Outlet pressure control and pipeline system of redrying steam heat accumulator

Abstract

The utility model discloses a redrying steam heat accumulator outlet pressure control and pipeline system. The system comprises a superheated steam pipeline, a heat accumulator, a safety valve, various valves, a blow-off pipeline, an emptying pipeline 7, a pressure regulating pipeline, a water supplementing pipeline, a liquid level meter assembly and the like. The superheated steam pipeline is provided with a stop valve and a check valve, superheated steam enables water in the heat accumulator to be heated and accumulate heat, and when steam used by a user is increased, the heat accumulator supplies steam through internal saturated water pressure drop. The water supplementing pipeline is provided with a water supplementing pump set, an electric valve set and the like. A blow-off pipeline at the bottom of the heat accumulator can discharge sewage to ensure water quality, a safety valve at the top guarantees safety, and an emptying pipeline 7 is used for overhauling. The liquid level meter assembly is composed of a ball valve, a differential pressure sensor and a glass tube liquid level meter. The pressure regulating valve group of the pressure regulating pipeline can realize automatic control according to the set pressure of the pressure control box, so that the outlet pressure of the heat accumulator is constant and is not influenced by the fluctuation of the tail end steam load.

Description

Technical Field

[0001] The utility model relates to the technical field of steam heating systems, and particularly relates to a pressure control at the outlet of a re-roasting steam accumulator and its pipeline system. Background Technique

[0002] An accumulator is a device that stores excess heat in the steam supply system of an industrial boiler and releases the stored heat when needed; in the steam supply system of an industrial boiler, if the steam consumption fluctuates greatly, it will not only cause fluctuations in the steam pressure and water level of the boiler, making the operation of the boiler difficult, but also lead to a decrease in the combustion efficiency of the boiler.

[0003] In the re-roasting process, in order to increase the pressure difference between the charging pressure and the discharging pressure of the accumulator by setting steam injection without changing the operating pressure of the boiler, the process steam pressure and the volume of the accumulator, the capacity of saturated water per unit volume to store steam becomes larger, and the total volume of the accumulator is reduced. When the pressure difference between the inlet and outlet of the accumulator is ≤ 0.3 MPa, a steam accumulator can also be added through this technology in cases where it is necessary to balance the steam load by peak shaving and valley filling. Multiple steam accumulators can be connected in parallel and share a set of steam injection systems.

[0004] To solve the above technical problems, Chinese Patent CN104048286A discloses a steam accumulator system. Without changing the operating pressure of the boiler, the process steam pressure and the volume of the accumulator, this system controls the high-pressure inlet steam parameters and the low-pressure inlet steam parameters of the steam injection steam to increase the pressure difference between the charging pressure and the discharging pressure of the accumulator, ensuring that when the pressure of the accumulator drops to a level where the production steam pressure cannot supply heat to the system, the high-pressure steam of the boiler is used to inject the steam inside the accumulator to achieve the purpose of releasing more steam. It controls the inlet pressure and the output pressure of the accumulator through an electric control valve and an injector, and maintains a relatively large pressure difference between the inlet and outlet to achieve a better heat storage effect. However, for this type of heat storage system to keep the outlet pressure at the control end constant, new motive steam needs to be added at any time as the motive force to inject the pressure inside the accumulator. When the steam consumption of the end equipment is small, it is difficult to control the outlet pressure stably. Therefore, this system maintains a constant outlet pressure difference.

[0005] In our factory's re-roasting plant, steam is required for leaf rewetting, leaf conditioning, baking, and flavoring of tobacco leaves, and the required steam is saturated steam. Since the boiler room is far from the workshop, to reduce the generation of condensed water during the long-distance transportation of steam, the boiler provides superheated steam and converts it into saturated steam through a steam accumulator.

[0006] Under normal conditions, the accumulator stores a large amount of water. When the steam consumption load is small, the remaining steam condenses into saturated water and stores the surplus heat inside the accumulator. When the steam consumption load is large, the pressure of the accumulator decreases, and the saturated water vaporizes to form steam to supply steam to the steam-using equipment. The accumulator assists in regulating the changing steam load, which can ensure the stability and economy of the steam heating system and equipment during peak hours. However, the steam pressure required by the re-drying process needs to be constantly supplied to ensure the stability of the heat during the processing. Therefore, it is necessary to ensure that the steam pressure at the outlet of the accumulator is constant. Summary of the Invention

[0007] In response to the requirement of constant steam pressure in the re-drying process, the present utility model proposes a pressure control for the outlet of a re-drying steam accumulator and its pipeline system. This system can maintain the constant steam pressure at the outlet of the accumulator to meet the requirements of the re-drying process. The specific technical solutions are as follows:

