Valve system with anti-locking function

Abstract

To prevent steam leakage accompanied by elimination of a locking phenomenon.SOLUTION: Drain is generated from steam transferred via a piping system, and the drain flows into a steam trap 1 from an inflow pipe 71, and is retained in a valve chamber. The steam trap 1 appropriately discharges the drain to an outflow pipe 72 in accordance with a drain retention amount. When a steam locking phenomenon in which steam intervenes in a part of the drain in the piping system occurs, the steam trap 1 cannot discharge the drain, therefore, a bypass valve 4 is opened, and the drain and the intervening steam are detoured and discharged via bypass pipes 73, 74. The bypass valve 4 can adjust a flow rate of the drain.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The valve system with a locking prevention function according to the present application relates to a technique for eliminating the locking phenomenon in which a basic valve cannot open due to a stagnation of fluid in a basic flow path. [Background technology]

[0002] Industrial plants are often equipped with piping systems that transport steam generated in boilers at high temperature and pressure to the equipment at which it is supplied. When the steam is used in the equipment, drain (condensed water from the steam) is generated and discharged from the equipment's exhaust pipe. At this time, steam may flow out of the exhaust pipe along with the drain, but to avoid steam loss, it is necessary to discharge only the drain to the outside.

[0003] For this reason, a steam trap is installed in the discharge pipe. A float-type steam trap has a hollow float built into the valve chamber. As condensate flows into the valve chamber of the steam trap and accumulates, the float rises and opens the condensate discharge port located at the bottom of the valve chamber, automatically discharging the condensate to the outside. After the condensate is discharged, the float descends and closes the condensate discharge port, preventing steam leakage.

[0004] However, in a steam trap, depending on the conditions of the inflowing steam and condensate, steam may get trapped in part of the condensate in the piping system, including the valve chest of the steam trap, blocking the flow of condensate and preventing the condensate from being properly discharged. This phenomenon is known as steam locking.

[0005] A heating cylinder is disclosed as a technology for eliminating this steam locking phenomenon in Patent Document 1. This heating cylinder 100 supplies steam to a cylinder body 10 to heat an object in contact with the outer circumferential surface of the cylinder body 10.

[0006] Within the cylinder body 10, the steam that has absorbed heat condenses to produce drain. This drain is taken out from the drain pipe 20 through drain piping 31 and is discharged by the operation of a steam trap 40 provided on the drain piping 31. A bypass pipe 32 that connects the upstream side and downstream side of the steam trap 40 is provided in the drain piping 31, and a valve 50 is disposed on this bypass pipe 32. The valve 50 opens and closes under the control of a control unit 60.

[0007] When steam locking occurs, the drain is not properly drained and accumulates inside the cylinder body 10, causing the water level to rise. This rise in water level is detected by the water level sensor 13, and based on this, the control unit 60 opens the valve 50. As a result, the drain is bypassed and drained through the bypass pipe 32, and the steam locking phenomenon is resolved. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-86248 Summary of the Invention [Problem to be solved by the invention]

[0009] In the heating cylinder 100 disclosed in Patent Document 1, when the steam locking phenomenon occurs, the valve 50 is opened to discharge the condensate from the bypass pipe 32 regardless of the condensate retention state. Here, in the steam locking phenomenon, it is not always clear at which point in the piping system the steam is present, and the condensate retention state varies.

[0010] For this reason, if the valve 50 is fully opened to drain the condensate regardless of the state of condensate accumulation, steam may leak from the bypass pipe 32 in the short time between the resolution of the steam locking phenomenon and the closing of the valve 50. Depending on the state of steam and condensate transport, the steam locking phenomenon may occur frequently, and each time condensate is drained from the bypass pipe 32, so even if the steam leaks for only a short time, a loss due to steam leakage occurs.

[0011] Therefore, an object of the present invention is to provide a valve system with an anti-locking function that can reliably prevent steam leakage due to the elimination of the locking phenomenon. [Means for solving the problem]

[0012] The valve system with the locking release function is A basic flow path through which a fluid passes from upstream to downstream. a basic valve that is provided on the basic flow path and can be opened or closed, blocking the passage of the fluid when closed and allowing the passage of the fluid when opened; an opening / closing means for closing or opening the basic valve; a bypass flow path connecting the upstream basic flow path of the basic valve with the downstream basic flow path; an auxiliary valve that is provided on the bypass flow path and can be opened or closed, and that opens when a locking phenomenon occurs in which the basic valve cannot be opened due to a stagnation state of the fluid in the basic flow path, and allows the fluid to pass through the bypass flow path; It is equipped with The auxiliary valve is capable of adjusting the flow rate of the fluid passing through the bypass flow path. It is characterized by: [Effects of the Invention]

[0013] In the valve system with anti-locking function according to the present application, the auxiliary valve provided in the bypass flow path opens in response to the occurrence of a locking phenomenon in which the basic valve cannot open due to fluid stagnation in the basic flow path, thereby allowing the fluid to pass through the bypass flow path. This auxiliary valve is capable of adjusting the flow rate of the fluid passing through the bypass flow path.

