An organic rankine cycle power generation system and method for a megawatt offshore platform

Abstract

The application relates to an organic Rankine cycle power generation system and method for a megawatt offshore platform, characterized in that the system comprises a heat source device, an ORC and a cold source device and a control device; the heat source device is used for heat exchange between heat conducting oil and a heat source from a smoke self-ignition machine, the heated heat conducting oil enters the ORC and the cold source device; the ORC and the cold source device are used for heat exchange between the heated heat conducting oil and a working medium and pressurization to obtain high-temperature and high-pressure working medium steam, the high-temperature and high-pressure working medium steam drives a generator to generate power, and the working medium steam after work is completed is condensed to form liquid working medium and then continues to be heat exchanged with the heat conducting oil; the control device is used for controlling the work of various components in the heat source device and the ORC and the cold source device, and the application can be widely applied to the field of waste heat power generation.

Description

Technical Field

[0001] This invention relates to the field of waste heat power generation, and in particular to an organic Rankine cycle power generation system and method for megawatt-class offshore platforms. Background Technology

[0002] With global population growth and economic development, the demand for energy is constantly increasing. The current reliance on fossil fuels cannot meet this demand indefinitely, and their use also causes environmental and climate problems. Therefore, seeking new, renewable energy sources has become a necessary and inevitable trend. Many industrial production processes require heating, cooling, and drying of materials, generating significant amounts of waste heat, leading to energy waste and environmental pollution. Utilizing these industrial waste heat resources can help reduce energy costs, improve energy efficiency, and mitigate environmental pollution.

[0003] The Organic Rankine Cycle (ORC) is a novel method for generating electricity using low-temperature waste heat. Compared to traditional steam power generation, the ORC utilizes waste heat at even lower temperatures, resulting in higher power generation efficiency and lower costs. Furthermore, the ORC allows for breakthroughs in miniaturization, integration, and intelligentization. Offshore platforms face complex environments and unstable energy supplies, necessitating a power generation method adaptable to varying environments and load changes. The low-temperature power generation capacity and high efficiency of the ORC can effectively meet the electricity demands of offshore platforms.

[0004] However, existing organic Rankine cycle (ORC) power generation systems utilizing industrial waste heat on offshore platforms have the following drawbacks: 1) Environmental issues related to chemicals: ORC systems require the use of certain amounts of organic chemicals, necessitating consideration of their environmental impact and treatment methods. For example, the widely used organic working fluid R245fa has a global warming potential of 1030°C. 2) Limited applicability: ORC systems have relatively limited applications, suitable only for specific scenarios such as industrial production sites or offshore platforms that can provide stable waste heat resources. 3) Efficiency limitations: The efficiency of ORC systems is constrained by the characteristics of the working fluid and the optimization of circulation parameters, making them susceptible to external environmental influences. 4) High maintenance difficulty: Offshore platforms operate in harsh environments, and equipment is easily affected by waves, oxidation, corrosion, etc., requiring frequent maintenance and increasing operating costs. 5) Large-scale equipment: Offshore platforms require significant energy output, necessitating large-scale ORC systems. 6) High investment costs: ORC systems require substantial investment, including equipment, manpower, and maintenance costs. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide an organic Rankine cycle power generation system and method for megawatt-class offshore platforms, which can solve the technical problems of environmentally unfriendly chemicals, low system efficiency, high maintenance difficulty, large-scale equipment, and high investment costs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: On the one hand, it provides an organic Rankine cycle power generation system for megawatt-class offshore platforms, including a heat source device, an ORC and a cold source device, and a control device;

[0007] The heat source device is used to exchange heat between the heat transfer oil and the heat source from the flue gas auto-combustion engine, and the heated heat transfer oil enters the ORC and cold source device.

[0008] The ORC and cold source device are used to exchange heat between the heated heat transfer oil and the working fluid and pressurize it to obtain high temperature and high pressure working fluid vapor. The high temperature and high pressure working fluid vapor drives the generator to generate electricity. After the working fluid exhaust vapor has done its work, it is condensed to form liquid working fluid and continues to exchange heat with the heat transfer oil.

[0009] The control device is used to control the operation of the heat source device, ORC, and various components within the cold source device.

[0010] Furthermore, the heat source device includes a thermal oil furnace, a circulating pump, an expansion tank, and an oil storage tank;

[0011] The air inlet of the thermal oil furnace is connected to the flue gas auto-combustion engine, the air outlet of the thermal oil furnace is connected to the chimney, the thermal oil inlet of the thermal oil furnace is connected to the thermal oil outlet of the circulating pump, and the thermal oil outlet of the thermal oil furnace is connected to the ORC and cold source device and the thermal oil inlet of the circulating pump respectively; the thermal oil inlet of the circulating pump is also connected to the thermal oil outlet of the expansion tank and the thermal oil outlet of the ORC and cold source device, and the thermal oil inlet of the expansion tank is connected to the thermal oil outlet of the oil storage tank;

[0012] The thermal oil furnace is used to exchange heat between the heat source of the flue gas auto-combustion engine and the thermal oil output by the circulating pump, so that the thermal oil is heated by the heat source and enters the ORC and cold source device. The heat source after heat exchange is discharged to the atmosphere through the chimney. The circulating pump is used to pressurize the thermal oil. The expansion tank is used to absorb the expansion of the thermal oil during the heating process. The oil storage tank is used to store the thermal oil.

