Screw refrigeration compressor directly driven by natural gas screw expander

Abstract

The utility model relates to the technical field of new energy, in particular to a screw refrigeration compressor directly driven by a natural gas screw expander. Comprising an axial bearing, a radial bearing, an expansion machine body, an expansion machine male rotor, an expansion machine female rotor, an expansion machine air inlet end seat, a compressor exhaust end seat, a mechanical shaft seal, a compressor male rotor, a compressor female rotor, a compressor body, a balance piston and a bearing gland. High-pressure natural gas of the natural gas pipeline network enters an expansion cavity of the expansion machine to be expanded, the expansion machine male rotor and the expansion machine female rotor are driven to rotate to do work, and the expanded low-pressure natural gas is discharged. The expansion machine male rotor drives the compressor male rotor to rotate through the coupler, so that the compressor female rotor is driven to rotate synchronously, low-pressure refrigerants enter the compression cavity to be compressed, the compressed high-pressure refrigerants are discharged, and the mechanical shaft seal seals natural gas in the expansion cavity and the refrigerants in the compression cavity. The balance piston balances the axial gas force of the expansion machine male rotor and the compressor male rotor.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, and in particular to a screw refrigeration compressor directly driven by a natural gas screw expander. Background Art

[0002] Natural gas is mainly transported to users at all levels through the national pipeline network, provincial pipeline network and urban pipeline network. Its pressure level is generally reduced from 10MPa of the national pipeline network to 4.0MPa of the provincial pipeline network, and then to 0.8MPa of each city pipeline network before being transported to end users. The pressure reduction process is generally achieved through the pressure reducing valve of the pressure regulating station. At the same time, the decompressed natural gas will freeze and cause ice blockage in the pipeline. The temperature of the natural gas must be increased by adding heat, which not only wastes a lot of energy, but also poses a safety hazard.

[0003] In order to solve the problem of pressure energy recovery between natural gas pipelines, a screw refrigeration compressor directly driven by a natural gas screw expander is proposed. The screw refrigeration compressor uses the pressure difference of natural gas to drive the screw expander to rotate and directly drive the screw refrigeration compressor to work and output cooling capacity. It can be used for ice making, process cooling water or natural gas liquefaction. It has the advantages of simple structure, high efficiency and low cost, and can effectively solve the problem of pressure energy recovery between natural gas pipelines. Therefore, it has great promoting significance for improving the economy and safety of natural gas pipeline operation. Utility Model Content

[0004] Based on the above purpose, the utility model provides a screw refrigeration compressor directly driven by a natural gas screw expander, which utilizes the pressure difference of natural gas to drive the screw expander to rotate and directly drive the screw refrigeration compressor to work and output cooling capacity. It has the advantages of simple structure, high efficiency and low cost, and can effectively solve the problem of pressure energy recovery between natural gas pipelines.

[0005] A screw refrigeration compressor directly driven by a natural gas screw expander, comprising an axial bearing, a radial bearing, an expander male rotor, an expander female rotor, an expander body, an expander air inlet end seat, a mechanical shaft seal, a compressor male rotor, a compressor female rotor, a compressor body, a compressor exhaust end seat, a gland and a balancing piston, etc.

[0006] Furthermore, the expander male rotor and the expander female rotor are a pair of mutually meshing spiral concave and convex teeth, and the gear ratio is 4:6 or 5:7.

[0007] Furthermore, the expander body has an 8-shaped cavity, a natural gas exhaust port on the lower side, and an oil injection port in the 8-shaped cavity.

[0008] Furthermore, the expander suction end seat has a bearing hole, an oil injection port is provided in the bearing hole, and a natural gas suction port is provided on the upper side.

[0009] Furthermore, the compressor male rotor and the compressor female rotor are a pair of mutually meshing spiral concave and convex teeth, and the gear ratio thereof is 4:6 or 5:7.

[0010] Furthermore, the compressor body has an 8-shaped cavity, a refrigerant air intake port on the upper side, and an oil injection port in the 8-shaped cavity.

[0011] Furthermore, the expander male rotor and the compressor male rotor are connected together through a diaphragm coupling.

[0012] Furthermore, the compressor exhaust end seat has a bearing hole, an oil injection port is provided in the bearing hole, and a refrigerant exhaust port is provided on the lower side.

[0013] Furthermore, the balancing piston is driven by oil pressure and is used to balance the axial gas forces of the expander male rotor and the compressor male rotor.

