Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a negative pressure protection and safety relief device for working medium in a negative pressure pipeline, which can be used for protecting the connection position of a helium cryogenic transmission pipeline exposed to air and providing protection for the pipeline in case of overpressure. The invention further aims to provide a negative pressure pipeline working medium negative pressure protection method.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
One aspect of the present invention provides a negative pressure protection and safety relief device for a working medium in a negative pressure pipeline, comprising:
the two ends of the sealing cover are sealed to form a protection cavity;
The ball valve is characterized in that one end of the ball valve is communicated with the sealing cavity in a sealing way through a pipeline, and the other end of the ball valve is communicated with the vacuum generating device or the helium gas providing device;
One end of the primary safety valve is connected with a pipeline to be protected through a connecting pipeline, and the primary safety valve is provided with a first jump pressure.
Further, the device also comprises a second-level safety valve, one end of the second-level safety valve is communicated with the protection cavity through a pipeline, the other end of the second-level safety valve is communicated with the recovery and purification system, and the second-level safety valve is provided with a second jump pressure which is larger than the first jump pressure.
Further, the device further comprises a blasting assembly, one end of the blasting assembly is communicated with the pipeline to be protected through a pipeline, and the blasting assembly is provided with a third tripping pressure which is larger than the second tripping pressure.
Further, the explosion protection device comprises a three-way valve, wherein the first end of the three-way valve is communicated with a pipeline to be protected, the second end of the three-way valve is communicated with the first-stage safety valve through a pipeline, and the third end of the three-way valve is communicated with the explosion assembly through a pipeline.
Further, the safety cover includes barrel, head, sealing cover flange and base flange, the head is used for sealedly the top of barrel, the sealing cover welds the bottom of barrel, the base flange with sealing cover flange fixed connection is used for sealedly the bottom of barrel.
Further, a helium gas leakage detecting port is further formed in the base flange and used for detecting the leakage condition of the helium gas in the protection cavity.
Further, the first-stage safety valve comprises a first valve body, a first air inlet, a first air outlet, a first valve core and a first jump controller, wherein the first air inlet, the first air outlet, the first valve core and the first jump controller are arranged on the first valve body, the first air inlet is communicated with the connecting pipeline, the first air outlet discharges helium into the protection cavity, and the first jump controller is used for controlling the jump of the first valve core according to the pressure condition of the pipeline to be protected.
Further, the second-stage safety valve comprises a second valve body, a second air inlet, a second air outlet, a second valve core and a second tripping controller, wherein the second air inlet, the second air outlet, the second valve core and the second tripping controller are arranged on the second valve body, the second air inlet is communicated with the protection cavity, the second air outlet is communicated with the recovery and purification system, and the second tripping controller is used for controlling the tripping of the first valve core according to the pressure condition in the protection cavity.
Furthermore, a sealing ring is also arranged between the base flange and the sealing cover flange in a pressing mode.
The invention also provides a negative pressure pipeline working medium negative pressure protection and safety release method, which is based on the negative pressure pipeline working medium negative pressure protection and safety release device and comprises the following steps:
Opening the ball valve, and closing the primary safety valve, the secondary safety valve and the blasting assembly;
vacuumizing the protection cavity through the ball valve, and stopping when the vacuum degree reaches a set value;
filling helium into the protection cavity through the ball valve, wherein the purity of the helium is the same as that of the helium in the pipeline to be protected;
when negative pressure is formed in the pipeline to be protected, helium in the protection cavity enters the pipeline to be protected of the negative pressure;
When the pressure of the pipeline to be protected is larger than the first tripping pressure, the primary safety valve trips and moves through the first exhaust port to exhaust gas into the protection cavity;
When the pressure in the protection cavity is larger than the second tripping pressure of the secondary safety valve, exhausting the gas to the recovery and purification system through the second exhaust port;
when the first-stage safety valve or the second-stage safety valve fails and cannot jump in time, the rupture disk jumps when the third jump pressure of the rupture disk is reached, and pressure is released to the atmosphere.
Due to the adoption of the technical scheme, the invention has the following advantages:
1. according to the negative pressure pipeline working medium negative pressure protection and safety relief device provided by the invention, helium (99.999%) with the same purity as that in a system is supplied into the sealing cover cylinder of the negative pressure pipeline working medium negative pressure protection and safety relief assembly through the ball valve, and when the pipeline runs at negative pressure, helium in the sealing cover cylinder is sucked into a low-temperature transmission pipeline through the connecting screw thread of the safety valve, and the sucked helium has the same purity as that of the helium, so that the pollution of air to the helium circulating environment in the pipeline is effectively avoided.
