Natural gas turbine decompression power generation system

Abstract

The utility model discloses a natural gas turbine pressure reduction power generation system which solves the problem that energy is difficult to recycle efficiently in the natural gas pressure reduction process. A natural gas turbine pressure reduction power generation system comprises a turbo-expander, a gear box, an interstage heat exchanger, a regulating valve and a power generator, the turbo-expander comprises a high-pressure turbine part sleeve and a low-pressure turbine part sleeve, the gear box comprises a high-speed shaft and a low-speed shaft, the high-pressure turbine part sleeve and the low-pressure turbine part sleeve are connected to the two ends of the high-speed shaft of the gear box, and the interstage heat exchanger is connected with the regulating valve. The generator is connected to one end of a low-speed shaft of the gearbox, the adjusting valve is connected to the inlet end of the high-pressure turbine part sleeve, and the interstage heat exchanger is connected between an outlet of the high-pressure turbine part sleeve and an inlet of the low-pressure turbine part sleeve.

Description

TECHNICAL FIELD

[0001] The utility model relates to natural gas pressure reducing technical field especially is related to a natural gas turbine pressure reducing power generation system. BACKGROUND

[0002] In the natural gas transmission and distribution process, the natural gas with high pressure in the previous stage is usually adjusted to the required pressure in the downstream by a pressure reducing device. At present, the pressure reducing device mainly adopts a pressure reducing valve, which leads to that the pressure energy is mainly consumed to overcome the flow resistance in the whole pressure reduction process from high pressure to low pressure of the natural gas, and the mechanical energy cannot be generated externally, resulting in a large amount of energy loss. In order to recover this part of energy, the natural gas turbine pressure reducing power generation system is an important form.

[0003] The existing natural gas turbine pressure reducing power generation system has weak variable condition adaptability and low system efficiency, and it is difficult to adapt to the large fluctuation of the upstream natural gas pressure and flow. Therefore, in order to better recover the natural gas differential pressure energy, it is an urgent problem to be solved to develop a natural gas turbine pressure reducing power generation system which is efficient, has wide adaptability to working conditions and has reliable structure. SUMMARY

[0004] The utility model aims at overcoming the deficiency of prior art, provides a natural gas turbine pressure reducing power generation system, solves the difficulty that the energy is difficult to be recovered and utilized efficiently in the natural gas pressure reducing process.

[0005] The utility model discloses a natural gas turbine pressure reducing power generation system, including turbine expander, gear box, interstage heat exchanger, regulating valve, generator, the turbine expander includes high pressure turbine part cover, low pressure turbine part cover, the gear box includes high speed shaft, low speed shaft, the high pressure turbine part cover, low pressure turbine part cover is connected to the high speed shaft both ends of gear box, the generator is connected to the low speed shaft one end of gear box, the regulating valve is connected to the import end of high pressure turbine part cover, the interstage heat exchanger is connected between high pressure turbine part cover export, low pressure turbine part cover import.

[0006] A natural gas turbine pressure reducing power generation system, including turbine expander, gear box, interstage heat exchanger, regulating valve, generator, the turbine expander includes high pressure turbine part cover, low pressure turbine part cover, the gear box includes high speed shaft, low speed shaft, the high pressure turbine part cover, low pressure turbine part cover is connected to the high speed shaft both ends of gear box, the generator is connected to the low speed shaft one end of gear box, the regulating valve is connected to the import end of high pressure turbine part cover, the interstage heat exchanger is connected between high pressure turbine part cover export, low pressure turbine part cover import.

[0007] Preferably, high pressure turbine part cover is equipped with high pressure turbine, high pressure nozzle, low pressure turbine part cover is equipped with low pressure turbine, low pressure nozzle, the high pressure turbine, low pressure turbine are all axial flow turbine.

[0008] Preferably, the high pressure nozzle, low pressure nozzle can adjust the angle.

[0009] Preferably, the high pressure turbine, low pressure turbine can adjust turbine stage number.

