A nitrogen compressor nitrogen supplementing device easy to adjust

Abstract

The application discloses an easily-adjusted nitrogen compressor nitrogen supplement device, relates to the technical field of nitrogen compressors, and adopts a nitrogen supplement pipeline structure in which a main path and a bypass path are connected in parallel, and combines a three-stage closed-loop cooperative control architecture to realize intelligent and accurate regulation of a nitrogen supplement process of the nitrogen compressor, to rapidly charge pressure through the large-diameter main path in a starting stage, to enter a smooth switching stage when pressure approaches a set value, to gradually close the main path valve while gradually opening the bypass path regulating valve to avoid pressure impact, to continuously and slightly regulate pressure through the bypass path pressure regulating valve in a normal operation stage to control first-stage inlet pressure fluctuation in a very small range, and to automatically open the main path to perform emergency auxiliary nitrogen supplement under abnormal working conditions. Meanwhile, an automatic pressure relief unit is arranged on an outlet pipeline to realize automatic overpressure protection, and the problems of poor regulation accuracy and large pressure fluctuation of a traditional large-diameter manual valve are solved, and the operation stability and reliability of the nitrogen compressor are remarkably improved, and equipment shutdown and product quality fluctuation caused by abnormal pressure are avoided.

Description

Technical Field

[0001] This invention relates to the field of nitrogen compressor technology, and more specifically to an easily adjustable nitrogen compressor nitrogen replenishment device. Background Technology

[0002] Nitrogen compressors are pressurization devices specifically designed for nitrogen media. They follow the ideal gas law PV=nRT and use mechanical structures to do work on nitrogen, reducing the sealed volume of the gas and converting mechanical energy into nitrogen pressure energy, thereby increasing nitrogen pressure.

[0003] The nitrogen compressor's primary inlet nitrogen replenishment valve is mostly a DN200 manual valve. After the nitrogen compressor starts running, nitrogen needs to be continuously replenished. However, due to the large pipe diameter, it is difficult to control the flow rate by opening and closing the valve on site, resulting in large pressure fluctuations and unstable flow rate. This affects the cold energy transportation of the cryogenic unit, leading to poor product quality. Furthermore, the nitrogen compressor's vent valve is an HV101, which cannot achieve automatic overpressure relief, easily leading to system overpressure. Once the entire machine detects abnormal gas pressure fluctuations, it directly triggers abnormal equipment shutdowns, which affect actual production.

[0004] However, it should be added that if an electronically controlled valve is used for gas pressure control, the operating conditions of the compressor must also be considered. When the gas pressure environment of the entire unit fluctuates, it may cause irreversible damage to the compressor. In view of the above, this invention proposes a solution. Summary of the Invention

[0005] The purpose of this invention is to provide an easily adjustable nitrogen compressor nitrogen replenishment device to solve the above-mentioned technical problems.

[0006] The objective of this invention can be achieved through the following technical solution: an easily adjustable nitrogen compressor nitrogen replenishment device, comprising a nitrogen compressor and a nitrogen replenishment pipeline, wherein the nitrogen replenishment pipeline is divided into a main pipeline and a bypass pipeline, characterized in that...

[0007] The main nitrogen supply line is equipped with a first shut-off valve.

[0008] The bypass nitrogen supply line is connected in parallel with the main nitrogen supply line, and a second shut-off valve, a pressure regulating valve and a third shut-off valve are installed on it in sequence.

[0009] The first pressure detection element is installed at the first-stage inlet of the nitrogen compressor to detect the gas pressure at the first-stage inlet.

[0010] The outlet pipeline is connected to the outlet of the nitrogen compressor and is equipped with an automatic pressure relief valve.

[0011] The second pressure sensing element is installed on the outlet pipe and is used to detect the gas pressure at the compressor outlet.

[0012] The controller is electrically connected to the first pressure sensing element, the second pressure sensing element, the pressure regulating valve, and the automatic pressure relief valve, respectively, and is used to receive pressure detection signals and control the opening degree of the pressure regulating valve and the automatic pressure relief valve.

[0013] The nitrogen supplementation process includes the following steps:

[0014] The main nitrogen supply pipeline is located at the first-stage inlet of the nitrogen compressor;

[0015] A pressure regulating unit is installed on the bypass nitrogen supply line. The pressure regulating unit detects the gas pressure at the first-stage inlet of the nitrogen compressor in real time and automatically adjusts the nitrogen flow rate of the bypass nitrogen supply line according to the detected pressure value, so that the first-stage inlet pressure is maintained within a preset range.

