Non-condensable gas and lubricating oil coupling and separating device of organic Rankine cycle system

Abstract

The invention discloses a non-condensable gas and lubricating oil coupling and separating device of an organic Rankine cycle system, and relates to the technical field of organic Rankine cycle power generation. The device comprises a primary separator, a secondary separator, an organic working medium-non-condensable gas separator and related accessories which are connected through pipelines. Through the multi-stage coupling process of primary separation, re-separation and energy recovery, working medium recovery and condensation and non-condensable gas separation and condensation, gradient utilization of waste heat of the system is achieved through the re-separator, lubricating oil separation, non-condensable gas removal and working medium recovery are organically integrated, and triple-effect synergistic separation and internal energy exchange of the system are achieved. The separation efficiency and the energy utilization rate are remarkably improved, efficient and stable operation of the system is guaranteed, meanwhile, near-zero-loss recovery of the working medium and the lubricating oil is achieved, and prominent economic and environment-friendly values are achieved.

Description

Technical Field

[0001] This invention relates to the field of organic Rankine cycle power generation technology, and more specifically to a device for coupling and separating non-condensable gases and lubricating oil in an organic Rankine cycle system. Background Technology

[0002] The Organic Rankine Cycle (ORC) system is an important technology for power generation using medium- and low-temperature heat sources (such as industrial waste heat, geothermal energy, and solar energy). In this system, organic matter is used as the working medium (called the "organic working fluid"). It absorbs heat in the evaporator, turning into high-temperature, high-pressure steam, which drives a turbine to generate electricity. The steam then condenses into a liquid in the condenser and is pumped back to the evaporator, completing the cycle. Common organic working fluids include R245fa, R123, and pentane. However, in actual operation, the system faces two common and mutually influential technical challenges: First, trace amounts of lubricating oil inevitably seep into the circulation system from the mechanical seals of rotating equipment such as turbines, forming a mixture with the organic working fluid. This lubricating oil adheres to the heat exchange surfaces in heat exchange components such as condensers, forming an oil film that severely degrades heat transfer efficiency and leads to system performance degradation. Second, trace amounts of non-condensable gases such as air inevitably seep into the system during initial operation or after long-term operation. These non-condensable gases accumulate in the condenser, causing the condensation pressure to rise, which in turn reduces the turbine's working efficiency and affects the stable operation of the system.

[0003] Traditional solutions typically treat lubricating oil separation and non-condensable gas emission as two separate issues, such as by installing individual oil separators and vacuum exhaust devices. This approach has significant drawbacks: independent oil separators struggle to completely separate the fine oil mist mixed with the working fluid vapor, resulting in limited separation efficiency; and the emission of non-condensable gases often carries a large amount of uncondensed working fluid vapor, leading to working fluid loss and resource waste. Current technologies lack an integrated solution capable of efficiently and synergistically separating lubricating oil, non-condensable gases, and organic working fluids, failing to fundamentally address the coupled negative impacts of these two components on system performance.

[0004] Therefore, developing a device that can achieve three-way coupling and separation of organic working fluid, lubricating oil and non-condensable gas is of great significance for improving the overall efficiency and operational reliability of organic Rankine cycle systems. Summary of the Invention