2. When the pressure of the pipeline is too high in the process of travel, the primary safety valve is lifted, a small amount of helium can be stored in the sealed cover cylinder, and when the pressure is continuously increased, the secondary safety valve is lifted. When the safety valve fails, the rupture disk breaks open and releases pressure to the atmosphere, a parallel stage protection mechanism is formed, and the reliability of the safety relief system is improved. The safety exhaust helium is discharged into a recovery system, so that closed circulation recovery is formed, and the waste of helium and the pollution of local environment are avoided.
Detailed Description
Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
The embodiment of the invention provides a negative pressure pipeline working medium negative pressure protection and safety relief device, which comprises a sealing cover, a ball valve and a primary safety valve, wherein two ends of the sealing cover are sealed to form a protection cavity, one end of the ball valve is communicated with the sealing cavity in a sealing way through a pipeline, the other end of the ball valve is communicated with a vacuum generating device or a helium gas providing device, one end of the primary safety valve is connected with a pipeline to be protected through a connecting pipeline, and the primary safety valve has a first jump pressure. The negative pressure pipeline working medium negative pressure protection and safety relief device can be used for negative pressure protection of the connection position of the helium low-temperature transmission pipeline exposed to the air and provides protection for pipeline overpressure.
Example 1
As shown in fig. 1 to 5, the negative pressure pipeline working medium negative pressure protection and safety relief device comprises a sealing cover 1, a ball valve 2 and a primary safety valve 8, wherein two ends of the sealing cover 1 are sealed to form a protection cavity. One end of the ball valve 2 is communicated with the inside of the protection cavity in a sealing way through a pipeline, the other end of the ball valve 2 is communicated with a vacuum generating device or a helium gas providing device through an interface 3, one end of the primary safety valve 8 is connected with a pipeline to be protected (not shown in the figure) through a connecting pipeline 4, and the primary safety valve 8 is provided with a first jump pressure.
When the negative pressure pipeline working medium negative pressure protection and safety relief device is used for negative pressure protection, the ball valve 2 is opened, the vacuum generation device is used for vacuumizing the protection cavity, the vacuum generation device stops when the vacuum degree reaches a set value, helium is injected into the protection cavity, and the purity of the helium is the same as that of the helium in the pipeline to be protected.
When the pipeline to be protected runs under negative pressure, helium in the sealing cover 1 is sucked into the low-temperature transmission pipeline through the connecting screw thread of the safety valve, and the sucked helium has the same purity as the sucked helium, so that the pollution of air to the helium circulation environment in the pipeline is effectively avoided. Therefore, the negative pressure pipeline working medium negative pressure protection and safety relief device can be used for negative pressure protection at the connecting position of the helium low-temperature transmission pipeline exposed to the air.
When the pressure of the pipeline to be protected is too high in the course of travel, the primary safety valve 8 is lifted, a small amount of helium can be stored into the sealing cover 1, and then the pressure of the low-temperature transmission pipeline is relieved, so that overpressure protection is provided.
Further, in order to make the overpressure protection more reliable, the negative pressure pipeline working medium negative pressure protection and safety relief device further comprises a secondary safety valve 7, one end of the secondary safety valve 7 is communicated with the protection cavity through a pipeline, the other end of the secondary safety valve is communicated with a recovery and purification system (not shown in the figure), and the secondary safety valve 7 is provided with a second jump pressure, wherein the second jump pressure is larger than the first jump pressure.
When the pressure of the pipeline to be protected is too high in the course, the pipeline to be protected is connected with the connecting pipeline 4 in parallel, the two pipelines have the same pressure, the pressure in the pipeline to be protected is transmitted to the primary safety valve 8 through the eduction pipe 4 of the protected pipeline, when the pressure in the pipeline is superpressure and is larger than the set value of the primary safety valve 8, the primary safety valve 8 jumps, the exhaust port of the safety valve is used for exhausting gas into the protection cavity, when the pressure in the pipeline is continuously superpressure, the exhaust is continuously carried out into the protection cavity, and when the pressure in the protection cavity is continuously increased and is larger than the set value of the secondary safety valve 7, the secondary safety valve 7 jumps, and helium in the protection cavity is discharged to the recovery and purification system through the exhaust port of the safety valve.
Further, the device further comprises a blasting assembly 6, one end of the blasting assembly 6 is communicated with the pipeline to be protected through a pipeline, and the blasting assembly 6 is provided with a third tripping pressure which is larger than the second tripping pressure.
When the primary safety valve 8 or the secondary safety valve 7 fails and cannot take off in time, the bursting pressure of the bursting component 6 is slightly higher than the taking-off pressure of the secondary safety valve 7, and when the bursting pressure of the bursting component 6 is reached, the bursting component 6 takes off and releases pressure to the atmosphere, so that the safety accidents caused by continuous increase of the pressure in the protection cavity and the pipeline to be protected are avoided.
