawater required for the same power generation is reduced, reducing the energy consumption of seawater extraction, thereby improving the overall efficiency of the ocean thermal energy power generation system.
[0046] Furthermore, in an embodiment of the present invention, the high-pressure gaseous working medium in a supercritical state becomes exhaust steam in a subcritical state after expanding and doing work inside the expander 31; the outlet end of the expander 31 is used to transport the exhaust steam to the condenser 13 of the Rankine cycle system 1; the condenser 13 is used to allow the exhaust steam to exchange heat with cold seawater to obtain a condensed liquid working medium; the working medium pump 14 is used to pressurize the condensed liquid working medium to obtain a high-pressure liquid working medium, and pump the high-pressure liquid working medium into the evaporator 11.
[0047] It should be noted that exhaust steam refers to a gaseous working medium in a low-pressure, medium-temperature state.
[0048] In this embodiment, the exhaust steam in a subcritical state is condensed by exchanging heat with cold seawater in the condenser 13 to obtain a condensed liquid working medium, thereby completing the condensation process in the supercritical Rankine cycle. The condensed liquid working medium is pressurized by the working medium pump 14 to obtain a high-pressure liquid working medium, and the high-pressure liquid working medium is pumped to the evaporator 11 by the working medium pump 14, thereby completing the pressurization process in the supercritical Rankine cycle.
[0049] Furthermore, to address the problem of working fluids such as water having high critical points, making them inconvenient to use in systems based on ocean temperature differential energy for power generation, in embodiments of the present invention, the high-pressure liquid working fluid is an organic working fluid. Because organic working fluids typically have lower critical temperatures and pressures, they can vaporize and liquefy in the presence of low-temperature heat sources, effectively converting thermal energy into mechanical or electrical energy.
[0050] In this embodiment, the working process of the power generation system combining ocean temperature difference energy and solar energy of the present invention is described:
[0051] First, the evaporator 11 causes the high-pressure liquid working medium to exchange heat with the warm seawater to convert the high-pressure liquid working medium into a subcritical high-pressure gaseous working medium, and the subcritical high-pressure gaseous working medium is transported to the solar collector 12; it should be noted that the subcritical state refers to a state in which the temperature and pressure of the working medium are lower than its critical point. In the subcritical state, the working medium can exist in both liquid and gas phases.
[0052] Then, the solar collector 12 heats the high-pressure gaseous working medium in the subcritical state to a supercritical state, and transports the high-pressure gaseous working medium in the supercritical state to the expander 31 of the Rankine cycle system 1; it should be noted that the supercritical state means that the temperature and pressure of the working medium exceed its critical point. In this state, the working medium no longer has a clear distinction between liquid and gas, but is in a supercritical state between liquid and gas.
[0053] Afterwards, the high-pressure gaseous working medium in the supercritical state expands inside the expander 31 to perform work, driving the transmission part of the expander 31 to drive the generator 32 to generate electricity.
[0054] Then, the high-pressure gaseous working medium in the supercritical state expands and does work inside the expander 31 and becomes exhaust steam in the subcritical state; it should be noted that exhaust steam refers to a gaseous working medium in a low-pressure, medium-temperature state.
[0055] Next, the outlet end of the expander 31 delivers the exhaust steam to the condenser 13 of the Rankine cycle system 1;
[0056] Afterwards, the condenser 13 performs heat exchange between the exhaust steam and the cold seawater to obtain condensed liquid working fluid.
[0057] Finally, the working medium pump 14 of the Rankine cycle system 1 pressurizes the condensed liquid working medium to obtain high-pressure liquid working medium, and delivers the high-pressure liquid working medium to the evaporator 11 .
[0058] In addition, for warm seawater pumps, cold seawater pumps and mixing containers, the operation process is:
[0059] The warm seawater pump 2 sequentially pumps the warm seawater through the evaporator 11 of each stage of the Rankine cycle system 1, so that the warm seawater exchanges heat with the evaporator 11 of each stage of the Rankine cycle system 1;
[0060] The cold seawater pump 4 of the Rankine cycle system 1 sequentially pumps the cold seawater through the condenser 13 of each stage of the Rankine cycle system 1, so that the cold seawater exchanges heat with the condenser 13 of each stage of the Rankine cycle system 1;
[0061] The mixing container of the power generation system receives and mixes warm seawater from the evaporator 11 of the Nth-stage Rankine cycle system 1 and cold seawater from the condenser 13 of the first-stage Rankine cycle system 1 , and discharges the mixed seawater into the seawater stratosphere.