[0005] The purpose of this invention is to provide a coupling and separation device for non-condensable gases and lubricating oil in an organic Rankine cycle system, so as to overcome the shortcomings of the prior art, achieve efficient and synergistic separation of lubricating oil and non-condensable gases in organic working fluid, and ensure efficient and stable operation of the system.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system, connected between the evaporator and condenser of the system, includes: The primary separator has its inlet connected to the outlet of the evaporator via pipe A, and is used to receive the high-temperature organic working fluid-lubricating oil mixture. It is equipped with a separation screen inside. The gas phase outlet of the primary separator is connected to the gas phase space of the condenser via pipe B. The re-separator has its liquid phase inlet connected to the liquid phase outlet of the primary separator for receiving the organic working fluid-lubricating oil mixture from the primary separator. The re-separator also includes a heat exchange channel, the inlet of which is connected to the top gas phase space of the condenser via pipe a, for introducing a medium-temperature organic working fluid vapor-non-condensable gas mixture as a heat source. The gas phase outlet of the re-separator is connected to the gas phase space of the condenser via pipe C for discharging the low-temperature organic working fluid vapor generated by the evaporation of the organic working fluid-lubricating oil mixture. An organic working fluid-noncondensable gas separator has its inlet connected to the outlet of the heat exchange channel of the re-separator via pipe b, for receiving the low-temperature organic working fluid vapor-noncondensable gas mixture after flowing through the heat exchange channel and being cooled. A refrigeration unit, coupled to the organic working fluid-noncondensable gas separator, is used to provide cooling capacity to it; The lubricating oil tank is connected to the liquid phase outlet of the re-separator via pipeline D; A non-condensable gas exhaust device is connected to the gas phase outlet of the organic working fluid-non-condensable gas separator; A liquid working fluid pump is installed in the middle of pipeline E. One end of pipeline E is connected to the liquid phase outlet of the organic working fluid-noncondensable gas separator, and the other end is connected to the liquid phase space of the condenser, for transporting liquid organic working fluid.

[0007] Furthermore, the re-separator is a partitioned heat exchanger, and its internal heat exchange channels are coils or jacketed structures.

[0008] Furthermore, the organic working fluid-noncondensable gas separator is equipped with a heat exchange coil, which is connected to the refrigerant circuit of the refrigeration unit.

[0009] Furthermore, the non-condensable gas exhaust device is an automatic exhaust valve or a vacuum pump controlled by a pressure signal.

[0010] Furthermore, the separation mesh is woven from metal wires or polymer materials.

[0011] Furthermore, the re-separator is covered with an insulation layer.

[0012] Furthermore, the re-separator is configured to utilize a heat source from pipe a to raise the temperature of the organic working fluid-lubricating oil mixture inside it above the evaporation temperature of the organic working fluid, and to keep the lubricating oil in a liquid state.

[0013] Another object of the present invention is to provide a method for coupling and separating non-condensable gases and lubricating oil in an organic Rankine cycle system. The method employs the aforementioned device for coupling and separating non-condensable gases and lubricating oil in an organic Rankine cycle system, and includes the following steps: Preliminary separation: The organic working fluid-lubricating oil mixture from the evaporator is introduced into the primary separator, where preliminary separation is performed using a separation screen; Re-separation and energy recovery: The organic working fluid-lubricating oil mixture separated by the primary separator is introduced into the re-separator, and the organic working fluid vapor-non-condensable gas mixture from the top of the condenser is introduced as a heat source to heat it, causing the organic working fluid to evaporate. Organic working fluid recovery and condensation: The low-temperature organic working fluid vapor generated by the evaporation of organic working fluid in the re-separator is introduced into the condenser through pipeline C for condensation and recovery. Non-condensable gas separation and condensation: The organic working fluid vapor-non-condensable gas mixture, which has been cooled after flowing through the heat exchange channel of the re-separator, is introduced into the organic working fluid-non-condensable gas separator through pipeline b for deep condensation, thereby achieving non-condensable gas separation. Discharge and Recirculation: Non-condensable gases are discharged through the exhaust device, and the liquid organic working fluid condensed in the organic working fluid-non-condensable gas separator is pumped back to the condenser through the liquid working fluid pump. At the same time, the lubricating oil separated in the re-separator is introduced into the lubricating oil tank.

[0014] Furthermore, in the re-separation and energy recovery process, the heating temperature is 40°C to 50°C.

[0015] Another object of the present invention is to provide an organic Rankine cycle power generation system, including an evaporator, a turbine, a condenser and a main circulating working fluid pump, wherein the system integrates a non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system.

