WO2023040184A1

WO2023040184A1 - High temperature and high pressure-resistant internal cooling static sealing device

Info

Publication number: WO2023040184A1
Application number: PCT/CN2022/076889
Authority: WO
Inventors: 吴加林
Original assignee: 成都佳灵绿色能源有限责任公司
Priority date: 2021-09-18
Filing date: 2022-02-18
Publication date: 2023-03-23

Abstract

A high temperature and high pressure-resistant internal cooling static sealing device, comprising an impeller mechanical mechanism (2), a motor (9), and an outer cover (10). A spindle (1) of the impeller mechanical mechanism (2) is connected to a motor shaft of the motor (9), the outer cover (10) at least encloses the motor (9) and the motor shaft, the outer cover (10) is provided with an inlet pipe (11), a low-temperature liquid enters the outer cover (10) from the inlet pipe (11) to cool the motor (9), and heat absorbed from the motor (9) turns into high-temperature steam and enters the impeller mechanical mechanism (2) to participate in circulation, thereby converting bearing dynamic sealing of the impeller mechanical mechanism (2) into static sealing. The sealing device can lower the sealing level, eliminate mutual leakage between internal and external gases, and reduce the use of a sealing oil.

Description

High temperature and high pressure internal cooling static sealing device

technical field

The invention relates to the technical field of power devices, in particular to a high temperature and high pressure resistant internal cooling static sealing device.

Background technique

A power plant refers to a device that converts mechanical energy into electrical energy or converts electrical energy into mechanical energy; the former refers to turbogenerators and turboexpanders, and the latter refers to various blowers. Compressors such as centrifugal compressors are one A machine that relies on the input of mechanical energy to increase the gas pressure and discharge the gas. At present, the commonly used centrifugal compressor mainly includes two parts: the motor and the impeller of the compressor. When the motor rotates, the impeller will also be higher than the rotation. The gas inlet from the front of the casing enters the impeller inside the casing along the axial direction, and the high-speed rotating impeller accelerates the gas, then decelerates it and changes it into radial motion, so that the kinetic energy is converted into potential energy (pressure) and finally along the radial direction of the impeller. , from the gas outlet pipe of the casing, leaving the compressor for use by the user;

This prior art centrifugal compressor has the following problems. A sealing device called a shaft seal is installed between the part of the output shaft of the motor that penetrates the housing and the housing. However, for high-temperature, high-pressure and large-capacity occasions, this It is impossible for the sealing device to completely eliminate the leakage of gas. If the compressed gas is flammable, explosive, toxic and harmful, once leakage occurs, it will cause environmental pollution and seriously damage the health of operators. Therefore, this problem must be solved. Power The device can be well developed and applied.

Contents of the invention

Aiming at one or more of the existing problems in the prior art, the present invention provides a high temperature and high pressure resistant internally cooled static sealing device, including an impeller mechanical mechanism, a motor and an outer cover, the main shaft of the impeller mechanical mechanism and the motor of the motor Shaft connection, the outer cover at least seals the motor and the motor shaft, the outer cover is provided with an inlet pipe, the low-temperature liquid enters the outer cover through the inlet pipe, cools the motor, absorbs the heat of the motor and turns it into high-temperature steam, enters the impeller mechanical mechanism to participate in the cycle, Thus, the dynamic seal of the bearing of the impeller mechanical mechanism is transformed into a static seal.

Optionally, the impeller mechanism includes an impeller compartment and an impeller located in the impeller compartment, the impeller is fixed on the main shaft, part of the main shaft is located in the outer cover, the low-temperature and high-pressure liquid enters the outer cover through the inlet pipe, and is heated by the fan in the motor shaft. After being pressed, it enters the motor for cooling, and absorbs the heat of the motor to become high-temperature and high-pressure steam. Since the pressure of the high-temperature and high-pressure steam inside the outer cover is greater than the internal pressure of the impeller mechanism, the high-temperature and high-pressure steam enters the interior of the impeller mechanism through the bearing gap on the main shaft, thus realizing the impeller mechanism. Mechanism bearing high temperature and high pressure resistant internal cooling static seal.