[0014] Furthermore, in the possible implementation mode of the utility model, the expander male rotor and the compressor male rotor are connected as a whole through the diaphragm coupling, and the high-pressure natural gas of the natural gas pipeline network enters the expansion chamber through the air intake port on the upper side of the expander suction end seat to expand, driving the expander male rotor and the expander female rotor to rotate and do work, and the expanded low-pressure natural gas is discharged through the exhaust port on the lower side of the expander body. The expander male rotor directly drives the compressor male rotor connected to it through the coupling to rotate, and the compressor male rotor drives the compressor female rotor to rotate synchronously, and the low-pressure refrigerant enters the compression chamber through the air intake port on the upper side of the compressor body for compression, and the compressed high-pressure refrigerant is discharged through the exhaust port on the lower side of the compressor exhaust end seat. The mechanical shaft seal seals the natural gas inside the expander expansion chamber and the refrigerant in the compressor compression chamber, and the balance piston balances the axial gas force of the expander male rotor and the compressor male rotor.

[0015] Beneficial effects of the utility model:

[0016] The utility model utilizes the pressure difference of natural gas to drive the expander positive rotor and the expander negative rotor to rotate. The expander positive rotor and the compressor positive rotor are connected as a whole through a coupling, thereby directly driving the compressor positive rotor and the compressor negative rotor to rotate, thereby realizing compression work on the refrigerant. This novel design efficiently recovers the pressure energy of natural gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a schematic diagram of a screw refrigeration compressor directly driven by a natural gas screw expander.

[0019] Figure 2 This is the appearance diagram of a screw refrigeration compressor directly driven by a natural gas screw expander. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0021] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] like Figure 1 As shown, a screw refrigeration compressor directly driven by a natural gas screw expander includes a cylindrical roller bearing A01, an expander body 02, an expander male rotor 03, an expander female rotor 04, an angular contact bearing A05, an expander suction end seat 06, an expander bearing retaining ring 07, an expander gland A08, an expander mechanical shaft seal assembly 09, an expander gland B10, an expander piston cylinder 11, an expander balance piston 12, an expander gland C13, an expander gland C14, a cylindrical roller bearing B15, a compressor body 16, a compressor male rotor 17, a compressor female rotor 18, an angular contact bearing B19, a compressor exhaust end seat 20, a compressor bearing retaining ring 21, a compressor gland A22, a compressor mechanical shaft seal assembly 23, a compressor gland B24, a compressor piston cylinder 25, a compressor balance piston 26, a compressor gland C27, a compressor gland D28 and a diaphragm coupling 29.

[0023] The expander body 02 has an 8-shaped cavity with an oil injection port in the 8-shaped cavity, a bearing hole on the left side with an oil injection port in the bearing hole, and a natural gas exhaust port A on the lower side.

[0024] The expander male rotor 03 has a 4-tooth spiral convex tooth structure.

[0025] The expander female rotor 04 has a 6-tooth spiral concave tooth structure.

[0026] The expander suction end seat 06 has a bearing hole, a natural gas suction port B on the upper side, and oil injection ports C1, C2 and C3 on the bottom.

[0027] The expander mechanical shaft seal assembly 09 seals the natural gas in the expander body 02 cavity to prevent it from leaking to the outside.

[0028] The expander piston cylinder 11 and the expander balancing piston 12 form an oil chamber. High-pressure lubricating oil is pumped into the oil chamber from the C4 port to drive the expander balancing piston 12 to move rightward, which is used to balance the axial gas force of the expander male rotor 03 and the compressor male rotor 17.

[0029] The compressor body 16 has an 8-shaped cavity with an oil injection port in the 8-shaped cavity, a bearing hole on the right side with an oil injection port in the bearing hole, and a refrigerant suction port D on the upper side.

[0030] The compressor male rotor 17 has a 4-tooth spiral convex tooth structure, and the expander male rotor 03 and the compressor male rotor 17 are connected together through a diaphragm coupling 29.

[0031] The compressor female rotor 18 has a 6-tooth helical concave tooth structure.

[0032] The compressor exhaust end seat 20 has a bearing hole, a refrigerant exhaust port E at the lower side, and oil injection ports F1, F2 and F3 at the upper side.

[0033] The compressor piston cylinder 25 and the compressor balance piston 26 form an oil chamber. High-pressure lubricating oil is pumped into the oil chamber from the F4 port to drive the compressor balance piston 26 to move leftward, which is used to balance the axial gas force of the expander male rotor 03 and the compressor male rotor 17.