[0013] Furthermore, the ORC and cold source device include a superheater, an evaporator, a preheater, an expansion generator, a regenerator, a condenser, a working fluid pump, and a working fluid storage tank;

[0014] The heat transfer oil inlet of the superheater is connected to the heat transfer oil outlet of the heat transfer oil furnace; the heat transfer oil outlet of the superheater is connected to the heat transfer oil inlet of the evaporator; the heat transfer oil outlet of the evaporator is connected to the heat transfer oil inlet of the preheater; the working fluid inlet of the preheater is connected to the first working fluid outlet of the regenerator; the working fluid outlet of the preheater is connected to the working fluid inlet of the evaporator; the working fluid outlet of the evaporator is connected to the working fluid inlet of the superheater; and the working fluid outlet of the superheater is connected to the working fluid inlet of the expansion generator and the first working fluid inlet of the condenser, respectively. The working fluid outlet of the expander generator is connected to the first working fluid inlet of the regenerator, the second working fluid inlet of the regenerator is connected to the working fluid outlet of the working fluid pump, the second working fluid outlet of the regenerator is connected to the second working fluid inlet of the condenser, the third working fluid inlet of the condenser is connected to the working fluid outlet of the working fluid storage tank, the working fluid inlet of the working fluid storage tank is connected to the nitrogen self-system, the working fluid outlet of the condenser is connected to the working fluid inlet of the working fluid pump, the circulating water inlet of the condenser is connected to the cold source outlet, and the circulating water outlet of the condenser is connected to the cold source inlet.

[0015] The preheater is used to preheat the high-pressure liquid working fluid after it has been initially heated by the regenerator using heat transfer oil from the evaporator; the evaporator is used to heat the preheated high-pressure liquid working fluid using heat transfer oil from the superheater; the superheater is used to heat the high-pressure working fluid vapor to a superheated state using heat transfer oil heated from the heat transfer oil furnace, thereby obtaining high-temperature and high-pressure working fluid vapor; the expander generator is used to expand the high-temperature and high-pressure working fluid vapor to generate electricity, and to obtain exhaust working fluid vapor after the work has been done; the regenerator is used to exchange heat between the high-pressure liquid working fluid output from the working fluid pump and the exhaust working fluid vapor output from the expander generator; the condenser is used to condense the cooled working fluid into a cold source, forming a liquid working fluid that enters the working fluid pump; the working fluid pump is used to pressurize the liquid working fluid from the condenser to obtain a high-pressure liquid working fluid; and the working fluid storage tank is used to store the liquid working fluid.

[0016] Furthermore, the control device includes a temperature sensor, a flow sensor, a pressure sensor, a level controller, a temperature controller, a flow controller, a pressure controller, and a host computer;

[0017] The thermal oil furnace, circulating pump, and superheater are each equipped with a temperature sensor at their respective inlet and outlet. The superheater, evaporator, regenerator, and working fluid pump are each equipped with a flow sensor at their respective inlet and outlet. The preheater, regenerator, and working fluid pump are each equipped with a pressure sensor at their respective inlet and outlet. The temperature sensor is used to collect the temperature of the fluid at the corresponding location. The flow sensor is used to collect the flow rate of the fluid at the corresponding location. The pressure sensor is used to collect the pressure of the fluid at the corresponding location.

[0018] The host computer is connected to the level controller, temperature controller, flow controller, and pressure controller, respectively. The level controller and flow controller are connected to each of the flow sensors, the temperature controller is connected to each of the temperature sensors, and the pressure controller is connected to each of the pressure sensors. The host computer is used to control the liquid level of the evaporator to stabilize based on the real-time flow rate collected by each of the flow sensors; to control the operation of the corresponding thermal oil furnace, circulating pump, and superheater based on the real-time temperature collected by each of the temperature sensors and a preset temperature range based on the temperature controller; to control the opening or closing of the inlet and outlet valves of the corresponding superheater, evaporator, regenerator, and working fluid pump based on the real-time flow rate collected by each of the flow sensors and a preset flow range based on the flow controller; and to control the opening or closing of the inlet and outlet valves of the corresponding preheater, regenerator, and working fluid pump, as well as the operation of the working fluid pump, based on the real-time pressure collected by each of the pressure sensors and a preset pressure range based on the pressure controller.

[0019] Furthermore, the working medium is any one or any mixture of organic working media selected from dimethyl sulfoxide, dimethylcyclopentane, ethylene glycol dimethyl ether, dimethylformamide, dichloromethane, dichloroethane, benzene, toluene, hexamethyldisiloxane, n-pentane, n-butane, isobutane, cyclopentane, R141b, cyclohexane, acetone, and 3-chloropropene.

[0020] Furthermore, the superheater, evaporator, preheater, regenerator, and condenser are any one or a combination of spray type, shell and tube type, finned type, and spiral type.

[0021] Furthermore, the superheater, evaporator, preheater, regenerator, and condenser are made of any one or a combination of tungsten copper alloy, nickel alloy, stainless steel, titanium alloy, aluminum, copper, and carbon fiber.

[0022] On the other hand, an organic Rankine cycle power generation method for megawatt-class offshore platforms is provided, comprising:

[0023] The heat source device exchanges heat between the heat transfer oil and the heat source from the flue gas auto-combustion engine, and the heated heat transfer oil enters the ORC and cold source device.

[0024] The ORC and cold source device exchange heat between the heated heat transfer oil and the working fluid and pressurize it to obtain high-temperature and high-pressure working fluid vapor. The high-temperature and high-pressure working fluid vapor drives the generator to generate electricity. After the working fluid exhaust vapor has done its work, it condenses to form liquid working fluid and continues to exchange heat with the heat transfer oil.

[0025] The control device controls the operation of various components within the heat source device, ORC, and cold source device.

[0026] Furthermore, the heat source device exchanges heat between the heat transfer oil and the heat source from the flue gas auto-combustion engine. The heated heat transfer oil then enters the ORC and cold source device, including:

[0027] The expansion tank absorbs the expansion of the heat transfer oil from the storage tank during the heating process, and the circulating pump pressurizes the heat transfer oil before it enters the heat transfer oil furnace.

[0028] The thermal oil heater exchanges heat between the heat source from the flue gas auto-ignition engine and the pressurized thermal oil, so that the thermal oil is heated by the heat source and enters the superheater in the ORC and cold source device. The heat source after heat exchange is discharged to the atmosphere through the chimney.

