Mixed refrigerant supplementing valve group for LNG (Liquefied Natural Gas) device

Abstract

The utility model relates to the technical field of LNG (Liquefied Natural Gas) equipment, in particular to a mixed refrigerant supplementing valve group for an LNG device. The mixed refrigerant supplementing valve group for the LNG device comprises a valve body, U-shaped auxiliary channels which are communicated with each other are fixedly installed on the valve body, a plugging disc is installed on the valve body, an electromagnetic valve is installed on the valve body, and a one-way valve is fixedly installed at a refrigerant discharging opening. The valve body between the plugging disc and the electromagnetic valve forms an agent storage chamber structure, and a pressurizing component is arranged in the agent storage chamber. According to the mixed refrigerant supplementing valve set for the LNG device, automatic supplementing of mixed refrigerants is achieved through a linkage structure of the pressurizing component and the contact piece type switch, when the mixed refrigerants in the refrigerant storage chamber are accumulated to the preset amount, the valve element pushes the valve rod to drive the pressing rod to trigger the contact piece type switch, then the electromagnetic valve is automatically opened, supplementing is completed, and the working efficiency is improved. Compared with an existing natural flow supplementing mode, the structure has the advantages that the refrigerant flow speed is greatly increased, and the supplementing efficiency is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of LNG equipment technology, and in particular to a mixed refrigerant replenishment valve assembly for LNG plants. Background Technology

[0002] In LNG (liquefied natural gas) production, storage and transportation systems, the mixed refrigerant is the core refrigeration medium. Its loss, leakage or composition deviation during the circulation process will directly lead to a decrease in refrigeration efficiency, a surge in energy consumption, and even a shutdown of the unit, which will seriously affect the stable operation and economy of the entire LNG unit. Therefore, timely and accurate replenishment of the mixed refrigerant is a key link to ensure the continuous and efficient operation of the LNG unit.

[0003] The current mainstream method for replenishing mixed refrigerant in the industry mostly adopts a simple structure of "direct pipeline connection + manual valve control". When the valve is opened, mixed refrigerant is poured in for replenishment. However, due to the lack of an effective pressurization and stable control structure after the valve is activated, some of the replenished mixed refrigerant may be intermittent due to insufficient gas pressure, or even experience interruption or backflow. This results in slow refrigerant replenishment flow rate and low efficiency. At the same time, the compressor intake pressure is prone to fluctuation, which can lead to abnormal compressor operation and shorten the service life of the equipment.

[0004] Therefore, it is necessary to provide a new mixed refrigerant replenishment valve assembly for LNG plants to solve the above-mentioned technical problems. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a mixed refrigerant replenishment valve assembly for LNG plants.

[0006] The mixed refrigerant replenishment valve assembly for LNG units provided by this utility model includes a valve body, on which a U-shaped auxiliary channel is fixedly installed and interconnected, and the two ports at the connection between the U-shaped auxiliary channel and the valve body are respectively the inlet port and the outlet port.

[0007] A sealing disc for sealing the valve body is fixedly installed near the inlet of the valve body, and a solenoid valve is fixedly installed on the pipe body near the outlet of the valve body, and a one-way valve is fixedly installed at the outlet of the valve body.

[0008] The valve body between the sealing disc and the solenoid valve forms a storage chamber structure, and a pressurizing component is provided in the storage chamber. The mixed refrigerant flowing into the storage chamber is pressurized by the pressurizing component. A contact switch electrically connected to the solenoid valve is installed on the disc surface opposite to the inlet of the sealing disc, and a pressing rod for opening and closing the contact switch is installed on the pressurizing component.

[0009] Preferably, the pressurizing component includes a valve core, which is slidably installed in the storage chamber, and a valve stem is fixedly installed at the end of the valve core opposite to the discharge port. The valve stem passes through a limiting ring fixedly installed in the valve body and is slidably connected to the limiting ring. A rod cap is fixedly installed at the through end of the valve stem, and a spring is sleeved on the valve stem. The pressing rod is fixedly installed at one end of the valve stem on the back of the rod cap.

[0010] Preferably, one end of the spring is fixedly connected to the end of the valve core opposite to the discharge port, and the other end of the spring is fixedly connected to the end of the limiting ring opposite to the inlet port.