[0016] The present invention provides a coupling and separation device for non-condensable gases and lubricating oil in an organic Rankine cycle system, which has the following significant advantages compared with the prior art: 1. This invention achieves highly efficient and coordinated separation of organic working fluid, lubricating oil, and non-condensable gases, solving the problem of mutual interference in traditional separation methods. Traditional methods treat lubricating oil separation and non-condensable gas emission as independent issues, making complete separation difficult and prone to working fluid loss. This invention organically integrates the separation of these three components through a four-stage coupled process: initial separation, re-separation and energy recovery, organic working fluid recovery and condensation, and non-condensable gas separation and condensation. The initial separator removes most of the lubricating oil; the re-separator utilizes system waste heat to achieve deep gas-liquid separation of the working fluid and lubricating oil; the separated pure working fluid vapor is directly returned to the condenser for recovery via pipeline C (organic working fluid recovery and condensation); while the working fluid stream containing non-condensable gases enters a dedicated separator for final treatment via pipeline b (non-condensable gas separation and condensation). This design completely separates working fluid recovery and non-condensable gas removal along their paths, avoiding the problem of working fluid vapor being entrained during non-condensable gas removal in traditional methods, achieving highly efficient and thorough separation, and ensuring power generation efficiency and stability at the system level.

[0017] 2. This invention overcomes the bottleneck of energy waste and achieves tiered utilization of waste heat within the system. One of the core innovations of this invention lies in using the re-separator as an energy exchange hub. It utilizes the medium-temperature organic working fluid vapor-non-condensable gas mixture (through pipeline a) drawn from the top of the condenser as a heat source to heat the organic working fluid-lubricating oil mixture to be separated, causing the working fluid to evaporate. This process cleverly couples the energy requirements of the "separation of non-condensable gases" and "recovery of working fluid": on the one hand, the waste heat of the medium-temperature mixture promotes deep separation of the lubricating oil; on the other hand, the process itself creates favorable conditions for the subsequent condensation and separation of non-condensable gases. This "waste-to-waste" energy utilization method significantly reduces the additional energy consumption of the separation system and improves the overall energy efficiency.

[0018] 3. This invention achieves near-zero loss of working fluid and lubricating oil in a closed-loop recovery process, improving the system's economic efficiency and environmental friendliness. The entire separation process of this invention constitutes a closed-loop resource recovery cycle. Lubricating oil is effectively separated and collected in an oil tank for reuse; the organic working fluid is recovered almost completely through working fluid recovery condensation in pipeline C and pumped back through pipeline E. This extreme recovery of the working fluid and lubricating oil not only saves on ongoing operating costs but also avoids the environmental impact of working fluid leakage, enabling the system to achieve high-efficiency operation while possessing outstanding economic benefits and environmental value. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the process flow of the device described in this invention; In the picture: 1-Evaporator, 2-Turbine, 3-Condenser, 4-Primary Separator, 5-Separation Screen, 6-Re-Separator 7-Lubricating oil tank, 8-Organic working fluid-non-condensable gas separator, 9-Non-condensable gas exhaust device, 10-Liquid working fluid pump, 11-Refrigeration unit; A-High-temperature organic working fluid-lubricating oil mixture pipeline, B-High-temperature organic working fluid gas pipeline, C-Low-temperature organic working fluid gas pipeline, D-Lubricating oil liquid pipeline, E-Liquid organic working fluid pipeline, a-Medium-temperature organic working fluid vapor-non-condensable gas mixture, b-Low-temperature organic working fluid vapor-non-condensable gas mixture. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] This invention provides a coupling and separation device for non-condensable gases and lubricating oil in an organic Rankine cycle system. Its core innovation lies in constructing a separation loop that is tightly coupled with the main cycle and integrates energy. This loop, through the organic integration and process optimization of four stages—initial separation, re-separation and energy recovery, organic working fluid recovery and condensation, and non-condensable gas separation and condensation—not only efficiently and synergistically solves the problem of separating lubricating oil and non-condensable gases in the organic working fluid, but also achieves the cascade utilization of waste heat within the system, fundamentally improving the overall performance of the organic Rankine cycle. The "organic working fluid" refers to the organic substance used as the working fluid in the organic Rankine cycle system, which undergoes a phase change (evaporation and condensation) during the cycle to achieve heat-work conversion. Common organic working fluids include, but are not limited to, alkanes (such as R245fa, R123), siloxanes, toluene, etc., and their selection depends on factors such as the heat source temperature. The device and method of this invention are universally applicable to these organic working fluids.