[0008] A pressure control for the outlet of a re-drying steam accumulator and its pipeline system, characterized in that the system includes a superheated steam pipeline, an accumulator, and a pressure regulating pipeline;

[0009] The accumulator is a horizontal oval head storage tank, with a steam inlet, a steam outlet, and a water replenishment port provided at the top, and a blowdown port provided at the bottom;

[0010] The steam inlet is connected to the superheated steam pipeline. One end of the superheated steam pipeline is connected to the steam inlet of the accumulator, and the other end is connected to the superheated steam, for connecting the superheated steam and the accumulator, and transporting the superheated steam provided by the boiler house to the accumulator through the superheated steam pipeline. A stop valve and a check valve are provided on the superheated steam pipeline;

[0011] The steam outlet is connected to the pressure regulating pipeline. A pressure regulating valve group composed of a stop valve, a filter, and a pneumatic pressure regulating valve, and a pressure control box are provided on the pressure regulating pipeline.

[0012] Further, a safety valve for automatic exhaust and pressure relief during overpressure is provided at the top of the accumulator, and at least two safety valves are included.

[0013] Further, a vent pipeline 7 for maintenance pressure relief is provided at the top of the accumulator, and a stop valve is provided on the vent pipeline 7.

[0014] Further, the pressure regulating valve group is composed of 3 stop valves, 1 filter, 1 pneumatic pressure regulating valve, and 1 pressure control box.

[0015] Further, a pressure gauge for displaying the pressure before and after pressure regulation on-site is installed at each of the front and rear of the pressure regulating valve group.

[0016] Further, a pressure sensor is also provided on the pressure regulating pipeline, and the pressure sensor is installed at the rear end of the pressure regulating valve group.

[0017] Further, the water replenishing port is connected to a water replenishing pipeline for continuously replenishing new water to the heat accumulator.

[0018] Further, a water replenishing pump set and an electric valve set are arranged on the water replenishing pipeline.

[0019] Further, a stop valve and a filter are arranged at the water inlet end of the water replenishing pipeline. A filter screen for preventing impurities such as iron filings from entering the water replenishing pump and damaging the impeller is arranged inside the filter.

[0020] Further, a bypass branch for water replenishment is arranged on the water replenishing pipeline when the electric valve set fails.

[0021] The working principle of the present utility model: A pressure control for the outlet of a re-roasting steam accumulator and its pipeline system. The system includes a superheated steam pipeline (2), an accumulator (1), a safety valve (6), a blowdown pipeline (5), a vent pipeline 7, a pressure regulating pipeline (3), a water replenishing pipeline (4) and a liquid level gauge assembly (8). During actual production, when using this device for tobacco leaf re-roasting, superheated steam is transmitted to the accumulator (1) through the superheated steam pipeline (2). A stop valve for connection and a check valve for ensuring the one-way flow of steam and avoiding backflow are arranged on the superheated steam pipeline (2); the superheated steam entering the accumulator (1) heats the water inside to the saturation temperature corresponding to the pressure, so that the accumulator (1) stores heat.

[0022] Steam supply and pressure regulation:

[0023] When the steam consumption of the end steam-using equipment increases, the internal pressure of the accumulator (1) decreases. When the steam consumption of the end steam-using equipment decreases, the internal pressure of the accumulator (1) increases. Due to the pressure difference, the internal saturated water supplies steam outward through the pressure drop.

[0024] In the pressure regulating pipeline (3) at the top of the accumulator (1), the pressure control box (32) sets the required pressure at the end. The pneumatic pressure regulating valve adjusts according to the signal of the pressure control box (32). The pressure sensor feeds back the actual pressure after pressure regulation to the pressure control box (32), and the pressure control box (32) then feeds back the signal to the actuator of the pneumatic pressure regulating valve. The diaphragm inside the actuator drives the valve seat to adjust according to the signal, so that the pressure after the pressure regulating valve group (31) is consistent with the set pressure, thereby ensuring that the steam outlet pressure of the accumulator (1) is constant and not affected by the fluctuation of the end steam-using load. When the pneumatic pressure regulating valve fails, it can be switched to the bypass stop valve for steam supply.

[0025] When the pressure in the accumulator (1) exceeds the limit, the safety valve (6) at the top of the accumulator (1) automatically discharges steam to relieve pressure and maintain the stability of the internal pressure of the accumulator (1).

[0026] Water replenishing process:

[0027] Since the heat of superheated steam of the same mass is about 1.1 times that of saturated steam, the accumulator (1) needs to continuously supplement new water. The makeup water pump pumps water from an external water source.

[0028] The water first passes through the stop valve and filter before the makeup water pump. The filter screen in the filter prevents impurities from entering the makeup water pump and damaging the impeller. Then it passes through the stop valve and the electric valve group (41) after the makeup water pump and enters the accumulator (1). Under normal circumstances, the water enters through the electric regulating valve; when the electric valve group (41) fails, the bypass valve is opened for water replenishment.

