Steam Pipeline Intelligent Drainage System

Abstract

The present invention discloses an intelligent steam pipe drainage system, in which a drainage control valve is added to the drainage system of the prior art, and the drainage control valve includes a variable pressure pipe, a constant pressure pipe and a control valve, and the variable pressure pipe and the constant pressure pipe are at different distances from the steam pipe. The pressure difference between the variable pressure pipe and the constant pressure pipe is changed by utilizing the different temperatures of superheated steam and saturated steam, so as to promote the automatic opening and closing of the control valve. The system solves the drainage control problem of the steam pipe network with large steam flow rate changes, and can automatically close the drainage system during the period of conveying superheated steam, and automatically open the drainage system during the period of conveying saturated steam, thereby reducing the drainage loss during the period of conveying superheated steam and saving energy.

Description

Technical Field

[0001] The present invention relates to the technical field of steam pipelines, and in particular to a system for automatically opening or closing a steam pipeline drain device according to steam state parameters. Background Art

[0002] In recent years, in order to save energy, reduce emissions and improve the comprehensive utilization efficiency of energy, the national and local governments have issued relevant policies to vigorously promote centralized heating in industrial parks. A large number of steam pipelines have been built in various industrial parks, and the medium transported by most steam pipelines is superheated steam. Due to heat dissipation losses during pipeline transportation, the temperature of superheated steam will gradually drop to saturation and produce condensed water. Therefore, it is necessary to set drain points at appropriate locations to discharge the condensed water in the steam pipeline in time to prevent accidents such as water hammer in the steam pipeline system.

[0003] At present, the commonly used steam pipe drainage system settings are as follows: Figure 1 As shown in the figure, when the steam transported by the pipeline is superheated steam, since it does not produce condensate, the shut-off valve of the drain system can be closed in theory to avoid the discharge of condensate and leaked steam due to the heat dissipation and condensation of blind ends such as the water collecting tank and the drain pipe, so as to reduce heat loss. However, since the steam pipeline transport flow is variable, the steam transport parameters of the same section of the pipeline are variable, that is, some pipelines transport superheated steam for a period of time and saturated steam for another period of time. It is difficult to manually close the drain system during the period of transporting superheated steam and open the drain system during the period of transporting saturated steam. Therefore, most steam pipeline drain systems are opened for a long time and are always in working state. During the period of transporting superheated steam, since the water collecting tank and the drain pipe are blind end pipelines, the steam does not flow. After heat dissipation, the superheat of the steam gradually decreases until it is saturated and becomes condensate. The condensate produced is continuously discharged by the automatic drain valve. Therefore, even during the period of transporting superheated steam, the drain system will still discharge condensate and leaked steam, thereby increasing the heat loss of the steam pipeline. Summary of the invention

[0004] In view of this, the present invention provides an intelligent pipeline drain system, which solves the problem of drain control in a steam pipeline network with large steam flow changes. The system can automatically close the drain system during the period of transporting superheated steam and automatically open the drain system during the period of transporting saturated steam.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A steam pipeline intelligent drain system, comprising a steam pipeline, a condensate collecting tank, a drain pipe, and a shutoff valve and an automatic drain valve arranged on the drain pipe, wherein the steam pipeline is wrapped with an insulation layer, a drain control valve is arranged between the shutoff valve and the drain valve, and the drain control valve comprises a variable pressure pipe, a constant pressure pipe and a control valve; the control valve comprises a valve body, a controller and a valve core, the two ends of the valve core are respectively located in the valve body and the controller and a bellows for sealing and isolation is arranged at the connection, the two ends of the valve body are connected with the drain pipe and a valve seat for blocking the connection is arranged inside, the valve seat has a valve port and the shape of the valve port is consistent with the top of the valve core The controller is a hollow structure and is provided with a membrane inside. The membrane divides the inside of the controller into an upper chamber and a lower chamber, and the bottom end of the valve core is connected to the membrane; one end port of the variable pressure conducting pipe is connected to the upper chamber of the controller, and the other end of the variable pressure conducting pipe is semi-annular and the semi-annular pipe wall is tightly fitted with the outer wall of the steam pipe; one end port of the constant pressure conducting pipe is connected to the lower chamber of the controller, and the other end of the constant pressure conducting pipe is semi-annular and the annular pipe wall is arranged in the insulation layer; the ports of the semi-annular ends of the variable pressure conducting pipe and the constant pressure conducting pipe are both located above the steam pipe and are respectively connected to the inside of the steam pipe.