[0022] like Figure 1 As shown, this embodiment provides a non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system, connected between the evaporator 1 and the condenser 3 of the system. The separation device, as a functional module, is integrated into the main cycle and mainly consists of a primary separator 4, a secondary separator 6, an organic working fluid-non-condensable gas separator 8, a lubricating oil tank 7, a non-condensable gas exhaust device 9, a liquid working fluid pump 10, and a refrigeration unit 11. All components are connected through specific pipelines to form a highly efficient closed-loop separation system.

[0023] The primary separator 4 performs preliminary oil separation. Its inlet is connected to the outlet of the evaporator 1 via pipe A to receive the high-temperature, high-pressure organic working fluid-lubricating oil mixture from the evaporator. The primary separator 4 is equipped with a highly efficient gas-liquid separation element, preferably a separation mesh 5 woven from stainless steel wire, the mesh size of which can be designed according to the working fluid properties and flow rate to effectively capture micron-sized lubricating oil mist. After preliminary separation by the separation mesh 5, the high-temperature organic working fluid vapor, from which most of the lubricating oil has been removed, enters the gas phase space of the condenser 3 via pipe B for the main condensation process. The condensed lubricating oil droplets and the small amount of entrained liquid working fluid forming a mixture settle to the bottom of the primary separator 4 by gravity.

[0024] The re-separator 6 is the core component of this device for achieving energy coupling and deep separation. Its liquid phase inlet is directly connected to the bottom liquid phase outlet of the primary separator 4 to receive the aforementioned organic working fluid-lubricating oil mixture. More importantly, the re-separator 6 itself is constructed as a partitioned heat exchanger, with its internal heat exchange channels being coils or jacketed structures. Its main container holds the mixture to be separated, and it has an independent heat exchange channel inside, which can be specifically implemented as a coil structure. The inlet of this heat exchange channel is connected to the top gas phase space of the condenser 3 via pipe a, to introduce the medium-temperature organic working fluid vapor-non-condensable gas mixture that has not been condensed due to the presence of non-condensable gases in the system. This mixture serves as an ideal heat source entering the heat exchange channel of the re-separator 6. After heat exchange, in the main container of the re-separator 6, the pure, low-temperature organic working fluid vapor generated by the evaporation of the mixture returns directly to the condenser 3 through its gas phase outlet and pipe C. The cooled mixture in the heat exchange channel is discharged from the outlet of the heat exchange channel.

[0025] In addition, the re-separator 6 is preferably covered with an insulation layer. The main purpose of this insulation layer is to minimize heat loss from the re-separator 6 to the surrounding environment during operation. Since the re-separation process utilizes the waste heat of the medium-temperature (e.g., 40-70°C) mixed gas to heat the mixed liquid, the heat source grade is low, and energy is particularly valuable. Effective insulation measures can ensure that the heat from pipeline a can be efficiently used to heat the mixed liquid, maintaining its internal temperature uniformly and stably within the evaporation temperature range of the organic working fluid, thereby ensuring that the organic working fluid can fully evaporate while keeping the lubricating oil in a liquid state. This not only directly ensures the deep separation effect of the lubricating oil and the organic working fluid and the recovery rate of the working fluid, but also indirectly improves the efficiency of the entire energy coupling process and reduces system heat loss. This insulation layer can be common insulation materials such as rock wool, glass wool, or polyurethane foam.

[0026] The organic working fluid-noncondensable gas separator 8 performs the final purification task. Its inlet is precisely connected via pipe b to the heat exchange channel outlet of the aforementioned re-separator 6 to receive the pre-cooled, low-temperature organic working fluid vapor mixture containing noncondensable gases. Preferably, the separator 8 has its own heat exchange coil, which is connected to the refrigerant circuit of an external refrigeration unit 11. The refrigeration unit 11 provides deep cooling below the main condensing temperature, for example, controlling the temperature below 0°C, to ensure sufficient condensation of the organic working fluid vapor.

