Air-resistance-free pipeline control valve

Abstract

The air-resistance-free pipeline control valve comprises a valve deck, a valve body is fixedly installed on the bottom face of the valve deck through a double-end stud and a hexagon nut, an inner valve deck is fixedly installed in an inner cavity of the valve deck, an anti-steam-resistance valve plate is fixedly installed in a cavity of the inner valve deck, and the surface of the anti-steam-resistance valve plate is attached to the bottom face of the inner valve deck. A valve seat is fixedly installed in a cavity of the inner valve deck and located below the anti-steam-resistance valve plate. And the bottom of the valve seat is embedded in the valve body. The valve has the beneficial effects that the structural design is reasonable, the conception is novel, the operation is convenient, the processing and manufacturing cost is low, the valve can be quickly opened and closed within the steam pressure range of 1.6 MPa.G to 15.0 MPa.G, the working performance is stable, the steam leakage rate is zero after the valve is closed, and external driving of media such as electric power and compressed air is not needed.

Description

Technical Field

[0001] The present invention relates to the technical field of valve equipment, and particularly to a non-air-blocking pipeline control valve. Background Art

[0002] In the process of the trend of large-scale and high-parameter development of petrochemical industry equipment, the high-temperature and ultra-high-pressure thermodynamic pipeline control valve is used as the preferred type of pipeline control valve for steam use equipment and steam transmission pipelines with superheated steam conditions, small volume, high sensitivity, and arbitrary installation due to its advantages such as being applicable to superheated steam conditions, small size, high sensitivity, and arbitrary installation. Its uses are very extensive. Currently, the high-temperature and ultra-high-pressure pipeline control valves on the market generally have the problem of not opening the valve, that is: the valve disc is tightly pressed on the sealing surface of the valve seat and cannot be separated from the valve seat, and the condensate cannot be quickly discharged through the pipeline control valve. The reasons for the problem are as follows: First, non-condensable gas accumulates in the upper part of the valve cover cavity. This gas exerts a certain downward pressure on the top surface of the valve disc. At the same time, the bottom surface of the valve disc is subjected to an upward jacking pressure from the inlet water pressure. Since the force-bearing area of the bottom surface of the valve disc is small and the force-bearing area of the top surface of the valve disc is large, the jacking force received by the bottom surface of the valve disc is not sufficient to overcome the downward pressure exerted by the non-condensable gas on the top surface of the valve disc, which is the main reason for not opening the valve, resulting in the failure of the control valve to work. Second, at high temperatures, the temperature in the pressure-changing chamber of the inner valve cover decreases too slowly, resulting in a large amount of condensate accumulating in the pipeline control valve or the transmission pipeline. When the pipeline control valve does not open the valve, the condensate stays in the pipeline control valve, reducing the heat exchange efficiency of the equipment and indirectly causing the operation of the pipeline control valve to be paralyzed; when the pipeline control valve does not open the valve, the condensate staying in the pipeline will cause a water hammer phenomenon. In severe cases, the water hammer phenomenon will cause the pipeline to tear at the pipeline elbow, and the leakage of high-temperature and high-pressure steam will trigger major safety accidents. In winter, when the condensate accumulates and cannot be discharged, it is also possible to freeze and crack the transmission pipeline, causing serious losses.

[0003] For medium and low-pressure pipeline control valves, a bimetallic ring can be used as a measure to forcibly open the valve. However, for ultra-high-pressure pipeline control valves, the temperature is too high, resulting in slow deformation of the bimetallic ring, so that it cannot meet the design requirements. Currently, for the ultra-high-pressure and superheated temperature working conditions, there is no high-temperature and ultra-high-pressure thermodynamic pipeline control valve without air-blocking problems available in China. Summary of the Invention

[0004] The purpose of the present invention is to provide a non-air-blocking pipeline control valve with reasonable structural design, novel concept, convenient operation, low processing and manufacturing cost, capable of quickly opening and closing within the steam pressure range of 1.6 - 15.0 MPa.G, stable working performance, zero steam leakage after the valve is closed, and without the need for external driving media such as electricity and compressed air.

[0005] The present invention relates to a non-air-lock pipeline control valve, which comprises a valve cover. The bottom surface of the valve cover is fixedly installed with a valve body through stud bolts and hexagon nuts. An inner valve cover is fixedly installed inside the inner cavity of the valve cover. An anti-steam-lock valve disc is fixedly installed inside the cavity of the inner valve cover. The surface of the anti-steam-lock valve disc fits with the bottom surface of the inner valve cover. A valve seat is fixedly installed inside the cavity of the inner valve cover and is arranged below the anti-steam-lock valve disc; the bottom of the valve seat is fitted into the valve body.

[0006] The anti-steam-lock valve disc includes an upper valve disc, a small through hole, a middle valve disc, an elliptical cavity, a lower valve disc, and a tiny through hole. A small through hole is opened at the middle position of the upper valve disc. The bottom surface of the upper valve disc is fixedly connected with the middle valve disc. The bottom surface of the middle valve disc is fixedly connected with the lower valve disc. An elliptical cavity is opened on the middle valve disc. A tiny through hole is opened on the lower valve disc. The small through hole communicates with the elliptical cavity, and the elliptical cavity communicates with the tiny through hole.

[0007] An anti-steam-lock valve disc is fixedly installed inside the cavity of the inner valve cover, which is composed of three valve discs: an upper valve disc, a middle valve disc, and a lower valve disc. The combination of the small through holes and tiny through holes with different diameters on the upper valve disc and the lower valve disc and the elliptical cavity in the middle layer is applied. The elliptical cavity has a buffering effect, which solves the problem that the flow resistance of air and other non-condensable gases passing through the tiny through holes is too large and the anti-steam-lock valve disc is lifted slowly, effectively solving the problem of air air-block and steam steam-lock formation in high-temperature and ultra-high-pressure thermal power pipeline control valves, resulting in the valve not opening.

[0008] The valve cover includes a second-stage inner cavity of the valve cover, a first inner cavity of the valve cover, a second inner cavity of the valve cover, and valve cover bolt through holes. A first inner cavity of the valve cover and a second inner cavity of the valve cover are arranged inside the valve cover. A second-stage inner cavity of the valve cover is arranged on the surface of the second inner cavity of the valve cover. Valve cover bolt through holes are arranged on the edge of the valve cover.

[0009] The inner valve cover includes a through hole on the inner cavity table of the valve cover, a second-stage end face of the inner valve cover, an upper end face of the inner valve cover, and a pressure-changing chamber. The upper end face of the inner valve cover fits with the inner cavity surface of the valve cover. A pressure-changing chamber is arranged inside the inner valve cover. A second-stage end face of the inner valve cover is arranged below the pressure-changing chamber. A through hole on the inner cavity table of the valve cover is arranged inside the inner valve cover. An anti-steam-lock valve disc is arranged inside the pressure-changing chamber, and a valve seat is installed in the through hole on the inner cavity table of the valve cover.

[0010] The arranged inner valve cover and the anti-steam-lock valve disc cooperate with each other. The cavity formed between the inner valve cover and the anti-steam-lock valve disc is the pressure-changing chamber. Its function is that the pressure-changing chamber determines the opening and closing frequency of the pipeline control valve. When the height of the pressure-changing chamber increases, the pipeline control valve increases the opening frequency; when the height of the pressure-changing chamber decreases, the pipeline control valve decreases the opening frequency. The reasonable cooperation between the two lies in that a reasonable height of the pressure-changing chamber can ensure the normal operation of the pipeline control valve, avoid the frequent opening of the steam trap due to the increase of the pressure-changing chamber, which wears the valve disc and reduces the service life; avoid the too long closing time of the pipeline control valve caused by the too low pressure-changing chamber, resulting in pipeline water collection and affecting the heat exchange efficiency of steam-using equipment.

