Low-pressure flash vapor pressure control system

Abstract

The utility model relates to flash system technical field discloses a kind of low-pressure flash steam pressure stabilizing control system, including low-pressure flash tank, deaerator, low-pressure flash condenser and go flare, which is connected with the inlet end of low-pressure flash condenser in the export end of low-pressure flash tank by first pipeline, and first pressure control valve is arranged on first pipeline;The inlet end of go flare is connected with the export end of low-pressure flash tank by second pipeline, and second pressure control valve is arranged on second pipeline;The inlet end of deaerator is connected with the export end of low-pressure flash tank by third pipeline, and first flow control valve and first flow transmitter are arranged on third pipeline, and first flow transmitter is located in the position close to deaerator.The system can effectively stabilize the pressure of low-pressure flash tank and deaerator, and ensure the overall stable operation of the system.The utility model's pressure and flow double-path independent regulation and control mechanism improves the stability, safety of overall operation of system, enhances the reliability and service life of equipment.

Description

Technical Field

[0001] This utility model belongs to the technical field of flash evaporation systems, specifically relating to a low-pressure flash steam pressure stabilization control system. Background Technology

[0002] In the flash evaporation system of existing gasification units, low-pressure flash steam is typically directly fed into the deaerator via a single pipeline for treatment. This method has significant inherent drawbacks: due to fluctuations in the gasifier's operating load and changes in upstream operating conditions, the pressure and flow rate of the low-pressure flash steam are continuously unstable, frequently exceeding the system's normal control range. This instability directly leads to two cascading problems: firstly, flash steam pressure fluctuations can easily cause overpressure in the low-pressure flash tank itself, threatening equipment safety; secondly, the uncontrollable nature of the flash steam volume causes the deaerator to be subjected to excessive gas surges, frequently triggering deaerator overpressure and activating the safety valve.

[0003] To alleviate deaerator pressure, operators are often forced to close the inlet valve, which in turn exacerbates pressure buildup in the low-pressure flash tank, creating a vicious cycle. Simultaneously, the disconnect between flash steam supply and the deaerator's actual heat demand necessitates additional low-pressure steam heating when gas supply is insufficient, resulting in energy waste; conversely, excess steam cannot be effectively utilized when gas supply is excessive. These problems not only keep the system in a critical safety state for extended periods, increasing the frequency of manual intervention and operational risks, but also accelerate structural fatigue and aging of critical equipment, severely impacting production safety and operational stability. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned problems and provide a low-pressure flash steam stabilization control system that can eliminate the bidirectional pressure fluctuation chain effect between the low-pressure flash tank and the deaerator, and prevent equipment overpressure and system instability caused by the uncontrolled pressure and flow of low-pressure flash steam.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This utility model provides a low-pressure flash steam stabilization and control system, including a low-pressure flash tank, a deaerator, a low-pressure flash condenser, and a flare.

[0007] The outlet of the low-pressure flash tank is connected to the inlet of the low-pressure flash condenser via a first pipe, and a first pressure control valve is installed on the first pipe. The outlet of the low-pressure flash tank is connected to the inlet of the flare via a second pipe, and a second pressure control valve is installed on the second pipe. The outlet of the low-pressure flash tank is connected to the inlet of the deaerator via a third pipe, and a first flow control valve and a first flow transmitter are installed on the third pipe, with the first flow transmitter located near the deaerator.

[0008] A further improvement of this invention is that a first pressure transmitter is provided at the outlet of the low-pressure flash tank.

[0009] A further improvement of this invention is that the first pressure transmitter is installed on the outlet pipe of the low-pressure flash tank.

[0010] A further improvement of this invention is that the signal output terminal of the first pressure transmitter is connected to the control signal input terminal of the second pressure control valve via a signal line.

[0011] A further improvement of this invention is that the signal output terminal of the first pressure transmitter is connected to the control signal input terminal of the first pressure control valve via a signal line.

[0012] A further improvement of this utility model is that the first flow transmitter is installed on the third pipeline and is located between the tee joint and the first flow control valve.

[0013] A further improvement of this invention is that the signal output terminal of the first flow transmitter is connected to the control signal input terminal of the first flow control valve via a signal line.

[0014] A further improvement of this utility model is that the outlet end of the low-pressure flash tank is connected to a three-way connector, and the three outlet ends of the three-way connector are respectively connected to the first pipe, the second pipe and the third pipe.

[0015] A further improvement of this invention is that a temperature transmitter is installed on the shell of the deaerator.