[0027] The auxiliary system includes: a lubricating oil tank 7, which is connected to the liquid phase outlet of the main container of the re-separator 6 via pipeline D, to collect the separated pure lubricating oil; a non-condensable gas exhaust device 9, which is connected to the gas phase outlet of the organic working fluid-non-condensable gas separator 8, preferably an automatic exhaust valve or a vacuum pump controlled by a pressure sensor, for automatically exhausting the accumulated non-condensable gas; and a liquid working fluid pump 10, whose inlet is connected to the liquid phase outlet of the organic working fluid-non-condensable gas separator 8 via pipeline E, and whose outlet is connected to the liquid phase space of the condenser 3, responsible for pumping the recovered liquid working fluid back to the main circulation.

[0028] The working process of the above-mentioned separation device is described in detail below.

[0029] Step 1: Initial separation.

[0030] The mixed gas from evaporator 1 undergoes preliminary purification in primary separator 4. The physical interception and condensation of the separation screen 5 removes the vast majority (e.g., over 90%) of the lubricating oil. This process significantly reduces the risk of lubricating oil entering the main condenser 3 from upstream, avoiding heat transfer deterioration caused by oil film covering the heat exchange surface, and laying the foundation for efficient system operation.

[0031] Step 2: Separation and energy recovery (the core link of energy coupling).

[0032] This process involves complex energy exchange and material separation. The initially separated mixture enters the main container of the re-separator 6, where it flows with a medium-temperature mixed gas (typically 5-15°C higher than the main condenser temperature) from pipe a within a heat exchange channel, undergoing indirect heat exchange. Utilizing this waste heat, which would otherwise be treated, as a heat source, the mixture is heated to a specific temperature range, typically controlled between 40°C and 50°C. This temperature must be precisely higher than the boiling point of the organic working fluid in the mixture (e.g., for R245fa), while remaining well below the boiling point of the lubricating oil, ensuring selective evaporation of the working fluid while the lubricating oil remains liquid. This achieves a "two birds with one stone" effect: deep gas-liquid separation of the working fluid and lubricating oil; and internal recovery of system waste heat, significantly reducing the energy consumption of the separation process itself. The pure working fluid vapor generated by evaporation prepares for the next recovery step, while the medium-temperature mixed gas, acting as a heat source, is pre-cooled, reducing the load on the subsequent chiller 11.

[0033] Step 3: Working fluid recovery and condensation (a clear working fluid recovery path).

[0034] Through pipeline C, the newly generated pure low-temperature organic working fluid vapor in the re-separator 6 is directly guided back to the main condenser 3. This independent path design ensures that the separated pure working fluid can return to the main cycle to participate in work in the most direct and efficient way, achieving almost zero loss recovery of the working fluid and avoiding the waste of working fluid that may be caused by sending all the gas to the exhaust treatment device in the traditional method.

[0035] Step 4: Non-condensable gas separation and condensation (complete removal of non-condensable gases).

[0036] The pre-cooled mixture containing non-condensable gases enters the organic working fluid-non-condensable gas separator 8 via pipe b. Under the deep cooling provided by the refrigeration unit 11, the organic working fluid vapor in the mixture is completely liquefied and separated from the non-condensable gases (such as air). Thus, the non-condensable gases and liquid working fluid are completely separated within the separator 8.

[0037] Step 5: Discharge and Recirculation (Closed-Loop Recycling of Resources).

[0038] This process is the final step in completing the entire separation process and maximizing resource recovery. It comprises three key parallel operations: Non-condensable gas emission: Non-condensable gases accumulated at the top of the organic working fluid-non-condensable gas separator 8 are discharged from the system through the non-condensable gas exhaust device 9 (such as an automatic exhaust valve), thereby permanently eliminating the negative impact of non-condensable gases on system efficiency.

[0039] Liquid working fluid reflux: The pure liquid organic working fluid that condenses at the bottom of separator 8 is pressurized by liquid working fluid pump 10 and stably pumped back to the liquid phase space of condenser 3 through pipeline E, and re-enters the main circulation to participate in the work, ensuring zero loss of working fluid.