[0007] In the above technical solution, the constant-pressure pressure conducting pipe is far away from the steam pipe and is less affected by the pipe temperature. Regardless of whether superheated steam or saturated steam is transported, the constant-pressure pressure conducting pipe is always filled with condensed water, so the pressure in the lower chamber of the controller is relatively stable; the semi-annular section of the variable-pressure pressure conducting pipe is close to the steam pipe. Since the temperatures of superheated steam and saturated steam are different, the medium in the semi-annular section of the variable-pressure pressure conducting pipe is changing: when superheated steam is transported in the steam pipe, the medium in the semi-annular part of the pipe is water vapor; when saturated steam is transported in the steam pipe, the medium in the semi-annular part of the pipe is condensed water; therefore, the height difference of the liquid column in the variable-pressure pressure conducting pipe is changing, which in turn causes the pressure in the upper chamber of the controller to change.

[0008] Furthermore, in the above technical solution, pressure-conducting pipe shut-off valves are provided at the ports of the semi-annular ends of the variable-pressure pressure-conducting pipe and the constant-pressure pressure-conducting pipe.

[0009] Furthermore, in the above technical solution, both the variable pressure guiding pipe and the constant pressure guiding pipe are provided with pressure guiding pipe exhaust valves.

[0010] Furthermore, in the above technical solution, the valve seat has a valve opening in the shape of a cone with a larger bottom and a smaller top.

[0011] The beneficial effect of the present invention is that the temperature of superheated steam and saturated steam is different, which causes the height of condensed water in the variable pressure pressure pipe to change, while the height of condensed water in the constant pressure pressure pipe is little affected by the change of superheated steam and saturated steam, resulting in different height differences between the two pressure pipes in different states, which in turn affects the pressure changes in the upper and lower chambers of the controller, promotes the opening and closing of the valve, and thus realizes intelligent automatic control of the hydrophobic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of a steam pipe drain system in the prior art;

[0013] Figure 2 It is a schematic diagram of the structure of the drainage system when the overhead steam pipeline in the present invention transports saturated steam;

[0014] Figure 3 It is a schematic diagram of the structure of the drainage system when the overhead steam pipeline in the present invention transports superheated steam;

[0015] Figure 4 It is a schematic diagram of the distribution structure of the variable pressure pipe and the constant pressure pipe on the overhead steam pipeline;

[0016] Figure 5 It is a schematic diagram of the structure of the drainage system when the direct buried steam pipeline in the present invention transports saturated steam;

[0017] Figure 6 It is a schematic diagram of the structure of the drainage system when the direct buried steam pipeline in the present invention transports superheated steam;

[0018] Figure 7 It is a schematic diagram of the distribution structure of the variable pressure pipe and the constant pressure pipe on the direct buried steam pipeline;

[0019] Among them, 1: steam pipe, 2: condensate collecting tank, 3: drain pipe, 4: shut-off valve, 5: automatic drain valve, 6: variable pressure pipe, 7: constant pressure pipe, 8: control valve, 81: valve body, 82: controller, 83: valve core, 84: bellows, 85: valve seat, 86: membrane, 9: insulation layer, 10: pressure pipe shut-off valve, 11: pressure pipe exhaust valve, 12: manual drain valve, 13: outer protective pipe. DETAILED DESCRIPTION

[0020] In order to better understand the present invention, the present invention is further described below through specific embodiments and accompanying drawings, but they are not intended to limit the present invention.

[0021] like Figures 2 to 7As shown, an intelligent steam pipe drain system includes a steam pipe 1, a condensate collecting tank 2, a drain pipe 3, and a shut-off valve 4, an automatic drain valve 5 and a manual drain 12 arranged on the drain pipe 3. The steam pipe 1 is provided with an insulation layer 9 on the outside. The condensate collecting tank 2 is arranged below the steam pipe 1 and is connected to the inner wall of the steam pipe 1. The drain pipe 3 is connected to the condensate collecting tank 2 for discharging condensate. The drain pipe 3 is provided with a shut-off valve 4 and a manual drain valve 12. These valves are used to manually open or close the drain system. The automatic drain valve 5 automatically discharges condensate in the pipeline system.

[0022] In order to achieve the purpose of automatically closing the drain system when conveying superheated steam and automatically opening when conveying saturated steam, the present invention sets a drain control valve between the cut-off valve 4 and the automatic drain valve 5, and the drain control valve includes three parts: a variable pressure pressure pipe 6, a constant pressure pressure pipe 7 and a control valve 8.

