阅读说明：本技术 带有轴承箱冷却的透平膨胀机用氮气密封系统及方法 (Nitrogen sealing system and method for turboexpander with bearing box cooling ) 是由 贾江平 周根标 李付俊 卢丹丹 柳黎光 裴大海 邓建平 杨岐平 边山成 刘拥军 于 2020-04-28 设计创作，主要内容包括：本发明提供了一种带有轴承箱冷却的透平膨胀机用氮气密封系统及方法,包括总管路、静叶调节腔A密封管路、静叶调节腔B密封管路、进气侧碳环密封管路、进气侧迷宫密封管路、排气侧碳环密封管路、排气侧迷宫密封管路和排气侧轴承箱冷却管路。本发明的系统兼具密封功能和轴承箱的冷却功能,可保证TRT长期高效运行,减少泄露面,减小损失,使得机组公辅系统的氮气耗量也会大大降低,降低设备运行成本。本发明对透平膨胀机的静叶调节腔、进气侧充氮口和排气侧充氮口采用氮气进行联合密封,可更进一步确保透平膨胀机运行时煤气不泄露,使操作员在现场安全操作,同时可避免环境污染。(The invention provides a nitrogen sealing system and a nitrogen sealing method for a turboexpander with bearing box cooling, which comprises a main pipeline, a stator blade adjusting cavity A sealing pipeline, a stator blade adjusting cavity B sealing pipeline, an air inlet side carbon ring sealing pipeline, an air inlet side labyrinth sealing pipeline, an exhaust side carbon ring sealing pipeline, an exhaust side labyrinth sealing pipeline and an exhaust side bearing box cooling pipeline. The system has the sealing function and the cooling function of the bearing box, can ensure the long-term high-efficiency operation of the TRT, reduces the leakage surface and the loss, greatly reduces the nitrogen consumption of the unit public and auxiliary systems, and reduces the equipment operation cost. The invention adopts nitrogen gas to carry out combined sealing on the stationary blade adjusting cavity, the air inlet side nitrogen charging port and the air outlet side nitrogen charging port of the turboexpander, can further ensure that coal gas is not leaked when the turboexpander runs, ensures that an operator can safely operate on site, and can simultaneously avoid environmental pollution.)

1. A nitrogen sealing system with bearing box cooling for a turboexpander comprises a turboexpander (1) and is characterized in that a stationary blade adjusting cavity nitrogen charging port (101), an air inlet side carbon ring sealing nitrogen charging port (102), an air inlet side labyrinth sealing nitrogen charging port (103), an exhaust side carbon ring sealing nitrogen charging port (104), an exhaust side labyrinth sealing nitrogen charging port (105) and an exhaust side bearing box nitrogen charging port (106) are arranged on the turboexpander (1);

the device also comprises a main pipeline (2), a stator blade adjusting cavity A sealing pipeline (3), a stator blade adjusting cavity B sealing pipeline (4), an air inlet side carbon ring sealing pipeline (5), an air inlet side labyrinth sealing pipeline (6), an exhaust side carbon ring sealing pipeline (7), an exhaust side labyrinth sealing pipeline (8) and an exhaust side bearing box cooling pipeline (35);

the gas outlet end of the static blade adjusting cavity A sealing pipeline (3) is communicated with a static blade adjusting cavity nitrogen filling port (101), the gas outlet end of the static blade adjusting cavity B sealing pipeline (4) is communicated with the static blade adjusting cavity nitrogen filling port (101), the gas outlet end of the gas inlet side carbon ring sealing pipeline (5) is communicated with a gas inlet side carbon ring sealing nitrogen filling port (102), the gas outlet end of the gas inlet side labyrinth sealing pipeline (6) is communicated with a gas inlet side labyrinth sealing nitrogen filling port (103), the gas outlet end of the gas outlet side carbon ring sealing pipeline (7) is communicated with a gas outlet side carbon ring sealing nitrogen filling port (104), and the gas outlet end of the gas outlet side labyrinth sealing pipeline (8) is communicated with a gas outlet side labyrinth sealing nitrogen filling port (105); the air outlet end of the cooling pipeline (35) of the exhaust side bearing box is communicated with a nitrogen charging port (106) of the exhaust side bearing box;

