An incondensable gas separation system based on an ORC power plant

Abstract

The application discloses a kind of based on ORC power generation device's non-condensable gas separation system, including ORC power generation device, the ORC power generation device is by working medium pump, evaporator, turbine generator and condenser, the working medium pump, the evaporator, the turbine generator and the condenser are sequentially connected by corresponding pipeline, and head and tail are connected;It further includes the non-condensable gas separation system that can separate the non-condensable gas in the ORC power generation device from the ORC power generation device, and the non-condensable gas separation system is accessed to the condenser.The application realizes the non-condensable gas emission process ORC power generation device without shutdown, guarantees equipment running time, improves annual power generation, increases power generation income, and emission time is controllable;Realize the non-condensable gas emission process will not cause organic working medium to discharge system, guarantee the stability of system working quality, reduce operating cost;Simple structure, high reliability and simple maintenance.

Description

Technical Field

[0001] This invention belongs to the field of ORC waste heat power generation technology, and more specifically, relates to a non-condensable gas separation system based on an ORC power generation device. Background Technology

[0002] The organic Rankine cycle (ORC) is a thermodynamic cycle based on replacing water, the traditional Rankine cycle medium, with a low-boiling-point organic working fluid (such as R245fa, R1233zd). It is particularly suitable for the development and utilization of medium- and low-grade industrial waste heat, as well as low- and medium-grade renewable energy sources such as solar, biomass, and geothermal energy. Organic Rankine cycle power generation technology not only has significant economic value but also contributes to energy conservation, emission reduction, and environmental protection.

[0003] ORC generator sets mainly consist of components such as an evaporator, turbine, generator, condenser, and working fluid pump. The organic working fluid absorbs heat from a low-temperature heat source (80-300℃) in the evaporator, generating steam with a certain pressure and temperature. This steam enters the turbine, driving it to perform work, thereby powering the generator to produce high-grade electrical energy. The steam discharged from the turbine releases heat to an external cold source in the condenser, condensing into a liquid state. Finally, it returns to the evaporator via the working fluid pump, completing the entire cycle.

[0004] Non-condensable gases are gases that, under specific temperature and pressure conditions in the condenser of an ORC power generation system, cannot condense into a liquid and remain in a gaseous state (such as nitrogen, oxygen, hydrogen, and carbon dioxide). The main pathways for non-condensable gases to enter the ORC generator set are:

[0005] When an ORC generator set system is flushed with organic working fluid and lubricating oil, non-condensable gases will enter the system.

[0006] Non-condensable gases may enter the system during equipment maintenance or replacement of spare parts.

[0007] When the unit is shut down, and the system pressure is lower than the outside atmospheric pressure, non-condensable gases can enter the system through low-pressure valves or sealed connections of equipment.

[0008] During the operation of an ORC generator set, if the organic working fluid contains non-condensable gases, it will significantly affect the condensation pressure of the organic working fluid in the condenser, ultimately impacting the power generation efficiency of the ORC generator set and reducing power output. Therefore, it is necessary to remove the non-condensable gases from the ORC power generation system while ensuring that the organic working fluid within the system does not leak.

[0009] Currently, the method for separating non-condensable gases in ORC generator sets utilizes the fact that these gases have a relatively low specific gravity. This involves opening the condenser shell-side vent valve or the vent valve at the highest point of the ORC power generation system, releasing the gases for a period of time, and then closing the valve. However, this method requires shutting down the ORC generator set, and the release time is difficult to control. This often leads to a reduction in the organic working fluid within the ORC power generation system, affecting the unit's power output and necessitating the replenishment of organic working fluid, thus increasing equipment operating costs. Summary of the Invention

[0010] In order to solve the problems existing in the prior art, the present invention aims to provide a non-condensable gas separation system based on an ORC power generation device, which can discharge non-condensable gases outside the system without stopping the machine, while keeping the organic working fluid inside the system from leaking, and the discharge time is controllable.

[0011] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0012] A non-condensable gas separation system based on an ORC power generation device includes an ORC power generation device, which consists of a working fluid pump, an evaporator, a turbine generator, and a condenser. The working fluid pump, the evaporator, the turbine generator, and the condenser are connected sequentially through corresponding pipes, and are connected end to end. The system also includes a non-condensable gas separation system that can separate the non-condensable gas inside the ORC power generation device from the ORC power generation device.