[0029] Furthermore, the ORC and cold source device exchange heat between the heated heat transfer oil and the working fluid and pressurize it to obtain high-temperature and high-pressure working fluid vapor. The high-temperature and high-pressure working fluid vapor drives the generator to generate electricity. The exhaust working fluid vapor, after completing its work, condenses to form liquid working fluid, which then continues to exchange heat with the heat transfer oil, including:

[0030] The liquid working fluid stored in the working fluid storage tank enters the working fluid pump through the condenser. The working fluid pump pressurizes the liquid working fluid to obtain high-pressure liquid working fluid, which then enters the preheater through the regenerator.

[0031] High-pressure liquid working fluid and heated heat transfer oil exchange heat through a preheater, evaporator and superheater to obtain high-temperature and high-pressure working fluid steam and cooled heat transfer oil. The cooled heat transfer oil is then pumped back into the heat transfer oil furnace.

[0032] An expander generator expands high-temperature, high-pressure working fluid steam to generate electricity, and obtains exhaust steam of the working fluid after it has done its work, which enters a regenerator.

[0033] The regenerator exchanges heat between the working fluid output from the working fluid pump and the exhaust steam of the working fluid output from the expansion generator. The heated working fluid enters the preheater, and the cooled working fluid enters the condenser.

[0034] The condenser condenses the cooled working fluid into a liquid state, which then enters the working fluid pump. The heated working fluid flows out of the condenser from the cold source inlet.

[0035] The present invention has the following advantages due to the adoption of the above technical solutions:

[0036] 1. High system efficiency: The selection of organic working fluid has a crucial impact on the efficiency and performance of the system. By studying the properties and characteristics of different organic working fluids, the most suitable organic working fluid for offshore platform applications can be selected, thereby improving the system's efficiency and stability. This invention uses an organic working fluid that is suitable for high-temperature heat sources and has high cycle thermal efficiency; at the same time, it is an environmentally friendly working fluid that reduces the greenhouse effect.

[0037] 2. High heat exchanger efficiency and low investment: The heat exchanger is one of the core components of the organic Rankine cycle power generation system, which directly affects the system's efficiency and performance. This invention improves the overall efficiency of the system by optimizing the heat exchanger design, increasing heat exchange efficiency and reducing the heat exchange area.

[0038] 3. The system adopts an intelligent control method, making operation and control simple: The host computer of this invention can monitor the operating status and performance of the system in real time, and make adjustments and optimizations according to the actual situation, thereby improving the efficiency and stability of the system.

[0039] 4. Smaller system footprint: Offshore platforms have strict space and weight restrictions. This invention uses more compact and efficient equipment to reduce the overall system footprint, thereby better adapting to the power generation needs of special environments such as offshore platforms.

[0040] 5. The expander generator of the present invention can adopt an axial flow expander, which is easy to scale up the equipment and can meet the large power demand of offshore platforms.

[0041] In summary, this invention can be widely applied in the field of waste heat power generation. Attached Figure Description

[0042] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0043] Figure 1 This is a schematic diagram of a structure provided in an embodiment of the present invention. Detailed Implementation

[0044] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0045] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0046] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0047] The organic Rankine cycle power generation system and method for megawatt-class offshore platforms provided in this invention utilizes the waste heat generated by the offshore platform as a heat source and seawater, air, or circulating water as a cold source to generate electricity through an organic Rankine cycle device. The selection of organic working fluid, heat exchanger, system optimization control, and system layout have been optimized, solving the technical problems of environmentally unfriendly chemicals, low system efficiency, high maintenance difficulty, large equipment size, and high investment costs.

[0048] Example 1

[0049] like Figure 1 As shown, this embodiment provides an Organic Rankine Cycle (ORC) power generation system for megawatt-class offshore platforms, including a heat source device 1, an ORC (Organic Rankine Cycle) system, a cold source device 2, and a control device. Figure 1 Arrows 101-107 indicate the flow of the working fluid, arrows 201-205 indicate the flow of the heat transfer oil, arrows 301-302 indicate the flow of circulating water, and arrows 401-402 indicate the flow of flue gas.

[0050] The heat source device 1 is used to exchange heat between the heat transfer oil and the heat source from the flue gas auto-combustion engine. The heated heat transfer oil enters the ORC and cold source device 2.

[0051] ORC and cold source device 2 are used to exchange heat between the heated heat transfer oil and the working fluid and pressurize it to obtain high temperature and high pressure working fluid vapor. The high temperature and high pressure working fluid vapor drives the generator to generate electricity. After the working fluid exhaust vapor has done its work, it is condensed to form liquid working fluid and continues to exchange heat with the heat transfer oil.

[0052] The control device is used to control the operation of heat source device 1, ORC, cold source device 2, and various components within the cold source device.

[0053] In a preferred embodiment, the heat source device 1 includes a thermal oil furnace 11, a circulating pump 12, an expansion tank 13, and an oil storage tank 14.

[0054] The air inlet of the thermal oil heater 11 is connected to the flue gas auto-combustion engine, the air outlet of the thermal oil heater 11 is connected to the chimney, the thermal oil inlet of the thermal oil heater 11 is connected to the thermal oil outlet of the circulating pump 12, and the thermal oil outlet of the thermal oil heater 11 is connected to the thermal oil inlet of the superheater 21 in the ORC and the thermal oil inlet of the circulating pump 12, respectively. The thermal oil heater 11 is used to exchange heat between the heat source of the flue gas auto-combustion engine and the thermal oil output by the circulating pump 12, so that the thermal oil is heated by the heat source and enters the superheater 21. The heat source after heat exchange is discharged to the atmosphere through the chimney.

[0055] The heat transfer oil inlet of the circulating pump 12 is also connected to the heat transfer oil outlet of the expansion tank 13 and the heat transfer oil outlet of the preheater 23 in the ORC and cold source device 2. The heat transfer oil inlet of the expansion tank 13 is connected to the heat transfer oil outlet of the oil storage tank 14. The circulating pump 12 is used to pressurize the heat transfer oil, the expansion tank 13 is used to absorb the expansion of the heat transfer oil during the heating process, and the oil storage tank 14 is used to store the heat transfer oil.