[0014] Therefore, the fluid can be appropriately discharged through the bypass flow path depending on the fluid stagnation state in the main flow path, and the auxiliary valve can be closed immediately after the locking phenomenon is resolved, thereby reliably preventing steam leakage due to the elimination of the locking phenomenon. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an overall configuration diagram showing a first embodiment of a valve system having a locking release function according to the present application. [Figure 2] 2 is a cross-sectional view of the steam trap 1 taken along the arrows II-II in FIG. 1. FIG. [Figure 3] 3 is a cross-sectional view of the bypass valve 4 taken along the arrows III-III shown in FIG. 1. FIG. [Figure 4] 4 is an enlarged cross-sectional view of the bypass valve seat 48 and the bypass valve body 62 shown in FIG. 3 in the vicinity thereof, showing the open state. FIG. [Figure 5] 4 is an enlarged cross-sectional view of the vicinity of the bypass valve seat 48 and the bypass valve body 62 shown in FIG. 3, showing the closed state of the valve. FIG. [Figure 6] FIG. 2 is a cross-sectional view of a steam trap 200 used in a second embodiment of a valve system having an anti-locking function according to the present application. [Figure 7] FIG. 2 is a cross-sectional view of a bypass valve 220 used in a second embodiment of a valve system having an anti-locking function according to the present application. [Figure 8] 7 is a graph showing the relationship between the change in temperature detected by the temperature sensor 201 shown in FIG. 6 and the opening degree of the valve. [Figure 9]10 is a graph showing changes in the temperature detected by the temperature sensor 201 in the third embodiment of the valve system having an anti-locking function according to the present application. [Figure 10] 10 is a graph showing the relationship between the inclination angle of the center line in the graph shown in FIG. 9 and the opening degree of the valve. DETAILED DESCRIPTION OF THE INVENTION

[0016] [Terminology used in the embodiments] The main terms used in the embodiments correspond to the following elements of the valve system having an anti-locking function according to the present application:

[0017] Steam trap 1, 200... Basic valve Bypass valve 4, 220... Auxiliary valve Float 10...Opening and closing means Bypass valve port 49: Auxiliary valve port Bypass valve body 62...valve body part Inlet pipe 71 and outlet pipe 72...basic flow path Bypass pipes 73, 74...bypass flow path Axis line L1...Reference line Temperature sensor 201: Detection means, temperature detection means Temperature signal...detection signal Steam or drainage fluid The steam locking phenomenon refers to the phenomenon in which steam gets trapped in a part of a piping system, including pipes and valves, blocking the inflow of condensate and causing the valve to malfunction. Fluid retention in the basic flow path refers to a situation in which condensate is retained in the valve chest of a steam trap or upstream of the valve chest, for example.

[0018] [First embodiment] A first embodiment of a valve system with an anti-locking function according to the present invention will be described with reference to Figures 1 to 5. The valve system in this embodiment is installed in a piping system of an industrial plant, etc. As shown in Figure 1, this valve system includes a steam trap 1, which is connected to an inlet pipe 71 and an outlet pipe 72.

[0019] Inlet pipe 71 communicates with a main pipe (not shown) of a piping system through which steam and condensate generated from the steam flow, and condensate flows into steam trap 1 through inlet pipe 71. Steam trap 1 appropriately discharges the condensate that has flowed in and accumulated inside to outlet pipe 72. In accordance with the flow of steam and condensate, the inlet pipe 71 side is upstream and the outlet pipe 72 side is downstream.

[0020] Bypass pipes 73 and 74 are connected to the inlet pipe 71 and the outlet pipe 72, respectively, with the steam trap 1 in between. The bypass pipes 73 and 74 are provided with a bypass valve 4. The bypass valve 4 is normally closed to block the passage of condensate through the bypass pipes 73 and 74, but when steam locking occurs, the valve opens to divert the condensate from the inlet pipe 71 and discharge it into the outlet pipe 72.

[0021] (Explanation of Steam Trap 1) The configuration and operation of the steam trap 1 will be described with reference to Figure 2. The steam trap 1 has a main body made up of a casing 7 and a casing lid 20. The casing 7 and the casing lid 20 are fixed together with bolts to form an airtight valve chest 16 inside.

[0022] Steam and condensate flow into this valve chest 16 in the direction of arrow 91 from the inlet pipe 71 through the inlet 7a. A strainer 12 with a mesh section is provided upstream of the valve chest 16, and the steam and condensate pass through this strainer 12 and flow into the valve chest 16. As a result, foreign matter such as dirt and scale mixed in the steam and condensate is captured by the mesh section of the strainer 12.