[0016] An automatic pressure relief unit is installed on the outlet pipeline of the nitrogen compressor to monitor the gas pressure at the compressor outlet in real time. When the outlet pressure exceeds the preset threshold, the pressure relief channel is automatically opened to release excess gas. When the outlet pressure returns to the preset range, the pressure relief channel is automatically closed.

[0017] Further configured, the automatic adjustment process of the pressure regulating unit includes the following:

[0018] Real-time acquisition of the pressure signal P1 at the primary inlet of the nitrogen compressor;

[0019] The collected pressure signal P1 is compared with the preset pressure setting value P0, and the pressure deviation ΔP = P1 - P0 is calculated.

[0020] Then, the opening adjustment amount of the regulating valve is calculated based on the magnitude and direction of the pressure deviation ΔP;

[0021] Then, adjust the opening of the regulating valve according to the calculated opening adjustment amount, thereby changing the nitrogen flow rate of the bypass nitrogen supply line, so that the first-stage inlet pressure approaches the set value P0.

[0022] Further settings include: when the pressure deviation ΔP is positive and greater than the first preset deviation value, reducing the opening of the regulating valve and reducing the nitrogen flow rate of the bypass nitrogen supply line;

[0023] When the pressure deviation ΔP is negative and less than the second preset deviation value, increase the opening of the regulating valve and increase the nitrogen flow rate of the bypass nitrogen supply line.

[0024] When the pressure deviation ΔP is between the first preset deviation value and the second preset deviation value, the current opening of the regulating valve remains unchanged.

[0025] The automatic pressure relief unit is further configured to include the following automatic pressure relief process:

[0026] Real-time acquisition of the pressure signal P2 at the outlet of the nitrogen compressor;

[0027] The collected pressure signal P2 is compared with the preset safe pressure threshold P. max Compare;

[0028] When P2≥P max When necessary, the pressure relief valve will automatically open to release pressure.

[0029] When P2≤P min When the pressure relief valve automatically closes, P min The preset recovery pressure value, and P min <P max .

[0030] Further configuration: The following control process is set between the main nitrogen supply line and the bypass nitrogen supply line:

[0031] During the start-up phase of the nitrogen compressor, open the valve on the main nitrogen supply line to quickly replenish nitrogen into the system, so that the system pressure can quickly reach the operating pressure.

[0032] Once the system pressure reaches the operating pressure, close the valve on the main nitrogen supply line and switch to the bypass nitrogen supply line for precise pressure and flow regulation.

[0033] When the regulating capacity of the bypass nitrogen supply line is insufficient to maintain stable system pressure, the valve of the main nitrogen supply line is opened for auxiliary nitrogen supply.

[0034] Further configuration: It is recommended to use a pressure balance model in the nitrogen compressor system. Based on the pressure balance mathematical model, the system pressure change trend is predicted in real time. Based on the predicted pressure change trend, the working status of the pressure regulating unit and the automatic pressure relief unit is adjusted in advance to achieve advance control of the gas path pressure.

[0035] The present invention has the following beneficial effects:

[0036] 1. By coordinating the rapid pressurization of the main pipeline with the fine adjustment of the bypass, the problem of slow pressurization speed of small-diameter pipelines is solved, and the defect of poor adjustment accuracy of large-diameter valves is overcome. The fluctuation range of the first-stage inlet pressure of the nitrogen compressor is controlled within the process requirements, which effectively improves the compressor's suction efficiency and the stability of cold energy transportation of the cryogenic device, and ensures product quality.

[0037] 2. The primary inlet pressure closed loop, outlet pressure safety closed loop, and main bypass coordinated control closed loop operate independently yet share information. When any closed loop malfunctions, the other closed loops automatically intervene to compensate and control, thus avoiding pressure runaway caused by a single fault at the system level. At the same time, by setting a pressure dead zone, the frequent valve operation is reduced, extending the service life of the equipment and reducing maintenance costs. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic block diagram illustrating the operation of an easily adjustable nitrogen compressor nitrogen replenishment device proposed in this invention. Detailed Implementation

[0040] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1: The existing nitrogen compressor nitrogen replenishment system mainly consists of three parts: the main nitrogen replenishment pipeline, the nitrogen compressor body, and the vent pipeline. The main nitrogen replenishment pipeline is directly connected to the primary inlet of the nitrogen compressor, and a large-diameter manual shut-off valve is installed on the pipeline as the only nitrogen replenishment control element; the vent pipeline is connected to the outlet of the nitrogen compressor, and a manual regulating valve is installed on the pipeline as the only means of system depressurization.