[0056] In a preferred embodiment, the ORC and cold source device 2 includes a superheater 21, an evaporator 22, a preheater 23, an expansion generator 24, a regenerator 25, a condenser 26, a working fluid pump 27, and a working fluid storage tank 28.

[0057] The heat transfer oil outlet of superheater 21 is connected to the heat transfer oil inlet of evaporator 22. The heat transfer oil outlet of evaporator 22 is connected to the heat transfer oil inlet of preheater 23. The working fluid inlet of preheater 23 is connected to the first working fluid outlet of regenerator 25. The working fluid outlet of preheater 23 is connected to the working fluid inlet of evaporator 22. The working fluid outlet of evaporator 22 is connected to the working fluid inlet of superheater 21. The working fluid outlet of superheater 21 is connected to the working fluid inlet of expansion generator 24 and the first working fluid inlet of condenser 26. The working fluid outlet of expansion generator 24 is connected to the first working fluid inlet of regenerator 25. The second working fluid inlet of regenerator 25 is connected to the working fluid outlet of working fluid pump 27. The second working fluid outlet of regenerator 25 is connected to the second working fluid inlet of condenser 26. The third working fluid inlet of condenser 26 is connected to the working fluid outlet of working fluid storage tank 28, the working fluid inlet of working fluid storage tank 28 is connected to the nitrogen self-system, the working fluid outlet of condenser 26 is connected to the working fluid inlet of working fluid pump 27, the circulating water inlet of condenser 26 is connected to the cold source outlet, and the circulating water outlet of condenser 26 is connected to the cold source inlet.

[0058] The superheater 21 is used to heat the high-pressure working fluid steam to a superheated state by using the heated working fluid from the heat transfer oil furnace 11. The resulting high-temperature and high-pressure working fluid steam enters the expansion generator 24, and the heat-exchanged working fluid enters the evaporator 22.

[0059] Evaporator 22 is used to heat the preheated high-pressure liquid working fluid through heat transfer oil from superheater 21. The resulting high-pressure working fluid vapor enters superheater 21, and the heat transfer oil after heat exchange enters preheater 23.

[0060] The preheater 23 is used to preheat the high-pressure liquid working fluid that has been initially heated from the regenerator 25 by using heat transfer oil from the evaporator 22. The preheated high-pressure liquid working fluid enters the evaporator 22, and the heat transfer oil after heat exchange enters the circulating pump 12.

[0061] The expander generator 24 is used to expand the high-temperature and high-pressure working fluid steam to generate electricity, and the exhaust working fluid steam after the work is done enters the regenerator 25.

[0062] Since the working fluid output by the expander 24 still has a high temperature, the regenerator 25 is used to exchange heat between the high-pressure liquid working fluid output by the working fluid pump 27 and the working fluid exhaust steam output by the expander 24. The high-pressure liquid working fluid after initial heating enters the preheater 23, and the cooled working fluid enters the condenser 26, which can reduce the load on the condenser 26 and increase the system efficiency.

[0063] The condenser 26 is used to condense the cooled working fluid into the cold source (e.g., seawater) to form a liquid working fluid that enters the working fluid pump 27. The cold source, after its temperature rises, flows out of the condenser 26 from the cold source inlet.

[0064] The working fluid pump 27 is used to pressurize the liquid working fluid from the condenser 26 to obtain a high-pressure liquid working fluid.

[0065] The working fluid storage tank 28 is used to store liquid working fluid, which is injected by nitrogen pressure from the nitrogen system to reduce the need for a working fluid injection pump.

[0066] In a preferred embodiment, the control device includes a temperature sensor, a flow sensor, a pressure sensor, a level controller LC, a temperature controller TC, a flow controller FC, a pressure controller PC, and a host computer.

[0067] Temperature sensors are installed at the inlet and outlet of each of the thermal oil heater 11, circulating pump 12 and superheater 21. Flow sensors are installed at the inlet and outlet of each of the superheater 21, evaporator 22, regenerator 25 and working fluid pump 27. Pressure sensors are installed at the inlet and outlet of each of the preheater 23, regenerator 25 and working fluid pump 27. Temperature sensors are used to collect the temperature of the fluid at the corresponding location, flow sensors are used to collect the flow rate of the fluid at the corresponding location, and pressure sensors are used to collect the pressure of the fluid at the corresponding location.

[0068] The host computer is connected to the level controller LC, temperature controller TC, flow controller FC, and pressure controller PC, respectively. The level controller LC and flow controller FC are connected to each flow sensor, the temperature controller TC is connected to each temperature sensor, and the pressure controller PC is connected to each pressure sensor. The host computer is used to control the liquid level of the evaporator 22 to stabilize it based on the real-time flow data collected by each flow sensor; and to control the operation of the corresponding thermal oil furnace 11, circulating pump 12, and superheater 21 through the temperature controller TC based on the real-time temperature data collected by each temperature sensor and a preset temperature range, in order to achieve stable temperature control; and to control the operation of the corresponding thermal oil furnace 11, circulating pump 12, and superheater 21 ... flow sensor. The flow rate collected in real time and the preset flow range are controlled by the flow controller FC to open or close the inlet and outlet valves of the corresponding superheater 21, evaporator 22, regenerator 25 and working fluid pump 27 to achieve stable flow control. Based on the pressure collected in real time by each pressure sensor and the preset pressure range, the pressure controller PC controls the opening or closing of the inlet and outlet valves of the corresponding preheater 23, regenerator 25 and working fluid pump 27 and the operation of working fluid pump 27 to achieve stable pressure control. In addition, artificial intelligence algorithms are used to optimize the control of working fluid evaporation temperature, evaporation pressure (arrow 108), superheat temperature and flow rate based on the collected historical data and real-time data.