[0062] The present invention also provides an offshore platform comprising the aforementioned combined ocean thermal energy and solar power generation system. The specific structure of the combined ocean thermal energy and solar power generation system is similar to the aforementioned embodiments. Since the present offshore platform utilizes all the technical solutions of all the aforementioned embodiments, it possesses at least all the beneficial effects of the technical solutions of the aforementioned embodiments, and therefore will not be further elaborated upon here.
[0063] Among them, the offshore platform can be an ocean power station, an offshore oil platform, an offshore aquaculture platform, etc., which will not be listed here one by one.
[0064] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.
Claims
1. A power generation system combining ocean temperature difference energy and solar energy, characterized in that: include: N-stage Rankine cycle systems, each stage of the Rankine cycle system comprising at least an evaporator and a solar collector, the working fluid outlet of the evaporator being in communication with the working fluid inlet of the solar collector; the seawater outlet of the evaporator in the k-1-stage Rankine cycle system being in communication with the seawater inlet of the evaporator in the k-stage Rankine cycle system; 2≤k≤N; a warm seawater pump, the warm seawater pump being connected to the seawater inlet of the evaporator of the first stage Rankine cycle system; A power generation device connected to a working medium outlet of the solar thermal collector; The evaporator is used for heat exchange between the supplied working fluid and the supplied warm seawater; the solar collector is used for heating the supplied working fluid; and the power generation equipment is used for generating electricity by utilizing the internal energy of the supplied working fluid.
2. The power generation system according to claim 1, wherein: The power generation system further includes a cold seawater pump; each stage of the Rankine cycle system further includes a condenser; The seawater outlet of the condenser in the k-th stage Rankine cycle system is connected to the seawater inlet of the condenser in the k-1-th stage Rankine cycle system; 2≤k≤N; The cold seawater pump is connected to the seawater inlet of the condenser of the Nth stage Rankine cycle system; The working fluid inlet of the condenser is connected to the power generation equipment, and the working fluid outlet of the condenser is communicated with the working fluid inlet of the evaporator; the condenser is used to perform heat exchange between the working fluid used by the power generation equipment during the power generation process and the supplied cold seawater.
3. The power generation system according to claim 2, wherein: The power generation system further comprises a mixing container, wherein a seawater inlet end of the mixing container is respectively connected to the evaporator of the Nth stage Rankine cycle system and the condenser of the first stage Rankine cycle system; The mixing container is used to receive and mix warm seawater from the evaporator of the Nth stage Rankine cycle system and cold seawater from the condenser of the first stage Rankine cycle system, and discharge the mixed seawater into the seawater stratosphere.
4. The power generation system according to claim 2, wherein: The power generation equipment includes an expander and a generator; the working medium outlet end of the solar collector is connected to the inlet end of the expander; the outlet end of the expander is connected to the condenser; and the driving end of the expander is transmission-connected to the generator.
5. The power generation system according to claim 4, wherein: Each stage of the Rankine cycle system further includes a working fluid pump, wherein the inlet end of the working fluid pump is communicated with the working fluid outlet end of the condenser, and the outlet end of the working fluid pump is communicated with the working fluid inlet end of the evaporator.
6. The power generation system according to claim 4, wherein: The evaporator is filled with a high-pressure liquid working medium; the evaporator is used to perform heat exchange between the high-pressure liquid working medium and the warm seawater, so that the high-pressure liquid working medium is converted into a high-pressure gaseous working medium in a subcritical state, and the high-pressure gaseous working medium in the subcritical state is transported to the solar thermal collector; The solar thermal collector is used to heat the high-pressure gaseous working medium in the subcritical state to a supercritical state, and to transport the high-pressure gaseous working medium in the supercritical state to the expander; The expander is used to expand the high-pressure gaseous working medium in the supercritical state to perform work, so as to drive the generator to generate electricity.
7. The power generation system according to claim 5, wherein: The high-pressure gaseous working medium in the supercritical state becomes exhaust steam in the subcritical state after expanding and performing work inside the expander; The outlet end of the expander is used to transport the exhaust steam to the condenser of the Rankine cycle system; The condenser is used to perform heat exchange between the exhaust steam and cold seawater to obtain condensed liquid working fluid; The working medium pump is used to pressurize the condensed liquid working medium to obtain the high-pressure liquid working medium, and pump the high-pressure liquid working medium into the evaporator.
8. The power generation system according to claim 1, wherein: The working fluid is an organic working fluid.
9. The power generation system according to claim 1, wherein: The number of stages of the N-stage Rankine cycle system is set to 2 or 3.
10. An offshore platform, characterized in that: A power generation system comprising a combination of ocean temperature difference energy and solar energy as claimed in any one of claims 1 to 9.