[0042] Furthermore, in practical use, it is necessary to consider that excessively high system pressure fluctuations and system pressure imbalances can affect the operation of the entire production line. For example, this can cause the primary inlet pressure of the nitrogen compressor to remain unstable for a long period of time, with large pressure fluctuations, directly affecting the compressor's suction efficiency and operational stability. To address this, the following technical solutions are proposed:

[0043] Reference Figure 1 This embodiment provides an easily adjustable nitrogen compressor nitrogen replenishment device, specifically including a nitrogen compressor, a nitrogen replenishment pipeline system, a pressure detection system, an automatic pressure relief system, and a controller. The nitrogen replenishment pipeline system adopts a parallel design of a main pipeline and a bypass pipeline. The main nitrogen replenishment pipeline is equipped with a first shut-off valve for rapid pressurization during system startup. The bypass nitrogen replenishment pipeline is connected in parallel with the main nitrogen replenishment pipeline, and is sequentially equipped with a second shut-off valve, a pressure regulating valve, and a third shut-off valve, forming a pressure regulating unit for fine-tuning the flow rate during normal system operation.

[0044] The first pressure detection element is installed at the first-stage inlet of the nitrogen compressor to detect the gas pressure P1 at the first-stage inlet in real time; the outlet pipeline is connected to the outlet of the nitrogen compressor and is equipped with an automatic pressure relief valve to form an automatic pressure relief unit; the second pressure detection element is installed on the outlet pipeline to detect the gas pressure P2 at the compressor outlet in real time.

[0045] The controller is electrically connected to the first pressure sensing element, the second pressure sensing element, the pressure regulating valve, and the automatic pressure relief valve, respectively, and is used to receive pressure detection signals and automatically control the opening degree of the pressure regulating valve and the automatic pressure relief valve according to the preset control logic.

[0046] The basic working process of this device is as follows: During the nitrogen compressor startup phase, the first shut-off valve is opened, and nitrogen is rapidly supplied to the system through the main nitrogen supply line, so that the system pressure reaches the operating pressure in a short time; when the system pressure reaches the preset operating pressure, the first shut-off valve is closed, and the bypass nitrogen supply line is switched to perform fine pressure and flow regulation; the controller automatically adjusts the opening of the pressure regulating valve according to the first-stage inlet pressure signal (P1) collected by the first pressure detection element, so that the first-stage inlet pressure is stably maintained within the preset range; at the same time, the controller automatically opens the automatic pressure relief valve to release pressure when the outlet pressure exceeds the preset safety threshold according to the outlet pressure signal (P2) collected by the second pressure detection element, and automatically closes the automatic pressure relief valve when the outlet pressure returns to the safe range.

[0047] Example 2: This example is based on Example 1, and further extends and expands the pressure balance model therein:

[0048] Because the pressure environment inside the nitrogen compressor is a relatively sealed environment, a pressure balance mathematical model of the nitrogen compressor system is established based on the ideal gas law PV=nRT and the basic principles of fluid mechanics. This forms a three-level closed-loop collaborative control architecture consisting of a first-level inlet pressure closed loop, an outlet pressure safety closed loop, and a main bypass collaborative control closed loop. The three closed loops operate independently but also share information and coordinate with each other: the first-level inlet pressure closed loop is responsible for adjusting the nitrogen supply flow in real time to maintain a stable intake pressure.

[0049] The outlet pressure safety closed loop is responsible for real-time monitoring of system pressure and automatic overpressure protection;

[0050] The main bypass coordinated control closed loop is responsible for intelligently switching the nitrogen replenishment path according to the system operating conditions, taking into account both the pressurization speed and the adjustment accuracy.