[0013] Furthermore, the non-condensable gas separation system includes a solenoid valve, a condenser separator, a working fluid reflux system, a discharge valve, and a refrigeration air conditioner. The solenoid valve, the condenser separator, and the working fluid reflux system are connected in sequence through corresponding pipes. The solenoid valve and the working fluid reflux system are respectively connected to the condenser through corresponding pipes, and the discharge valve and the refrigeration air conditioner are connected to the condenser separator through corresponding pipes.

[0014] Furthermore, a level gauge is installed on the condenser separator.

[0015] Furthermore, the working fluid reflux system includes a float switch, which is located at the bottom of the condenser separator and connected to the condenser via a corresponding pipe.

[0016] Furthermore, the working fluid reflux system includes a first control valve, a second control valve, and an ejector; the ejector is connected to the evaporator and the condenser via corresponding pipes, and then connected to the condenser via corresponding pipes; the first control valve is connected in series in the corresponding pipe between the evaporator and the ejector; the second control valve is connected in series in the corresponding pipe between the condenser and the ejector.

[0017] Furthermore, a filter is connected in series in the pipe between the evaporator and the ejector, and in the pipe between the condenser separator and the ejector.

[0018] Furthermore, the working fluid reflux system includes a transfer pump, which is connected to the condenser and the condensation separator via corresponding pipes, and a filter is connected in series between the transfer pump and the condensation separator.

[0019] Furthermore, the discharge valve is an electrically controlled switch valve.

[0020] Furthermore, the evaporator and the condenser are directly connected by a corresponding pipe, and a bypass valve is provided in the pipe between them; and a turbine valve is provided in the pipe between the evaporator and the turbine generator.

[0021] Furthermore, both the evaporator and the condenser are shell-and-tube heat exchangers.

[0022] The beneficial effects of this invention are as follows: By installing a non-condensable gas separation system on the ORC generator set, this invention enables the ORC power generation unit to operate without shutting down during the emission of non-condensable gases, ensuring equipment operating time, increasing annual power generation, and increasing power generation revenue; at the same time, it achieves controllable emission time; and it ensures that the emission of non-condensable gases does not cause additional discharge of organic working fluids into the system, ensuring the stability of organic working fluids within the ORC power generation unit and reducing the operating cost of the ORC power generation unit; secondly, the structure is simple, highly reliable, and easy to maintain, further reducing costs and increasing benefits.

[0023] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Specific embodiments of the present invention are given in detail in the following embodiments and their accompanying drawings. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0025] Fig. 1 This is the first embodiment of the non-condensable gas separation system of the present invention;

[0026] Fig. 2 This is a second embodiment of the non-condensable gas separation system of the present invention;

[0027] Fig. 3 This is the third embodiment of the non-condensable gas separation system of the present invention.

[0028] The following are the labels in the diagram: 1. Working fluid pump; 2. Evaporator; 3. Turbine generator; 4. Condenser; 5. Solenoid valve; 6. Condensation separator; 7. Drain valve; 8. Refrigeration and air conditioning unit; 9. Level gauge; 10. Float switch; 11. First control valve; 12. Second control valve; 13. Ejector; 14. Filter; 15. Transfer pump; 16. Bypass valve; 17. Turbine valve. Implementation

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

[0030] It should be noted that all directional indicators (such as up, down, left, right, front, back, upper end, lower end, top, bottom, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0031] See Figs. 1-3 As shown, a non-condensable gas separation system based on an ORC power generation device includes an ORC power generation device, which consists of a working fluid pump 1, an evaporator 2, a turbine generator 3, and a condenser 4. The working fluid pump 1, the evaporator 2, the turbine generator 3, and the condenser 4 are connected sequentially by corresponding pipes, and are connected end to end. The evaporator 2 is a shell-and-tube heat exchanger. During power generation, an organic working fluid (such as R245fa, R1233zd) is added to the evaporator 2. The organic working fluid absorbs heat from the heat source in the evaporator 2 and evaporates to form high-pressure steam. The organic working fluid enters the turbine generator 3 through the pipe between the evaporator 2 and the turbine generator 3, driving the turbine to do work and rotating the generator, realizing the conversion of low-grade heat energy into high-grade electrical energy. The high-pressure steam is converted into low-pressure steam and enters the condenser 4 through the pipe between the turbine generator 3 and the condenser 4. Under the action of the condenser 4, it becomes liquid again. The low-pressure liquid organic working fluid, under the pressure of the working fluid pump 1, re-enters the evaporator 2 through the pipe between the working fluid pump 1 and the evaporator 2, completing the organic working fluid cycle in the ORC power generation unit.