[0029] Drainage and maintenance:

[0030] After the accumulator (1) operates for a period of time, sludge and water with a high salt content will accumulate at the bottom. By opening the stop valve on the drain pipe (5), these impurities can be regularly discharged to ensure that the water quality and steam quality meet the standards.

[0031] When maintenance of the accumulator (1) is required, open the stop valve on the vent pipe (7) to vent the steam in the accumulator (1) to ensure the safety of maintenance personnel.

[0032] Liquid level monitoring:

[0033] The differential pressure sensor and glass tube liquid level gauge in the liquid level gauge assembly (8) monitor the liquid level height in the accumulator (1) in real time by measuring parameters such as the pressure difference at different positions inside the accumulator (1). At the same time, 3 ball valves can be used for work such as calibration and maintenance of the liquid level gauge when needed.

[0034] Compared with the prior art, the beneficial effects of the present utility model are: The system can achieve automatic control according to the set pressure at the steam outlet, ensuring that the steam outlet pressure of the accumulator is constant and not affected by the fluctuation of the end steam consumption load. Combining with the superheated steam pipeline, drain pipeline, vent pipeline 7, makeup water pipeline, etc. of the accumulator to form an efficient and stable re-roasting accumulator protection system, realizing high-precision control, high-efficiency production, high-quality supply, and long-term stable guarantee of process steam. Description of the drawings

[0035] Figure 1 It is a layout schematic diagram of the present utility model;

[0036] In the figure, 1 - accumulator; 2 - superheated steam pipeline; 3 - pressure regulating pipeline; 31 - pressure regulating valve group; 32 - control box; 4 - makeup water pipeline; 41 - electric valve group; 42 - bypass pipeline; 43 - makeup water pump group; 5 - drain pipeline; 6 - safety valve; 7 - vent pipeline; 8 - liquid level gauge assembly. Detailed implementation manners

[0037] To make the objectives, technical solutions, and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present utility model. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present utility model.

[0038] Embodiment 1: A pressure control for the outlet of a re-roasting steam accumulator 1 and its pipeline system. The system includes a superheated steam pipeline 2, an accumulator 1, a pressure regulating pipeline 3, a makeup water pipeline 4, an air vent pipeline 7, and a blowdown pipeline 5 that are respectively connected to the accumulator 1.

[0039] The accumulator 1 is a horizontal oval head storage tank. A steam inlet, a steam outlet, and a makeup water inlet are provided at the top of the tank body, and a blowdown port is provided at the bottom.

[0040] One end of the superheated steam pipeline 2 is connected to an external superheated steam source (boiler), and the other end is connected to the steam inlet on the tank body of the accumulator 1. One stop valve and one check valve are provided on the pipeline near the accumulator 1. The stop valve is used to manually control the on and off of the steam, and the check valve ensures that the steam can only flow in one direction into the accumulator 1 to prevent steam backflow. The superheated steam enters the accumulator 1 through this pipeline, heating the water inside the accumulator 1 to the saturation temperature corresponding to the pressure to achieve the heat storage function.

[0041] The pressure regulating pipeline 3 is connected to the steam outlet at the top of the accumulator 1. A pressure regulating valve group 31 and a pressure control box 32 are provided on the pipeline. The pressure regulating valve group 31 consists of 3 stop valves, 1 filter, and 1 pneumatic pressure regulating valve. One pressure gauge is installed before and after the pressure regulating valve group 31 for on-site display of the pressure before and after pressure regulation. One pressure sensor is also installed on the pipeline after the pressure regulating valve group 31. The power of the pneumatic pressure regulating valve is provided by compressed air. The pressure control box 32 controls the actuator of the pneumatic pressure regulating valve according to the set required pressure at the end and the actual pressure signal fed back by the pressure sensor, thereby achieving the regulation of the steam pressure and ensuring that the pressure after the pressure regulating valve group 31 is consistent with the set pressure and remains constant. When the pneumatic pressure regulating valve fails, the stop valves before and after it can be closed, and the bypass stop valve can be opened to supply steam to the end-use steam equipment.

[0042] The water replenishing pipeline 4 is connected to an external water source. A water replenishing pump set 43 and an electric valve set 41 are arranged on the water replenishing pipeline 4. One stop valve and one filter are installed in front of the water replenishing pump. A filter screen is provided inside the filter to filter out impurities such as iron filings in the water and prevent them from entering the water replenishing pump and damaging the impeller. One stop valve and the electric valve set 41 are arranged behind the water replenishing pump. The electric valve set 41 is composed of three stop valves, one filter, and one electric regulating valve. Under normal circumstances, the replenished water enters the heat accumulator 1 through the electric regulating valve. When the electric valve set 41 fails, the bypass valve on the bypass pipeline 42 can be opened for water replenishment.