the main pipeline is provided with a pneumatic film regulating valve (9), a main pipeline (2) at the air inlet end of the pneumatic film regulating valve (9) is a main pipeline air inlet section (201), and a main pipeline (2) at the air outlet end of the pneumatic film regulating valve (9) is a main pipeline air outlet section (202);

the main pipeline air outlet section (202) is respectively communicated with an air inlet end of the static blade adjusting cavity A sealing pipeline (3), an air inlet end of an air inlet side carbon ring sealing pipeline (5), an air inlet end of an air inlet side labyrinth sealing pipeline (6), an air inlet end of an exhaust side carbon ring sealing pipeline (7), an air inlet end of an exhaust side labyrinth sealing pipeline (8) and an air inlet end of an exhaust side bearing box cooling pipeline (35); the main pipeline air inlet section (201) is communicated with the air inlet end of the static blade adjusting cavity B sealing pipeline (4).

2. A nitrogen sealing system for a turboexpander with bearing housing cooling according to claim 1, wherein a first shut-off valve (10) is provided on the main line inlet section (201) upstream of the inlet end of the vane regulation cavity B seal line (4); the air source pressure adjusting mechanism comprises a self-operated adjusting valve (38) installed on the main pipeline air inlet section (201), a fourth ball valve (39) arranged at the air inlet end of the self-operated adjusting valve (38), a fifth ball valve (40) arranged at the air outlet end of the self-operated adjusting valve (38), and a sixth ball valve (41) connected with the self-operated adjusting valve (38) in parallel, wherein the air inlet end of the fourth ball valve (39) is connected with the air inlet end of the sixth ball valve (41), and the air outlet end of the fifth ball valve (40) is connected with the air outlet end of the sixth ball valve (41).

3. The nitrogen sealing system for the turboexpander with bearing box cooling according to claim 1, wherein a second shut-off valve (11) is provided on the vane adjustment chamber a seal line (3); a third stop valve (12) is arranged on the static blade adjusting cavity B sealing pipeline (4); a fourth stop valve (13) and a first check valve (14) are sequentially arranged on the air inlet side carbon ring sealing pipeline (5) from the air inlet end to the air outlet end; a fifth stop valve (15) and a second check valve (16) are sequentially arranged on the air inlet side labyrinth seal pipeline (6) from the air inlet end to the air outlet end; a sixth stop valve (17) and a third check valve (18) are sequentially arranged on the exhaust side carbon ring sealing pipeline (7) from the air inlet end to the air outlet end; a seventh stop valve (19) and a fourth check valve (20) are sequentially arranged on the exhaust side labyrinth seal pipeline (8) from the air inlet end to the air outlet end; and an eighth stop valve (36) and a fifth check valve (37) are sequentially arranged on the cooling pipeline (35) of the exhaust side bearing box from the air inlet end to the air outlet end.

4. The nitrogen sealing system for the turboexpander with the bearing box cooling function according to claim 1, wherein the pneumatic diaphragm regulating valve (9) is provided with a three-valve-group protection mechanism, the three-valve-group protection mechanism comprises a first ball valve (21) arranged at the air inlet end of the pneumatic diaphragm regulating valve (9), a second ball valve (22) arranged at the air outlet end of the pneumatic diaphragm regulating valve (9), and a third ball valve (23) connected in parallel with the pneumatic diaphragm regulating valve (9), the air inlet end of the first ball valve (21) is connected with the air inlet end of the third ball valve (23), and the air outlet end of the second ball valve (22) is connected with the air outlet end of the third ball valve (23).

5. The system for sealing off nitrogen for a turboexpander with cooling of the bearing housing according to claim 1, characterized in that said turboexpander (1) is a welded-casing type turboexpander.