[0011] The described valve seat includes a lower end of the valve seat, a valve seat conical surface, a valve seat top surface, a valve seat cylindrical surface, an upper end surface of the cylindrical surface, a first flow channel at the valve seat inlet, a second flow channel at the valve seat inlet, a V-shaped annular water seal groove, a V-shaped annular lift groove, and a water outlet flow channel. The bottom of the valve seat is provided with the lower end of the valve seat. The surface of the lower end of the valve seat is fixedly connected with the valve seat conical surface. The surface of the valve seat conical surface is connected with the valve seat cylindrical surface. The surface of the valve seat cylindrical surface is provided with the upper end surface of the cylindrical surface. The valve seat top surface is located on the upper surface of the valve seat. The valve seat top surface is provided with a V-shaped annular water seal groove. The bottom surface of the V-shaped annular water seal groove communicates with the water outlet flow channel. The water outlet flow channel is arranged inside the valve seat. The bottom port of the water outlet flow channel penetrates through the bottom surface of the valve seat. A V-shaped annular lift groove is arranged on the second surface of the valve seat. A first flow channel at the valve seat inlet is arranged inside the valve seat. The port of the first flow channel at the valve seat inlet penetrates through the side wall of the valve seat and is flush with the side wall of the valve seat. The other end of the first flow channel at the valve seat inlet communicates with a second flow channel at the valve seat inlet. The port of the second flow channel at the valve seat inlet penetrates through the valve seat top surface and is flush with the valve seat top surface. The number of V-shaped annular water seal grooves is two and they are arranged on both sides of the second flow channel at the valve seat inlet. The number of V-shaped annular lift grooves is two and they are arranged outside the V-shaped annular water seal grooves.

[0012] The provided V-shaped annular water seal groove and V-shaped annular lift groove, due to the relatively small water outlet flow channel of the valve seat and the limited lifting space for the steam block prevention valve piece, the V-shaped annular water seal groove can effectively gather high condensate and enable it to quickly enter the drainage flow channel. The design of the V-shaped annular lift groove effectively balances the pressure between the upper and lower parts of the steam block prevention valve piece, and accelerates the rapid opening of the air block prevention valve piece during the discharge of high-temperature condensate.

[0013] The described valve body includes a first middle cavity of the valve body, an orifice of the valve body middle cavity, a first flow channel at the valve body inlet, a second flow channel at the valve body inlet, a second middle cavity of the valve body, an internal thread of the valve body cavity, a valve body ring groove, and a valve body bolt through hole. A first flow channel at the valve body inlet is communicated and arranged on one side of the valve body. The end of the first flow channel at the valve body inlet is fixedly connected with a second flow channel at the valve body inlet. A second middle cavity of the valve body is communicated and arranged on the other side of the valve body. The end of the second middle cavity of the valve body is fixedly connected with a first middle cavity of the valve body. The outer wall surface of the first middle cavity of the valve body is provided with an internal thread of the valve body cavity. The surface of the first middle cavity of the valve body is provided with an orifice of the valve body middle cavity. The surface of the valve body is provided with a valve body ring groove.

[0014] A bracket is fixedly installed on the outer wall surface of the described inner valve cover. The bracket includes an inner cavity, an internal threaded hole of the bracket, and a lower plane ring groove of the bracket shoulder. The bracket internally is provided with an inner cavity. The inner wall surface of the inner cavity is provided with an internal threaded hole of the bracket. The bottom surface of the side wall of the bracket is provided with a lower plane ring groove of the bracket shoulder. The position of the lower plane ring groove of the bracket shoulder corresponds to the position of the valve body ring groove. A filter screen is installed between the lower plane ring groove of the bracket shoulder and the valve body ring groove.

[0015] Fasteners for connecting the valve cover and the valve body are fixedly installed through stud bolts and hex nuts, with stable installation to ensure the safe operation of the entire device. The valve cover is installed outside the bracket and the filter screen. Steam enters the inner cavity of the valve cover through the valve body and the filter screen, forming a steam insulation cavity for the valve cover. This structure effectively solves the problem of pressure fluctuation in the pressure-changing chamber caused by temperature changes. The phenomenon of air hammer refers to the frequent operation of the pipeline control valve without condensate discharge, resulting in steam leakage. The main reason for air hammer is the decrease in pressure in the pressure-changing chamber. Low atmospheric temperature will accelerate the temperature decrease in the pressure-changing chamber, and the steam in the pressure-changing chamber condenses into water, causing a rapid pressure drop to form air hammer. The steam insulation cavity effectively extends the time for the temperature in the pressure-changing chamber to decrease, avoiding a short-term pressure drop in the pressure-changing chamber. The non-air-blocking valve disc frequently jumps to form air hammer, which is a common problem in thermodynamic pipeline control valves. Although air hammer can avoid the problem of non-opening of the valve, every time the pressure in the pressure-changing chamber fluctuates, the valve disc jumps once, and the lower sealing surface of the valve disc frequently pats on the valve seat sealing surface, which not only exacerbates the wear of the sealing surface but also leaks steam. Air hammer causes the service life of the valve disc to be only about 3 months. Therefore, it can solve the problem of uncontrollable air hammer frequency and fully avoid the occurrence of the problem of non-opening of the valve. The provided bracket is used to fixedly install the filter screen. The filter screen is installed between the annular groove on the lower plane of the shoulder of the bracket and the annular groove of the valve body, with stable fixed installation to ensure the safe operation of the entire device. The setting of the filter screen can filter residues and avoid the blockage of the valve seat hole by residues, resulting in the failure of the steam trap.

[0016] A first sealing gasket is provided at the position where the inner valve cover contacts the valve seat; a second sealing gasket is provided at the position where the valve cover contacts the valve body.

[0017] The provided first sealing gasket and second sealing gasket can effectively solve the problem of sealing between the inner valve cover and the valve seat, and between the valve cover and the valve body, ensuring the safe and stable operation of the entire device.

[0018] Advantages of the present invention: 1) An anti-steam-blocking valve disc is fixedly installed in the inner cavity of the inner valve cover, which is composed of three valve discs: an upper valve disc, a middle valve disc, and a lower valve disc. The combination of two small through holes and micro through holes with different diameters in the upper valve disc and the lower valve disc and the elliptical cavity in the middle layer is applied. The elliptical cavity has a buffering effect, solving the problem that the flow resistance of air and other non-condensable gases passing through the micro through holes is too large, and the anti-steam-blocking valve disc is lifted slowly. It effectively solves the problem of non-opening of the valve caused by air blockage and steam locking in high-temperature and ultra-high-pressure thermodynamic pipeline control valves.

[0019] 2) The inner valve cover is arranged to cooperate with the steam block prevention valve disc. The cavity formed between the inner valve cover and the steam block prevention valve disc is the pressure change chamber. Its function is that the pressure change chamber determines the opening and closing frequency of the pipeline control valve. When the height of the pressure change chamber increases, the opening frequency of the drain valve of the pipeline control valve increases; when the height of the pressure change chamber decreases, the opening frequency of the pipeline control valve decreases. The reasonable cooperation between the two lies in that a reasonable height of the pressure change chamber can ensure the normal operation of the pipeline control valve, avoid the frequent opening of the pipeline control valve caused by the increase of the pressure change chamber, which wears the valve disc and reduces its service life; and avoid the too low height of the pressure change chamber resulting in too long closing time of the pipeline control valve, water collection in the pipeline, and affecting the heat exchange efficiency of the pipeline control valve.

[0020] 3) The V-shaped annular water seal groove and V-shaped annular lift groove are arranged. Since the water outlet flow channel of the valve seat is small and the lifting space of the steam block prevention valve disc is limited, the V-shaped annular water seal groove can effectively gather high condensate and quickly let it enter the drainage flow channel; the design of the V-shaped annular lift groove effectively balances the pressure between the upper and lower parts of the steam block prevention valve disc and accelerates the rapid opening of the anti-air block valve disc during the discharge of high-temperature condensate.