[0043] The venting pipeline 7 is installed on the top of the heat accumulator 1. One stop valve is arranged on this pipeline. When it is necessary to repair or maintain the heat accumulator 1, this stop valve is opened to vent the steam inside the heat accumulator 1, ensuring the safety of maintenance operations.

[0044] The sewage pipeline 5 is connected to the bottom of the heat accumulator 1. One stop valve is installed on the sewage pipeline 5. By opening this stop valve, the sludge and water with high salt content accumulated at the bottom of the heat accumulator 1 can be discharged, thereby ensuring the water quality inside the heat accumulator 1 and the quality of the output steam.

[0045] The device is also provided with a liquid level gauge assembly 8. The liquid level gauge assembly 8 is installed on the side of the heat accumulator 1 and is composed of three ball valves, a differential pressure sensor, and a glass tube liquid level gauge. Through the liquid level gauge assembly 8, the height of the water level inside the heat accumulator 1 can be monitored in real time, providing important liquid level information for the stable operation of the system.

[0046] Two safety valves 6 are also arranged on the top of the tank body of the heat accumulator 1; when the internal pressure of the heat accumulator 1 exceeds the set pressure of the safety valve 6, the safety valve 6 automatically opens for steam exhaust and pressure relief, ensuring the safe operation of the heat accumulator 1.

[0047] It should be understood that the above specific embodiments of the present invention are only used for exemplary illustration or explanation of the principle of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modification examples falling within the scope and boundary of the appended claims, or equivalent forms of such scope and boundary.

Claims

1. A reheating steam accumulator outlet pressure control and its piping system, characterized in that: The system comprises a superheated steam pipeline (2), a heat accumulator (1) and a pressure regulating pipeline (3); The heat accumulator (1) is a horizontal elliptical head storage tank, with a steam inlet, a steam outlet and a water supply port provided on the top, and a sewage outlet provided on the bottom; The steam inlet is connected to a superheated steam pipeline (2), one end of the superheated steam pipeline (2) is connected to the steam inlet of the heat accumulator (1), and the other end is connected to the superheated steam, and is used to connect the superheated steam and the heat accumulator (1), and transport the superheated steam provided by the boiler discharge room into the heat accumulator (1) through the superheated steam pipeline (2). A stop valve and a check valve are provided on the superheated steam pipeline (2); The steam outlet is connected to a pressure regulating pipeline (3), and the pressure regulating pipeline (3) is provided with a pressure regulating valve group (31) consisting of a stop valve, a filter, and a pneumatic pressure regulating valve, and a pressure control box (32).

2. A reheating steam accumulator outlet pressure control and piping system according to claim 1, characterized in that: The top of the heat accumulator (1) is also provided with a safety valve (6) for automatically exhausting steam and relieving pressure in the event of overpressure, and the safety valves (6) include at least two.

3. The outlet pressure control and piping system of a double-baked steam accumulator according to claim 1, characterized in that: The top of the heat accumulator (1) is also provided with a venting pipeline (7) for maintenance and pressure relief, and a stop valve is provided on the venting pipeline (7).

4. The outlet pressure control and piping system of a double-baked steam accumulator according to claim 1, characterized in that: The pressure regulating valve group (31) is composed of three stop valves, a filter, a pneumatic pressure regulating valve, and a pressure control box (32).

5. The outlet pressure control and piping system of a double-baked steam accumulator according to claim 1, characterized in that: A pressure gauge for displaying the pressure before and after the pressure regulation is installed on site at the front and rear of the pressure regulating valve group (31).

6. The outlet pressure control and piping system of a reheating steam accumulator according to claim 1, characterized in that: The pressure regulating pipeline (3) is also provided with a pressure sensor, which is installed at the rear end of the pressure regulating valve group (31).

7. The outlet pressure control and piping system of a double-baked steam accumulator according to claim 1, characterized in that: The water replenishment port is connected to the water replenishment pipeline (4) and is used to continuously replenish new water to the heat accumulator (1).

8. The outlet pressure control and piping system of a double-baked steam accumulator according to claim 7, characterized in that: The water supply pipeline (4) is provided with a water supply pump group (43) and an electric valve group (41).

9. The outlet pressure control and piping system of a double-baked steam accumulator according to claim 7, characterized in that: The water inlet end of the water supply pipeline (4) is also provided with a stop valve and a filter, and the filter is provided with a filter screen for preventing iron filings and impurities from entering the water supply pump and damaging the impeller.

10. The outlet pressure control and piping system of a double-baked steam accumulator according to claim 7, characterized in that: The water supply pipeline (4) is also provided with a bypass pipeline (42) connected in parallel with the electric valve group (41) for supplying water when the electric valve group (41) fails.

Images