[0023] A valve seat 27 is fixedly attached to the casing lid 20 on the downstream side of the valve chest 16, and a valve port 28 is formed in this valve seat 27. The valve port 28 communicates with the internal space of the valve seat 16 and further forms a flow path by communicating with a lid-side flow path 24 formed in the casing lid 20 and the outflow path 14 and outflow port 7b formed in the casing 7. This allows drainage accumulated in the valve chest 16 to be discharged from the valve port 28 toward the outflow pipe 72 in the direction of arrow 92.

[0024] A float 10 is disposed in the valve chamber 16. The float 10 is configured as a hollow sphere and is positioned so that it can float within the valve chamber 16. Under normal conditions, the float 10 sits on a valve seat 27 to close a valve port 28, preventing steam leakage from the steam trap 1. A plurality of support pieces 18 are provided within the valve chamber 16, which allow the float 10 to stably seat on the valve seat 27.

[0025] When condensate accumulates in the valve chamber 16 and the condensate level rises, the float 10 rises and opens in response. When the float 10 rises and opens, the condensate accumulated in the valve chamber 16 is driven by momentum based on the high pressure in the piping and flows out of the valve port 28 in the direction of arrow 92 and discharged into the outflow pipe 72. After being discharged, the condensate level in the valve chamber 16 drops, and the float 10 also drops and seats on the valve seat 27, restoring the valve to a closed position. In this way, the steam trap 1 repeatedly closes and opens depending on the condensate level in the valve chamber 16, and discharges the condensate from the piping system as appropriate.

[0026] A curved bimetal 22 is mounted on the casing cover 20 downstream of the valve chamber 16. The bimetal 22 is a temperature-sensitive member made by bonding two thin alloy plates with different expansion coefficients together. When the ambient temperature is high, the bimetal 22 bends and retracts its tip, but when the ambient temperature drops, it changes shape and opens wide in response. This causes the tip of the bimetal 22 to push up the float 10, forcibly opening the valve port 28 regardless of the drain water level. Figure 2 shows the state in which the bimetal 22 pushes up the float 10 and opens the valve port 28.

[0027] This bimetal 22 is provided to properly discharge low-temperature air and condensate from the valve port 28. For example, in the initial stage after the equipment starts operating, the valve chamber 16 is filled with low-temperature air, so the bimetal 22 pushes up the float 10, forcibly opening the valve port 28. Therefore, when steam transfer begins, the initial air is properly discharged from the valve port 28, preventing air binding. Similarly, low-temperature condensate flowing into the valve chamber 16 is also properly discharged from the valve port 28.

[0028] When high-temperature steam subsequently flows into the valve chamber 16, the bimetal 22 reacts to the high temperature and deforms its curved portion, causing its tip to retract toward the valve orifice 28. As a result, the float 10 continues to rise and fall according to the level of the accumulated drain as described above, without interference from the bimetal 22.

[0029] Incidentally, in the steam trap 1, a clogged condensate state may occur in which the valve port 28 is blocked by foreign matter, preventing the condensate from being properly discharged. As described above, foreign matter is captured by the strainer 12, but small foreign matter passes through the strainer 12 and enters the valve chest 16. To deal with such a clogged state, the steam trap 1 of this embodiment is provided with a cleaning bar 30. Note that in Figure 2, the cleaning bar 30 is shown as a side view rather than a cross section.

[0030] The cleaning bar 30 is threadedly held in a cylindrical holder 33 fixed to the casing lid 20, and can be rotated to move back and forth in the axial direction. The bar tip 31 of the cleaning bar 30 is located in the internal space of the valve seat 27 and is positioned toward the valve orifice 28.

[0031] An operating groove 32 is formed at the rear end of the cleaning bar 30. When cleaning the valve orifice 28, the operator fits a tool or the like into the operating groove 32 and rotates it to advance the cleaning bar 30 toward the valve orifice 28. This causes the bar tip 31 of the cleaning bar 30 to enter the valve orifice 28, allowing foreign matter to be removed from the valve orifice 28.

[0032] (Explanation of bypass valve 4) Next, the configuration of the bypass valve 4 will be described with reference to Figures 3 to 5. As shown in Figure 3, the bypass valve 4 includes a bypass casing 40. A bypass inlet 40a and a bypass outlet 40b are formed coaxially in the bypass casing 40. A bypass pipe 73 is connected to the bypass inlet 40a, and a bypass pipe 74 is connected to the bypass outlet 40b (see Figure 1).

[0033] A blow passage 41 is formed inside the bypass casing 40, and this blow passage 41 communicates with the bypass inlet 40a. A cylindrical screen 45 having a mesh portion is disposed in the blow passage 41.