[0010] Preferably, the turbine stage number of high pressure turbine is 1-2 stages, and the turbine stage number of low pressure turbine is 1-4 stages.

[0011] Preferably, the inter-stage heat exchanger adopts a shell-and-tube heat exchanger, and the tube passage of the shell-and-tube heat exchanger is provided for the natural gas to pass through, and the shell passage of the shell-and-tube heat exchanger is provided for the hot water to pass through.

[0012] Preferably, temperature sensors and pressure sensors are arranged on the pipeline of the inlet end of the high-pressure turbine sleeve, the pipeline of the upstream end and the downstream end of the inter-stage heat exchanger, and the pipeline of the outlet end of the low-pressure turbine sleeve.

[0013] Thanks to the above technical scheme, the natural gas turbo-expander power generation system has the following beneficial effects:

[0014] 1. The high-pressure natural gas is depressurized and generates electricity through the natural gas turbo-expander power generation system, so that the energy recovery and utilization in the natural gas depressurization process is realized.

[0015] 2. The turbine expander in the system adopts a combination of a high-pressure turbine sleeve and a low-pressure turbine sleeve, and an inter-stage heat exchanger is additionally arranged in the middle to heat the natural gas after expansion and cooling, so as to avoid the risk of ice blockage when the low-temperature natural gas is expanded and cooled again, improve the system safety, and increase the system power generation.

[0016] 3. The through-flow structure of the turbine expander adopts an adjustable nozzle, so that the turbine expander still has high efficiency and variable working condition adaptability under the condition of natural gas pressure and flow fluctuation.

[0017] 4. A plurality of sensors are arranged on the connecting pipeline to monitor the system state, and a PLC control valve is arranged to improve the automation level of the system. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 is a schematic view of the natural gas turbo-expander power generation system;

[0019] Fig. 2 is a structural schematic view of the high-pressure turbine sleeve;

[0020] Fig. 3 is a structural schematic view of the low-pressure turbine sleeve.

[0021] REFERENCE NUMERALS

[0022] In the drawings, 1 is a high-pressure turbine sleeve, 2 is a low-pressure turbine sleeve, 3 is a gear box, 4 is an inter-stage heat exchanger, 5 is a regulating valve, 6 is a generator, 7 is a PLC control cabinet, 8 is a high-pressure turbine, 9 is a high-pressure nozzle, 10 is a low-pressure turbine, 11 is a low-pressure nozzle, 12 is a natural gas flow route in the high-pressure turbine sleeve, 13 is a natural gas flow route in the low-pressure turbine sleeve, 14 is a natural gas inlet, and 15 is a natural gas outlet. DETAILED DESCRIPTION

[0023] Reference is made to Figs. 1-3The application discloses a natural gas turbine decompression power generation system which comprises a turboexpander, a gear box 3, an inter-stage heat exchanger 4, a regulating valve 5, a generator 6, a PLC control cabinet 7 and connecting pipelines.

[0024] The through-flow element in the high-pressure turbine sleeve 1 comprises a high-pressure turbine 8 and a high-pressure nozzle 9. The high-pressure turbine 8 is an axial turbine, the turbine stage number of which can be adjusted, and generally 1-2 stages are arranged. The high-pressure nozzle 9 is an adjustable nozzle, and the high-pressure nozzle 9 can adjust the angle according to the natural gas flow, change the through-flow, improve the variable working condition efficiency and adaptability through PLC control.

[0025] The through-flow element in the low-pressure turbine sleeve 2 comprises a low-pressure turbine 10 and a low-pressure nozzle 11. The low-pressure turbine 10 is an axial turbine, the turbine stage number of which can be adjusted, and generally 1-4 stages are arranged. The low-pressure nozzle 11 is an adjustable nozzle, and the low-pressure nozzle 11 can adjust the angle according to the natural gas flow, change the through-flow, improve the variable working condition efficiency and adaptability through PLC control.