[0069] In a preferred embodiment, the working fluid is an organic working fluid with high vapor pressure, high thermal conductivity, low viscosity, and high heat capacity and coefficient of thermal expansion. Specifically, it can be any one or any mixture of organic working fluids such as dimethyl sulfoxide, dimethylcyclopentane, ethylene glycol dimethyl ether, dimethylformamide, dichloromethane, dichloroethane, benzene, toluene, hexamethyldisiloxane, n-pentane, n-butane, isobutane, cyclopentane, R141b, cyclohexane, acetone, and 3-chloropropene. By selecting a suitable organic working fluid, the efficiency of the organic Rankine cycle power generation system can be improved, thereby enhancing the system's performance and reliability.

[0070] Specifically, select an organic working fluid with a higher vapor pressure: the higher the vapor pressure of the organic working fluid, the higher its saturated vapor pressure can be at low temperatures, thus enabling better utilization of low-temperature heat sources for power generation. Therefore, selecting an organic working fluid with a higher vapor pressure can improve the efficiency of the system.

[0071] Specifically, selecting an organic working fluid with high thermal conductivity is crucial: the higher the thermal conductivity of the organic working fluid, the more efficient it is at transferring heat in the heat exchanger. Therefore, selecting an organic working fluid with high thermal conductivity can improve the system's efficiency.

[0072] Specifically, choosing an organic working fluid with lower viscosity is beneficial: the lower the viscosity of the organic working fluid, the lower its flow resistance in the system, thereby reducing energy loss. Therefore, choosing an organic working fluid with lower viscosity can improve system efficiency.

[0073] Specifically, selecting organic working fluids with high heat capacity and coefficient of thermal expansion is beneficial. Higher heat capacity and coefficient of thermal expansion mean a stronger ability to store and transfer heat within the system, thus enabling better adaptation to different operating conditions. Therefore, selecting organic working fluids with high heat capacity and coefficient of thermal expansion can improve system efficiency.

[0074] In a preferred embodiment, the heat exchangers, namely superheater 21, evaporator 22, preheater 23, regenerator 25 and condenser 26, can all be any one or a combination of spray type, shell and tube type, finned type and spiral type. The materials of superheater 21, evaporator 22, preheater 23, regenerator 25 and condenser 26 can all be any one or a combination of tungsten copper alloy, nickel alloy, stainless steel, titanium alloy, aluminum, copper and carbon fiber.

[0075] Specifically, in an organic Rankine cycle power generation system, the heat exchanger is a crucial component. Its function is to transfer heat from the high-temperature organic working fluid to the working medium, thereby generating steam to drive a turbine generator to produce electricity. To optimize heat exchanger performance, the following methods can be employed: 1) Optimize the heat exchanger structure: Heat exchange efficiency can be improved by altering the structure, such as increasing the number of pipes or changing the pipe layout; 2) Optimize the working fluid flow rate and temperature: The operating state of the heat exchanger can be controlled by adjusting the flow rate and temperature of the organic working fluid to achieve optimal heat exchange; 3) Use high-efficiency heat exchanger materials: High-efficiency heat exchanger materials can be selected to improve heat exchange efficiency and corrosion resistance; 4) Employ intelligent control devices: Intelligent control devices can be used to monitor and adjust the operating state of the heat exchanger in real time to achieve optimal heat exchange. It is important to note that heat exchanger optimization requires comprehensive consideration of multiple factors, such as the properties of the working medium, the flow rate and temperature of the working fluid, and the heat exchanger materials, to achieve the best performance and effect.

[0076] In a preferred embodiment, the organic Rankine cycle power generation system of the present invention can use artificial intelligence algorithms to optimize the control of the working fluid evaporation temperature, evaporation pressure, superheat temperature and flow rate, including any one or a combination of neural network algorithms, genetic algorithms and fuzzy control algorithms. The artificial intelligence algorithm can predict the future system state by learning historical data and make control decisions based on the prediction results to optimize the system's operating efficiency and performance. Since the use of artificial intelligence algorithms for optimization control is a technical solution disclosed in the prior art, the specific process will not be described in detail here.

[0077] Specifically, the historical data learned by the organic Rankine cycle power generation system of the present invention includes any one or a combination of seawater temperature, offshore platform power load, gas turbine power generation load, gas turbine flue gas temperature, and gas turbine flue gas flow rate.

[0078] In a preferred embodiment, the present invention requires a reasonable layout based on the size, shape, and operational requirements of the equipment to facilitate its maintenance and repair.

[0079] In a preferred embodiment, the present invention requires a reasonable layout based on the operating requirements of the equipment and the characteristics of the thermal system in order to improve the efficiency and stability of the system.

[0080] In a preferred embodiment, the footprint of the organic Rankine cycle power generation system of the present invention depends mainly on the size and number of equipment. It needs to be rationally planned according to the layout and operation requirements of the equipment to avoid the footprint being too large or too small, which would affect the system's operating efficiency and economy.

[0081] In a preferred embodiment, environmental protection factors need to be considered in the layout and land use planning of the organic Rankine cycle power generation system of the present invention, such as reducing noise and reducing exhaust emissions, in order to protect the surrounding environment and the health of residents.

[0082] In a preferred embodiment, the expander generator 24 may be an axial flow expander, and the expander generator 24 may be used to reduce the footprint by sharing an oil station with other mechanical equipment such as a gas turbine (the flue gas of the present invention comes from the gas turbine).

[0083] In a preferred embodiment, the organic Rankine cycle power generation system of the present invention can be arranged in multiple layers. Preferably, the condenser 26 is arranged above the working fluid pump 27, the preheater 23, the evaporator 22 and the superheater 21 are arranged in the first layer, the second layer and the third layer respectively, and the expansion generator 24 is arranged above the condenser 26.

[0084] The following is a detailed description of the organic Rankine cycle power generation system for megawatt-class offshore platforms, using an eight-legged oil and gas processing platform with a modular drilling rig in the southern waters of China as a specific example. The platform is equipped with two 10MW gas turbine generator sets.