[0032] In this embodiment, see further. Figs. 1-3As shown, the evaporator 2 and the condenser 4 are directly connected by a corresponding pipe, and a bypass valve 16 is installed in the pipe between them; and a turbine valve 17 is installed in the pipe between the evaporator 2 and the turbine generator 3; during operation, the ORC power generation device is divided into bypass mode and turbine mode; when in bypass mode, the turbine valve 17 is closed, and the high-pressure steam enters the condenser 4 directly after being throttled and depressurized by the bypass valve 16. At this time, the ORC power generation device is in a non-power generation state; when in turbine mode, the bypass valve 16 is closed, and the high-pressure steam enters the turbine generator 3 through the turbine valve 17. At this time, the ORC power generation device is in a power generation state.

[0033] When the ORC power generation unit is operating, the non-condensable gases inside it gradually concentrate at the highest point between the turbine generator 3 outlet and the condenser 4, severely affecting the thermoelectric efficiency of the ORC generator set. Therefore, see [link to relevant documentation]. Figs. 1-3 As shown, it also includes a non-condensable gas separation system that can separate non-condensable gases inside the ORC power generation device from the ORC power generation device. Example

[0034] See Fig. 1 As shown, the non-condensable gas separation system is a gravity-fed system, comprising a solenoid valve 5, a condenser separator 6, a working fluid reflux system, a discharge valve 7, and a refrigeration air conditioner 8. The solenoid valve 5, the condenser separator 6, and the working fluid reflux system are connected sequentially via corresponding pipes. The solenoid valve 5 and the working fluid reflux system are respectively connected to the condenser 4 via corresponding pipes. The discharge valve 7 and the refrigeration air conditioner 8 are connected to the condenser separator 6 via corresponding pipes. The condenser separator 6 is a shell-and-tube heat exchanger. The discharge valve 7 is an electrically controlled on / off valve. The main function of the refrigeration air conditioner 8 is to supply a cold source to the condenser separator 6. When discharging non-condensable gases, the solenoid valve 5 and the discharge valve 7 are opened, allowing the non-condensable gas discharge process to proceed without requiring the ORC power generation unit to shut down, while ensuring controllable discharge time. (Continue to see...) Fig. 1 As shown, the working fluid reflux system includes a float switch 10, which is located at the bottom of the condenser 6 and connected to the condenser 4 via a corresponding pipe. It should be noted that the connection port of the pipe connecting the float switch 10 and the condenser 6 to the condenser 4 should be lower than the shell side of the condenser 6.

[0035] When separating the non-condensable gases within the ORC power generation unit:

[0036] Condensation process: Open the refrigeration air conditioner 8 and the solenoid valve 5, so that the non-condensable gas concentrated in the condenser 4 (highest point) can continuously enter the shell side of the condenser 6 through the pipe between the condenser 4 and the solenoid valve 5, and the pipe between the solenoid valve 5 and the condenser 6 under the action of the pressure difference caused by the temperature difference. At this time, the gaseous organic working substance mixed in the non-condensable gas is completely condensed into liquid after exchanging heat with the cold source in the condenser 6, and the non-condensable gas is located above the liquid surface of the organic working substance. When the liquid level in the condenser 6 reaches the set critical value, the non-condensable gas and the liquid organic working substance begin to separate.