[0011] Preferably, an abutment ring is fixedly installed in the main channel of the valve body, and the abutment ring and the solenoid valve are distributed on both sides of the discharge port.

[0012] Preferably, a pneumatic valve is installed on the main channel of the valve body, and the pneumatic valve is located at the end of the storage chamber and close to the sealing plate.

[0013] Preferably, threaded quick couplings are fixedly installed at both ends of the valve body.

[0014] Compared with related technologies, the mixed refrigerant replenishment valve assembly for LNG plants provided by this utility model has the following advantages:

[0015] This invention achieves automatic replenishment of mixed refrigerant through a linkage structure between a pressurizing component and a contact-type switch. When the mixed refrigerant in the storage chamber accumulates to a preset amount, the valve core pushes the valve rod, which in turn drives the pressure rod to trigger the contact-type switch, thereby automatically opening the solenoid valve to complete the replenishment. The entire process requires no manual operation. This structure significantly improves the flow rate and replenishment efficiency of the mixed refrigerant, while ensuring stable compressor intake pressure, avoiding compressor malfunctions caused by intake pressure fluctuations, and extending the service life of the equipment. Attached Figure Description

[0016] Figure 1 A schematic diagram of a preferred embodiment of the mixed refrigerant replenishment valve assembly for an LNG unit provided by this utility model;

[0017] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the structure.

[0018] The following are the labels in the diagram: 1. Valve body; 11. Limiting ring; 12. Abutment ring; 13. Threaded quick connector; 2. U-shaped auxiliary channel; 2a. Inlet; 2b. Outlet; 21. Check valve; 3. Sealing disc; 4. Solenoid valve; 5. Pressurizing component; 51. Valve core; 52. Valve stem; 53. Stem cap; 54. Spring; 6. Pressing rod; 7. Contact switch; 8. Air pressure valve. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model 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 of the present utility model and are not intended to limit the present utility model.

[0020] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0021] Please see Figures 1 to 2 This utility model provides a mixed refrigerant replenishment valve assembly for an LNG plant, which includes a valve body 1, a U-shaped auxiliary channel 2, and a pressurizing component 5.

[0022] In the embodiments of this utility model, please refer to Figure 1 and Figure 2 Both ends of the valve body 1 are fixedly installed with threaded quick connectors 13. The valve body 1 is fixedly installed with interconnected U-shaped auxiliary channels 2. The two pipe ports at the connection between the U-shaped auxiliary channels 2 and the valve body 1 are the inlet port 2a and the outlet port 2b, respectively. A sealing disc 3 for sealing the valve body 1 is fixedly installed near the inlet port 2a. A solenoid valve 4 is fixedly installed on the pipe of the valve body 1 near the outlet port 2b. A one-way valve 21 is fixedly installed at the outlet port 2b.

[0023] It should be noted that: when the threaded quick connector 13 at the end of valve body 1 near the inlet 2a is connected to the refrigerant mixing valve body, and the threaded quick connector 13 at the end of valve body 1 near the outlet 2b is connected to the inlet of the refrigerant mixing compressor, the movement path of the refrigerant is as follows (see attached diagram). Figure 2 (For example, to illustrate):

[0024] Refrigerant valve body connection → Left side threaded quick connector 13 → Valve body 1 → Inlet 2a → U-shaped auxiliary channel 2 → Discharge port 2b (one-way valve 21) → Refrigerant storage chamber in valve body 1 (after pressurization) → Solenoid valve 4 → Right side threaded quick connector 13 → Mixed refrigerant compressor inlet.

[0025] Since a one-way valve 21 is fixedly installed at the discharge port 2b, the one-way valve 21 only allows refrigerant to flow from the U-shaped auxiliary channel 2 to the storage chamber inside the valve body 1, preventing backflow of mixed refrigerant, ensuring the stability and safety of the mixed refrigerant replenishment process, and avoiding damage to the mixed refrigerant replenishment system and related equipment caused by backflow.

[0026] In the embodiments of this utility model, please refer to Figure 1 and Figure 2The valve body 1 between the sealing disc 3 and the solenoid valve 4 forms a storage chamber structure, and a pressurizing component 5 is provided in the storage chamber. The mixed refrigerant flowing into the storage chamber is pressurized by the pressurizing component 5. A contact switch 7 electrically connected to the solenoid valve 4 is installed on the disc surface of the sealing disc 3 away from the inlet 2a, and a pressing rod 6 for opening and closing the contact switch 7 is installed on the pressurizing component 5.