[0034] When drainage water flows through the bypass pipe 73, it flows in from the bypass pipe 73 through the bypass inlet 40a in the direction of arrow 93. The flowing in drainage water passes through the mesh portion of the screen 45, and foreign matter such as dirt and scale mixed in the drainage water is captured by this mesh portion. Furthermore, a connecting passage 42 communicating with the blow passage 41 is formed inside the bypass casing 40, and a bypass valve port passage 44 communicating with the bypass outlet 40b is also formed.

[0035] An opening is formed in the side surface of the bypass casing 40, and a cylindrical retaining member 50 is attached to cover this opening. The retaining member 50 is attached and fixed to the opening of the bypass casing 40 by screw connection. A bypass valve chamber 43 is formed between the bypass casing 40 and the retaining member 50, and is kept airtight by a gasket 59.

[0036] The bypass valve chamber 43 is connected to the aforementioned connecting passage 42 and bypass valve port passage 44. A disk-shaped bypass valve seat 48 is attached to the bypass valve port passage 44 at the connection point with the bypass valve chamber 43. A cylindrical bypass valve port 49 that opens toward the bypass valve chamber 43 is formed in this bypass valve seat 48. The center line of the bypass valve port 49 is aligned with the axis L1.

[0037] That is, the bypass valve 4 has a flow path formed by a bypass inlet 40a, a blow passage 41, a connecting passage 42, a bypass valve chamber 43, a bypass valve port 49, a bypass valve port passage 44, and a bypass outlet 40b, and the drain that flows into the bypass inlet 40a can be discharged from the bypass outlet 40b along the direction from arrow 93 to arrows 94 and 95.

[0038] A through-hole is formed in the center of the cylindrical holding member 50, and the center line of this through-hole is aligned with the axis L1. A bypass valve rod 61 is attached to the holding member 50 by passing through the through-hole. Note that in Figures 3 to 5, the bypass valve rod 61 is shown as a side view rather than a cross section. The bypass valve rod 61 is provided with a conical bypass valve element 62 at its tip, and the apex of the bypass valve element 62 is located on the axis L1. A valve rod operating groove 67 is formed at the rear end of the bypass valve rod 61.

[0039] A screw thread 63 is formed near the tip of the bypass valve stem 61, and is attached by threading into a screw groove 69 formed in a through-hole of the holding member 50. That is, by inserting a tool or the like into the valve stem operation groove 67 and operating it to rotate, the bypass valve stem 61 moves forward and backward along the axis L1 in accordance with the threaded engagement.

[0040] In order to maintain the airtightness of the bypass valve chamber 43, a packing 64 with a central hole formed therein is provided in the retaining member 50, and the bypass valve stem 61 passes through the central hole of this packing 64. The packing 64 is pressurized by a pressing member 65 that screws into the retaining member 50, thereby reliably maintaining the airtightness of the bypass valve chamber 43. A cap 51 is detachably attached to the rear end of the retaining member 50, and the cap 51 is positioned to cover the valve stem operating groove 67 of the bypass valve stem 61.

[0041] 4 and 5 are enlarged cross-sectional views of the vicinity of the bypass valve seat 48 and the bypass valve body 62. As shown in Fig. 4, the bypass valve seat 48 has a protruding portion 49a that protrudes toward the bypass valve chamber 43, and a bypass valve port 49 is formed at the tip of this protruding portion 49a. This bypass valve port 49 has a cylindrical shape with a thickness 82.

[0042] A wide-opening portion 49b that continues to the bypass valve port 49 is formed inside the bypass valve seat 48. The wide-opening portion 49b is configured as an inclined surface that widens from the tip end where the bypass valve port 49 is formed toward the rear end. A step portion 49c that continues to the wide-opening portion 49b is formed inside the bypass valve seat 48, and a cylindrical portion 49d that continues to the step portion 49c is further formed.

[0043] Meanwhile, a valve element base 61a is integrally formed at the tip of the bypass valve rod 61, and the aforementioned bypass valve element 62 is provided on this valve element base 61a. A protruding length 81 of the bypass valve element 62 from the valve element base 61a is formed to be sufficiently longer than a thickness 82 of the bypass valve port 49. In this embodiment, the protruding length 81 is configured to be approximately six times the thickness 82. The diameter of the conical bottom portion of the bypass valve element 62 is larger than the opening diameter of the bypass valve port 49.

[0044] 4 shows the open state of the bypass valve 4 when the bypass valve stem 61 reaches its limit position in the direction of arrow 99 (retraction direction). In this open state, the threaded engagement between the thread 63 of the bypass valve stem 61 and the thread groove 69 of the retaining portion 50 reaches its limit position in the direction of arrow 99, and the bypass valve body 62 is completely retracted in the direction of arrow 99 from the bypass valve port 49.