[0085] The circulating working fluid is cyclopentane; the preheater 23 is a spiral heat exchanger; the evaporator 22 is a spray heat exchanger; the condenser 26 is made of titanium alloy; the heat exchanger monitors the flow rate of the inlet and outlet fluids in real time through a flow sensor, and controls the inlet and outlet valves of the heat exchanger according to the set flow range, so that the fluid flow rate is near the design range and maintains a high heat exchange efficiency.

[0086] The system employs a neural network algorithm to learn and model historical data such as surrounding seawater temperature, offshore platform power load, gas turbine power generation load, gas turbine flue gas temperature, and gas turbine flue gas flow rate, thereby optimizing the control strategy.

[0087] The system layout adopts a multi-layer arrangement, with the preheater 23, evaporator 22 and superheater 21 set in the first, second and third layers respectively; the axial flow expander and the gas turbine share an oil station to reduce the footprint.

[0088] The system process flow is as follows:

[0089] 1) Flue gas circuit:

[0090] Flue gas from the gas combustion (200 kg / s, 400-500°C) enters the thermal oil furnace 11, and after exchanging heat with the thermal oil, its temperature drops to 120-200°C before being discharged to the platform chimney.

[0091] 2) Heat transfer oil circulation loop:

[0092] After absorbing heat from the flue gas and raising its temperature to 280–345°C, the heat transfer oil enters the superheater 21, evaporator 22, and preheater 23 of the ORC and cold source device 2. After its temperature decreases, it flows out of the ORC and cold source device 2, returning at a temperature of 150–180°C. The heat transfer oil returning from the ORC and cold source device 2 is pressurized to 0.4–0.6 MPaG by the circulation pump 12 and then re-enters the heat transfer oil furnace 11 to be heated to 280–345°C, completing the heat transfer oil circulation.

[0093] 3) Cyclopentane cycle loop:

[0094] The cyclopentane condensed in condenser 26 is pressurized to 3.68 MPaG by working fluid pump 27 and then sequentially enters regenerator 25, preheater 23, evaporator 22, and superheater 21, where it is heated to high temperature and high pressure by heat transfer oil to form cyclopentane vapor (150–280°C). The high-pressure cyclopentane vapor enters expander generator 24 to expand and perform work, driving the generator to generate 10,000–13,000 kW of electricity. The cyclopentane exhaust vapor (60–130°C) after performing work enters regenerator 25 and condenser 26, where it is condensed by circulating fresh water to form liquid cyclopentane (40–60°C). The liquid cyclopentane re-enters working fluid pump 27, forming a working fluid circulation loop.

[0095] 4) Circulating freshwater loop:

[0096] Seawater at 20–40°C from the platform enters condenser 26, where it condenses the cyclopentane exhaust vapor, raising the temperature by 5–10°C, and then flows back to the sea by gravity.

[0097] Example 2

[0098] This embodiment provides an organic Rankine cycle power generation method for megawatt-class offshore platforms, including the following steps:

[0099] 1) Heat source device 1 exchanges heat between the heat transfer oil and the heat source from the flue gas auto-combustion engine. The heated heat transfer oil then enters the ORC and cold source device 2, specifically:

[0100] 1.1) The expansion tank 13 absorbs the expansion of the heat transfer oil from the oil storage tank 14 during the heating process, and the circulating pump 12 pressurizes the heat transfer oil before it enters the heat transfer oil furnace 11.

[0101] 1.2) The heat transfer oil furnace 11 exchanges heat between the heat source from the flue gas self-ignition engine and the pressurized heat transfer oil, so that the heat transfer oil is heated by the heat source and enters the superheater 21 in the ORC and cold source device 2. The heat source after heat exchange is discharged to the atmosphere through the chimney.

[0102] 2) The ORC and cold source device 2 exchange heat between the heated heat transfer oil and the working fluid and pressurize it to obtain high-temperature and high-pressure working fluid vapor. The high-temperature and high-pressure working fluid vapor drives the generator to generate electricity. After the working fluid exhaust vapor has done its work, it condenses to form liquid working fluid and continues to exchange heat with the heat transfer oil. Specifically:

[0103] 2.1) The liquid working fluid stored in the working fluid storage tank 28 enters the working fluid pump 27 through the condenser 26. The working fluid pump 27 pressurizes the liquid working fluid to obtain a high-pressure liquid working fluid, which enters the preheater 23 through the regenerator 25.

[0104] 2.2) The high-pressure liquid working fluid and the heated heat transfer oil exchange heat through the preheater 23, evaporator 22 and superheater 21 to obtain high-temperature and high-pressure working fluid steam and cooled heat transfer oil. The cooled heat transfer oil re-enters the heat transfer oil furnace 11 through the circulating pump 12.

[0105] 2.2.1) The preheater 23 preheats the high-pressure liquid working fluid from the regenerator 25 after it has been initially heated by the heat transfer oil from the evaporator 22. The preheated high-pressure liquid working fluid enters the evaporator 22, and the heat transfer oil after heat exchange enters the circulating pump 12.

[0106] 2.2.2) Evaporator 22 heats the preheated high-pressure liquid working fluid through heat transfer oil from superheater 21. The resulting high-pressure working fluid vapor enters superheater 21, and the heat transfer oil after heat exchange enters preheater 23.

[0107] 2.2.3) The superheater 21 heats the high-pressure working fluid steam to a superheated state using the heated heat transfer oil from the heat transfer oil furnace 11. The resulting high-temperature and high-pressure working fluid steam enters the expansion generator 24, and the heat-exchanged heat transfer oil enters the evaporator 22.

[0108] 2.3) The expander generator 24 expands the high-temperature and high-pressure working fluid steam to generate electricity, and obtains the working fluid exhaust steam after the work is done, which enters the regenerator 25.

[0109] 2.4) The regenerator 25 exchanges heat between the working fluid output from the working fluid pump 27 and the working fluid exhaust steam output from the expansion generator 24. The heated working fluid enters the preheater 23, and the cooled working fluid enters the condenser 26.