[0026] The gear box 3 is a high reduction ratio gear box, and the high-speed shaft of the gear box 3 is a double-stretch shaft.

[0027] The inter-stage heat exchanger 4 adopts a tube-shell heat exchanger, the natural gas passes through the tube to reduce the pressure loss of the natural gas in the heat exchanger, and the hot water passes through the shell, so that the natural gas is reheated through the heat exchanger after being expanded and cooled by the high-pressure turbine sleeve 1, the natural gas enters the low-pressure turbine sleeve 2 to do work again, the ice blockage caused by extreme working conditions is avoided, the turbine is prevented from being damaged, and the safety and reliability of the system are improved.

[0028] Temperature sensors and pressure sensors are arranged on the connecting pipelines to monitor the parameter state of the system and improve the automation level of the system. In the embodiment, temperature sensors and pressure sensors are arranged on the pipeline at the inlet end of the high-pressure turbine sleeve 1, the upstream end and the downstream end of the inter-stage heat exchanger 4 and the pipeline at the outlet end of the low-pressure turbine sleeve 2.

[0029] Working principle:

[0030] The natural gas enters the high-pressure turbine portion sleeve 1 first to carry out primary expansion, drives the high-pressure turbine 8 to rotate, and then enters the inter-stage heat exchanger 4 to be heated, and then enters the low-pressure turbine portion sleeve 2 to carry out secondary expansion, drives the low-pressure turbine 10 to rotate, and then enters the low-pressure pipe network, wherein the rotation of the driving turbine drives the generator 6 to generate electricity, so as to realize the energy conversion of the pressure energy into mechanical energy and finally into electrical energy.

[0031] Finally, it should be pointed out that the above preferred embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present application.

Claims

1. A natural gas turbine pressure reduction power generation system characterized by: The turbine expander, the gear box, the inter-stage heat exchanger, the regulating valve and the generator, the turbine expander comprises a high-pressure turbine section sleeve and a low-pressure turbine section sleeve, the gear box comprises a high-speed shaft and a low-speed shaft, the high-pressure turbine section sleeve and the low-pressure turbine section sleeve are connected to the two ends of the high-speed shaft of the gear box, the generator is connected to one end of the low-speed shaft of the gear box, the regulating valve is connected to the inlet end of the high-pressure turbine section sleeve, and the inter-stage heat exchanger is connected between the outlet of the high-pressure turbine section sleeve and the inlet of the low-pressure turbine section sleeve.

2. A natural gas turbine pressure reduction power generation system according to claim 1, wherein: The high-pressure turbine section sleeve is internally provided with a high-pressure turbine and a high-pressure nozzle, and the low-pressure turbine section sleeve is internally provided with a low-pressure turbine and a low-pressure nozzle, and the high-pressure turbine and the low-pressure turbine are both axial turbines.

3. A natural gas turbine pressure reduction power generation system according to claim 2, wherein: The high-pressure nozzle and the low-pressure nozzle can be adjusted in angle.

4. A natural gas turbine pressure reduction power generation system according to claim 1, wherein: The high-pressure turbine and the low-pressure turbine can be adjusted in turbine stage number.

5. A natural gas turbine pressure reduction power generation system according to claim 4 wherein: The turbine stage number of the high-pressure turbine is 1-2 stages, and the turbine stage number of the low-pressure turbine is 1-4 stages.

6. A natural gas turbine pressure reduction power generation system according to claim 1 wherein: The inter-stage heat exchanger adopts a tube-shell heat exchanger, the tube passage of the tube-shell heat exchanger is used for passing natural gas, and the shell passage of the tube-shell heat exchanger is used for passing hot water.

7. A natural gas turbine pressure reduction power generation system according to claim 1 wherein: Temperature sensors and pressure sensors are arranged on the pipelines of the inlet end of the high-pressure turbine section sleeve, the upstream end and the downstream end of the inter-stage heat exchanger and the outlet end of the low-pressure turbine section sleeve.

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