The installation mode of the negative pressure pipeline working medium negative pressure protection and safety relief assembly is simple, the operation is convenient, and the installation of the negative pressure pipeline working medium negative pressure protection and safety relief assembly is realized through threads and flange connection. When the safety valve is required to be reset or the rupture disk is required to be replaced, the reset of the safety valve and the replacement of the rupture disk can be completed by disassembling the screw and the flange.
For easy to assemble connects, negative pressure pipeline working medium negative pressure protection and safety relief device includes three-way valve 5, three-way valve 5 first end with wait to protect through the pipeline intercommunication between the pipeline, the second end with through the pipeline intercommunication between the one-level relief valve 8, the third end with through the pipeline intercommunication between the blasting subassembly 6.
In order to improve the sealing reliability of the sealing cover, the protection cover comprises a cylinder 11, a sealing head 12, a sealing cover flange 13 and a base flange 14, wherein the sealing head 12 is used for sealing the top of the cylinder 11, the sealing cover 13 is welded at the bottom of the cylinder 11, and the base flange 14 is fixedly connected with the sealing cover flange 13 and used for sealing the bottom of the cylinder 11. The base flange 14 is provided with a mounting hole 142, and the connecting pipeline 4 passes through the mounting hole 142 to be connected with the primary safety valve 8.
In order to improve the sealing performance of the protection cavity, the base flange 14 is further provided with a helium gas leakage detecting port 142, and the helium gas leakage detecting port 142 is used for detecting the leakage condition of the helium gas in the protection cavity.
The base flange 14 is further provided with a helium gas leakage detecting port 141, and the helium gas leakage detecting port 141 is used for detecting the leakage condition of the helium gas in the protection cavity. The number of the helium gas leakage detecting holes 141 can be two, and the two helium gas leakage detecting holes 141 are symmetrically arranged on two sides of the base flange 14.
The primary safety valve 8 comprises a first valve body, a first air inlet 81, a first air outlet 82, a first valve core 83 and a first trip controller 4, wherein the first air inlet 81, the first air outlet 82, the first valve core 83 and the first trip controller 4 are arranged on the first valve body, the first air inlet 81 is communicated with the connecting pipeline 4, the first air outlet 82 discharges helium into the protection cavity, and the first trip controller 84 is used for controlling the first valve core 83 to trip according to the pressure condition of a pipeline to be protected.
The secondary safety valve 7 comprises a second valve body, a second air inlet 71, a second air outlet 72, a second valve core 73 and a second take-off controller 74, wherein the second air inlet 71, the second air outlet 72, the second valve core 73 and the second take-off controller 74 are arranged on the second valve body, the second air inlet 71 is communicated with the protection cavity, the second air outlet 72 is communicated with the recovery and purification system, and the second take-off controller 74 is used for controlling the first valve core 73 to take-off according to the pressure condition in the protection cavity.
The invention also provides a negative pressure pipeline working medium negative pressure protection and safety relief method, which is based on the negative pressure pipeline working medium negative pressure protection and safety relief device and comprises the following steps:
Opening the ball valve 2, and closing the primary safety valve 8, the secondary safety valve 7 and the blasting assembly 6;
Vacuumizing the protection cavity through the ball valve 2, and stopping when the vacuum degree reaches a set value;
filling helium into the protection cavity through the ball valve 2, wherein the purity of the helium is the same as that of helium in a pipeline to be protected;
when negative pressure is formed in the pipeline to be protected, helium in the protection cavity enters the pipeline to be protected of the negative pressure;
When the pressure of the pipeline to be protected is greater than the first jump pressure, the primary safety valve 8 jumps and moves through the first exhaust port 82 to exhaust gas into the protection cavity;
Venting the recovery and purification system through the second vent 72 when the pressure within the protection cavity is greater than the second trip pressure of the secondary relief valve 7;
when the primary safety valve 8 or the secondary safety valve 7 fails and fails to take off in time, the rupture disk takes off when the third take-off pressure of the blasting assembly 6 is reached, and pressure is released to the atmosphere.
The negative pressure pipeline working medium negative pressure protection and safety relief device and method provided by the invention can be used for negative pressure protection at the connecting position of the helium low-temperature transmission pipeline exposed to the air and provide protection for the pipeline in overpressure.
It should be noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present invention, and not for limiting the same, and although the present invention has been described in detail with reference to the above-mentioned embodiments, it should be understood by those skilled in the art that the technical solution described in the above-mentioned embodiments may be modified or some technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiments of the present invention.