[0021] 4) The fasteners for connecting the valve cover and the valve body are fixedly installed through stud bolts and hex nuts, with stable installation to ensure the safe operation of the whole device. The valve cover is installed outside the bracket and the filter net. Steam enters the inner cavity of the valve cover through the valve body and the filter net to form a steam insulation cavity for the valve cover. This structure effectively solves the problem of pressure fluctuation in the pressure change chamber caused by temperature change. The phenomenon of "idle stroke" means that the pipeline control valve frequently operates without condensate discharge, resulting in steam leakage. The main reason for causing "idle stroke" is the decrease in the pressure of the pressure change chamber; a low atmospheric temperature will accelerate the decrease in the temperature of the pressure change chamber, the steam in the pressure change chamber condenses into water, causing a rapid drop in pressure and forming "idle stroke". The steam insulation cavity effectively extends the time for the temperature of the pressure change chamber to decrease and avoids the rapid drop in pressure in the pressure change chamber within a short time; it also prevents the frequent start and stop of the airless valve disc to form "idle stroke". "Idle stroke" is a common problem in thermodynamic pipeline control valves. Although "idle stroke" can avoid the problem of non-opening of the valve, every time the pressure in the pressure change chamber fluctuates, the valve disc starts and stops once. The lower sealing surface of the valve disc frequently beats on the sealing surface of the valve seat, which not only aggravates the wear of the sealing surface but also leaks steam. "Idle stroke" causes the service life of the valve disc to be only about 3 months. Therefore, it can solve the problem of uncontrollable frequency of "idle stroke" and fully avoid the occurrence of the problem of non-opening of the valve. The bracket is provided for fixedly installing the filter net. The filter net is installed between the shoulder lower plane ring groove of the bracket and the ring groove of the valve body, with stable fixed installation to ensure the safe operation of the whole device. The filter net can filter residues and avoid the blockage of the valve seat hole by residues, resulting in the failure of the drain valve.

[0022] 5) The device is reasonably structured, novel in concept, convenient to operate, low in manufacturing cost, capable of quick opening and closing within the steam pressure range of 1.6 - 15.0 MPa.G, stable in working performance, with zero steam leakage after the valve is closed, and does not require external driving by media such as electricity and compressed air. It has good usage effects and is worthy of wide promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional view of a non-air-lock pipeline control valve of the present invention; Figure 2 is Figure 1 a cross-sectional view of the middle valve cover 3; Figure 3 is Figure 1 a top view of the middle valve cover 3; Figure 4 is Figure 1 a cross-sectional view of the inner valve cover 4; Figure 5 is Figure 1 a cross-sectional view of the non-steam-lock valve disc 5; Figure 6 is Figure 5 a cross-sectional view of the upper valve disc 5-1; Figure 7 is Figure 5 a top view of the upper valve disc 5-1; Figure 8 is Figure 5 a cross-sectional view of the middle valve disc 5-2; Figure 9 is Figure 5 a top view of the middle valve disc 5-2; Figure 10 is Figure 5 a cross-sectional view of the lower valve disc 5-3; Figure 11 is Figure 5 a bottom view of the lower valve disc 5-3; Figure 12 is Figure 1 a cross-sectional view of the inner valve seat 7; Figure 13 is Figure 1 a cross-sectional view of the bracket 9; Figure 14 is Figure 1 a cross-sectional view of the valve body 11; Figure 15 is Figure 14 a top view of the valve body 11; Figure 16 It is a schematic diagram of air, non-condensable gas, low-temperature condensate, high-temperature condensate, and steam in the cavity of a non-air-lock pipeline control valve of the invention; Figure 17Schematic diagram of discharging air and non-condensable gases in the initial state of the working principle of the present invention; Figure 18 Schematic diagram of the state of the pipeline control valve opening for draining when low-temperature condensate enters in the working principle of the present invention; Figure 19 Schematic diagram of the state of the pipeline control valve opening for draining when high-temperature condensate enters in the working principle of the present invention; Figure 20 Schematic diagram of the state of the steam entering the pipeline and the control valve closing to block steam in the working principle of the present invention.

[0024] In the figure: stud 1, hexagon nut 2, valve cover 3, two inner cavities of the valve cover 3-1, first inner cavity of the valve cover 3-2, second inner cavity of the valve cover 3-3, bolt through-hole of the valve cover 3-4, inner valve cover 4, stepped hole 4-1 in the inner cavity of the valve cover 4, end face of the two-stage of the inner valve cover 4-2, upper end face of the inner valve cover 4-3, pressure-changing chamber 4-4, steam-blocking valve disc 5, upper-layer valve disc 5-1, small through-hole 5-1-1, middle-layer valve disc 5-2, elliptical cavity 5-2-1, lower-layer valve disc 5-3, micro through-hole 5-3-1, upper end face of the air-blocking valve disc 5-4, lower end face of the air-blocking valve disc 5-5, first gasket 6, valve seat 7, lower end 7-1 of the valve seat, conical surface 7-2 of the valve seat, top surface 7-3 of the valve seat, cylindrical surface 7-4 of the valve seat, upper end surface 7-5 of the cylindrical surface, first flow channel 7-6 at the inlet of the valve seat, second flow channel 7-7 at the inlet of the valve seat, V-shaped annular water seal groove 7-8, V-shaped annular lift groove 7-9, water outlet flow channel 7-10, filter net 8, support 9, inner cavity 9-1, threaded inner hole 9-2 of the support, annular groove 9-3 on the lower plane of the shoulder of the support, second gasket 10, valve body 11, first middle cavity 11-1 of the valve body, orifice of the middle cavity of the valve body 11-2, first flow channel 11-3 at the inlet of the valve body, second flow channel 11-4 at the inlet of the valve body, second middle cavity 11-5 of the valve body, internal thread 11-6 in the inner cavity of the valve body, annular groove 11-7 of the valve body, bolt through-hole 11-8 of the valve body. Detailed implementation manners

[0025] Example 1. The following will further describe the present invention with reference to the accompanying drawings.

[0026] The present invention includes a stud 1, a hexagon nut 2, a valve cover 3, two platforms 3-1 in the inner cavity of the valve cover, a first inner cavity 3-2 of the valve cover, a second inner cavity 3-3 of the valve cover, a bolt through-hole 3-4 in the valve cover, an inner valve cover 4, a stepped hole 4-1 in the inner cavity of the inner valve cover 4, the end face of two platforms 4-2 of the inner valve cover, the upper end face 4-3 of the inner valve cover, a pressure transformation chamber 4-4, a steam resistance prevention valve disc 5, an upper layer valve disc 5-1, a small through-hole 5-1-1, a middle layer valve disc 5-2, an elliptical cavity 5-2-1, a lower layer valve disc 5-3, a tiny through-hole 5-3-1, the upper end face 5-4 of the steam resistance prevention valve disc, the lower end face 5-5 of the steam resistance prevention valve disc, a first gasket 6, a valve seat 7, the lower end 7-1 of the valve seat, a conical surface 7-2 of the valve seat, the top surface 7-3 of the valve seat, a cylindrical surface 7-4 of the valve seat, the upper end surface 7-5 of the cylindrical surface, a first flow channel 7-6 at the inlet of the valve seat, a second flow channel 7-7 at the inlet of the valve seat, a V-shaped annular water seal groove 7-8, a V-shaped annular lift groove 7-9, an outlet flow channel 7-10, a second gasket 10, a valve body 11, a first middle cavity 11-1 of the valve body, the orifice of the middle cavity 11-2 of the valve body, a first flow channel 11-3 at the inlet of the valve body, a second flow channel 11-4 at the inlet of the valve body, a second middle cavity 11-5 of the valve body, an internal thread 11-6 in the inner cavity of the valve body, an annular groove 11-7 in the valve body, a bolt through-hole 11-8 in the valve body. The specific structure includes a valve cover 3. The bottom surface of the valve cover 3 is fixedly installed with a valve body 11 through a stud 1 and a hexagon nut 2. An inner valve cover 4 is fixedly installed inside the inner cavity of the valve cover 3. A steam resistance prevention valve disc 5 is fixedly installed inside the cavity of the inner valve cover 4. The surface of the steam resistance prevention valve disc 5 is in contact with the bottom surface of the inner valve cover 4. A valve seat 7 is fixedly installed inside the cavity of the inner valve cover 4. The valve seat 7 is arranged below the steam resistance prevention valve disc 5. The bottom of the valve seat 7 is fitted into the valve body 11.