Optionally, it also includes a shutdown seal, which is used to connect the main shaft and the motor shaft, so that the high-temperature and high-pressure steam flows from the motor to the impeller in one direction, and blocks the gas flow from the impeller compartment to the motor in the opposite direction when the impeller mechanical device stops running , to prevent the motor from being heated.

Optionally, a temperature sensor is also included, and the temperature sensor is used to detect the temperature of the stator coil of the motor.

Optionally, a controller is also included. The controller controls the flow of the low-temperature and high-pressure liquid in the inlet pipe through the temperature of the stator coil detected by the temperature sensor. The higher the temperature of the stator coil, the greater the flow of the low-temperature and high-pressure liquid.

Optionally, it also includes a cooling pipeline, which is arranged between the shutdown seal and the rear wall of the impeller compartment.

Optionally, a first thermal insulation layer is also included, and the first thermal insulation layer surrounds the cooling pipeline.

Optionally, a second thermal insulation layer is also included, and the second thermal insulation layer is arranged between the outer cover and the rear wall of the impeller compartment.

Optionally, the inlet pipe is arranged at a position corresponding to the motor shaft on the motor non-power side of the housing.

Optionally, the turbomechanical mechanism and its main shaft are enclosed in a housing.

The sealing device of the present invention changes the dynamic seal of the shaft to an external static seal and has at least the following advantages and beneficial effects:

Eliminates the mutual leakage of internal and external gases, reduces the trouble of replenishing sealing oil and gas, reduces the configuration of related equipment, and reduces system costs. For example, the working pressure of the carbon dioxide compressor is much higher than the atmospheric pressure, and the dry gas seal is used, and the carbon ring seal leaks It is unavoidable, so the closed circulation system must be equipped with a regular automatic steam supply system, resulting in complex systems, high costs, and reduced reliability. Adopting the solution of the present invention can completely solve these problems;

The energy is recovered, and all the heat generated by the motor is recovered to the impeller mechanical mechanism, the efficiency of the impeller mechanical mechanism is improved, the temperature of the motor is reduced, the life of the motor is improved, and the energy consumption of the motor is reduced;

The present invention can be used in systems ranging from a few kilowatts to hundreds of thousands of kilowatts.

Description of drawings

Fig. 1 is the schematic diagram of an embodiment of the static sealing device of internal cooling of high temperature and high pressure resistance of the present invention;

Fig. 2 is a schematic diagram of another embodiment of the high temperature and high pressure resistant internal cooling static sealing device of the present invention;

Icons: 1-main shaft, 2-impeller mechanism, 3-rear wall, 4-second insulation layer, 5-cooling pipeline, 6-stop seal, 7-bearing seat, 8-coupling, 9-motor, 10-outer cover, 11-inlet pipe, 12-first insulation layer, 13-compression intake pipe, 14-compression exhaust pipe, 15-impeller chamber.

Detailed ways

The terms "first", "second", etc. are only used for distinguishing descriptions, and should not be construed as indicating or implying relative importance.

In the description of the present invention, it also needs to be explained that, unless otherwise clearly stipulated and limited, if the terms "setting", "installation", "connection" and "connection" appear, they should be understood in a broad sense, for example, it can be a fixed The connection can also be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

As shown in Figures 1 and 2, the static sealing device of the internal cooling of the high temperature and high pressure resistance includes an impeller mechanism 2, a motor 9 and a closed outer cover 10, and the main shaft 1 of the impeller mechanism is connected to the motor shaft of the motor, The outer cover at least seals the motor and the motor shaft. An inlet pipe is opened on the outer cover. The low-temperature liquid enters the outer cover through the inlet pipe to cool the motor. The heat absorbed by the motor becomes high-temperature steam and enters the impeller mechanical mechanism to participate in circulation, so that the impeller The bearing dynamic seal of the mechanical mechanism is transformed into a static seal.