[0037] Separation process: When the liquid organic working fluid in the condenser separator 6 reaches a certain level, the float switch 10 will automatically open. Under the action of gravity, the liquid organic working fluid in the condenser separator 6 returns to the condenser 4 through the pipe between the float switch 10 and the condenser 4. At the same time, the discharge valve 7 is opened, and the non-condensable gas in the condenser separator 6 is discharged directly into the environment through the pipe between the condenser separator 6 and the discharge valve 7. After separation is completed, the refrigeration air conditioner 8, the solenoid valve 5, and the discharge valve 7 are closed. Example

[0038] See Fig. 2 As shown, the non-condensable gas separation system is an ejector reflux system. Unlike Embodiment 1, the condenser separator 6 is equipped with a level gauge 9 for monitoring the liquid level within it, and the working fluid reflux system includes a first control valve 11, a second control valve 12, and an ejector 13. The ejector 13 is connected to the evaporator 2 and the condenser separator 6 via corresponding pipes, and then connected to the condenser 4 via corresponding pipes. The first control valve 11 is connected in series in the corresponding pipe between the evaporator 2 and the ejector 13. The second control valve 12... A control valve 12 is connected in series in the corresponding pipe between the condenser separator 6 and the ejector 13; and a filter 14 is connected in series in the pipe between the evaporator 2 and the ejector 13 and the pipe between the condenser separator 6 and the ejector 13 respectively; wherein, the main purpose of the filter 14 is to filter the liquid or gas entering the ejector 13, to prevent metal debris, welding slag particles, etc. from entering the ejector 13, causing damage to the ejector 13 and affecting its performance, and at the same time to prevent metal debris, welding slag particles, etc. from entering the ORC power generation unit.

[0039] When separating the non-condensable gases within the ORC power generation unit:

[0040] Condensation process: The refrigeration air conditioner 8 and the solenoid valve 5 are opened, allowing the non-condensable gas concentrated in the condenser 4 (highest point) to continuously pass through the pipe between the condenser 4 and the solenoid valve 5, and the pipe between the solenoid valve 5 and the condenser separator 6 under the action of the pressure difference caused by the temperature difference, and enter the shell side of the condenser separator 6. At this time, the gaseous organic working fluid mixed in the non-condensable gas is completely condensed into liquid after heat exchange with the cold source in the condenser separator 6, while the non-condensable gas is located above the liquid surface of the organic working fluid. When the level gauge 9 detects that the liquid level in the condenser separator 6 reaches the set critical value, the non-condensable gas and the liquid organic working fluid begin the separation process.

[0041] Separation process: When the level gauge 9 detects that the liquid level in the condenser 6 has reached the set critical value, the discharge valve 7 is opened. Under the pressure inside the condenser 6, the non-condensable gas is discharged directly into the environment through the pipe between the condenser 6 and the discharge valve 7. Then, the first control valve 11 and the second control valve 12 are opened, and under the action of the ejector 13, the liquid organic working fluid in the condenser 6 is ejected back into the condenser 4 through the pipe between the condenser 6 and the ejector 13 and between the ejector 13 and the condenser 4. After separation is completed, the refrigeration air conditioner 8, the solenoid valve 5, the discharge valve 7, the first control valve 11, and the second control valve 12 are closed. Example

[0042] See Fig. 3 As shown, the non-condensable gas separation system is a pump reflux system. Unlike Embodiment 1, the condenser separator 6 is also equipped with a level gauge 9 for monitoring the liquid level within it. The working fluid reflux system includes a transfer pump 15, which is connected to the condenser 4 and the condenser separator 6 via corresponding pipes. A filter 14 is connected in series between the transfer pump 15 and the condenser separator 6. The main purpose of the filter 14 is to filter the liquid entering the transfer pump 15, preventing metal debris, welding slag particles, etc., from entering and damaging the pump, thus affecting its performance. It also prevents metal debris, welding slag particles, etc., from entering the ORC power generation unit.

[0043] When separating the non-condensable gases within the ORC power generation unit:

[0044] Condensation process: The refrigeration air conditioner 8 and the solenoid valve 5 are opened, allowing the non-condensable gas concentrated in the condenser 4 (highest point) to continuously pass through the pipe between the condenser 4 and the solenoid valve 5, and the pipe between the solenoid valve 5 and the condenser separator 6 under the action of the pressure difference caused by the temperature difference, and enter the shell side of the condenser separator 6. At this time, the gaseous organic working fluid mixed in the non-condensable gas is completely condensed into liquid after heat exchange with the cold source in the condenser separator 6, while the non-condensable gas is located above the liquid surface of the organic working fluid. When the level gauge 9 detects that the liquid level in the condenser separator 6 reaches the set critical value, the non-condensable gas and the liquid organic working fluid begin the separation process.