[0034] In the possible implementation scheme of the utility model, the cylindrical roller bearing A01 is installed in the bearing hole of the expander body 02, the expander male rotor 03 is installed in the 8-shaped cavity of the expander body 02 from the right side, and is connected with the inner ring of the cylindrical roller bearing A01 by interference, and the expander female rotor 04 is installed in the 8-shaped cavity of the expander body 02 from the right side, and is connected with the inner ring of the cylindrical roller bearing A01 by interference. After the cylindrical roller bearing A01 and the angular contact bearing A05 are successively installed in the bearing hole of the expander suction end seat 06, they are installed from the right side shaft end of the expander male rotor 03, and the expander suction end seat 06 is connected to the expander body 02 as a whole, the expander male rotor 03 is connected with the inner rings of the cylindrical roller bearing A01 and the angular contact bearing A05 by interference, and the expander female rotor 04 is connected with the inner rings of the cylindrical roller bearing A01 and the angular contact bearing A05 by interference. After the expander bearing retaining ring 07 is installed into the bearing hole of the expander suction end seat 06, the expander gland A08 is installed into the bearing hole of the suction end seat 06, and the cylindrical roller bearing A01 and the angular contact bearing A05 are pressed. The expander mechanical shaft seal assembly 09 passes through the expander male rotor 03 from the right inner ring of the expander body 02, and its outer ring is installed into the bearing hole of the expander suction end seat 06 and is close to the outer ring end face of the angular contact bearing A05. The expander gland B10 is installed into the bearing hole of the suction end seat 06, and the cylindrical roller bearing A01, the angular contact bearing A05 and the expander mechanical shaft seal assembly 09 are pressed. The expander piston cylinder 11 is installed from the left side of the expander body 02, and the expander balance piston 12 is installed into the expander piston cylinder 11 from the left side of the expander body 02, and is connected to the expander male rotor 03 as a whole. The expander gland C13 is installed into the expander body 02 from the left side to press the outer ring of the expander piston cylinder 08, and the expander gland C14 is installed into the expander body 02 from the left side.

[0035] The cylindrical roller bearing B15 is installed in the bearing hole of the compressor body 16, the compressor male rotor 17 is installed in the 8-shaped cavity of the compressor body 16 from the left side, and is connected with the inner ring of the cylindrical roller bearing B15 by interference, and the compressor female rotor 18 is installed in the 8-shaped cavity of the compressor body 16 from the left side, and is connected with the inner ring of the cylindrical roller bearing B15 by interference. After the cylindrical roller bearing B15 and the angular contact bearing B19 are successively installed in the bearing hole of the compressor exhaust end seat 20, they are installed from the left axial end of the compressor male rotor 17, and the compressor exhaust end seat 20 is connected to the compressor body 16 as a whole, the compressor male rotor 17 is connected with the inner rings of the cylindrical roller bearing B15 and the angular contact bearing B19 by interference, and the compressor female rotor 18 is connected with the inner rings of the cylindrical roller bearing B15 and the angular contact bearing B19 by interference. After the compressor bearing retaining ring 21 is installed into the bearing hole of the compressor exhaust end seat 20, the compressor gland A22 is installed into the bearing hole of the compressor exhaust end seat 20, and the cylindrical roller bearing B15 and the angular contact bearing B19 are pressed. The inner ring of the compressor mechanical shaft seal assembly 23 passes through the compressor male rotor 17 from the left side of the compressor body 16, and its outer ring is installed into the bearing hole of the compressor exhaust end seat 20 and is close to the outer ring end face of the angular contact bearing B19. The compressor gland B24 is installed into the bearing hole of the compressor exhaust end seat 20, and the cylindrical roller bearing B15, the angular contact bearing B19 and the compressor mechanical shaft seal assembly 23 are pressed. The compressor piston cylinder 25 is installed from the right side of the compressor body 16, and the compressor balance piston 26 is installed into the compressor piston cylinder 25 from the right side of the compressor body 16, and is connected to the compressor male rotor 17 as a whole. The compressor gland C27 is installed into the compressor body 16 from the left side to press the outer ring of the expander piston cylinder 08, and the expander gland D28 is installed into the compressor body 16 from the left side.

[0036] The diaphragm coupling 29 connects the expander male rotor 03 and the compressor male rotor 17 together.