6. A method for sealing a nitrogen gas for a turboexpander with bearing box cooling, characterized in that the method comprises the steps of filling the nitrogen gas for the vane regulation chamber, the intake side carbon ring seal, the intake side labyrinth seal, the exhaust side carbon ring seal and the exhaust side labyrinth seal of the turboexpander (1) with the nitrogen gas sealing system for a turboexpander with bearing box cooling according to any one of claims 1 to 5, and cooling the exhaust side bearing box of the turboexpander (1) with the nitrogen gas.

7. The method for sealing with nitrogen a turboexpander with cooling of bearing housing of claim 6, wherein in the method, the pressure after the regulating valve is 0.4 to 0.6 MPa; keeping the pressure behind the regulating valve higher than the pressure of the sealed coal gas by 20-30 kPa, regulating a pneumatic film regulating valve (9) in real time according to the real-time detection value of the pressure behind the regulating valve and the pressure of the sealed coal gas, and conveying nitrogen subjected to pressure regulation by the pneumatic film regulating valve (9) to a stationary blade regulating cavity nitrogen charging port (101), an air inlet side carbon ring sealed nitrogen charging port (102), an air inlet side labyrinth sealed nitrogen charging port (103), an air outlet side carbon ring sealed nitrogen charging port (104), an air outlet side labyrinth sealed nitrogen charging port (105) and an air outlet side bearing box nitrogen charging port (106)) for sealing and cooling;

when the temperature of an exhaust side bearing of the turbo expander (1) is more than or equal to 90 ℃ or the temperature of the exhaust side bearing is more than 10 ℃ higher than that of an air inlet side bearing, an exhaust side bearing box cooling pipeline (35) is opened to cool a nitrogen charging port (106) of an exhaust side bearing box.

8. The method of claim 7, wherein the post-regulator pressure is the nitrogen pressure collected at the collection point at the manifold outlet section (202); the sealed gas pressure is the gas pressure collected by taking an exhaust pipeline on the exhaust side of the turboexpander (1) or a balance pipeline of the turboexpander (1) as a collection point.

9. The method for sealing a nitrogen gas for a turboexpander with cooling of a bearing housing according to claim 7, wherein when the pressure in the vane regulation cavity is less than 50kPa, the vane regulation cavity is sealed by the vane regulation cavity a seal line (3) and the vane regulation cavity B seal line (4) is closed; when the pressure in the stator blade adjusting cavity is larger than or equal to 50kPa, the stator blade adjusting cavity is sealed by the stator blade adjusting cavity B sealing pipeline (4), and the stator blade adjusting cavity A sealing pipeline (3) is closed.

Technical Field

The invention belongs to the field of metallurgy, relates to a turboexpander, and particularly relates to a nitrogen sealing system and method for a turboexpander with a bearing box cooling function.

Background

In the metallurgical industry, blast furnace gas generated by blast furnace iron making firstly passes through dust removing equipment and then passes through a pressure reducing valve group to be supplied to users, and the original pressure energy and heat energy in the blast furnace gas are greatly wasted. In order to recover the energy lost in the blast furnace gas, it is necessary to increase a blast furnace gas top pressure turbine power generation unit (TRT). In dry and wet dust removal TRT, dry and wet dual-purpose TRT, shared TRT, blast furnace blast and energy recovery unit (BPRT) and sintering waste heat and blast furnace top pressure energy recovery combined generator Set (STRT), a turbine expander is used, and the TRT is a necessary device for blast furnace energy conservation and environmental protection.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a nitrogen sealing system and a nitrogen sealing method for a turboexpander with a cooling bearing box, and solve the technical problem that the sealing of a gas turbine and the cooling of the bearing box are difficult to be considered in the prior art.