[0045] 5 shows the bypass valve 4 in a closed state, with the inclined surface, which is the side surface of the conical bypass valve body 62, abutting against the tip edge of the bypass valve port 49, causing the bypass valve stem 61 to be positioned at the limit position in the direction of arrow 98 (the direction of entry). As a result, the bypass valve port 49 is completely closed, and the passage of condensate is blocked.

[0046] (Explanation of the operation to eliminate the steam locking phenomenon) As mentioned above, under normal circumstances, condensate generated from steam in a piping system is appropriately discharged from the outflow pipe 72 by repeatedly opening and closing the steam trap 1 (see Figure 1). However, if the steam locking phenomenon occurs, in which steam is trapped in part of the condensate in the piping system, condensate will no longer flow into the valve chest 16 of the steam trap 1, preventing the float 10 from floating. As a result, the steam trap 1 will be unable to open, and condensate will not be properly discharged.

[0047] When such a steam locking phenomenon occurs, in this embodiment, the bypass valve 4 is opened while adjusting the opening degree, and the drain is diverted through the bypass pipes 73 and 74 and discharged into the outflow pipe 72. This allows the steam present in the piping system to be discharged along with the drain, thereby eliminating the steam locking phenomenon. The operation for eliminating this steam locking will be described in detail below.

[0048] Normally, the bypass valve 4 is in the closed state shown in Figure 5. In this closed state, the operator recognizes that the discharge of condensate from the outflow pipe 72 has stopped and understands that the steam locking phenomenon has occurred. Then, the operator removes the cap 51 of the bypass valve 4 shown in Figure 3, inserts a tool or the like into the valve stem operating groove 67 of the bypass valve stem 61, and rotates it in the loosening direction.

[0049] As a result, the bypass valve rod 61 moves in the direction of arrow 99 along the axis L1, and the bypass valve element 62 also gradually retreats away from the tip edge of the bypass valve port 49. In this embodiment, the state in which the bypass valve element 62 is away from the tip edge of the bypass valve port 49 is the open valve state.

[0050] Here, the bypass valve element 62 has a conical shape as described above, and the side surface is formed as a slope. Therefore, the opening degree of the bypass valve port 49 gradually increases as the bypass valve element 62 retracts in the direction of arrow 99, depending on the inclination of the slope of the bypass valve element 62. Conversely, when the bypass valve stem 61 is rotated in the tightening direction from the open state, the opening degree of the bypass valve port 49 gradually decreases depending on the inclination of the slope of the bypass valve element 62.

[0051] That is, as the operator rotates the bypass valve stem 61 in the loosening or tightening direction, the opening degree of the bypass valve 4 changes, and the flow rate of the drain water diverted and discharged through the bypass pipes 73 and 74 can be freely adjusted.

[0052] In the steam locking phenomenon, it is not always clear how much steam is present in which part of the piping system. For this reason, it is difficult to determine the timing for closing the bypass valve 4. In addition, if the bypass valve 4 is suddenly fully opened, it may take time to completely close the bypass valve 4 after the steam locking phenomenon is resolved, which may result in leakage of useful steam that should be transported through the piping system from the bypass pipes 73 and 74.

[0053] In this regard, in this embodiment, the operator can adjust the flow rate of the bypass pipes 73 and 74 while rotating the bypass valve stem 61 to discharge the drain, and therefore the bypass valve 4 can be gradually opened slightly to eliminate the steam locking phenomenon. Therefore, once the steam locking phenomenon is eliminated, the bypass valve 4 can be immediately closed (FIG. 5).

[0054] That is, the drain can be appropriately discharged through the bypass pipes 73 and 74 depending on the state of the drain accumulation, and the bypass valve 4 can be closed immediately after the steam locking phenomenon is resolved, so that steam leakage due to the resolution of the steam locking phenomenon can be reliably prevented.

[0055] As described above, the protruding length 81 of the bypass valve body 62 is formed to be sufficiently longer than the thickness 82 of the bypass valve port 49 (see FIG. 4), so that the bypass valve port 49 can be reliably opened even when the pressure in the piping system is low.

[0056] That is, particularly under low pressure, a liquid film is generated by the surface tension of the drain, and this liquid film may block the bypass valve port 49. If the thickness of the bypass valve port 49 is longer than the protruding length of the bypass valve disc 62, even if the bypass valve disc 62 enters the bypass valve port 49, a situation may occur in which the liquid curtain remains blocking the bypass valve port 49 and the valve cannot be opened.