[0045] Separation process: When the level gauge 9 detects that the liquid level in the condenser separator 6 has reached the set critical value, the solenoid valve 5 is closed and the discharge valve 7 is opened. Under the pressure inside the condenser separator 6, the non-condensable gas is discharged directly into the environment through the pipe between the condenser separator 6 and the discharge valve 7. Then, the transfer pump 15 is turned on, and the liquid in the condenser separator 6 flows back to the condenser 4 through the pipe between the condenser separator 6 and the transfer pump 15, and between the transfer pump 15 and the condenser 4. After separation is completed, the refrigeration air conditioner 8, the solenoid valve 5, the discharge valve 7, and the transfer pump 15 are closed.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A non-condensable gas separation system for an ORC-based power plant, characterized by: The utility model provides an ORC power generation device, the ORC power generation device is by working medium pump (1), evaporimeter (2), turbine generator (3) and condenser (4) are constituteed, working medium pump (1), evaporimeter (2), turbine generator (3) and condenser (4) are connected in proper order through corresponding pipeline, and the head and tail are connected, still include a can with the ORC power generation device inside noncondensable gas separation system that noncondensable gas of ORC power generation device is separated, the noncondensable gas separation system includes electromagnetic valve (5), condensing separator (6), working medium backflow system, discharge valve (7) and refrigeration air conditioner (8), electromagnetic valve (5), condensing separator (6) and working medium backflow system are connected in proper order through corresponding pipeline, and the working medium backflow system is connected with the working medium backflow system respectively through corresponding pipeline in condenser (4), discharge valve (7) and refrigeration air conditioner (8) are connected with condensing separator (6) through corresponding pipeline, working medium backflow system includes a float ball switch (10), float ball switch (10) is arranged at the bottom end of condensing separator (6), and float ball switch (10) is connected with condenser (4) through corresponding pipeline, the pipeline between float ball switch (10) and condensing separator (6) is connected with the connection port of condenser (4) and should be lower than the shell side of condensing separator (6).

2. The non-condensable gas separation system for an ORC-based power plant of claim 1, wherein: The condensing separator (6) is provided with a liquid level gauge (9).

3. The non-condensable gas separation system for an ORC-based power plant of claim 2, wherein: The working medium backflow system includes a first control valve (11), a second control valve (12), and an ejector (13). The ejector (13) is connected with the evaporimeter (2) and the condensing separator (6) through corresponding pipelines and then connected with the condenser (4) through a corresponding pipeline. The first control valve (11) is connected in series in the corresponding pipeline between the evaporimeter (2) and the ejector (13). The second control valve (12) is connected in series in the corresponding pipeline between the condensing separator (6) and the ejector (13).

4. The non-condensable gas separation system for an ORC-based power plant of claim 3, wherein: The pipeline between the evaporimeter (2) and the ejector (13) and the pipeline between the condensing separator (6) and the ejector (13) are each connected in series with a filter (14).

5. The non-condensable gas separation system for an ORC-based power plant of claim 2, wherein: The working medium backflow system includes a delivery pump (15) connected with the condenser (4) and the condensing separator (6) through corresponding pipelines, and the pipeline between the delivery pump (15) and the condensing separator (6) is connected in series with a filter (14).

6. The non-condensable gas separation system for an ORC-based power plant of claim 1, wherein: The discharge valve (7) is an electrically controlled on-off valve.

7. The non-condensable gas separation system for an ORC-based power plant of claim 1, wherein: The evaporimeter (2) and the condenser (4) are directly connected through a corresponding pipeline, and a bypass valve (16) is arranged in the pipeline between them. A turbine valve (17) is arranged in the pipeline between the evaporimeter (2) and the turbine generator (3).

8. The non-condensable gas separation system for an ORC-based power plant of claim 1, wherein: The evaporimeter (2) and the condensing separator (6) are both shell-and-tube heat exchangers.

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