In order to solve the technical problems, the invention adopts the following technical scheme:

a nitrogen sealing system for a turboexpander with bearing box cooling comprises a turboexpander, wherein a stationary blade adjusting cavity nitrogen charging port, an air inlet side carbon ring sealing nitrogen charging port, an air inlet side labyrinth sealing nitrogen charging port, an exhaust side carbon ring sealing nitrogen charging port, an exhaust side labyrinth sealing nitrogen charging port and an exhaust side bearing box nitrogen charging port are arranged on the turboexpander;

the device also comprises a main pipeline, a stator blade adjusting cavity A sealing pipeline, a stator blade adjusting cavity B sealing pipeline, an air inlet side carbon ring sealing pipeline, an air inlet side labyrinth sealing pipeline, an exhaust side carbon ring sealing pipeline, an exhaust side labyrinth sealing pipeline and an exhaust side bearing box cooling pipeline;

the gas outlet end of the sealing pipeline of the static blade adjusting cavity A is communicated with a nitrogen charging port of the static blade adjusting cavity, the gas outlet end of the sealing pipeline of the static blade adjusting cavity B is communicated with the nitrogen charging port of the static blade adjusting cavity, the gas outlet end of the carbon ring sealing pipeline of the gas inlet side is communicated with the carbon ring sealing nitrogen charging port of the gas inlet side, the gas outlet end of the labyrinth sealing pipeline of the gas inlet side is communicated with the labyrinth sealing nitrogen charging port of the gas inlet side, the gas outlet end of the carbon ring sealing pipeline of the gas outlet side is communicated with the carbon ring sealing nitrogen charging port of the gas outlet side, and the gas outlet end of the labyrinth sealing pipeline of the; the air outlet end of the cooling pipeline of the exhaust side bearing box is communicated with a nitrogen charging port of the exhaust side bearing box;

the main pipeline is provided with a pneumatic membrane regulating valve, the main pipeline at the air inlet end of the pneumatic membrane regulating valve is a main pipeline air inlet section, and the main pipeline at the air outlet end of the pneumatic membrane regulating valve is a main pipeline air outlet section;

the main pipeline air outlet section is respectively communicated with an air inlet end of a static blade adjusting cavity A sealing pipeline, an air inlet end of an air inlet side carbon ring sealing pipeline, an air inlet end of an air inlet side labyrinth sealing pipeline, an air inlet end of an exhaust side carbon ring sealing pipeline, an air inlet end of an exhaust side labyrinth sealing pipeline and an air inlet end of an exhaust side bearing box cooling pipeline; the main pipeline air inlet section is communicated with the air inlet end of the static blade adjusting cavity B sealing pipeline.

The invention also has the following technical characteristics:

a first stop valve is arranged on the main pipeline air inlet section at the upstream of the air inlet end of the static blade adjusting cavity B sealing pipeline; the air source pressure adjusting mechanism comprises a self-operated adjusting valve arranged on the main pipeline air inlet section, a fourth ball valve arranged at the air inlet end of the self-operated adjusting valve, a fifth ball valve arranged at the air outlet end of the self-operated adjusting valve and a sixth ball valve connected with the self-operated adjusting valve in parallel, the air inlet end of the fourth ball valve is connected with the air inlet end of the sixth ball valve, and the air outlet end of the fifth ball valve is connected with the air outlet end of the sixth ball valve.

A second stop valve is arranged on the static blade adjusting cavity A sealed pipeline; a third stop valve is arranged on the sealing pipeline of the static blade adjusting cavity B; a fourth stop valve and a first check valve are sequentially arranged on the air inlet side carbon ring sealing pipeline from the air inlet end to the air outlet end; a fifth stop valve and a second check valve are sequentially arranged on the air inlet side labyrinth seal pipeline from the air inlet end to the air outlet end; a sixth stop valve and a third check valve are sequentially arranged on the exhaust side carbon ring sealing pipeline from the air inlet end to the air outlet end; a seventh stop valve and a fourth check valve are sequentially arranged on the exhaust side labyrinth seal pipeline from the air inlet end to the air outlet end; and the exhaust side bearing box cooling pipeline is sequentially provided with an eighth stop valve and a fifth check valve from the air inlet end to the air outlet end.

The pneumatic membrane regulating valve on be provided with three valves protection mechanism, three valves protection mechanism including setting up the first ball valve at pneumatic membrane regulating valve inlet end, set up the second ball valve at pneumatic membrane regulating valve end of giving vent to anger, still include the third ball valve parallelly connected with pneumatic membrane regulating valve, the inlet end of first ball valve links to each other with the inlet end of third ball valve, the end of giving vent to anger of second ball valve links to each other with the end of giving vent to anger of third ball valve.