In one embodiment, as shown in FIG. 1, the impeller mechanism includes an impeller compartment 15 and an impeller located in the impeller compartment, the impeller is fixed on the main shaft, part of the main shaft is located in the outer cover, and the low-temperature and high-pressure liquid enters through the inlet pipe. The outer cover is pressurized by the fan (not shown) in the motor shaft and then enters the motor for cooling. It absorbs the heat of the motor and turns it into high-temperature and high-pressure steam. Since the pressure of the high-temperature and high-pressure steam inside the outer cover is greater than the internal pressure of the impeller mechanism, the high-temperature and high-pressure steam passes through the main shaft The gap of the upper bearing enters the interior of the impeller mechanism, thereby realizing the high temperature and high pressure internal cooling static seal of the impeller mechanism bearing. If there is no such measure, the gas inside the impeller mechanism will leak a lot from the inside to the outside.

In one embodiment, as shown in FIG. 1, the sealing device further includes a shutdown seal 6, which is used to communicate with the main shaft and the motor shaft, so that high-temperature and high-pressure steam flows from the motor to the impeller in one direction, blocking the stoppage of the impeller mechanical device. During operation, the gas in the impeller compartment flows in the opposite direction to the motor to prevent the motor from being heated.

In one embodiment, the sealing device further includes a temperature sensor (not shown) for detecting the temperature of the stator coil of the motor.

Preferably, the sealing device further includes a controller (not shown), the controller controls the flow of the low-temperature and high-pressure liquid in the inlet pipe through the temperature of the stator coil detected by the temperature sensor, the higher the temperature of the stator coil, the higher the temperature of the low-temperature high-pressure liquid The greater the flow.

In one embodiment, as shown in FIG. 1 , the sealing device further includes a cooling pipeline 5 arranged between the shutdown seal and the rear wall 3 of the impeller compartment.

Preferably, a first thermal insulation layer 12 is also included, and the first thermal insulation layer surrounds the cooling pipeline.

In one embodiment, as shown in FIG. 1 , the sealing device further includes a second thermal insulation layer 4 , and the second thermal insulation layer is arranged between the outer casing 10 and the rear wall 3 of the impeller compartment.

In one embodiment, as shown in Figure 1, the inlet pipe on the outer cover is arranged at the position corresponding to the motor shaft on the non-power side of the outer cover, so that the same low-temperature and high-pressure liquid as the working fluid of the impeller mechanical mechanism enters the inside of the motor to The motor is cooled, absorbing the heat of the motor and turning it into high-temperature and high-pressure steam, which flows from the motor side through the bearing gap to the impeller mechanical mechanism in one direction.

In one embodiment, the sealing device is a semi-closed externally sealed internal cooling turbine, as shown in Figure 1, the sealing device includes an inlet pipe 11 (low temperature inlet pipe or/and low temperature inlet pipe), motor 9 , impeller cabin 15, impeller, main shaft 1, bearing seat 7, shutdown seal 6 and coupling 8, the motor shaft of motor 9 is connected with the main shaft 1 of impeller 2 by coupling 8, and are all fixed on the same rigid base (fixed impeller power machinery, bearing seat and motor chassis), a completely closed outer cover 10 is used to connect the motor 9 with the rear wall 3 of the impeller cabin, and the motor 9 and the bearing seat 7 are all sealed in the outer cover 10 to completely transform the dynamic seal. For static sealing, an inlet pipe 11 is provided at the position corresponding to the shaft on the non-power side of the motor of the outer cover 10, and the inlet pipe corresponds to a position in the opposite direction along the motor shaft, and a shaft fan is installed inside the ordinary motor to seal it in the outer cover, and Installed on the other side of the motor with no shaft protruding, the low-temperature and high-pressure liquid that is close to 0 degrees and exactly the same as the working medium of the impeller mechanism enters the closed outer cover from the outer cover 10 through the inlet pipe 11, and is blown by the motor shaft fan after being absorbed. The motor 9 is cooled to the inside of the motor 9. Since the pressure of the low-temperature and high-pressure liquid added outside is greater than the pressure of the power unit, the motor shaft of the motor 9 communicates with the main shaft 1 of the impeller 2 through the shutdown seal 6, and the gas can only flow from the motor 9. It flows in one direction to the side of the impeller 2, and controls the flow rate of the low-temperature gas by detecting the temperature of the stator coil to ensure that the stator coil of the motor 9 works within a specified temperature range.