[0110] 2.5) The condenser 26 condenses the initially cooled working fluid into the cold source, forming a liquid working fluid that enters the working fluid pump 27. The cold source, after its temperature rises, flows out of the condenser 26 from the cold source inlet.

[0111] 3) The control device controls the operation of various components within the heat source device 1, ORC, and cold source device 2, specifically:

[0112] 3.1) Throughout the process, temperature sensors installed at the inlet and outlet of the thermal oil furnace 11, circulating pump 12 and superheater 21 collect the temperature of the fluid at the corresponding location in real time; flow sensors installed at the inlet and outlet of the superheater 21, evaporator 22, regenerator 25 and working fluid pump 27 collect the flow rate of the fluid at the corresponding location in real time; and pressure sensors installed at the inlet and outlet of the preheater 23, regenerator 25 and working fluid pump 27 collect the pressure of the fluid at the corresponding location in real time.

[0113] 3.2) The host computer controls the liquid level of evaporator 22 to stabilize based on the real-time flow rate collected by each flow sensor via the liquid level controller LC; it controls the operation of the corresponding thermal oil furnace 11, circulating pump 12, and superheater 21 via the temperature controller TC based on the real-time temperature collected by each temperature sensor and the preset temperature range to achieve stable temperature control; it controls the opening or closing of the inlet and outlet valves of the corresponding superheater 21, evaporator 22, regenerator 25, and working fluid pump 27 via the flow controller FC based on the real-time flow rate collected by each flow sensor and the preset flow range to achieve stable flow control; it controls the opening or closing of the inlet and outlet valves of the corresponding preheater 23, regenerator 25, and working fluid pump 27, as well as the operation of working fluid pump 27, via the pressure controller PC based on the real-time pressure collected by each pressure sensor and the preset pressure range to achieve stable pressure control; and it uses artificial intelligence algorithms to optimize the control of working fluid evaporation temperature, evaporation pressure, superheating temperature, and flow rate based on the collected historical and real-time data.

[0114] The above embodiments are only used to illustrate the present invention. The structure, connection method and manufacturing process of each component can be varied. All equivalent transformations and improvements made on the basis of the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. An organic Rankine cycle power generation system for megawatt-class offshore platforms, characterized in that, Includes heat source devices, ORC and cold source devices, and control devices; The heat source device is used to exchange heat between the heat transfer oil and the heat source from the flue gas auto-combustion engine, and the heated heat transfer oil enters the ORC and cold source device. The ORC and cold source device are used to exchange heat between the heated heat transfer oil and the working fluid and pressurize it to obtain high temperature and high pressure working fluid vapor. The high temperature and high pressure working fluid vapor drives the generator to generate electricity. After the working fluid exhaust vapor has done its work, it is condensed to form liquid working fluid and continues to exchange heat with the heat transfer oil. The control device is used to control the operation of the heat source device, ORC, and various components within the cold source device; The heat source device includes a thermal oil furnace, a circulating pump, an expansion tank, and an oil storage tank; The air inlet of the thermal oil furnace is connected to the flue gas auto-combustion engine, the air outlet of the thermal oil furnace is connected to the chimney, the thermal oil inlet of the thermal oil furnace is connected to the thermal oil outlet of the circulating pump, and the thermal oil outlet of the thermal oil furnace is connected to the ORC and cold source device and the thermal oil inlet of the circulating pump respectively; the thermal oil inlet of the circulating pump is also connected to the thermal oil outlet of the expansion tank and the thermal oil outlet of the ORC and cold source device, and the thermal oil inlet of the expansion tank is connected to the thermal oil outlet of the oil storage tank; The thermal oil furnace is used to exchange heat between the heat source of the flue gas auto-combustion engine and the thermal oil output by the circulating pump, so that the thermal oil is heated by the heat source and enters the ORC and cold source device. The heat source after heat exchange is discharged to the atmosphere through the chimney. The circulating pump is used to pressurize the thermal oil. The expansion tank is used to absorb the expansion of the thermal oil during the heating process. The oil storage tank is used to store the thermal oil. The ORC and cold source device includes a superheater, evaporator, preheater, expansion generator, regenerator, condenser, working fluid pump, and working fluid storage tank. The heat transfer oil inlet of the superheater is connected to the heat transfer oil outlet of the heat transfer oil furnace; the heat transfer oil outlet of the superheater is connected to the heat transfer oil inlet of the evaporator; the heat transfer oil outlet of the evaporator is connected to the heat transfer oil inlet of the preheater; the working fluid inlet of the preheater is connected to the first working fluid outlet of the regenerator; the working fluid outlet of the preheater is connected to the working fluid inlet of the evaporator; the working fluid outlet of the evaporator is connected to the working fluid inlet of the superheater; and the working fluid outlet of the superheater is connected to the working fluid inlet of the expansion generator and the first working fluid inlet of the condenser, respectively. The working fluid outlet of the expander generator is connected to the first working fluid inlet of the regenerator, the second working fluid inlet of the regenerator is connected to the working fluid outlet of the working fluid pump, the second working fluid outlet of the regenerator is connected to the second working fluid inlet of the condenser, the third working fluid inlet of the condenser is connected to the working fluid outlet of the working fluid storage tank, the working fluid inlet of the working fluid storage tank is connected to the nitrogen self-system, the working fluid outlet of the condenser is connected to the working fluid inlet of the working fluid pump, the circulating water inlet of the condenser is connected to the cold source outlet, and the circulating water outlet of the condenser is connected to the cold source inlet. The preheater is used to preheat the high-pressure liquid working fluid after it has been initially heated by the regenerator using heat transfer oil from the evaporator; the evaporator is used to heat the preheated high-pressure liquid working fluid using heat transfer oil from the superheater; the superheater is used to heat the high-pressure working fluid vapor to a superheated state using heat transfer oil heated from the heat transfer oil furnace, obtaining high-temperature and high-pressure working fluid vapor; the expander generator is used to expand the high-temperature and high-pressure working fluid vapor to generate electricity, and obtain working fluid exhaust steam after the work has been done; the regenerator is used to exchange heat between the high-pressure liquid working fluid output from the working fluid pump and the working fluid exhaust steam output from the expander generator; the condenser is used to condense the cooled working fluid into a cold source, forming liquid working fluid that enters the working fluid pump; the working fluid pump is used to pressurize the liquid working fluid from the condenser to obtain high-pressure liquid working fluid; the working fluid storage tank is used to store the liquid working fluid. The control device includes a temperature sensor, a flow sensor, a pressure sensor, a level controller, a temperature controller, a flow controller, a pressure controller, and a host computer; The thermal oil furnace, circulating pump, and superheater are each equipped with a temperature sensor at their respective inlet and outlet. The superheater, evaporator, regenerator, and working fluid pump are each equipped with a flow sensor at their respective inlet and outlet. The preheater, regenerator, and working fluid pump are each equipped with a pressure sensor at their respective inlet and outlet. The temperature sensor is used to collect the temperature of the fluid at the corresponding location. The flow sensor is used to collect the flow rate of the fluid at the corresponding location. The pressure sensor is used to collect the pressure of the fluid at the corresponding location. The host computer is connected to the level controller, temperature controller, flow controller, and pressure controller, respectively. The level controller and flow controller are connected to each of the flow sensors, the temperature controller is connected to each of the temperature sensors, and the pressure controller is connected to each of the pressure sensors. The host computer is used to control the liquid level of the evaporator to stabilize based on the real-time flow rate collected by each of the flow sensors; to control the operation of the corresponding thermal oil furnace, circulating pump, and superheater based on the real-time temperature collected by each of the temperature sensors and a preset temperature range based on the temperature controller; to control the opening or closing of the inlet and outlet valves of the corresponding superheater, evaporator, regenerator, and working fluid pump based on the real-time flow rate collected by each of the flow sensors and a preset flow range based on the flow controller; and to control the opening or closing of the inlet and outlet valves of the corresponding preheater, regenerator, and working fluid pump, as well as the operation of the working fluid pump, based on the real-time pressure collected by each of the pressure sensors and a preset pressure range based on the pressure controller.