[0016] A further improvement of this invention is that a level transmitter is installed on the shell of the low-pressure flash tank.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention provides a low-pressure flash steam stabilization control system. By connecting a first pipe leading to the low-pressure flash condenser, a second pipe leading to the flare, and a third pipe leading to the deaerator in parallel at the outlet of the low-pressure flash tank, it achieves the dual benefits of pressure stabilization and energy optimization. Firstly, the system effectively stabilizes the pressure of the low-pressure flash tank. When the pressure inside the tank fluctuates, the pressure control valve automatically adjusts its opening based on the pressure signal, diverting excess steam through the low-pressure flash condenser or to the flare, preventing overpressure in the tank. Secondly, the system precisely stabilizes the deaerator pressure. The steam flow rate entering the deaerator is independently and precisely controlled by a flow control valve, and a flow transmitter provides real-time monitoring, ensuring that the gas flow rate remains stable within the safe operating range of the deaerator, fundamentally avoiding deaerator overpressure and the tripping of its safety valve. In addition, the system can ensure the overall stable operation of the system. This dual-path independent control mechanism for pressure and flow not only solves the chain safety risks caused by pressure fluctuations and flow loss of control in the original system, but also optimizes energy utilization, reduces unnecessary low-pressure steam replenishment consumption, and the directional diversion of excess steam also reduces energy waste, improves the overall stability, safety and production efficiency of the system, and enhances the reliability and service life of the equipment.

[0019] Furthermore, a first pressure transmitter is installed at the outlet of the low-pressure flash tank, which can accurately detect pressure changes inside the low-pressure flash tank in real time, providing direct feedback signals for the automatic adjustment of the pressure control valve, forming the core monitoring node for pressure closed-loop control.

[0020] Furthermore, the signal output terminal of the first flow transmitter is connected to the control signal input terminal of the first flow control valve via a signal line. This signal connection enables real-time monitoring and automatic closed-loop control of the steam flow entering the deaerator, ensuring that the actual flow accurately matches the set value, thereby eliminating the risk of deaerator overpressure caused by flow fluctuations. Attached Figure Description

[0021] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the present invention and do not specifically limit the shapes and proportions of the components of the present invention.

[0022] Figure 1 This is a schematic diagram of the low-pressure flash steam stabilization control system of this utility model.

[0023] The components are: 1. Low-pressure flash tank; 2. Deaerator; 3. Low-pressure flash condenser; 4. Flare; 5. First pressure control valve; 6. First pressure transmitter; 7. Second pressure control valve; 8. First flow control valve; 9. First flow transmitter. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] In the description of the embodiments of this utility model, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, they are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the utility model. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0028] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings:

[0031] like Figure 1 As shown, this utility model proposes a low-pressure flash steam pressure stabilization control system, including a low-pressure flash tank 1, a deaerator 2, a low-pressure flash condenser 3, and a flare 4. The outlet of the low-pressure flash tank 1 is connected to the inlet of the low-pressure flash condenser 3 via a first pipe, on which a first pressure control valve 5 is installed. The outlet of the low-pressure flash tank 1 is connected to the inlet of the flare 4 via a second pipe, on which a second pressure control valve 7 is installed. The outlet of the low-pressure flash tank 1 is connected to the inlet of the deaerator 2 via a third pipe, on which a first flow control valve 8 and a first flow transmitter 9 are installed. The first flow transmitter 9 is located near the deaerator 2. A first pressure transmitter 6 is installed at the outlet of the low-pressure flash tank 1, mounted on the outlet pipe of the low-pressure flash tank 1. The first pressure transmitter 6 can accurately detect pressure changes within the low-pressure flash tank 1 in real time, providing direct feedback signals for the automatic adjustment of the pressure control valves, forming the core monitoring node for closed-loop pressure control.

[0032] This invention adds a first pipe and a second pipe before the low-pressure flash steam enters the deaerator 2, connecting the low-pressure flash condenser 3 and the flare 4 respectively, and changes the control to pressure. At the same time, the low-pressure flash steam entering the deaerator 2 is changed to flow control. The amount of low-pressure flash gas entering the deaerator 2 can be adjusted by the temperature of the ash water in the deaerator 2. Excess gas can be released through the downstream system of the low-pressure flash condenser 3 or the second pipe to the flare 4. This also avoids the use of low-pressure steam in the deaerator 2, thus achieving energy saving and consumption reduction.

[0033] The signal output terminal of the first pressure transmitter 6 is connected to the control signal input terminal of the second pressure control valve 7 via a signal line; the signal output terminal of the first pressure transmitter 6 is connected to the control signal input terminal of the first pressure control valve 5 via a signal line; in terms of pressure control, by real-time monitoring of the low flash pressure and automatic adjustment of the opening of the pressure control valve, excess steam is diverted to the low-pressure flash condenser 3 and the flare 4, ensuring that the low flash pressure is stable within the set range, and completely eliminating the impact of pressure fluctuations on production.