[0057] In this regard, in this embodiment, the protrusion length 81 of the bypass valve element 62 is sufficiently longer than the thickness 82 of the bypass valve port 49, and the tip of the bypass valve element 62 can be positioned protruding toward the rear end of the bypass valve port 49 when the bypass valve element 62 is inserted into the bypass valve port 49. As a result, the tip of the bypass valve element 62 breaks through the liquid film, allowing the condensate to flow out along the slope of the bypass valve element 62 and reliably opening the valve. Therefore, the influence of the surface tension of the condensate can be avoided even under low pressure, and the condensate can be reliably discharged from the bypass pipes 73 and 74.

[0058] [Second embodiment] Next, a second embodiment of a valve system with a locking prevention function according to the present invention will be described with reference to Figures 6 to 8. Components that have the same configurations and operate in the same manner as in the first embodiment described above will be assigned the same reference numerals, and descriptions thereof will be omitted. This embodiment is substantially different from the first embodiment in that a temperature sensor 201 is provided in the steam trap 200 (see Figure 6), and an actuator 205 is provided in the bypass valve 220 (see Figure 7).

[0059] As shown in Fig. 6, a temperature sensor 201 is attached to the casing 7 of the steam trap 200. In Fig. 6, the temperature sensor 201 is shown in a side view. The temperature sensor 201 has a detection head 202, which is provided upstream of the valve port 28. In this embodiment, the detection head 202 is disposed to the side of the valve chest 16, and detects the temperature of the casing 7, thereby detecting the temperature of the condensate remaining in the valve chest 16. The temperature sensor 201 has a communication function, and can transmit the temperature of the condensate in the valve chest 16 detected by the detection head 202 as a temperature signal.

[0060] The temperature signal transmitted by the temperature sensor 201 is provided to the bypass valve 220. As shown in FIG. 7, the bypass valve 220 in this embodiment includes an actuator 205. In FIG. 7, the actuator 205 is shown as a block diagram. The actuator 205 includes a drive unit 209 mainly composed of a motor, and the drive unit 209 is connected to the rear end of the bypass valve stem 61. The actuator 205 further includes a receiving unit 206, a control unit 207, and a memory 208.

[0061] The temperature signal emitted by the temperature sensor 201 (FIG. 6) is received by the receiving unit 206 directly or indirectly (for example, via a server), and this temperature signal is taken in from the receiving unit 206 to the control unit 207. Then, the control unit 207 issues a command to the driving unit 209 in accordance with data (described later) stored in the memory 208, and operates to rotate the bypass valve rod 61, thereby moving the bypass valve rod 61 forward and backward in the directions of the arrows 98 and 99 along the axis L1.

[0062] 8 is a graph showing the relationship between the change in the temperature detected by the temperature sensor 201 and the valve opening. The change in the detected temperature is shown as a curve x. Data showing the relationship between the detected temperature and the valve opening is stored in advance in the memory 208.

[0063] Under normal circumstances, condensate generated in the piping system flows from the inlet pipe 71 into the valve chest 16 of the steam trap 200, and as the float 10 floats, the valve port 28 opens appropriately, allowing the condensate to be discharged into the outlet pipe 72. That is, under normal circumstances when no steam locking phenomenon is occurring, high-temperature condensate continuously flows into the valve chest 16 of the steam trap 200, and the temperature detected by the temperature sensor 201 indicates a substantially constant high temperature. The reference temperature a20 shown in Figure 8 is a threshold value for determining this constant high temperature under normal circumstances, and is stored in advance in the memory 208.

[0064] If steam locking occurs, where steam is trapped in part of the drain in the piping system, the flow of drain into the valve chamber 16 is blocked, preventing the float from rising and preventing the drain accumulated in the valve chamber 16 from being discharged. As a result, the drain in the valve chamber 16 releases heat over time, gradually decreasing in temperature, and the detected temperature falls below the reference temperature a20.

[0065] When the temperature drops below the reference temperature a20, the control unit 207 determines that the steam locking phenomenon has occurred, and issues a command to the drive unit 209 to rotate the bypass valve stem 61 in a direction to loosen it. As a result, the bypass valve stem 61 moves in the direction of arrow 99 along the axis L1, and the bypass valve element 62 retreats from the bypass valve port 49 (see FIG. 7).

[0066] As described in the first embodiment, the opening degree of the bypass valve port 49 changes depending on the slope of the bypass valve body 62, so the control unit 207 can adjust the opening degree of the bypass valve port 49 by controlling the rotation of the bypass valve rod 61.

[0067] 8, the control unit 207 adjusts the flow rate of the drain by controlling the opening of the bypass valve 220 in accordance with the detected temperature. The state in which the bypass valve element 62 completely closes the bypass valve port 49 (FIG. 5) is defined as the opening of the valve being "0%," and the state in which the bypass valve element 62 is completely retracted from the bypass valve port 49 and no longer interferes with the outflow of the drain is defined as the opening of the valve being "100%."