[0051] In this architecture, when any one closed loop malfunctions, the other two closed loops will automatically intervene to compensate and control the system. For example, when the bypass regulating valve becomes stuck, causing the inlet pressure to drop, the main bypass coordination closed loop will automatically open the main shut-off valve to provide auxiliary nitrogen replenishment. At the same time, the outlet pressure safety closed loop will closely monitor changes in outlet pressure to prevent negative system pressure caused by insufficient nitrogen replenishment. This architecture avoids the problem of pressure runaway caused by a single fault at the system level, and improves system reliability compared to the traditional single-point control mode.

[0052] In response to the problems mentioned in Example 1, such as "poor adjustment accuracy with large diameter and slow pressurization speed with small diameter," the following technical solutions are proposed, specifically tailored to different operating conditions of the nitrogen compressor:

[0053] Rapid pressurization phase: When the system starts up and the primary inlet pressure P1 < 0.7 × P0 (P0 is the preset operating pressure), the controller fully opens the first shut-off valve and fully closes the pressure regulating valve. At this time, nitrogen gas rapidly enters the system through the large-diameter main nitrogen supply pipeline, allowing the system pressure to rise to near the operating pressure in the shortest possible time. This phase solves the problem of slow pressurization speed in small-diameter pipelines and shortens the compressor start-up preparation time.

[0054] Smooth switching phase: When the primary inlet pressure P1 ≥ 0.7 × P0, the system enters smooth switching mode. The controller gradually closes the first shut-off valve at a rate of 0.5~1.5% / s, while simultaneously opening the pressure regulating valve at a synchronous rate. During this process, the controller calculates the total nitrogen supplement flow rate in real time and maintains it relatively stable, avoiding pressure surges during the main / bypass switching process. This phase solves the problem of steep pressure rises and falls caused by traditional hard switching methods, achieving a smooth transition without oscillations.

[0055] Fine-tuning stage: After the first shut-off valve is fully closed, the system enters the fine-tuning mode for normal operation. At this time, only the bypass nitrogen supply line is responsible for nitrogen supply. The controller automatically adjusts the opening of the pressure regulating valve based on the real-time pressure signal collected by the first pressure detection element, achieving micro-volume, continuous, and high-precision nitrogen supply regulation. This stage utilizes the high-precision characteristics of the small-diameter regulating valve to control the fluctuation range of the first-stage inlet pressure within the process range.

[0056] Emergency auxiliary nitrogen replenishment stage: When the system experiences a significant nitrogen leak or a substantial increase in downstream load, causing the pressure regulating valve opening to reach over 90% for more than 30 seconds, and the primary inlet pressure P1 < 0.95 × P0, the controller automatically opens the first shut-off valve for auxiliary nitrogen replenishment. When the pressure regulating valve opening drops below 50% and the system pressure stabilizes, the controller automatically closes the first shut-off valve and switches back to the bypass independent regulation mode. This stage solves the problem of insufficient single bypass regulation capacity and ensures system pressure stability under abnormal operating conditions.

[0057] The controller calculates the first-stage inlet pressure deviation ΔP = P1 - P0 in real time and performs different adjustment methods based on the magnitude and direction of ΔP:

[0058] When |ΔP|≤ΔPde (ΔPde is the preset pressure dead zone value, usually taken as ±0.5% of P0), the controller maintains the current opening of the pressure regulating valve unchanged. This design avoids frequent valve operation caused by small pressure fluctuations in the system itself, reducing the number of valve operations by more than 70% and effectively extending the valve's service life.

[0059] When ΔP > ΔPde, it indicates that the system pressure is too high. The controller automatically calculates the closing range of the regulating valve based on the magnitude of ΔP. The larger ΔP is, the larger the closing range is, and the nitrogen supply flow is reduced quickly.

[0060] When ΔP < -ΔPde, it indicates that the system pressure is too low. The controller 6 automatically calculates the opening range of the regulating valve based on the absolute value of ΔP. The larger the deviation, the larger the opening range, thus quickly increasing the nitrogen supply flow.

