A gas bearing low temperature booster turbine expander

Abstract

The present invention discloses a gas bearing low temperature booster turbine expander, comprising an intermediate housing, wherein the two ends of the intermediate housing are respectively connected to the expansion end and the booster end, a rotor is rotatably arranged in the intermediate housing, an expansion wheel and a booster wheel are respectively arranged at the two ends of the rotor, the expansion wheel and the booster wheel are respectively located in the turbine volute and the booster volute, a gas bearing is sleeved on the rotor, the gas bearing comprises a first gas bearing and a second gas bearing, the first gas bearing is used to support the expansion wheel, the second gas bearing is used to support the booster wheel, and the expansion end and the booster end are both placed in a cold box. The gas bearing low temperature booster turbine expander of the present invention places both the expansion end and the booster end of the expander in a cold box, changes the boost at normal temperature to the boost at low temperature, effectively isolates the atmospheric heat from being conducted into the expander, and at the same time, by arranging a partition in the cold box, it is ensured that the expander is easy to assemble and disassemble, has high efficiency, and operates reliably and stably.

Description

Technical Field

[0001] The invention belongs to the field of booster turbine expanders, and in particular relates to a gas bearing low-temperature booster turbine expander. Background Art

[0002] Turbine expander is a key equipment necessary for obtaining cold energy in air separation equipment, natural gas (petroleum gas) liquefaction separation equipment, and low-temperature crushing equipment. It is the heart that ensures the stable operation of the entire set of equipment. As the core equipment of air separation products, the turbine expander basically provides all the cold energy of the air separation equipment. Its performance directly determines the technical level of the entire set of products. Its main principle is to use a certain pressure of gas to perform adiabatic expansion in the turbine expander to do external work and consume the internal energy of the gas itself, so that the gas itself is strongly cooled to achieve the purpose of refrigeration. In daily life, when you use a gas cylinder to inflate, you will find that the cylinder body is hot. That is because the piston compresses the gas and the gas releases heat. If it is the other way around, its principle is similar to that of an expander (more precisely, a piston expander). The energy output by the turbine expander is recovered by the coaxial compressor or consumed by the brake fan.

[0003] At present, domestic expander manufacturers do not have low-temperature turbo expander products, but only a few imported oil-bearing low-temperature turbo expanders. As for gas-bearing low-temperature turbo expanders, there is no domestic product in use, and even abroad, it is rare to hear of any use cases. The main difficulties are concentrated in the design, stability, structure, installation and maintenance.

[0004] At present, the conventional normal temperature booster turbine expander only has a cold box at the expansion end, and the booster end is at normal temperature, which cannot completely prevent heat from being transferred to the expander. If a low temperature booster turbine expander is used instead, the original normal temperature boost ratio can be increased by about half, and the pressure difference before and after the boost can generally be increased by more than 0.2MPa, which improves the low temperature value of the cooling capacity and is more conducive to the effect of low temperature distillation. The most important thing is that it can improve the extraction rate of the product, reduce unit energy consumption, improve the economy of the device, achieve the purpose of energy conservation and emission reduction, and improve the technical level of domestic expanders and air separation. In addition, when the expander is running, the impeller and the sealing cover occasionally have contact and friction failures. At this time, the impeller and the sealing cover must be disassembled for repair. There are also improvement requirements in the existing technology that need to meet the convenience of maintenance.

[0005] Therefore, it is necessary to provide a gas bearing low temperature booster turbine expander which can improve working efficiency and is convenient for maintenance. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention, on the premise of claiming the priority of "A Gas Bearing Low-Temperature Boosting Turbine Expander" with application number 202120265763.4, provides a gas bearing low-temperature boosting turbine expander that can effectively isolate the atmospheric heat from being conducted into the expander, while ensuring that the expander is easy to assemble and disassemble, has high efficiency, and operates reliably and stably.

[0007] In order to achieve part or all of the above objects, the present invention provides the following technical solutions:

[0008] A gas bearing low temperature supercharging turbine expander comprises an intermediate casing, the two ends of the intermediate casing are respectively connected to the expansion end and the supercharging end, a rotor is rotatably arranged in the intermediate casing, an expansion wheel and a supercharging wheel are respectively arranged at the two ends of the rotor, the expansion wheel and the supercharging wheel are respectively located in the turbine volute and the supercharger volute, a gas bearing is sleeved on the rotor, the gas bearing comprises a first gas bearing and a second gas bearing, the first gas bearing is used to support the expansion wheel, the second gas bearing is used to support the supercharging wheel, and the expansion end and the supercharging end are both placed in a cold box. Since both the expansion end and the supercharging end are in a low temperature state, the original normal temperature supercharging is changed to low temperature supercharging, the supercharging ratio can be increased by about 50%, and the pressure difference before and after supercharging can generally increase by 0.2MPa, thereby improving the low temperature value of the cooling capacity and being more conducive to the effect of low temperature distillation. The nitrogen production equipment applied to the current single-tower reflux expander has increased the extraction rate by ~15% and reduced the unit energy consumption by ~20%. Compared with the double-tower nitrogen production equipment, the double tower is changed into a single tower, the manufacturing cost is greatly reduced, and the process liquid nitrogen pump is reduced, the demand for dynamic equipment is reduced, and the failure rate is reduced.