The turbine expander is a welded casing type turbine expander.

The invention also discloses a method for sealing the nitrogen for the turboexpander with the bearing box cooling, which adopts the nitrogen sealing system for the turboexpander with the bearing box cooling to carry out nitrogen filling sealing on the static blade adjusting cavity, the air inlet side carbon ring seal, the air inlet side labyrinth seal, the exhaust side carbon ring seal and the exhaust side labyrinth seal of the turboexpander, and carry out nitrogen filling cooling on the exhaust side bearing box of the turboexpander.

Specifically, in the method, the pressure behind the regulating valve is 0.4-0.6 MPa; keeping the pressure behind the regulating valve higher than the pressure of the sealed coal gas by 20-30 kPa, regulating the pneumatic film regulating valve in real time according to the real-time detection value of the pressure behind the regulating valve and the pressure of the sealed coal gas, and conveying the nitrogen regulated by the pneumatic film regulating valve to a nitrogen charging port of a stationary blade regulating cavity, a nitrogen charging port of a carbon ring seal at an air inlet side, a nitrogen charging port of a labyrinth seal at the air inlet side and a nitrogen charging port of a carbon ring seal at an air exhaust side, a nitrogen charging port of a labyrinth seal at an air exhaust side and a nitrogen charging port of a bearing box at an air exhaust side) for sealing and;

and when the temperature of the bearing at the exhaust side of the turbo expander is more than or equal to 90 ℃ or the temperature of the bearing at the exhaust side is higher than the temperature of the bearing at the air inlet side by more than 10 ℃, opening a cooling pipeline of the bearing box at the exhaust side to cool a nitrogen filling opening of the bearing box at the exhaust side.

Specifically, the pressure behind the regulating valve is the pressure of nitrogen collected by taking the gas outlet section of the main pipe as a collecting point; the sealed gas pressure is the gas pressure collected by taking the exhaust pipeline on the exhaust side of the turboexpander or the balance pipeline of the turboexpander as a collection point.

Specifically, when the pressure in the stator blade adjusting cavity is smaller than 50kPa, the stator blade adjusting cavity A sealing pipeline is adopted to seal the stator blade adjusting cavity, and the stator blade adjusting cavity B sealing pipeline is closed; when the pressure in the stator blade adjusting cavity is larger than or equal to 50kPa, the stator blade adjusting cavity B sealing pipeline is adopted to seal the stator blade adjusting cavity, and the stator blade adjusting cavity A sealing pipeline is closed.

Compared with the prior art, the invention has the following technical effects:

the system has the sealing function and the cooling function of the bearing box, can ensure the long-term high-efficiency operation of the TRT, reduces the leakage surface and the loss, greatly reduces the nitrogen consumption of the unit public and auxiliary systems, and reduces the equipment operation cost.

In the invention, the fixed blade adjusting cavity, the air inlet side nitrogen charging port and the air outlet side nitrogen charging port of the turboexpander are sealed in a combined way by adopting nitrogen, so that the coal gas is further prevented from leaking when the turboexpander runs, operators can operate safely on site, and meanwhile, the environmental pollution can be avoided.

The invention firstly seals the static blade adjusting cavity of the turboexpander by adopting nitrogen. The nitrogen seal is arranged in the stator blade adjusting cavity, so that the following effects can be brought:

a sealing cavity is arranged between the static blade bearing cylinder of the turboexpander and the shell, and the leakage of coal gas to the adjusting cavity can be avoided by adding nitrogen sealing.

The cleanliness of the stator blade adjusting cavity can be ensured, the problems of increased friction force of a stator blade crank and difficult rotation of the stator blade caused by gas leakage can be avoided, and the service life of the stator blade adjusting mechanism can be ensured and prolonged.

The problems of static blade adjusting clamping stagnation and asynchronization of the two sides of the static blade adjusting oil cylinders can be solved.