[0068] For example, at time "P21", the detected temperature is "a21", which is lower than the reference temperature "a20", and the corresponding valve opening is "75%", so the control unit 207 issues a command to the drive unit 209 to rotate the bypass valve rod 61 so that the bypass valve port 49 is opened to 75%.

[0069] In this way, the drain is discharged bypassing the bypass pipes 73 and 74 while being controlled by flow rate adjustment, and the steam locking phenomenon is resolved. As a result, high-temperature drain begins to flow into the steam trap 200, and the temperature detected by the temperature sensor 201 gradually increases, eventually reaching the reference temperature a20 at time point "P22".

[0070] In this embodiment, the opening degree of the bypass valve 220 is adjusted in response to the detected temperature, so that the opening degree of the bypass valve 220 is close to 0% immediately before the point "P22" when the steam locking phenomenon is resolved and the reference temperature a20 is reached. Therefore, immediately after the steam locking phenomenon is resolved, the bypass valve 220 is closed.

[0071] That is, the drain can be appropriately discharged through the bypass pipes 73 and 74 depending on the drain accumulation state, and the bypass valve 220 can be closed immediately when the steam locking phenomenon is resolved, so that steam leakage due to the resolution of the steam locking phenomenon can be reliably prevented.

[0072] Furthermore, in this embodiment, when the steam locking phenomenon occurs, the drain can be automatically and appropriately discharged through the bypass valve 220 depending on the drain accumulation state, thereby more efficiently eliminating the steam locking phenomenon.

[0073] [Third embodiment] Next, a third embodiment of a valve system having a locking release function according to the present invention will be described with reference to Figures 9 and 10. The valve system according to this embodiment has a configuration similar to that of the valve system according to the second embodiment. The substantial difference from the second embodiment is the content of the rotation control program for the bypass valve stem 61 executed by the control unit 207 of the actuator 205.

[0074] In the graph of Fig. 9, the change in the detected temperature of the drain in the valve chest 16 is represented by a curve x. In this embodiment, the degree of change in the detected temperature is determined as the slope of the change in the curve x, and the opening of the bypass valve port 49 is adjusted in accordance with this slope angle. Fig. 10 shows the relationship between the slope angle and the valve opening, and in this embodiment, the slope angle and the valve opening are set to be proportional to each other. The data in Fig. 10 showing the relationship between the slope angle and the valve opening is stored in advance in the memory 208 of the actuator 205.

[0075] As shown in FIG. 10, in this embodiment, when the change in curve x is gradual and the inclination angle is small, the valve opening is set to be small, and when the change in curve x is rapid and the inclination angle is large, the valve opening is set to be large.

[0076] Specifically, the control unit 207 calculates the center line of the curve x for a predetermined calculation time i3 that has been set in advance, determines the inclination angle of the center line, and issues a command to the drive unit 209 to rotate the bypass valve stem 61 so that the valve opening becomes equal to the inclination angle. Note that, during normal times when the steam locking phenomenon is not occurring, the temperature detected by the temperature sensor 201 indicates a substantially constant high temperature, and the inclination angle of the curve x is "0 degrees," so the opening of the bypass valve 220 is "0%" and the closed state is maintained.

[0077] When the steam locking phenomenon occurs, the detected temperature drops, and accordingly the control unit 207 rotates the bypass valve stem 61. For example, for time point "P32" in Fig. 9, the curve x of the detected temperature from time point "P32" to time point "P31" which is calculated time "i3" back is extracted, and the inclination angle of the center line k1 of the curve x during this period relative to the x-axis is calculated.

[0078] If the tilt angle is "35 degrees," the corresponding valve opening is "38.9%" as shown in FIG. 10, so the control unit 207 issues a command to the drive unit 209 to rotate the bypass valve stem 61 so that the bypass valve port 49 is opened to 38.9%.

[0079] In this embodiment, the inclination angle of the center line relative to the x-axis is calculated as an absolute value, so the inclination direction of the center line does not affect the calculated inclination angle. For example, for time point "P34," the curve x of the detected temperature from time point "P34" to time point "P33," which is calculated by going back calculation time "i3" from time point "P34," is extracted, and the inclination angle of the center line k2 of curve x during this period relative to the x-axis is calculated. In this case, the inclination angle is calculated as "30 degrees."

[0080] In this way, the drain is discharged bypassing the bypass pipes 73 and 74 while being controlled by flow rate adjustment, and the steam locking phenomenon is resolved. As a result, high-temperature drain begins to flow into the steam trap 200, and the temperature detected by the temperature sensor 201 gradually increases, eventually stabilizing at a constant high temperature at time point "P35."