Preferably, the main shaft 1, the bearing seat 7 and the coupling 8 are made of stainless steel to reduce heat conduction; a heat insulating material (second insulation layer 4) is installed between the outer cover 10 and the rear wall 3, and the rear wall 3 of the entire impeller compartment is covered Sealed with heat insulating material, between the bearing seat 7 and the impeller 2, there is a section of cooling pipeline 5 with heat preservation and shutdown heat insulation function installed outside the shaft. The length of the cooling pipeline is determined according to the working temperature (the higher the working temperature, the The longer the length of the cooling pipeline is, when the working temperature of the whole machine is low, such as lower than 150 degrees, the cooling pipeline 5 may not be used. The cooling pipeline 5 is close to the side of the bearing seat 7, and the shutdown sealing device 6 is installed. When the impeller stops When in motion, the stop seal 6 will block the gas flow from the side of the impeller 2 to the side of the motor 9, preventing the high-temperature gas from the side of the impeller 2 from flowing to the side of the motor 9 to heat the motor 9 to prevent damage to the motor 9; the bearing inside the bearing housing 7 adopts High temperature resistant bearings, lubricated with grease; the electric power line of the motor and the monitoring system line are connected through the glass melting and casting sealing sleeve (aviation joint) installed on the outer cover 10.

In a specific embodiment, the sealing device is a carbon dioxide compressor, the inlet pressure is 3 MPa, the temperature is 390 degrees, the exhaust pressure is 3.2 MPa, the temperature is 400 degrees, the flow rate is 60 kg/s, the motor power is 630 kw, and the motor The efficiency is 0.87, the value of motor loss converted into heat energy is 630*(1-0.87)=82kj, and the carbon dioxide liquid with a pressure of 3.3 MPa and a temperature of -3 degrees is input into the closed outer cover 10 through the inlet pipe 11, and the carbon dioxide liquid enters After the outer cover 10 evaporates immediately and becomes gas, but the pressure does not change. Its latent heat of evaporation is 245kgj/Kg, and the required carbon dioxide liquid flow rate relative to the motor loss of the present embodiment is 82÷245=0.34kg. This flow rate is the same as that of the sealing device The ratio of the total flow is 0.34÷60=0.0057, and all the heat lost by the motor is recovered.

In one embodiment, as shown in Figure 2, the impeller mechanism and its main shaft are encapsulated in the outer cover, that is to say, the motor 9, the motor shaft, the impeller mechanism 2, and the main shaft 1 of the impeller mechanism are all sealed in the outer cover In 10, the low-temperature and high-pressure liquid enters the outer cover through the inlet pipe and absorbs the heat of the motor to become high-temperature and high-pressure steam. Since the pressure of the high-temperature and high-pressure steam inside the outer cover is greater than that inside the impeller mechanism, the high-temperature and high-pressure steam can only flow from the motor side to the impeller mechanism through the bearing gap. One-way flow on the side, thus realizing the internal cooling of the motor.

In one embodiment, the sealing device is a fully sealed internal cooling turbine, which is suitable for small power mechanical mechanisms.

In one embodiment, as shown in Figure 2, the sealing device is a fully sealed internally cooled gas compressor, including a compressor body, a main shaft, an outer cover, a motor, a motor shaft, an inlet pipe, a compressed air intake pipe and a compressed exhaust pipe , the gas enters from the compressed intake pipe 13, and is discharged from the compressed exhaust pipe after being compressed. The low-temperature and high-pressure inlet pipe 11 is installed on the rear side of the motor 9, and the low-temperature liquid is input. After the low-temperature liquid enters the sealed outer cover, it absorbs the heat of the motor and evaporates immediately. Become low-temperature high-pressure steam, because its pressure is greater than the pressure of the main shaft inlet of the compressor body, so the gas flows to the main shaft inlet of the compressor body in one direction, so the motor is cooled, and the flow of low-temperature gas is controlled by detecting the temperature of the stator coil. The liquid flow is limited, which will not overwhelm the host and affect the basic compression function of the compressor body.