[0034] The signal output of the first flow transmitter 9 is connected to the control signal input of the first flow control valve 8 via a signal line. For flow control, a separate first flow control valve 8 is installed on the pipeline entering the deaerator 2. By setting a flow threshold or cascading control with the temperature of the deaerator 2, the intake air volume is automatically adjusted to ensure that the gas flow rate never exceeds the deaerator 2's tolerance limit, thus eliminating the risk of overpressure at its source. This fully automatic closed-loop control of pressure and flow minimizes manual intervention and improves production efficiency.

[0035] As a preferred option, the first flow transmitter 9 is installed on the third pipeline and is located between the tee joint and the first flow control valve 8.

[0036] The outlet end of the low-pressure flash tank 1 is connected to a tee connector, and the three outlet ends of the tee connector are respectively connected to the first pipe, the second pipe and the third pipe.

[0037] A temperature transmitter is installed on the shell of the deaerator 2. The temperature transmitter can monitor the internal temperature of the deaerator 2 in real time and provide a key feedback signal to the first flow control valve 8 to achieve dynamic matching between the flash steam supply and the heat demand of the deaerator 2, so as to avoid energy waste and equipment damage caused by overheating or insufficient heat.

[0038] A level transmitter is installed on the shell of the low-pressure flash tank 1, which can monitor the changes in the liquid level inside the low-pressure flash tank 1 in real time, providing key parameters for process control, avoiding gas carryover caused by excessively high liquid level or pump cavitation caused by excessively low liquid level, and ensuring the stability of the flash process and the safe operation of the equipment.

[0039] Many embodiments and applications beyond the examples provided will be apparent to those skilled in the art upon reading the foregoing description. Therefore, the scope of this teaching should not be determined by reference to the foregoing description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed utility model subject matter.

[0040] The above content provides a further detailed description of this utility model. It should not be considered that the specific embodiments of this utility model are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of this utility model, and all such deductions or substitutions should be considered to fall within the scope of protection of this utility model as defined by the submitted claims.

Claims

1. A low-pressure flash steam stabilization control system, characterized in that, It includes a low-pressure flash tank (1), a deaerator (2), a low-pressure flash condenser (3), and a flare (4); The outlet of the low-pressure flash tank (1) is connected to the inlet of the low-pressure flash condenser (3) via a first pipe, and a first pressure control valve (5) is provided on the first pipe; the outlet of the low-pressure flash tank (1) is connected to the inlet of the flare (4) via a second pipe, and a second pressure control valve (7) is provided on the second pipe; the outlet of the low-pressure flash tank (1) is connected to the inlet of the deaerator (2) via a third pipe, and a first flow control valve (8) and a first flow transmitter (9) are provided on the third pipe, with the first flow transmitter (9) located near the deaerator (2).

2. The low-pressure flash steam stabilization control system according to claim 1, characterized in that, A first pressure transmitter (6) is installed at the outlet of the low-pressure flash tank (1).

3. A low-pressure flash steam stabilization control system according to claim 2, characterized in that, The first pressure transmitter (6) is installed on the outlet pipe of the low-pressure flash tank (1).

4. A low-pressure flash steam stabilization control system according to claim 2, characterized in that, The signal output terminal of the first pressure transmitter (6) is connected to the control signal input terminal of the second pressure control valve (7) via a signal line.

5. A low-pressure flash steam stabilization control system according to claim 2, characterized in that, The signal output terminal of the first pressure transmitter (6) is connected to the control signal input terminal of the first pressure control valve (5) via a signal line.

6. A low-pressure flash steam stabilization control system according to claim 1, characterized in that, The outlet end of the low-pressure flash tank (1) is connected to a three-way connector, and the three outlet ends of the three-way connector are respectively connected to the first pipe, the second pipe and the third pipe.

7. A low-pressure flash steam stabilization control system according to claim 6, characterized in that, The first flow transmitter (9) is installed on the third pipeline and is located between the tee and the first flow control valve (8).

8. A low-pressure flash steam stabilization control system according to claim 7, characterized in that, The signal output terminal of the first flow transmitter (9) is connected to the control signal input terminal of the first flow control valve (8) via a signal line.

9. A low-pressure flash steam stabilization control system according to claim 1, characterized in that, A temperature transmitter is installed on the housing of the deaerator (2).

10. A low-pressure flash steam stabilization control system according to claim 1, characterized in that, A level transmitter is installed on the shell of the low-pressure flash tank (1).

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