[0027] The steam resistance prevention valve disc 5 mentioned above includes an upper layer valve disc 5-1, a small through-hole 5-1-1, a middle layer valve disc 5-2, an elliptical cavity 5-2-1, a lower layer valve disc 5-3, and a tiny through-hole 5-3-1. A small through-hole 5-1-1 is opened at the middle position of the upper layer valve disc 5-1. The bottom surface of the upper layer valve disc 5-1 is fixedly connected to a middle layer valve disc 5-2. The bottom surface of the middle layer valve disc 5-2 is fixedly connected to a lower layer valve disc 5-3. An elliptical cavity 5-2-1 is opened on the middle layer valve disc 5-2. A tiny through-hole 5-3-1 is opened on the lower layer valve disc 5-3. The small through-hole 5-1-1 is communicated with the elliptical cavity 5-2-1, and the elliptical cavity 5-2-1 is communicated with the tiny through-hole 5-3-1.

[0028] The valve cover 3 mentioned above includes two platforms 3-1 in the inner cavity of the valve cover, a first inner cavity 3-2 of the valve cover, a second inner cavity 3-3 of the valve cover, and a bolt through-hole 3-4 in the valve cover. A first inner cavity 3-2 and a second inner cavity 3-3 of the valve cover are arranged inside the valve cover 3. Two platforms 3-1 in the inner cavity of the valve cover are arranged on the surface of the second inner cavity 3-3 of the valve cover. A bolt through-hole 3-4 is arranged on the edge of the valve cover 3.

[0029] The inner valve cover 4 described above includes a valve cover inner cavity step hole 4-1, an inner valve cover second step end face 4-2, an upper end face 4-3 of the inner valve cover, and a pressure conversion chamber 4-4. The upper end face 4-3 of the inner valve cover is in contact with the inner cavity surface of the valve cover 3. A pressure conversion chamber 4-4 is provided inside the inner valve cover 4. The inner valve cover second step end face 4-2 is provided below the pressure conversion chamber 4-4. A valve cover inner cavity step hole 4-1 is provided inside the inner valve cover 4. A steam resistance prevention valve piece 5 is provided inside the pressure conversion chamber 4-4. A valve seat 7 is installed inside the valve cover inner cavity step hole 4-1.

[0030] The valve seat 7 described above includes a lower end 7-1 of the valve seat, a valve seat conical surface 7-2, a top surface 7-3 of the valve seat, a valve seat cylindrical surface 7-4, an upper end surface 7-5 of the cylindrical surface, a first flow channel 7-6 at the valve seat inlet, a second flow channel 7-7 at the valve seat inlet, a V-shaped annular water seal groove 7-8, a V-shaped annular lift groove 7-9, and a water outlet flow channel 7-10. The bottom of the valve seat 7 is provided with a lower end 7-1 of the valve seat. The surface of the lower end 7-1 of the valve seat is fixedly connected with a valve seat conical surface 7-2. The surface of the valve seat conical surface 7-2 is connected with a valve seat cylindrical surface 7-4. The surface of the valve seat cylindrical surface 7-4 is provided with an upper end surface 7-5 of the cylindrical surface. The top surface 7-3 of the valve seat is located on the upper surface of the valve seat 7. A V-shaped annular water seal groove 7-8 is provided on the top surface 7-3 of the valve seat. The bottom surface of the V-shaped annular water seal groove 7-8 is communicated with a water outlet flow channel 7-10. The water outlet flow channel 7-10 is arranged inside the valve seat 7. The bottom port of the water outlet flow channel 7-10 penetrates the bottom surface of the valve seat 7. A V-shaped annular lift groove 7-9 is provided on the second step surface of the valve seat 7. A first flow channel 7-6 at the valve seat inlet is provided inside the valve seat 7. The port of the first flow channel 7-6 at the valve seat inlet penetrates the side wall of the valve seat 7 and is flush with the side wall of the valve seat 7. The other end of the first flow channel 7-6 at the valve seat inlet is communicated with a second flow channel 7-7 at the valve seat inlet. The port of the second flow channel 7-7 at the valve seat inlet penetrates the top surface 7-3 of the valve seat and is flush with the top surface 7-3 of the valve seat. The number of the V-shaped annular water seal grooves 7-8 is two and they are arranged on both sides of the second flow channel 7-7 at the valve seat inlet. The number of the V-shaped annular lift grooves 7-9 is two and they are arranged outside the V-shaped annular water seal grooves 7-8.

[0031] The valve body 11 described above includes a first middle cavity 11-1 of the valve body, an orifice part 11-2 of the valve body middle cavity, a first flow channel 11-3 at the valve body inlet, a second flow channel 11-4 at the valve body inlet, a second middle cavity 11-5 of the valve body, an internal thread 11-6 of the valve body inner cavity, a valve body ring groove 11-7, and a valve body bolt through hole 11-8. A first flow channel 11-3 at the valve body inlet is communicated and arranged on one side of the valve body 11. The end of the first flow channel 11-3 at the valve body inlet is fixedly connected with a second flow channel 11-4 at the valve body inlet. A second middle cavity 11-5 of the valve body is communicated and arranged on the other side of the valve body 11. The end of the second middle cavity 11-5 of the valve body is fixedly connected with a first middle cavity 11-1 of the valve body. An internal thread 11-6 of the valve body inner cavity is provided on the outer wall surface of the first middle cavity 11-1 of the valve body. An orifice part 11-2 of the valve body middle cavity is provided on the surface of the first middle cavity 11-1 of the valve body. A valve body ring groove 11-7 is provided on the surface of the valve body 11.

[0032] A first gasket 6 is provided at the position where the inner valve cover 4 contacts the valve seat 7; a second gasket 10 is provided at the position where the valve cover 3 contacts the valve body 11.

[0033] Usage method, according to Figures 17 - 20 : In the initial stage of operation, air and other non-condensable gases flow through the inlet flow channels 11-3 and 11-4 of the valve body 11 in sequence → the inner cavity 3-2 of the valve cover → pass through the filter net 8 → enter the inner cavity 3-3 of the valve cover → the inner cavity 9-1 of the support → the hard seal at the orifice 11-2 of the valve seat conical surface 7-2 and the middle cavity 11-1 of the valve body, preventing the medium from passing over the valve seat 7 and the opening and closing parts of the anti-air-lock valve piece 5 and leaking from this position to the middle cavity 11-1 and 11-5 of the valve body and then to the pipeline. Therefore, the only flow path for air and other non-condensable gases is that the inlet flow channels 7-6 and 7-7 of the valve seat generate an upward thrust on the anti-air-lock valve piece 5, and the air and other non-condensable gases in the pressure-changing chamber 4-4 of the inner valve cover are squeezed → pass through the small holes 5-1 in the upper valve piece of the anti-air-lock valve piece 5 → the different-shaped cavity 5-2 of the middle valve piece → the small hole 5-3 in the different-shaped cavity 5-2, that is, the small hole in the lower valve piece → the V-shaped water seal groove 7-8 of the valve seat. The anti-air-lock valve piece 5 is gradually lifted, and the air and other non-condensable gases in the inlet flow channel 7-7 of the valve seat quickly fill the V-shaped annular water seal groove 7-8 and the V-shaped annular lift groove 7-9 of the valve seat from the gap lifted by the anti-air-lock valve piece 5. As the air and other non-condensable gases entering the V-shaped annular lift groove 7-9 increase, the lifting force quickly pushes the anti-air-lock valve piece 5 to the maximum distance, and a large amount of air and non-condensable gases flow through the V-shaped annular water seal groove 7-8 of the valve seat → the water outlet flow channel 7-10 → the first middle cavity 11-1 of the valve body, the second middle cavity 11-5 of the valve body → and are discharged in sequence.