[0023] The control valve 8 includes a valve body 81, a controller 82, a valve core 83 and a bellows 84. The valve body 81 is located above the controller 82. The left and right ends of the valve body 81 are connected to the drain pipe 3. A valve seat 85 is provided inside the valve body 81. A valve port is provided at the center of the valve seat 85, so that condensed water enters the valve body 81 from below the valve seat 85 and then flows out from above the valve seat 85 through the valve port. Specifically, the valve port is a cone structure with a large bottom and a small top. The upper and lower ends of the valve core 83 extend into the valve body 81 and the controller 82 respectively. The top of the valve core 83 is provided with a valve port that is connected to the valve port. A matching conical sealing table surface, a bellows 84 is provided at the connection between the valve core 83, the valve body 81 and the controller 82, and the bellows 84 is used for sealing and isolating the valve body 81 and the controller 82; the controller 82 is a hollow structure and is provided with a membrane 86 inside. The membrane 86 divides the interior of the controller 82 into an upper chamber and a lower chamber, and the bottom end of the valve core 83 is connected to the membrane 86; specifically, a hard disc is provided on the membrane 86, and the bottom end of the valve core 83 is connected to the hard disc. The membrane needs to have a larger stroke and higher sensitivity, and a corrugated membrane can be selected.

[0024] The variable pressure pipe 6 and the constant pressure pipe 7 are similar in shape and are both connected between the steam pipe and the controller 82. Preferably, the variable pressure pipe 6 and the constant pressure pipe 7 are arranged in parallel. Specifically, one end of the variable pressure pipe 6 is connected to the upper chamber of the controller 82, and the other end is semi-circular and connected to the upper opening of the steam pipe 1. The radius of the semi-circular section of the variable pressure pipe 6 is the same as the radius of the outer wall of the steam pipe 1, so that the pipe wall of the semi-circular section is closely attached to the outer wall of the steam pipe 1. One end of the constant pressure pipe 7 is connected to the lower chamber of the controller 82, and the other end of the constant pressure pipe 7 is also semi-circular and connected to the upper opening of the steam pipe 1. The radius of the semi-circular section of the constant pressure pipe 7 is larger than the radius of the outer wall of the steam pipe 1 but slightly smaller than the radius of the outer wall of the insulation layer 11, so that the constant pressure pipe 7 is laid in the insulation layer. Preferably, the radius of the semi-circular section of the constant pressure pipe 7 is 50 mm smaller than the radius of the outer wall of the insulation layer. The ports of the semi-circular ends of the pressure-changing pressure-conducting pipe 6 and the constant-pressure pressure-conducting pipe 7 are slightly higher than the steam pipe 1 and are respectively connected to the inside of the steam pipe 1. For the convenience of maintenance, the pressure-changing pressure-conducting pipe 6 and the constant-pressure pressure-conducting pipe 7 are provided with a pressure-conducting pipe cut-off valve 10 at the inlet of the steam pipe 1. When working, the pressure-conducting pipe cut-off valve 10 is in an open state. When maintenance is performed, the pressure-conducting pipe cut-off valve 10 can be closed. The horizontal sections of the pressure-changing pressure-conducting pipe 6 and the constant-pressure pressure-conducting pipe 7 are provided with a pressure-conducting pipe exhaust valve 11.

[0025] When the steam pipeline is an overhead pipeline, the arrangement of the variable pressure pipe 6, the constant pressure pipe 7 and the control valve is as follows: Figures 2 to 4 As shown, the valve group of the entire drain system is located lower than the steam pipe, and the variable pressure pipe 6 and the constant pressure pipe 7 are laid from top to bottom to the controller. The variable pressure pipe 6 and the constant pressure pipe 7 can be divided into: a semi-annular section, a vertical section and a horizontal section. The semi-annular section is located inside the insulation layer, and the vertical section and the horizontal section are both located outside the insulation layer. The connection between the semi-annular section and the steam pipe 1 is located directly above the steam pipe.

[0026] When the steam pipeline is a direct buried pipeline, the steam pipe and drain pipe are covered with steel outer protective pipes outside the insulation layer. The arrangement of the variable pressure pipe 6, the constant pressure pipe 7 and the control valve is as follows: Figures 5 to 7 As shown, the valve group of the entire steam trap system is located higher than the steam pipe, and the variable pressure pipe 6 and the constant pressure pipe 7 are arranged in a "U" shape. The variable pressure pipe 6 and the constant pressure pipe 7 are first laid from top to bottom to the lower space of the steam pipe (inside the outer protective pipe 13), and then laid from bottom to top along the outer protective pipe 13 of the steam trap to the controller. The variable pressure pipe 6 and the constant pressure pipe 7 can be divided into: a semi-annular section, a vertical section and a horizontal section. The semi-annular section is located in the insulation layer of the steam pipe 1, and the vertical section and the horizontal section are both located between the outer protective pipe and the insulation layer. The connection between the semi-annular section and the steam pipe 1 is located directly above the steam pipe.