[0061] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

[0062] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0063] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An easily adjustable nitrogen compressor nitrogen replenishment device, comprising a nitrogen compressor and a nitrogen replenishment pipeline, wherein the nitrogen replenishment pipeline is divided into a main pipeline and a bypass pipeline, characterized in that, The main nitrogen supply line is equipped with a first shut-off valve. The bypass nitrogen supply line is connected in parallel with the main nitrogen supply line, and a second shut-off valve, a pressure regulating valve and a third shut-off valve are installed on it in sequence. The first pressure detection element is installed at the first-stage inlet of the nitrogen compressor to detect the gas pressure at the first-stage inlet. The outlet pipeline is connected to the outlet of the nitrogen compressor and is equipped with an automatic pressure relief valve. The second pressure sensing element is installed on the outlet pipe and is used to detect the gas pressure at the compressor outlet. The controller is electrically connected to the first pressure sensing element, the second pressure sensing element, the pressure regulating valve, and the automatic pressure relief valve, respectively, and is used to receive pressure detection signals and control the opening degree of the pressure regulating valve and the automatic pressure relief valve. The nitrogen supplementation process includes the following steps: The main nitrogen supply pipeline is located at the first-stage inlet of the nitrogen compressor; A pressure regulating unit is installed on the bypass nitrogen supply line. The pressure regulating unit detects the gas pressure at the first-stage inlet of the nitrogen compressor in real time and automatically adjusts the nitrogen flow rate of the bypass nitrogen supply line according to the detected pressure value, so that the first-stage inlet pressure is maintained within a preset range. An automatic pressure relief unit is installed on the outlet pipeline of the nitrogen compressor to monitor the gas pressure at the compressor outlet in real time. When the outlet pressure exceeds the preset threshold, the pressure relief channel is automatically opened to release excess gas. When the outlet pressure returns to the preset range, the pressure relief channel is automatically closed.

2. The nitrogen replenishment device for an easily adjustable nitrogen compressor according to claim 1, characterized in that, The automatic adjustment process of the pressure regulating unit includes the following: Real-time acquisition of the pressure signal P1 at the primary inlet of the nitrogen compressor; The collected pressure signal P1 is compared with the preset pressure setting value P0, and the pressure deviation ΔP = P1 - P0 is calculated. Then, the opening adjustment amount of the regulating valve is calculated based on the magnitude and direction of the pressure deviation ΔP; Then, adjust the opening of the regulating valve according to the calculated opening adjustment amount, thereby changing the nitrogen flow rate of the bypass nitrogen supply line, so that the first-stage inlet pressure approaches the set value P0.

3. The easily adjustable nitrogen compressor nitrogen replenishment device according to claim 2, characterized in that, When the pressure deviation ΔP is positive and greater than the first preset deviation value, reduce the opening of the regulating valve and reduce the nitrogen flow rate of the bypass nitrogen supply line. When the pressure deviation ΔP is negative and less than the second preset deviation value, increase the opening of the regulating valve and increase the nitrogen flow rate of the bypass nitrogen supply line. When the pressure deviation ΔP is between the first preset deviation value and the second preset deviation value, the current opening of the regulating valve remains unchanged.

4. The easily adjustable nitrogen compressor nitrogen replenishment device according to claim 3, characterized in that, The automatic pressure relief process of the automatic pressure relief unit includes the following: Real-time acquisition of the pressure signal P2 at the outlet of the nitrogen compressor; The collected pressure signal P2 is compared with the preset safe pressure threshold P. max Compare; When P2≥P max When necessary, the pressure relief valve will automatically open to release pressure. When P2≤P min When the pressure relief valve automatically closes, P min The preset recovery pressure value, and P min <P max .

5. The easily adjustable nitrogen compressor nitrogen replenishment device according to claim 4, characterized in that, The following control process is set up between the main nitrogen supply line and the bypass nitrogen supply line: During the start-up phase of the nitrogen compressor, open the valve on the main nitrogen supply line to quickly replenish nitrogen into the system, so that the system pressure can quickly reach the operating pressure. Once the system pressure reaches the operating pressure, close the valve on the main nitrogen supply line and switch to the bypass nitrogen supply line for precise pressure and flow regulation. When the regulating capacity of the bypass nitrogen supply line is insufficient to maintain stable system pressure, the valve of the main nitrogen supply line is opened for auxiliary nitrogen supply.

6. The easily adjustable nitrogen compressor nitrogen replenishment device according to claim 5, characterized in that, It is recommended to develop a pressure balance model for the nitrogen compressor system. Based on the pressure balance mathematical model, the system pressure change trend can be predicted in real time. Based on the predicted pressure change trend, the working status of the pressure regulating unit and the automatic pressure relief unit can be adjusted in advance to achieve advance control of the gas circuit pressure.

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