[0034] The state during the process of the pipeline control valve opening to discharge low-temperature condensate, that is, the valve-opening state: After the air and other non-condensable gases are discharged, the low-temperature condensate exits in a similar manner to the air and other non-condensable gases, flowing through the first inlet flow channel 11-3 of the valve body, the second inlet flow channel 11-4 of the valve body to the first middle cavity 11-1 of the valve body, the second middle cavity 11-5 of the valve body → and is discharged.

[0035] The state during the process of the pipeline control valve opening to discharge high-temperature condensate, that is, the valve-opening state: After the low-temperature condensate, high-temperature condensate follows. The high-temperature condensate flows through the first inlet flow channel 11-3 of the valve body, the second inlet flow channel 11-4 of the valve body to the first middle cavity 11-1 of the valve body, the second middle cavity 11-5 of the valve body → and is discharged in a similar manner to the air and other non-condensable gases; during this process, a certain amount of flash steam will be generated in the pressure-changing chamber 4-4 by the high-temperature condensate, and the amount of this flash steam is not sufficient to affect the drainage process of this valve.

[0036] The steam enters the process state of the pipeline control valve closing, i.e., the valve closing state: After high-temperature condensate water, there is steam in sequence. It passes through the first flow channel 11-3 at the valve body inlet, the second flow channel 11-4 at the valve body inlet → the inner cavity 3-2 of the valve cover → through the filter screen 8 → into the inner cavity 3-3 of the valve cover → the inner cavity 9-1 of the support. The steam flows into the only flow channel, the valve seat inlet flow channels 7-6 and 7-7, and enters the pressure-changing chamber from the bottom 5-5 of the anti-air-lock valve disc 5. At this time, the steam flow rate increases, the kinetic energy decreases, and a part of the steam reaches the top 5-4 of the anti-air-lock valve disc 5. In addition, there is still a certain amount of flash steam generated by the high-temperature condensate water accumulated in the pressure-changing chamber 4-4 of the inner valve cover. The pressure in the pressure-changing chamber 4-4 increases, pressing the anti-air-lock valve disc 5 towards the valve seat 7. Under the action of the pressure in the pressure-changing chamber, a downward pressing force is generated at the top 5-4 of the anti-air-lock valve disc 5. The steam inlet 7-7 generates an upward lifting force on the lower end face 5-5 of the anti-air-lock valve disc. The force-bearing area of the steam acting on the top 5-4 of the anti-air-lock valve disc in the pressure-changing chamber 4-4 of the valve cover is a multiple of the force-bearing area of the lower end face 5-5 of the anti-air-lock valve disc 5. Therefore, the lifting force is less than the pressure, and the anti-air-lock valve disc 5 is tightly pressed on the top surface 7-3 of the valve seat. The pipeline control valve closes, realizing the steam-blocking function of the pipeline control valve.

[0037] At this time, the first inner cavity 3-2 and the second inner cavity 3-3 of the valve cover are filled with steam, forming a steam heat-insulating cover for the valve seat 7, the anti-air-lock valve disc 5, and the inner valve cover 4. This steam heat-insulating cover effectively prevents the valve disc from frequently starting and jumping due to the too rapid decrease in temperature in the pressure-changing chamber 4-4 of the inner valve cover. For example: Installed outdoors in winter, the flash steam in the pressure-changing chamber 4-4 dissipates heat to the outside and condenses into water. The pressure in the pressure-changing chamber 4-4 decreases. The valve disc is quickly lifted at the steam inlet 7-7 of the valve seat. The pipeline control valve opens, and a burst of steam is instantly leaked to the pipeline through the valve seat outlet 7-10. At the same time, a part of the steam enters the pressure-changing chamber 4-4 and quickly presses the valve disc onto the top surface 7-3 of the valve seat. The valve disc seats and the pipeline control valve closes. The steam entering the pressure-changing chamber 4-4 continues to dissipate heat to the outside and condenses into water. The pressure in the pressure-changing chamber decreases, and the valve disc is lifted again. The pipeline control valve opens and leaks steam, repeating the above process. Therefore, the valve disc is frequently lifted within one minute and instantaneously seats more than three times, which is usually called the "empty hitting" phenomenon. This phenomenon will cause the valve disc to deform, severely wear the valve disc, and the steam-water valve function of the valve seat sealing surface to fail. This device, with the steam heat-insulating cover structure formed by the valve cover 3, solves the problem of "empty hitting".

[0038] As the high-temperature condensate in the pipeline gradually forms, the steam in the flow channel of the pipeline control valve and the steam in the pressure-changing chamber 4-4 gradually condense. The pressure in the pressure-changing chamber 4-4 decreases, and the steam-blocking prevention valve disc 5 is lifted again, and the steam trap opens again, repeating the above working process; during this working process, the small through-hole 5-1-1, the elliptical cavity 5-2-1, the tiny through-hole 5-3-1 of the steam-blocking prevention valve disc 5 are connected to the V-shaped annular water seal groove 7-8, which can effectively control the condensation of the steam in the pressure-changing chamber 4-4 and solve the problem of steam locking, that is: when superheated steam enters the pipeline control valve cavity, the process of its condensation into water is relatively slow, resulting in slow water conveyance of the pipeline control valve, which is steam locking.

[0039] If the valve is installed in a working condition with more air, the air can pass through the small through-hole 5-1-1 → the elliptical cavity 5-2-1 → the tiny through-hole 5-3-1, that is, the tiny through-hole 5-3-1 of the lower valve disc 5-3 enters the V-shaped annular water seal groove 7-8 of the valve seat 7, and is discharged together with the high-temperature condensate when the steam trap opens.

[0040] To sum up, the steam-blocking prevention valve disc 5 of the present invention is composed of three valve discs: the upper valve disc 5-1, the middle valve disc 5-2, and the lower valve disc 5-3. By applying the combination of the small through-holes 5-1-1 and the tiny through-holes 5-3-1 with different diameters of the upper valve disc 5-1 and the lower valve disc 5-3 and the elliptical cavity 5-2-1 in the middle layer, the elliptical cavity 5-2-1 has a buffering effect, solves the problem that the flow resistance of air and other non-condensable gases passing through the tiny through-hole 5-3-1 is too large, and the steam-blocking prevention valve disc 5 is lifted slowly, effectively solving the problem of "non-opening valve" caused by air blockage and steam locking commonly existing in high-temperature and super-high-pressure thermal power pipeline control valves.