[0040] Lubricating oil recovery: Meanwhile, the pure lubricating oil remaining after deep separation in the re-separator 6 flows into the lubricating oil tank 7 through pipeline D by gravity or pressure difference for storage, so as to be recycled.

[0041] In summary, this invention integrates lubricant separation, non-condensable gas removal, and system energy utilization through ingenious process design and component coupling. The resulting synergistic effect far exceeds the effect of simply adding up individual functions. It not only ensures thorough separation and resource recovery rate but also achieves a comprehensive improvement in the efficiency, stability, and economy of the organic Rankine cycle system through system-level energy integration and optimization.

[0042] This embodiment provides a method for coupling and separating non-condensable gases and lubricating oil in an organic Rankine cycle system. The method employs the aforementioned device for coupling and separating non-condensable gases and lubricating oil in an organic Rankine cycle system, and includes the following steps: Preliminary separation: The organic working fluid-lubricating oil mixture from the evaporator (1) is introduced into the primary separator (4) and preliminarily separated using the separation screen (5); Re-separation and energy recovery: The organic working fluid-lubricating oil mixture separated by the primary separator (4) is introduced into the re-separator (6), and the organic working fluid vapor-non-condensable gas mixture from the top of the condenser (3) is introduced as a heat source to heat the organic working fluid and make it evaporate. Organic working fluid recovery and condensation: The low-temperature organic working fluid vapor generated by the evaporation of organic working fluid in the re-separator (6) is introduced into the condenser (3) through pipeline C for condensation and recovery; Non-condensable gas separation and condensation: The organic working fluid vapor-non-condensable gas mixture that has been cooled after flowing through the heat exchange channel of the re-separator (6) is introduced into the organic working fluid-non-condensable gas separator (8) through the pipeline b for deep condensation to achieve non-condensable gas separation. Discharge and return: Non-condensable gases are discharged through the exhaust device (9), and the liquid organic working medium condensed in the organic working medium-non-condensable gas separator (8) is sent back to the condenser (3) through the liquid working medium pump (10). At the same time, the lubricating oil separated in the re-separator (6) is introduced into the lubricating oil tank (7).

[0043] In the re-separation and energy recovery process, the heating temperature is 40°C to 50°C.

[0044] This embodiment provides an organic Rankine cycle power generation system, including an evaporator (1), a turbine (2), a condenser (3), and a main circulating working fluid pump. The system integrates a non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system. The coupling and separation device is connected to the evaporator (1) and the condenser (3) via pipelines A, B, C, D, E, a, and b, and operates according to the separation method described in this invention to achieve the synergistic separation and recovery of the organic working fluid, lubricating oil, and non-condensable gas.

[0045] Embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of one or more computer-usable storage media (including, but not limited to, disk storage, etc.) containing computer-usable program code. CD - ROM It takes the form of a computer program product implemented on (such as optical memory, etc.).

[0046] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0047] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0048] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1The steps of the function specified in one or more boxes.

[0049] Contents not described in detail in this specification are prior art known to those skilled in the art. It is hereby indicated that the above description is intended to help those skilled in the art understand this invention, but does not limit the scope of protection of this invention. Any equivalent substitutions, modifications, improvements, or simplifications of the above descriptions that do not depart from the essential content of this invention fall within the scope of protection of this invention.