[0037] The high-pressure natural gas of the natural gas network enters the expansion chamber through the air inlet B on the upper side of the expander suction end seat 06 to expand, driving the expander male rotor 03 and the expander female rotor 04 to rotate and do work, and the expanded low-pressure natural gas is discharged through the exhaust port A on the lower side of the expander body 02. The expander male rotor 03 directly drives the compressor male rotor 17 connected to it through the diaphragm coupling 29 to rotate, and the compressor male rotor 17 drives the compressor female rotor 18 to rotate synchronously, and the low-pressure refrigerant enters the compression chamber through the air inlet D on the upper side of the compressor body 16 for compression, and the compressed high-pressure refrigerant is discharged through the exhaust port E on the lower side of the compressor exhaust end seat 20.

[0038] The utility model is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. A screw refrigeration compressor directly driven by a natural gas screw expander, characterized in that: The invention comprises a cylindrical roller bearing A (01), an expander body (02), an expander male rotor (03), an expander female rotor (04), an angular contact bearing A (05), an expander suction end seat (06), an expander bearing retaining ring (07), an expander gland A (08), an expander mechanical shaft seal assembly (09), an expander gland B (10), an expander piston cylinder (11), an expander balancing piston (12), an expander gland C (13), an expander gland C (14), a cylindrical roller Bearing B (15), compressor body (16), compressor male rotor (17), compressor female rotor (18), angular contact bearing B (19), compressor exhaust end seat (20), compressor bearing retaining ring (21), compressor gland A (22), compressor mechanical shaft seal assembly (23), compressor gland B (24), compressor piston cylinder (25), compressor balance piston (26), compressor gland C (27), compressor gland D (28) and diaphragm coupling (29).

2. A screw refrigeration compressor directly driven by a natural gas screw expander according to claim 1, characterized in that: The expander body (02) has an 8-shaped cavity, an oil injection port is provided in the 8-shaped cavity, a bearing hole is provided on the left side, an oil injection port is provided in the bearing hole, and a natural gas exhaust port A is provided on the lower side.

3. The screw refrigeration compressor directly driven by a natural gas screw expander according to claim 1, characterized in that: The expander male rotor (03) and the expander female rotor (04) are a pair of helically meshed convex-concave tooth structures with a ratio of 4:6 or 5:

7.

4. The screw refrigeration compressor directly driven by a natural gas screw expander according to claim 1, characterized in that: The expander suction end seat (06) has a bearing hole, a natural gas suction port B on the upper side, and oil injection ports C1, C2 and C3 on the bottom.

5. The screw refrigeration compressor directly driven by a natural gas screw expander according to claim 1, characterized in that: The expander piston cylinder (11) and the expander balancing piston (12) form an oil chamber, and high-pressure lubricating oil is pumped into the oil chamber from the C4 port to drive the expander balancing piston 12 to move rightward, so as to balance the axial gas force of the expander male rotor (03) and the compressor male rotor (17).

6. The screw refrigeration compressor directly driven by a natural gas screw expander according to claim 1, characterized in that: The compressor body (16) has an 8-shaped hole cavity, and an oil injection port is arranged in the 8-shaped hole cavity; a bearing hole is arranged on the right side, and an oil injection port is arranged in the bearing hole; and a refrigerant suction port D is arranged on the upper side.

7. The screw refrigeration compressor directly driven by a natural gas screw expander according to claim 1, characterized in that: The compressor male rotor (17) and the compressor female rotor (18) are a pair of helically meshed convex-concave tooth structures with a ratio of 4:6 or 5:

7.

8. The screw refrigeration compressor directly driven by a natural gas screw expander according to claim 1, characterized in that: The compressor exhaust end seat (20) has a bearing hole, a refrigerant exhaust port E at the lower side, and oil injection ports F1, F2 and F3 at the upper side.

9. The screw refrigeration compressor directly driven by a natural gas screw expander according to claim 1, characterized in that: The compressor piston cylinder (25) and the compressor balance piston (26) form an oil chamber, and high-pressure lubricating oil is pumped into the oil chamber from the F4 port to drive the compressor balance piston 26 to move leftward, so as to balance the axial gas force of the expander male rotor (03) and the compressor male rotor (17).

10. The screw refrigeration compressor directly driven by a natural gas screw expander according to claim 1, characterized in that: The diaphragm coupling (29) connects the expander male rotor (03) and the compressor male rotor (17) together, and the expander male rotor (03) directly drives the compressor male rotor (17) to rotate and perform work under the expansion effect of natural gas.

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