[0081] In this embodiment, the opening degree of the bypass valve 220 is adjusted in accordance with the inclination angle of the center line of the curve x with respect to the x-axis, i.e., the degree of change in the detected temperature, so that just before the time point "P35" when the steam locking phenomenon is resolved, the inclination angle approaches "0 degrees" and the opening degree of the bypass valve 220 also approaches "0%." Therefore, after the steam locking phenomenon is resolved, the bypass valve 220 can be immediately closed.

[0082] That is, the drain can be appropriately discharged through the bypass pipes 73 and 74 depending on the drain accumulation state, and the bypass valve 220 can be closed immediately when the steam locking phenomenon is resolved, so that steam leakage due to the resolution of the steam locking phenomenon can be reliably prevented.

[0083] Furthermore, in this embodiment, when the steam locking phenomenon occurs, the drain can be automatically and appropriately discharged through the bypass valve 220 depending on the drain accumulation state, thereby more efficiently eliminating the steam locking phenomenon.

[0084] [Other embodiments] In the above-described embodiment, the float-type steam traps 1, 200 are used as an example of the basic valve, but this is not limited to this, and any valve having a different configuration can be used as long as it is provided on the basic flow path (such as the inlet pipe 71 and the outlet pipe 72) and blocks the passage of a fluid (such as steam or drain) when closed and allows the passage of a fluid when opened.

[0085] Furthermore, in the above-described embodiment, the bypass valve 4, 220 is exemplified as an auxiliary valve, but this is not limiting. Valves with other configurations may be employed as long as they are provided in the bypass flow path (bypass pipes 73, 74, etc.), open in response to a locking phenomenon in which a basic valve (steam trap 1, 200, etc.) cannot open due to a stagnation of fluid (steam, condensate, etc.) in the basic flow path (inlet pipe 71, outlet pipe 72, etc.), and allow fluid to pass through the bypass flow path. Note that, although it is assumed that the bypass valve 4 is normally closed, the bypass valve may also be slightly open under normal circumstances. By keeping the bypass valve slightly open, condensate discharge can be promoted by the Venturi effect even when the pressure upstream is low.

[0086] In the above-described embodiment, the bypass valve element 62 has a conical shape as the valve element portion, and the bypass valve port 49 has been illustrated as the auxiliary valve port portion, but the present invention is not limited to these, and other shapes and structures may be employed. For example, the valve element portion may be configured in a truncated cone shape instead of a cone shape, and further, a shape other than a cone shape may be employed.

[0087] In addition, in the above-described embodiment, the temperature sensor 201 is used as an example of the detection means, and a temperature signal is used as an example of the detection signal, but the present invention is not limited to this, and other configurations can be adopted as long as they detect a locking phenomenon (such as a steam locking phenomenon) and output a signal. For example, a vibration detection means can be adopted that detects drain discharge sound as vibration instead of temperature, and detects a locking phenomenon when the discharge sound is not generated. [Explanation of symbols]

[0088] 1, 200: Steam trap 4, 220: Bypass valve 10: Float 49: Bypass valve port 62: Bypass valve body 71: Inlet pipe 72: Outlet pipe 73, 74: Bypass pipe L1: Axis 201: Temperature sensor

Claims

1. A basic flow path through which a fluid passes from upstream to downstream. a basic valve that is provided on the basic flow path and can be opened or closed, blocking the passage of the fluid when closed and allowing the passage of the fluid when opened; an opening / closing means for closing or opening the basic valve; a bypass flow path connecting the upstream basic flow path of the basic valve with the downstream basic flow path; an auxiliary valve that is provided on the bypass flow path and can be opened or closed, and that opens when a locking phenomenon occurs in which the basic valve cannot be opened due to a stagnation state of the fluid in the basic flow path, and allows the fluid to pass through the bypass flow path; It is equipped with The auxiliary valve is capable of adjusting the flow rate of the fluid passing through the bypass flow path. A valve system having a locking release function.

2. 2. The valve system with a locking release function according to claim 1, The auxiliary valve is an auxiliary valve port portion through which the fluid passes, the auxiliary valve port portion having a center line disposed along the reference line; a valve body portion that moves into or out of the auxiliary valve port portion along the reference line and adjusts the flow rate of the fluid passing through the auxiliary valve port portion; It is equipped with The length of the valve body portion in the reference line direction is longer than the length of the auxiliary valve port portion in the reference line direction. A valve system having a locking release function.

3. In the valve system with a locking release function according to claim 1 or 2, a detection means for detecting the locking phenomenon and outputting a detection signal is provided in the basic flow path; the auxiliary valve adjusts the flow rate of the fluid passing through the bypass flow path based on the detection signal. A valve system having a locking release function.

4. In the valve system with a locking release function according to claim 3, the detecting means is a temperature detecting means for detecting the temperature of the fluid flowing through the basic flow path upstream of the basic valve or the temperature of the fluid flowing into the basic valve. A valve system having a locking release function.

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