Claims

1. A non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system, connected between the evaporator (1) and the condenser (3) of the system, characterized in that, include: The primary separator (4) has its inlet connected to the outlet of the evaporator (1) via pipe A, and is used to receive the high-temperature organic working fluid-lubricating oil mixture. It is equipped with a separation screen (5) inside. The gas phase outlet of the primary separator (4) is connected to the gas phase space of the condenser (3) via pipe B. The re-separator (6) has its liquid phase inlet connected to the liquid phase outlet of the primary separator (4) for receiving the organic working fluid-lubricating oil mixture from the primary separator (4); the re-separator (6) is also provided with a heat exchange channel, the inlet of which is connected to the top gas phase space of the condenser (3) via pipe a, for introducing a medium-temperature organic working fluid vapor-non-condensable gas mixture as a heat source; the gas phase outlet of the re-separator (6) is connected to the gas phase space of the condenser (3) via pipe C, for discharging the low-temperature organic working fluid vapor generated by the evaporation of the organic working fluid-lubricating oil mixture; The organic working fluid-noncondensable gas separator (8) has its inlet connected to the outlet of the heat exchange channel of the re-separator (6) via pipe b, and is used to receive the low-temperature organic working fluid vapor-noncondensable gas mixture after flowing through the heat exchange channel and being cooled. A refrigeration unit (11) is coupled to the organic working fluid-noncondensable gas separator (8) to provide it with cooling capacity; The lubricating oil tank (7) is connected to the liquid phase outlet of the re-separator (6) via pipeline D; Non-condensable gas exhaust device (9) is connected to the gas phase outlet of the organic working fluid-non-condensable gas separator (8); A liquid working fluid pump (10) is installed in the middle of pipeline E. One end of pipeline E is connected to the liquid phase outlet of the organic working fluid-noncondensable gas separator (8), and the other end is connected to the liquid phase space of the condenser (3) for transporting liquid organic working fluid.

2. The non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system according to claim 1, characterized in that, The re-separator (6) is a partitioned heat exchanger, and its internal heat exchange channels are coils or jacketed structures.

3. The non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system according to claim 1, characterized in that, The organic working fluid-noncondensable gas separator (8) is equipped with a heat exchange coil, which is connected to the refrigerant circuit of the refrigeration unit (11).

4. The non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system according to claim 1, characterized in that, The non-condensable gas exhaust device (9) is an automatic exhaust valve or a vacuum pump controlled by a pressure signal.

5. The non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system according to claim 1, characterized in that, The separation mesh (5) is woven from metal wires or polymer materials.

6. The non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system according to claim 1, characterized in that, The re-separator (6) is covered with an insulation layer.

7. A non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system according to claim 1 or 2, characterized in that, The re-separator (6) is configured to utilize a heat source from pipe a to bring the temperature of the organic working fluid-lubricating oil mixture inside it above the evaporation temperature of the organic working fluid and to keep the lubricating oil in a liquid state.

8. A method for coupling and separating non-condensable gases and lubricating oil in an organic Rankine cycle system, characterized in that, The method employs a non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system as described in any one of claims 1-7, and includes the following steps: Preliminary separation: The organic working fluid-lubricating oil mixture from the evaporator (1) is introduced into the primary separator (4) and preliminarily separated using the separation screen (5); Re-separation and energy recovery: The organic working fluid-lubricating oil mixture separated by the primary separator (4) is introduced into the re-separator (6), and the organic working fluid vapor-non-condensable gas mixture from the top of the condenser (3) is introduced as a heat source to heat the organic working fluid and make it evaporate. Organic working fluid recovery and condensation: The low-temperature organic working fluid vapor generated by the evaporation of organic working fluid in the re-separator (6) is introduced into the condenser (3) through pipeline C for condensation and recovery; Non-condensable gas separation and condensation: The organic working fluid vapor-non-condensable gas mixture that has been cooled after flowing through the heat exchange channel of the re-separator (6) is introduced into the organic working fluid-non-condensable gas separator (8) through the pipeline b for deep condensation to achieve non-condensable gas separation; Discharge and return: Non-condensable gases are discharged through the exhaust device (9), and the liquid organic working medium condensed in the organic working medium-non-condensable gas separator (8) is sent back to the condenser (3) through the liquid working medium pump (10). At the same time, the lubricating oil separated in the re-separator (6) is introduced into the lubricating oil tank (7).

9. The method for coupling and separating non-condensable gases and lubricating oil in an organic Rankine cycle system according to claim 8, characterized in that, In the re-separation and energy recovery process, the heating temperature is 40°C to 50°C.

10. An organic Rankine cycle power generation system, comprising an evaporator (1), a turbine (2), a condenser (3), and a main circulating working fluid pump, characterized in that, The system integrates a non-condensable gas and lubricating oil coupling and separation device for an organic Rankine cycle system according to any one of claims 1-7.

Images