[0027] The pressurizing component 5 includes a valve core 51, which is slidably installed in the storage chamber. A valve stem 52 is fixedly installed at the end of the valve core 51 away from the discharge port 2b. The valve stem 52 passes through a limiting ring 11 fixedly installed inside the valve body 1 and is slidably connected to the limiting ring 11. A rod cap 53 is fixedly installed at the end of the valve stem 52 that passes through it. A spring 54 is sleeved on the valve stem 52. One end of the spring 54 is fixedly connected to the end of the valve core 51 away from the discharge port 2b, and the other end of the spring 54 is fixedly connected to the end of the limiting ring 11 away from the inlet port 2a. A pressing rod 6 is fixedly installed on the back of the rod cap 53 at one end of the valve stem 52. An abutment ring 12 is fixedly installed inside the valve body 1, and the abutment ring 12 and the solenoid valve 4 are distributed on both sides of the discharge port 2b.

[0028] It should be noted that when the mixed refrigerant enters the storage chamber through the one-way valve 21, the solenoid valve 4 is closed, and the one-way valve 21 is in a one-way inlet-outlet state. Therefore, as the amount of mixed refrigerant in the storage chamber increases, the valve core 51 pushes the valve stem 52 to slide towards the sealing plate 3. At this time, the spring 54 is compressed. When the pressure rod 6 abuts against the closed contact switch 7, the solenoid valve 4 is activated by the contact switch 7 to form a passage. Therefore, under the action of the spring 54, the valve core 51 quickly injects all the mixed refrigerant in the storage chamber into the air inlet of the mixed refrigerant compressor. Thus, the mixed refrigerant pressurized by the pressurizing component 5 is replenished to the mixed refrigerant compressor. Compared with the existing natural flow replenishment method, the pressurizing component 5 greatly improves the mixed refrigerant flow rate and replenishment efficiency, which can quickly meet the replenishment needs of the LNG unit for mixed refrigerant. The injection of refrigerant at a stable high pressure into the compressor air inlet ensures the stability of the compressor air inlet pressure and guarantees the stable and continuous operation of the LNG unit.

[0029] In addition, when the pressure rod 6 disengages from the contact switch 7 and the solenoid valve 4 is closed, the one-way valve 21 blocks the backflow of the mixed refrigerant in the storage chamber. At this time, the U-shaped auxiliary channel 2 continuously replenishes the mixed refrigerant in the storage chamber. With the flow limiting of the abutment ring 12 and the pressure balance of the pressure valve 8, the mixed refrigerant is always retained in the storage chamber. When the mixed refrigerant in the storage chamber accumulates to the preset amount, that is, when the pressure rod 6 triggers the contact switch 7 again and the solenoid valve 4 is opened, the refrigerant in the storage chamber can flow into the compressor quickly and stably under the pressure of the valve core 51, completing the mixed refrigerant replenishment. In order to increase the amount of mixed refrigerant replenished at one time, the solenoid valve 4 can be a hydraulic buffer type solenoid valve (that is, a precision oil circuit and small hole are designed in the moving chamber of the valve core, and the damping effect of hydraulic oil is used to achieve smooth and slow closing, which is existing technology and will not be described in detail here).

[0030] In this application, the automatic replenishment of the mixed refrigerant is achieved through the linkage structure of the pressurizing component 5 and the contact switch 7. When the refrigerant in the storage chamber accumulates to the preset amount, the valve core 51 pushes the valve rod 52 to drive the pressure rod 6 to trigger the contact switch 7, thereby automatically opening the solenoid valve 4 to complete the replenishment. The entire process requires no manual operation, effectively avoiding delays or deviations caused by human operation, reducing labor intensity, and ensuring the timeliness and accuracy of replenishment. The spring 54 in the pressurizing component 5 stores elastic potential energy during the sliding process of the valve core 51. When the solenoid valve 4 is opened, the spring 54 releases its potential energy to push the valve core 51 to quickly squeeze the mixed refrigerant in the storage chamber, so that the mixed refrigerant is injected into the compressor inlet in a stable high-pressure state. This structure greatly improves the flow rate and replenishment efficiency of the mixed refrigerant, while ensuring the stability of the compressor inlet pressure, avoiding abnormal compressor operation caused by inlet pressure fluctuations, and extending the service life of the equipment.