[0027] The working principle of this intelligent drain system is as follows: the semi-annular section of the constant pressure pipe is located in the insulation layer and is separated from the steam pipe by a certain thickness of insulation material, so the temperature inside the pipe is relatively low, and the steam condenses and fills the pipe. Regardless of whether superheated steam or saturated steam is transported, the terminal pressure P2 remains relatively constant. The semi-annular section of the variable pressure pipe is close to the steam pipe and is located between the insulation layer and the steam pipe. The temperature is close to the steam temperature inside the steam pipe. The pressure pipe outside the semi-annular section is full of condensed water. The height of the liquid column in the semi-annular section pressure pipe is related to the steam state of the steam pipe. When conveying saturated steam, the temperature of the semi-annular section pressure pipe is lower than the saturation temperature. The steam in the pipe enters the semi-annular section and condenses and fills it. The terminal pressure P1 (the pressure of the condensed water in the upper chamber of the controller on the membrane) is equal to P2 (the pressure of the condensed water in the lower chamber of the controller on the membrane); when conveying superheated steam, the temperature of the semi-annular section pressure pipe is higher than the saturation temperature. The semi-annular section pressure pipe is full of steam due to the evaporation of condensed water. The height of its liquid column is lower than the liquid column of the constant pressure pressure pipe. The terminal pressure P1 is lower than P2, forming a pressure difference.

[0028] Therefore, when the steam pipeline transports saturated steam, P1 = P2, the membrane is in a balanced state, the valve core and the valve seat are at a certain distance, and the valve is open. Figure 2 and Figure 5 , the steam trap control valve opens, and the condensate is removed in time through the steam trap to ensure the safe operation of the steam pipeline. When the steam pipeline transports superheated steam, P1 < P2, and the pressure P2 pushes the membrane 6 upward, and the valve core and the valve seat gradually approach each other until they are closed, and the steam trap control valve is closed. Figure 3 and Figure 6 No condensate is produced when superheated steam is transported. The drain system is closed in time, which can stop the drain valve from discharging condensate and save energy.

[0029] Of course, the above are only specific application examples of the present invention and do not constitute any limitation on the protection scope of the present invention. In addition to the above embodiments, the present invention may also have other implementations, and any technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims

1. An intelligent steam pipe drain system, comprising a steam pipe (1), a condensate collecting tank (2), a drain pipe (3), and a cut-off valve (4) and an automatic drain valve (5) arranged on the drain pipe (3), wherein the steam pipe (1) is wrapped with an insulation layer (9), and is characterized in that: A drain control valve is provided between the cut-off valve (4) and the automatic drain valve (5), and the drain control valve comprises a variable pressure pipe (6), a constant pressure pipe (7) and a control valve (8); The control valve (8) comprises a valve body (81), a controller (82) and a valve core (83); the two ends of the valve core (83) are respectively located in the valve body (81) and the controller (82), and a bellows (84) for sealing and isolating is provided at the connection; the two ends of the valve body (81) are connected to the drain pipe (3) and a valve seat (85) for blocking the connection is provided inside; the valve seat (85) has a valve port and the shape of the valve port matches the sealing table at the top of the valve core (83); the controller (82) is a hollow structure and a membrane (86) is provided inside; the membrane (86) divides the inside of the controller (82) into an upper chamber and a lower chamber; the bottom end of the valve core (83) is connected to the membrane (86); One end port of the variable pressure conducting pipe (6) is in communication with the upper chamber of the controller (82), and the other end of the variable pressure conducting pipe (6) is semi-annular, and the semi-annular pipe wall is tightly fitted with the outer wall of the steam pipe (1); one end port of the constant pressure conducting pipe (7) is in communication with the lower chamber of the controller (82), and the other end of the constant pressure conducting pipe (7) is semi-annular, and the annular pipe wall is arranged in the insulation layer (9); the semi-annular ends of the variable pressure conducting pipe (6) and the constant pressure conducting pipe (7) are both located above the steam pipe (1) and are in communication with the inside of the steam pipe (1).

2. The intelligent steam pipe drain system according to claim 1, characterized in that: Pressure-conducting pipe shutoff valves (10) are provided at the ports of the semi-annular ends of the variable-pressure pressure-conducting pipe (6) and the constant-pressure pressure-conducting pipe (7).

3. The intelligent steam pipe drain system according to claim 1, characterized in that: The variable pressure guiding pipe (6) and the constant pressure guiding pipe (7) are both provided with pressure guiding pipe exhaust valves (11).

4. The intelligent steam pipe drain system according to claim 1, characterized in that: The valve opening on the valve seat (85) is in the shape of a cone with a larger bottom and a smaller top.

Images