2. The organic Rankine cycle power generation system for megawatt-class offshore platforms as described in claim 1, characterized in that, The working medium is any one or any mixture of organic working media including dimethyl sulfoxide, dimethylcyclopentane, ethylene glycol dimethyl ether, dimethylformamide, dichloromethane, dichloroethane, benzene, toluene, hexamethyldisiloxane, n-pentane, n-butane, isobutane, cyclopentane, R141b, cyclohexane, acetone, and 3-chloropropene.

3. The organic Rankine cycle power generation system for megawatt-class offshore platforms as described in claim 1, characterized in that, The superheater, evaporator, preheater, regenerator, and condenser are any one or a combination of spray type, shell and tube type, finned type, and spiral type.

4. An organic Rankine cycle power generation system for megawatt-class offshore platforms as described in claim 1, characterized in that, The superheater, evaporator, preheater, regenerator, and condenser are made of any one or a combination of tungsten copper alloy, nickel alloy, stainless steel, titanium alloy, aluminum, copper, and carbon fiber.

5. A method for generating electricity using an organic Rankine cycle system for a megawatt-class offshore platform, based on any one of claims 1 to 4, characterized in that, include: The heat source device exchanges heat between the heat transfer oil and the heat source from the flue gas auto-combustion engine, and the heated heat transfer oil enters the ORC and cold source device. The ORC and cold source device exchange heat between the heated heat transfer oil and the working fluid and pressurize it to obtain high-temperature and high-pressure working fluid vapor. The high-temperature and high-pressure working fluid vapor drives the generator to generate electricity. After the working fluid exhaust vapor has done its work, it condenses to form liquid working fluid and continues to exchange heat with the heat transfer oil. The control device controls the operation of various components within the heat source device, ORC, and cold source device.

6. The organic Rankine cycle power generation method for megawatt-class offshore platforms as described in claim 5, characterized in that, The heat source device exchanges heat between the heat transfer oil and the heat source from the flue gas auto-combustion engine. The heated heat transfer oil then enters the ORC and cold source device, including: The expansion tank absorbs the expansion of the heat transfer oil from the storage tank during the heating process, and the circulating pump pressurizes the heat transfer oil before it enters the heat transfer oil furnace. The thermal oil heater exchanges heat between the heat source from the flue gas auto-ignition engine and the pressurized thermal oil, so that the thermal oil is heated by the heat source and enters the superheater in the ORC and cold source device. The heat source after heat exchange is discharged to the atmosphere through the chimney.

7. The organic Rankine cycle power generation method for megawatt-class offshore platforms as described in claim 5, characterized in that, The ORC and cold source device exchange heat between the heated heat transfer oil and the working fluid, and pressurize it to obtain high-temperature and high-pressure working fluid vapor. This high-temperature and high-pressure working fluid vapor drives a generator to generate electricity. The exhaust working fluid vapor, after performing its work, condenses to form a liquid working fluid, which then continues to exchange heat with the heat transfer oil, including: The liquid working fluid stored in the working fluid storage tank enters the working fluid pump through the condenser. The working fluid pump pressurizes the liquid working fluid to obtain high-pressure liquid working fluid, which then enters the preheater through the regenerator. High-pressure liquid working fluid and heated heat transfer oil exchange heat through a preheater, evaporator and superheater to obtain high-temperature and high-pressure working fluid steam and cooled heat transfer oil. The cooled heat transfer oil is then pumped back into the heat transfer oil furnace. An expander generator expands high-temperature, high-pressure working fluid steam to generate electricity, and obtains exhaust working fluid steam after the work is done, which enters a regenerator. The regenerator exchanges heat between the working fluid output from the working fluid pump and the exhaust steam of the working fluid output from the expansion generator. The heated working fluid enters the preheater, and the cooled working fluid enters the condenser. The condenser condenses the cooled working fluid into a liquid state, which then enters the working fluid pump. The heated working fluid flows out of the condenser from the cold source inlet.

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