In one embodiment, the sealing device is a fully enclosed internally cooled trifluoromethane high-temperature compressor. The specific structure is shown in Figure 2. Due to technological needs, it is required to increase the trifluoromethane r23 gas at 190 degrees and 1 MPa to 200 degrees 1.2 MPa, the common fully enclosed refrigeration compressor cannot meet the above requirements because the motor cannot bear such a high temperature, so the fully enclosed internal cooling compressor of the present invention is adopted; the compressor body can adopt any compressor (for example, Scroll compressor or scroll compressor), the gas enters from the compression inlet pipe 13, and is discharged from the compression exhaust pipe 14 after being compressed. An inlet pipe 11 is provided at the low temperature and high pressure on the rear side of the motor 9, and the input pressure is 24 degrees below zero. 1.3 MPa of liquid trifluoromethane, the liquid trifluoromethane absorbs the heat of the motor and evaporates immediately after entering the sealed outer cover, and becomes a low-temperature and high-pressure steam. Because its pressure is greater than the pressure at the main shaft inlet end of the compressor body, the gas flows to the compressor in one direction. When the body and liquid evaporate into gas, the heat generated by both the stator and the rotor of the motor will be taken away by cooling, so the motor will be cooled.

It is very difficult to solve the sealing of bearings in high-temperature and high-pressure turbomachinery. Using the sealing device of the present invention simplifies complex problems, transforms the moving and rotating seal into a static seal, and the cost can be reduced to a fraction to Few 1/10.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

A high temperature and high pressure resistant internal cooling static sealing device, characterized in that it includes an impeller mechanical mechanism, a motor and an outer cover, the main shaft of the impeller mechanical mechanism is connected to the motor shaft of the motor, and the outer cover at least seals the motor and the motor shaft , there is an inlet pipe on the outer cover, and the low-temperature liquid enters the outer cover through the inlet pipe to cool the motor, absorb the heat of the motor and turn it into high-temperature steam and enter the impeller mechanical mechanism to participate in the cycle, so that the dynamic seal of the bearing of the impeller mechanical mechanism is changed to static type seal.
The sealing device according to claim 1, wherein the impeller mechanical mechanism includes an impeller compartment and an impeller located in the impeller compartment, the impeller is fixed on the main shaft, part of the main shaft is located in the outer cover, and the low-temperature and high-pressure liquid passes through the inlet pipe Enter the outer cover, pressurized by the fan in the motor shaft, enter the motor for cooling, absorb the heat of the motor and turn it into high-temperature and high-pressure steam. The inside of the mechanical mechanism, thus realizing the high temperature and high pressure resistant internal cooling static seal of the bearing of the impeller mechanical mechanism.
The sealing device according to claim 2, characterized in that it also includes a shutdown seal, which is used to communicate with the main shaft and the motor shaft, so that the high-temperature and high-pressure steam flows from the motor to the impeller in one direction, preventing the impeller mechanical device from stopping At the same time, the gas in the impeller compartment flows in the opposite direction to the motor to prevent the motor from being heated.
The sealing device according to claim 2, further comprising a temperature sensor for detecting the temperature of the stator coil of the motor.
The sealing device according to claim 4, further comprising a controller, the controller controls the flow rate of the low-temperature and high-pressure liquid in the inlet pipe through the temperature of the stator coil detected by the temperature sensor, the higher the temperature of the stator coil, the higher the temperature of the stator coil, The flow rate of low temperature and high pressure liquid is greater.
The sealing device according to claim 3, characterized in that it further comprises a cooling pipeline arranged between the shutdown seal and the rear wall of the impeller compartment.
The sealing device according to claim 6, further comprising a first insulation layer, and the first insulation layer surrounds the cooling pipeline.
The sealing device according to claim 1, characterized in that it further comprises a second thermal insulation layer, and the second thermal insulation layer is arranged between the outer cover and the rear wall of the impeller compartment.
The sealing device according to claim 1, wherein the inlet pipe is arranged at a position corresponding to the motor shaft on the non-power side of the motor.
The sealing device according to claim 1, wherein the impeller mechanism is enclosed in a sealed housing.