Through the design of the nitrogen sealing system of the stator blade adjusting cavity, the operation environment in the stator blade adjusting cavity of the turboexpander can be effectively optimized, and the service lives of the stator blade, the adjusting mechanism and the sealing ring of the turboexpander are effectively guaranteed and prolonged.

(IV) under the condition of realizing that the coal gas is not leaked, the nitrogen seal of the adjusting cavity adopts two sealing pipelines, the nitrogen is consumed according to the actual pressure of the static blade adjusting cavity, and the nitrogen consumption is greatly saved.

Drawings

Fig. 1 is a schematic diagram of the overall structure of a nitrogen sealing system with cooling.

The meaning of the individual reference symbols in the figures is: 1-a turboexpander, 2-a main pipeline, 3-a stator vane adjusting cavity A sealing pipeline, 4-a stator vane adjusting cavity B sealing pipeline, 5-an inlet side carbon ring sealing pipeline, 6-an inlet side labyrinth sealing pipeline, 7-an exhaust side carbon ring sealing pipeline, 8-an exhaust side labyrinth sealing pipeline, 9-a pneumatic membrane regulating valve, 10-a first stop valve, 11-a second stop valve, 12-a third stop valve, 13-a fourth stop valve, 14-a first check valve, 15-a fifth stop valve, 16-a second check valve, 17-a sixth stop valve, 18-a third check valve, 19-a seventh stop valve, 20-a fourth check valve, 21-a first ball valve, 22-a second ball valve, 23-a third ball valve, 24-a pressure sensor, 25-a flow sensor, 26-a temperature sensor, 27-a pressure gauge, 28-a pressure gauge, 29-a pressure difference transmitter, 30-a first pressure leading pipe, 31-a second pressure leading pipe, 32-an isolator, 33-a controller and 34-a valve self-contained positioner; 35-an exhaust side bearing box cooling pipeline, 36-an eighth stop valve, 37-a fifth check valve, 38-a self-operated regulating valve, 39-a fourth ball valve, 40-a fifth ball valve and 41-a sixth ball valve;

101-a nitrogen charging port of a static blade adjusting cavity, 102-a nitrogen charging port of a carbon ring seal at an air inlet side, 103-a nitrogen charging port of a labyrinth seal at the air inlet side, 104-a nitrogen charging port of a carbon ring seal at an exhaust side, 105-a nitrogen charging port of a labyrinth seal at an exhaust side, and 106-a nitrogen charging port of a bearing box at the exhaust side;

201-a main pipeline gas inlet section, 202-a main pipeline gas outlet section;

p1 is the sealed gas pressure collection point, P2 is the pressure collection point after the regulating valve.

The present invention will be explained in further detail with reference to examples.

Detailed Description

The turbo-expander in the present invention is mainly a blast furnace gas turbo-expander. The working medium of the blast furnace gas turbine expansion machine is blast furnace gas, and belongs to combustible toxic gas. In order to prevent gas leakage, a nitrogen sealing system is required to be arranged besides a labyrinth + end face carbon ring sealing mode, and the nitrogen sealing system can effectively prevent gas leakage at the TRT shaft end, the static blade adjusting cavity and other parts.

The TRT device is a device which utilizes the pressure energy and the heat energy of the byproduct of blast furnace smelting, namely blast furnace top gas, to ensure that the gas is expanded through a turbine expander to do work, and drives a generator to generate electricity or other equipment to recover energy. The TRT device does not consume any fuel, does not change the quality of raw gas, is the most economical equipment without pollution and public hazard, and can replace a pressure reducing valve bank to regulate and stabilize the top pressure of the furnace. The TRT working medium is blast furnace gas, belongs to combustible toxic gas and can not be leaked outside absolutely, so a nitrogen sealing system is needed to realize the sealing of the shaft end and the adjusting cavity. The shaft end sealing adopts a labyrinth + end face carbon ring sealing mode, and nitrogen sealing is additionally arranged, so that the operation safety is improved.

All parts in the present invention are those known in the art, unless otherwise specified.

The following embodiments of the present invention are provided, and it should be noted that the present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention are within the protection scope of the present invention.