[0041] Embodiment 2. The present invention includes a stud 1, a hexagonal nut 2, a valve cover 3, two inner cavities 3-1 in the valve cover, a first inner cavity 3-2 of the valve cover, a second inner cavity 3-3 of the valve cover, a bolt through-hole 3-4 in the valve cover, an inner valve cover 4, a hole 4-1 in the inner cavity of the inner valve cover 4, an end face 4-2 of the two-stage inner valve cover, an upper end face 4-3 of the inner valve cover, a pressure-changing chamber 4-4, a steam-blocking valve disc 5, an upper valve disc 5-1, a small through-hole 5-1-1, a middle valve disc 5-2, an elliptical cavity 5-2-1, a lower valve disc 5-3, a micro through-hole 5-3-1, an upper end face 5-4 of the steam-blocking valve disc, a lower end face 5-5 of the steam-blocking valve disc, a first gasket 6, a valve seat 7, a lower end 7-1 of the valve seat, a conical surface 7-2 of the valve seat, a top surface 7-3 of the valve seat, a cylindrical surface 7-4 of the valve seat, an upper end surface 7-5 of the cylindrical surface, a first flow channel 7-6 at the inlet of the valve seat, a second flow channel 7-7 at the inlet of the valve seat, a V-shaped annular water seal groove 7-8, a V-shaped annular lift groove 7-9, an outlet flow channel 7-10, a filter screen 8, a bracket 9, an inner cavity 9-1, a threaded inner hole 9-2 of the bracket, a circumferential groove 9-3 on the lower plane of the shoulder of the bracket, a second gasket 10, a valve body 11, a first middle cavity 11-1 of the valve body, an orifice 11-2 of the middle cavity of the valve body, a first flow channel 11-3 at the inlet of the valve body, a second flow channel 11-4 at the inlet of the valve body, a second middle cavity 11-5 of the valve body, an internal thread 11-6 in the inner cavity of the valve body, an annular groove 11-7 of the valve body, and a bolt through-hole 11-8 of the valve body. The specific structure includes a valve cover 3. The bottom surface of the valve cover 3 is fixedly installed with a valve body 11 through a stud 1 and a hexagonal nut 2. An inner valve cover 4 is fixedly installed inside the inner cavity of the valve cover 3. A steam-blocking valve disc 5 is fixedly installed inside the inner cavity of the inner valve cover 4. The surface of the steam-blocking valve disc 5 is in contact with the bottom surface of the inner valve cover 4. A valve seat 7 is fixedly installed inside the inner cavity of the inner valve cover 4. The valve seat 7 is arranged below the steam-blocking valve disc 5. The bottom of the valve seat 7 is fitted into the valve body 11.

[0042] The steam-blocking valve disc 5 mentioned above includes an upper valve disc 5-1, a small through-hole 5-1-1, a middle valve disc 5-2, an elliptical cavity 5-2-1, a lower valve disc 5-3, and a micro through-hole 5-3-1. A small through-hole 5-1-1 is provided at the middle position of the upper valve disc 5-1. The bottom surface of the upper valve disc 5-1 is fixedly connected to the middle valve disc 5-2. The bottom surface of the middle valve disc 5-2 is fixedly connected to the lower valve disc 5-3. An elliptical cavity 5-2-1 is provided on the middle valve disc 5-2. A micro through-hole 5-3-1 is provided on the lower valve disc 5-3. The small through-hole 5-1-1 is communicated with the elliptical cavity 5-2-1, and the elliptical cavity 5-2-1 is communicated with the micro through-hole 5-3-1.

[0043] The valve cover 3 mentioned above includes two inner cavities 3-1 in the valve cover, a first inner cavity 3-2 of the valve cover, a second inner cavity 3-3 of the valve cover, and a bolt through-hole 3-4 in the valve cover. A first inner cavity 3-2 and a second inner cavity 3-3 are provided inside the valve cover 3. The surface of the second inner cavity 3-3 is provided with two inner cavities 3-1 in the valve cover. A bolt through-hole 3-4 is provided at the edge of the valve cover 3.

[0044] The inner valve cover 4 described above includes a valve cover inner cavity step hole 4-1, an inner valve cover second step end face 4-2, an upper end face 4-3 of the inner valve cover, and a pressure conversion chamber 4-4. The upper end face 4-3 of the inner valve cover is attached to the inner cavity surface of the valve cover 3. A pressure conversion chamber 4-4 is arranged inside the inner valve cover 4. An inner valve cover second step end face 4-2 is arranged below the pressure conversion chamber 4-4. A valve cover inner cavity step hole 4-1 is arranged inside the inner valve cover 4. A steam resistance prevention valve piece 5 is arranged inside the pressure conversion chamber 4-4. A valve seat 7 is installed inside the valve cover inner cavity step hole 4-1.

[0045] The valve seat 7 described above includes a lower end 7-1 of the valve seat, a valve seat conical surface 7-2, a valve seat top surface 7-3, a valve seat cylindrical surface 7-4, an upper end surface 7-5 of the cylindrical surface, a first flow channel 7-6 at the valve seat inlet, a second flow channel 7-7 at the valve seat inlet, a V-shaped annular water seal groove 7-8, a V-shaped annular lift groove 7-9, and a water outlet flow channel 7-10. The bottom of the valve seat 7 is provided with a lower end 7-1 of the valve seat. The surface of the lower end 7-1 of the valve seat is fixedly connected with a valve seat conical surface 7-2. The surface of the valve seat conical surface 7-2 is connected with a valve seat cylindrical surface 7-4. The surface of the valve seat cylindrical surface 7-4 is provided with an upper end surface 7-5 of the cylindrical surface. The valve seat top surface 7-3 is located on the upper surface of the valve seat 7. A V-shaped annular water seal groove 7-8 is arranged on the valve seat top surface 7-3. The bottom surface of the V-shaped annular water seal groove 7-8 is communicated with a water outlet flow channel 7-10. The water outlet flow channel 7-10 is arranged inside the valve seat 7. The bottom port of the water outlet flow channel 7-10 penetrates through the bottom surface of the valve seat 7. A V-shaped annular lift groove 7-9 is arranged on the second step surface of the valve seat 7. A first flow channel 7-6 at the valve seat inlet is arranged inside the valve seat 7. The port of the first flow channel 7-6 at the valve seat inlet penetrates through the side wall of the valve seat 7 and is flush with the side wall of the valve seat 7. The other end of the first flow channel 7-6 at the valve seat inlet is communicated with a second flow channel 7-7 at the valve seat inlet. The port of the second flow channel 7-7 at the valve seat inlet penetrates through the valve seat top surface 7-3 and is flush with the valve seat top surface 7-3. The number of the V-shaped annular water seal grooves 7-8 is two, which are arranged on both sides of the second flow channel 7-7 at the valve seat inlet. The number of the V-shaped annular lift grooves 7-9 is two, which are arranged outside the V-shaped annular water seal grooves 7-8.

[0046] The valve body 11 described above includes a first middle cavity 11-1 of the valve body, a mouth part 11-2 of the valve body middle cavity, a first flow channel 11-3 at the valve body inlet, a second flow channel 11-4 at the valve body inlet, a second middle cavity 11-5 of the valve body, an internal thread 11-6 of the valve body cavity, a valve body ring groove 11-7, and a valve body bolt through hole 11-8. A first flow channel 11-3 at the valve body inlet is communicated and arranged on one side of the valve body 11. The end of the first flow channel 11-3 at the valve body inlet is fixedly connected with a second flow channel 11-4 at the valve body inlet. A second middle cavity 11-5 of the valve body is communicated and arranged on the other side of the valve body 11. The end of the second middle cavity 11-5 of the valve body is fixedly connected with a first middle cavity 11-1 of the valve body. An internal thread 11-6 of the valve body cavity is arranged on the outer wall surface of the first middle cavity 11-1 of the valve body. A mouth part 11-2 of the valve body middle cavity is arranged on the surface of the first middle cavity 11-1 of the valve body. A valve body ring groove 11-7 is arranged on the surface of the valve body 11.

[0047] A bracket 9 is fixedly installed on the outer wall surface of the inner valve cover 4. The bracket 9 includes an inner cavity 9-1, an internal threaded hole 9-2 of the bracket, and a lower plane annular groove 9-3 of the bracket shoulder. An inner cavity 9-1 is provided inside the bracket 9, an internal threaded hole 9-2 of the bracket is provided on the inner wall surface of the inner cavity 9-1, and a lower plane annular groove 9-3 of the bracket shoulder is provided on the bottom surface of the side wall of the bracket 9. The position of the lower plane annular groove 9-3 of the bracket shoulder corresponds to the position of the valve body annular groove 11-7. A filter screen 8 is installed between the lower plane annular groove 9-3 of the bracket shoulder and the valve body annular groove 11-7.

[0048] A first gasket 6 is arranged at the position where the inner valve cover 4 contacts the valve seat 7; a second gasket 10 is arranged at the position where the valve cover 3 contacts the valve body 11.