[0009] A cold box is provided at each of the expansion end and the boost end for heat preservation. Since the structure of the gas bearing low-temperature booster turbine expander is relatively symmetrical, a small cold box identical to that of the expansion end can be provided at the boost end, or the entire expander can be placed in the heat preservation cold box.

[0010] In a possible embodiment, the expansion end and the boost end share a cold box for heat preservation.

[0011] Two parallel partitions are arranged in the cold box, and the partitions divide the internal space of the cold box into an expansion end space, an intermediate space and a boost end space. In this way, when the expansion end or the boost end needs to be repaired, only the corresponding end needs to be removed for repair without affecting the other end.

[0012] The intermediate shell is provided with two parallel mounting flanges in the circumferential direction, and the partitions are respectively connected to the mounting flanges, so as to facilitate the mounting and dismounting of the partitions and the intermediate shell.

[0013] The mounting flanges are respectively fixed with insulation boards, and the partitions are respectively connected to the insulation boards. The insulation boards are first mounted on the mounting flanges, and then the partitions are mounted on the insulation boards, which increases the installation space of the partitions and facilitates operation.

[0014] The insulation board is made of epoxy glass cloth board, which has good insulation performance and will not break at low temperatures as a non-metallic material; the partition is made of stainless steel, which has good comprehensive insulation and welding performance.

[0015] The cold box is provided with access doors leading to the expansion end space and the boost end space respectively.

[0016] The intermediate housing is radially distributed with a bearing gas inlet, an expansion end sealing gas inlet, a boost end sealing gas inlet, a boost wheel back gas reflux inlet, and a boost wheel back gas outlet at the axial center. The double sealing gas can be used to adjust the sealing gas pressure to balance the axial force of the rotor and improve the operating stability of the expander. The boost wheel back gas outlet can lead the high-pressure gas behind the boost wheel to the low-pressure booster inlet as needed.

[0017] The wheel back seals of the expansion wheel and the boost wheel are both made of epoxy glass cloth plates to reduce cooling losses.

[0018] Compared with the prior art, the beneficial effects of the present invention are mainly as follows: the expansion end and the boosting end of the expander are both placed in a cold box, the boosting at normal temperature is changed to the boosting at low temperature, and the atmospheric heat is effectively isolated from being conducted into the expander, thereby improving the boosting efficiency; at the same time, by arranging a partition in the cold box, the expansion end and the boosting end of the expander are ensured to be easy to assemble and disassemble, efficient, and reliable and stable in operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a top cross-sectional schematic diagram of a gas bearing low-temperature booster turbine expander according to the first embodiment of the present invention;

[0021] Figure 2 for Figure 1 A schematic diagram of the main cross-section of a medium gas bearing cryogenic booster turbine expander;

[0022] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0023] Figure markings: 1-intermediate casing, 11-gas bearing air inlet, 12, 12'-mounting flange, 100-cold box, 101, 101'-partition, 102, 102'-access door, 2-expansion end, 3-boosting end, 4, 4'-insulation board, 41, 41'-connecting plate, 5, 5'-first fastener, 6, 6'-second fastener. DETAILED DESCRIPTION

[0024] The technical solutions in the specific embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Embodiment 1:

[0026] Combination Figure 1 and Figure 2 The gas bearing low-temperature booster turbine expander shown includes an intermediate casing 1, the two ends of which are respectively connected to the expansion end 2 and the boosting end 3, a rotor is rotatably arranged in the intermediate casing 1, an expansion wheel and a boosting wheel are respectively arranged at the two ends of the rotor, the expansion wheel and the boosting wheel are respectively located in the turbine volute and the booster volute, and the wheel back seals of the expansion wheel and the boosting wheel are both made of epoxy glass cloth plates to reduce cold run losses.

[0027] A gas bearing is sleeved on the rotor, and the gas bearing includes a first gas bearing and a second gas bearing, the first gas bearing is used to support the expansion wheel, and the second gas bearing is used to support the supercharger wheel. A bearing gas inlet 11, an expansion end sealing gas inlet, a supercharger end sealing gas inlet, a supercharger wheel back gas reflux inlet, and a supercharger wheel back gas outlet are distributed radially from the axial center of the intermediate housing 1.

[0028] The expansion end 2 and the boost end 3 are both placed in a cold box. In this embodiment, the expansion end 2 and the boost end 3 share a cold box 100 for heat preservation. In other embodiments, the expansion end 2 and the boost end 3 can also be provided with small cold boxes for heat preservation.