[0031] Furthermore, a pneumatic valve 8 is installed on the main channel of the valve body 1, and the pneumatic valve 8 is located at the end of the storage chamber and close to the sealing plate 3. Thus, when the valve core 51 slides, the pneumatic valve 8 can balance the air pressure in the storage chamber on the left side of the valve core 51. At the same time, a dustproof net can be installed on the pneumatic valve 8 to reduce the cleanliness of the gas entering the storage chamber on the left side of the valve core 51.

[0032] It is worth noting that the internal contacts of this contact switch 7 are made of metal alloys (such as copper-nickel alloy) with good low-temperature toughness and stable conductivity, and the switch shell is made of low-temperature resistant engineering plastics (such as polytetrafluoroethylene) to avoid shell cracking or contact deformation caused by low temperature. At the same time, an insulation sleeve is added to the outside of the contact switch 7. The insulation sleeve is made of polyurethane foam material to reduce the impact of low temperature environment on the inside of the switch.

[0033] In addition, spring 54 is made of high-temperature alloy spring or composite fiber reinforced spring. These materials have stronger fatigue resistance and can significantly extend the service life of spring 54.

[0034] The circuits and controls involved in this utility model are all existing technologies, and will not be described in detail here.

[0035] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A mixed refrigerant make-up valve set for LNG plant, comprising a valve body (1) in which a main channel is formed, a U-shaped auxiliary channel (2) is formed on the valve body (1) and communicates with the main channel, and two pipe openings of the U-shaped auxiliary channel (2) communicating with the main channel are an agent inlet (2a) and an agent outlet (2b), characterized in that: a blocking disc (3) for blocking the valve body (1) is fixedly installed in the main channel on the right side of the agent inlet (2a), an electromagnetic valve (4) is fixedly installed in the main channel on the right side of the agent outlet (2b), and a one-way valve (21) is fixedly installed in the U-shaped auxiliary channel (2) at the agent outlet (2b); the main channel between the blocking disc (3) and the electromagnetic valve (4) constitutes a refrigerant storage chamber structure, a pressurizing component (5) is arranged in the refrigerant storage chamber, the mixed refrigerant flowing into the refrigerant storage chamber is pressurized by the pressurizing component (5), a touch switch (7) electrically connected with the electromagnetic valve (4) is installed on the disc surface of the blocking disc (3) away from the agent inlet (2a), and a pressing rod (6) for opening and closing the touch switch (7) is installed on the pressurizing component (5).

2. The mixed refrigerant makeup valve package for LNG plants as set forth in claim 1, wherein, The pressurizing component (5) comprises a valve core (51) which is slidingly installed in the refrigerant storage chamber, one end of the valve core (51) away from the agent outlet (2b) is fixedly installed with a valve rod (52), the valve rod (52) passes through a limiting ring (11) fixedly installed in the valve body (1) and is slidingly connected with the limiting ring (11), a rod cap (53) is fixedly installed on the passing end of the valve rod (52), a spring (54) is sleeved on the valve rod (52), and the pressing rod (6) is fixedly installed on one end of the valve rod (52) away from the rod cap (53).

3. The LNG plant mixed refrigerant makeup valve train of claim 2 wherein, One end of the spring (54) is fixedly connected with one end of the valve core (51) away from the agent outlet (2b), and the other end of the spring (54) is fixedly connected with one end of the limiting ring (11) away from the agent inlet (2a).

4. The LNG plant mixed refrigerant makeup valve train of claim 3 wherein, A butt ring (12) is fixedly installed in the main channel of the valve body (1), and the butt ring (12) is distributed on both sides of the agent outlet (2b) with the electromagnetic valve (4).

5. The LNG plant mixed refrigerant makeup valve train of claim 1 wherein, An air pressure valve (8) is installed on the main channel of the valve body (1), and the air pressure valve (8) is located at the end of the refrigerant storage chamber and close to the blocking disc (3).

6. The LNG plant mixed refrigerant makeup valve train of claim 1 wherein, Threaded quick couplings (13) are fixedly installed at both ends of the valve body (1).

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