[0049] Usage method, according to Figures 17 - 20 : In the initial stage of operation, air and other non-condensable gases sequentially flow from the inlet flow channels 11-3 and 11-4 of the valve body 11 → the inner cavity 3-2 of the valve cover → pass through the filter screen 8 → enter the inner cavity 3-3 of the valve cover → the inner cavity 9-1 of the bracket → the hard seal at the orifice 11-2 of the conical surface 7-2 of the valve seat and the middle cavity 11-1 of the valve body, preventing the medium from leaking from this place across the valve seat 7 and the opening and closing member of the anti-air-lock valve piece 5 into the middle cavities 11-1 and 11-5 of the valve body and then to the pipeline. Therefore, the only flow path for air and other non-condensable gases is that the inlet flow channels 7-6 and 7-7 of the valve seat generate an upward thrust on the anti-air-lock valve piece 5, and the air and other non-condensable gases in the pressure-changing chamber 4-4 of the inner valve cover are squeezed → pass through the upper valve piece small holes 5-1 of the anti-air-lock valve piece 5 → the middle valve piece cavity 5-2 → the lower valve piece 5-3, that is, the small holes of the lower valve piece → the V-shaped water seal groove 7-8 of the valve seat. The anti-air-lock valve piece 5 is gradually lifted, and the air and other non-condensable gases in the inlet flow channel 7-7 of the valve seat quickly fill the V-shaped annular water seal groove 7-8 and the V-shaped annular lift groove 7-9 of the valve seat from the gap lifted by the anti-air-lock valve piece 5. As the air and other non-condensable gases entering the V-shaped annular lift groove 7-9 increase, the lifting force quickly pushes the anti-air-lock valve piece 5 to the maximum distance, and a large amount of air and non-condensable gases sequentially flow from the V-shaped annular water seal groove 7-8 of the valve seat → the water outlet flow channel 7-10 → the first middle cavity 11-1 of the valve body, the second middle cavity 11-5 of the valve body → and are discharged.

[0050] The state during the process of the steam trap opening to discharge low-temperature condensed water, that is, the valve opening state: After the air and other non-condensable gases are discharged, the low-temperature condensed water flows out in a similar manner to the air and other non-condensable gases, sequentially from the first inlet flow channel 11-3 of the valve body, the second inlet flow channel 11-4 of the valve body to the first middle cavity 11-1 of the valve body, the second middle cavity 11-5 of the valve body → and is discharged.

[0051] The state of the steam trap during the process of opening to discharge high-temperature condensate, i.e., the open-valve state: After low-temperature condensate, high-temperature condensate follows. The high-temperature condensate, similar to air and other non-condensable gases, sequentially flows from the first flow path 11-3 at the valve body inlet, the second flow path 11-4 at the valve body inlet to the first middle cavity 11-1 of the valve body, the second middle cavity 11-5 of the valve body → and is discharged; during this process, a certain amount of flash steam will be generated in the pressure-changing chamber 4-4 by the high-temperature condensate, and the amount of this flash steam is not sufficient to affect the drainage process of this valve.

[0052] The state of the steam trap during the process of steam entering and closing, i.e., the closed-valve state: After high-temperature condensate, steam follows. It sequentially flows from the first flow path 11-3 at the valve body inlet, the second flow path 11-4 at the valve body inlet → the inner cavity 3-2 of the valve cover → passes through the filter screen 8 → enters the inner cavity 3-3 of the valve cover → the inner cavity 9-1 of the support. The steam flows into the only flow path, the seat inlet flow paths 7-6 and 7-7, and enters the pressure-changing chamber from the bottom 5-5 of the anti-air-lock valve disc 5. At this time, the steam flow rate increases, the kinetic energy decreases, and a part of the steam reaches the top 5-4 of the anti-air-lock valve disc 5. In addition, there is still a certain amount of flash steam generated by the high-temperature condensate accumulated in the pressure-changing chamber 4-4 of the inner valve cover. The pressure in the pressure-changing chamber 4-4 increases, pressing the anti-air-lock valve disc 5 towards the valve seat 7. Under the action of the internal pressure in the pressure-changing chamber, a downward pressing force is generated at the top 5-4 of the anti-air-lock valve disc 5, and an upward lifting force is generated at the lower end face 5-5 of the anti-air-lock valve disc by the steam flow inlet 7-7 at the seat. The multiple of the force-bearing area of the steam acting on the top 5-4 of the anti-air-lock valve disc in the pressure-changing chamber 4-4 of the valve cover to the force-bearing area of the lower end face 5-5 of the anti-air-lock valve disc is such that, therefore, the lifting force is less than the pressure, and the anti-air-lock valve disc 5 is tightly pressed on the top surface 7-3 of the valve seat, and the steam trap closes the valve, realizing the steam-blocking function of the steam trap.

[0053] At this time, the first inner cavity 3-2 and the second inner cavity 3-3 of the valve cover are filled with steam, forming a steam heat-insulating cover for the valve seat 7, the anti-air-lock valve disc 5, and the inner valve cover 4. This steam heat-insulating cover effectively prevents the valve disc from frequently starting and jumping due to the too rapid decrease in temperature in the pressure-changing chamber 4-4 of the inner valve cover. For example: Installed outdoors in winter, the flash steam in the pressure-changing chamber 4-4 dissipates heat to the outside and condenses into water, the pressure in the pressure-changing chamber 4-4 decreases, and the valve disc is quickly lifted at the steam flow inlet 7-7 of the seat, the steam trap opens the valve, and instantly a stream of steam leaks to the pipeline through the seat outlet 7-10. At the same time, a part of the steam enters the pressure-changing chamber 4-4 and quickly presses the valve disc onto the top surface 7-3 of the valve seat, and the valve disc seats and the steam trap closes the valve. The steam entering the pressure-changing chamber 4-4 continues to dissipate heat to the outside and condenses into water, the pressure in the pressure-changing chamber decreases, the valve disc is lifted again, and the steam trap opens the valve and leaks steam, repeating the above process. Therefore, the valve disc is frequently lifted and instantly seated more than three times within one minute, which is usually called the "empty beating" phenomenon. This phenomenon will cause the valve disc to deform, severely wear the valve disc, and the steam trap function of the seat sealing surface fails. This device, with the steam heat-insulating cover structure formed by the valve cover 3, solves the problem of "empty beating".

[0054] As high-temperature condensed water gradually forms in the pipeline, the steam in the flow path of the steam trap and the steam in the pressure-changing chamber 4-4 gradually condense. The pressure in the pressure-changing chamber 4-4 decreases, and the anti-steam-lock valve disc 5 is lifted again, and the steam trap opens the valve again, repeating the above working process. During this working process, the small through-hole 5-1-1, the elliptical cavity 5-2-1, the micro through-hole 5-3-1 of the anti-steam-lock valve disc 5 are connected to the V-shaped annular water seal groove 7-8, which can effectively control the condensation of steam in the pressure-changing chamber 4-4 and solve the problem of steam locking, that is: when superheated steam enters the pipeline control valve cavity, the process of its condensation into water is relatively slow, resulting in slow water conveyance of the pipeline control valve, which is steam locking.

[0055] If the valve is installed in a working condition with more air, the air can pass through the small through-hole 5-1-1 → the elliptical cavity 5-2-1 → the micro through-hole 5-3-1, that is, the micro through-hole 5-3-1 of the lower valve disc 5-3 enters the V-shaped annular water seal groove 7-8 of the valve seat 7, and is discharged together with the high-temperature condensed water when the pipeline control valve opens the valve.

[0056] In summary, the anti-steam-block valve disc 5 in this device is composed of three valve discs: the upper valve disc 5-1, the middle valve disc 5-2, and the lower valve disc 5-3. The combination of the small through-holes 5-1-1 and the micro through-holes 5-3-1 with different diameters of the upper valve disc 5-1 and the lower valve disc 5-3 and the elliptical cavity 5-2-1 in the middle layer is applied. The elliptical cavity 5-2-1 has a buffering effect, solves the problem that the flow resistance of air and other non-condensable gases passing through the micro through-hole 5-3-1 is too large, and the anti-steam-lock valve disc 5 is lifted slowly, effectively solving the problem of non-opening of the air blockage and steam locking commonly existing in the high-temperature and super-high-pressure thermal power pipeline control valve.