[0029] Two parallel partitions 101 and 101' are arranged in the cold box 100, dividing the internal space of the cold box 100 into an expansion end space, an intermediate space and a boost end space. The partition 101 is located in the expansion end space, and the partition 101' is located in the boost end space.

[0030] like Figure 3As shown, two parallel mounting flanges 12, 12' are provided in the circumferential direction of the intermediate casing 1, wherein the mounting flange 12 is fixedly connected to the connecting plate 41 by a first fastener 5, and is fixedly connected to the insulation plate 4 by a second fastener 6 in the circumferential direction of the connecting plate 41, and the insulation plate 4 is connected to the partition 101; the mounting flange 12' is fixedly connected to the connecting plate 41' by a first fastener 5', and is fixedly connected to the insulation plate 4' by a second fastener 6' in the circumferential direction of the connecting plate 41', and the insulation plate 4' is connected to the partition 101', thereby completing the installation of the expansion end 2, the boosting end 3 and the cold box 100 of the gas bearing low-temperature booster turbine expander.

[0031] In this embodiment, the insulation plates 4 and 4' are made of epoxy glass cloth plates, which have good insulation properties and will not break at low temperatures as non-metallic materials; the partitions 101 and 101' are made of stainless steel, which has good comprehensive insulation and welding properties, specifically S30408, grade 06Cr19Ni10, and can withstand low temperatures below -196 degrees.

[0032] like Figure 1 As shown, the cold box 100 is provided with access doors 102, 102' leading to the expansion end space and the boost end space, respectively.

[0033] When the expansion end 2 needs to be overhauled, the cold box 100 on one side of the expansion end space is sanded, and the expansion end space is entered through the access door 102. First, the connector between the partition 101 and the insulation board 4 is removed, and then the second fastener 6 is removed, the connecting plate 41 is separated from the insulation board 4, and then the first fastener 5 is removed, and the connecting plate 41 is separated from the mounting flange 12. At this time, the expansion joint, filter, movement, etc. of the expansion end 2 can be disassembled for overhaul, and the boost end 3 located in the boost end space is completely unaffected.

[0034] Similarly, when the boost end 3 needs to be overhauled, the cold box 100 on one side of the boost end space is sanded, and the boost end space is entered through the access door 102'. First, the connector between the partition 101' and the insulation board 4' is removed, and then the second fastener 6' is removed, and the connecting plate 41' is separated from the insulation board 4'. Then the first fastener 5' is removed, and the connecting plate 41' is separated from the mounting flange 12'. At this time, the expansion joint, filter, movement, etc. of the boost end 3 can be disassembled for overhaul, and the expansion end 2 located in the expansion end space is completely unaffected.

[0035] The gas bearing low temperature booster turbine expander provided by the present invention is introduced in detail above. The structure and working principle of the present invention are explained by using specific examples in this article. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A gas bearing low temperature supercharged turbine expander, comprising an intermediate casing (1), wherein two ends of the intermediate casing (1) are respectively connected to an expansion end (2) and a supercharging end (3), a rotor is rotatably arranged in the intermediate casing (1), an expansion wheel and a supercharging wheel are respectively arranged at two ends of the rotor, the expansion wheel and the supercharging wheel are respectively located in a turbine volute and a supercharger volute, a gas bearing is sleeved on the rotor, the gas bearing comprises a first gas bearing and a second gas bearing, the first gas bearing is used to support the expansion wheel, and the second gas bearing is used to support the supercharging wheel, It is characterized in that The expansion end (2) and the boost end (3) are both placed in a cold box. The expansion end (2) and the boost end (3) share a cold box (100) for heat insulation. Two parallel partitions (101, 101') are provided in the cold box (100). The partitions (101, 101') divide the internal space of the cold box (100) into an expansion end space, an intermediate space and a boost end space. The intermediate shell (1) is circumferentially provided with two parallel mounting flanges (12, 12'). The partitions (101, 101') are respectively connected to the mounting flanges (12, 12'). The mounting flanges (12, 12') are respectively fixedly connected to heat insulation plates (4, 4'). The partitions (101, 101') are respectively connected to the heat insulation plates (4, 4').

2. The gas bearing cryogenic turbo expander according to claim 1, It is characterized in that The insulation plates (4, 4') are made of epoxy glass cloth plates, and the partition plates (101, 101') are made of stainless steel.

3. The gas bearing cryogenic turbo expander according to claim 1, It is characterized in that The cold box (100) is provided with access doors (102, 102') leading to the expansion end space and the boost end space, respectively.

4. The gas bearing cryogenic turbo expander according to claim 1, It is characterized in that The intermediate housing (1) is provided with a bearing gas inlet (11), an expansion end sealing gas inlet, a boost end sealing gas inlet, a boost wheel back gas reflux inlet, and a boost wheel back gas outlet distributed radially at the axial center thereof.

5. The gas bearing cryogenic turbo expander according to claim 1, It is characterized in that The wheel back seals of the expansion wheel and the booster wheel are both made of epoxy glass cloth plates.

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