[0057] The annular groove 9-3 on the lower plane of the bracket shoulder of the bracket 9 in this device corresponds to the annular groove 11-7 of the valve body, effectively pressing the filter screen 8 tightly and minimizing the gap, avoiding residue from blocking the valve seat hole and causing the pipeline control valve to fail, and the fixation is safer and more reliable.

Claims

1. A non-air-lock pipeline control valve, comprising a valve cover (3), wherein the bottom surface of the valve cover (3) is fixedly installed with a valve body (11) through a stud (1) and a hexagon nut (2), and is characterized in that: An inner valve cover (4) is fixedly installed inside the inner cavity of the valve cover (3). An anti-steam-blocking valve disc (5) is fixedly installed inside the cavity of the inner valve cover (4). The surface of the anti-steam-blocking valve disc (5) is in contact with the bottom surface of the inner valve cover (4). A valve seat (7) is fixedly installed inside the cavity of the inner valve cover (4), and the valve seat (7) is arranged below the anti-steam-blocking valve disc (5); the bottom of the valve seat (7) is fitted inside the valve body (11).

2. The airless pipeline control valve according to claim 1, wherein: The anti-steam-blocking valve disc (5) includes an upper valve disc (5-1), a small through-hole (5-1-1), a middle valve disc (5-2), an elliptical cavity (5-2-1), a lower valve disc (5-3), and a tiny through-hole (5-3-1). A small through-hole (5-1-1) is opened at the middle position of the upper valve disc (5-1). The bottom surface of the upper valve disc (5-1) is fixedly connected to the middle valve disc (5-2). The bottom surface of the middle valve disc (5-2) is fixedly connected to the lower valve disc (5-3). An elliptical cavity (5-2-1) is opened on the middle valve disc (5-2). A tiny through-hole (5-3-1) is opened on the lower valve disc (5-3). The small through-hole (5-1-1) communicates with the elliptical cavity (5-2-1), and the elliptical cavity (5-2-1) communicates with the tiny through-hole (5-3-1).

3. The airless blockage pipeline control valve according to claim 2, characterized in that: The valve cover (3) includes a valve cover inner cavity second platform (3-1), a valve cover first inner cavity (3-2), a valve cover second inner cavity (3-3), and valve cover bolt through-holes (3-4). A valve cover first inner cavity (3-2) and a valve cover second inner cavity (3-3) are arranged inside the valve cover (3). The surface of the valve cover second inner cavity (3-3) is provided with a valve cover inner cavity second platform (3-1). Valve cover bolt through-holes (3-4) are arranged on the edge of the valve cover (3).

4. The airless pipeline control valve according to claim 3, wherein: The inner valve cover (4) includes a valve cover inner cavity platform hole (4-1), an inner valve cover second platform end face (4-2), an inner valve cover upper end face (4-3), and a pressure-changing chamber (4-4). The inner valve cover upper end face (4-3) is in contact with the inner cavity surface of the valve cover (3). A pressure-changing chamber (4-4) is arranged inside the inner valve cover (4). An inner valve cover second platform end face (4-2) is arranged below the pressure-changing chamber (4-4). A valve cover inner cavity platform hole (4-1) is arranged inside the inner valve cover (4). The anti-steam-blocking valve disc (5) is arranged inside the pressure-changing chamber (4-4), and the valve seat (7) is installed inside the valve cover inner cavity platform hole (4-1).

5. The airless pipeline control valve according to claim 4, characterized in that: The described valve seat (7) includes a valve seat lower end (7-1), a valve seat conical surface (7-2), a valve seat top surface (7-3), a valve seat cylindrical surface (7-4), a cylindrical surface upper end (7-5), a valve seat inlet first flow channel (7-6), a valve seat inlet second flow channel (7-7), a V-shaped annular water seal groove (7-8), a V-shaped annular lift groove (7-9), and a water outlet flow channel (7-10). The bottom of the valve seat (7) is provided with a valve seat lower end (7-1), and the surface of the valve seat lower end (7-1) is fixedly connected to a valve seat conical surface (7-2). The surface of the valve seat conical surface (7-2) is connected to a valve seat cylindrical surface (7-4). The surface of the valve seat cylindrical surface (7-4) is provided with a cylindrical surface upper end (7-5). The valve seat top surface (7-3) is located on the upper surface of the valve seat (7), and the valve seat top surface (7-3) is provided with a V-shaped annular water seal groove (7-8). The bottom surface of the V-shaped annular water seal groove (7-8) communicates with a water outlet flow channel (7-10). The water outlet flow channel (7-10) is arranged inside the valve seat (7), and the bottom surface port of the water outlet flow channel (7-10) penetrates through the bottom surface of the valve seat (7). A V-shaped annular lift groove (7-9) is provided on the second platform of the valve seat (7). A valve seat inlet first flow channel (7-6) is arranged inside the valve seat (7). The port of the valve seat inlet first flow channel (7-6) penetrates through the side wall of the valve seat (7) and is flush with the side wall of the valve seat (7). The other end of the valve seat inlet first flow channel (7-6) communicates with a valve seat inlet second flow channel (7-7). The port of the valve seat inlet second flow channel (7-7) penetrates through the valve seat top surface (7-3) and is flush with the valve seat top surface (7-3). The number of V-shaped annular water seal grooves (7-8) is two, and they are arranged on both sides of the valve seat inlet second flow channel (7-7). The number of V-shaped annular lift grooves (7-9) is two, and they are arranged outside the V-shaped annular water seal grooves (7-8).

6. The airless pipeline control valve according to claim 5, characterized in that: The described valve body (11) includes a valve body first middle cavity (11-1), a valve body middle cavity opening (11-2), a valve body inlet first flow channel (11-3), a valve body inlet second flow channel (11-4), a valve body second middle cavity (11-5), an inner cavity thread of the valve body (11-6), a valve body ring groove (11-7), and a valve body bolt through hole (11-8). A valve body inlet first flow channel (11-3) is communicated and arranged on one side of the valve body (11), and the end of the valve body inlet first flow channel (11-3) is fixedly connected to a valve body inlet second flow channel (11-4). A valve body second middle cavity (11-5) is communicated and arranged on the other side of the valve body (11), and the end of the valve body second middle cavity (11-5) is fixedly connected to a valve body first middle cavity (11-1). The outer wall surface of the valve body first middle cavity (11-1) is provided with an inner cavity thread of the valve body (11-6). The surface of the valve body first middle cavity (11-1) is provided with a valve body middle cavity opening (11-2). A valve body ring groove (11-7) is provided on the surface of the valve body (11).

7. The airless pipeline control valve according to claim 6, characterized in that: A bracket (9) is fixedly installed on the outer wall surface of the inner valve cover (4). The bracket (9) includes an inner cavity (9-1), an internal threaded hole of the bracket (9-2), and a lower plane annular groove of the bracket shoulder (9-3). An inner cavity (9-1) is arranged inside the bracket (9), an internal threaded hole of the bracket (9-2) is arranged on the inner wall surface of the inner cavity (9-1), a lower plane annular groove of the bracket shoulder (9-3) is arranged on the bottom surface of the side wall of the bracket (9), and the position of the lower plane annular groove of the bracket shoulder (9-3) corresponds to the position of the valve body annular groove (11-7). A filter screen (8) is installed between the lower plane annular groove of the bracket shoulder (9-3) and the valve body annular groove (11-7).

8. The airless pipeline control valve according to claim 7, characterized in that: A first gasket (6) is arranged at the position where the inner valve cover (4) contacts the valve seat (7); a second gasket (10) is arranged at the position where the valve cover (3) contacts the valve body (11).

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