System for comprehensively utilizing complementary energy of natural gas pipeline station

Abstract

The utility model relates to the technical field of natural gas, and discloses a natural gas pipeline station complementary energy comprehensive utilization system which comprises a waste heat power generation subsystem and a hydrogen production and doping subsystem which are electrically connected with each other. The utility model solves the problem that the complementary energy of the natural gas pipeline network is difficult to fully utilize in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of natural gas, in particular to a system for comprehensive utilization of surplus energy in a natural gas pipeline station. Background Art

[0002] With increasing CO2 emissions and global warming, low-carbon emission reduction is becoming increasingly urgent. Rational utilization of surplus energy at natural gas pipeline stations can effectively improve energy efficiency and reduce greenhouse gas emissions, making it an effective path to achieving my country's "dual carbon" goals. The surplus energy in natural gas pipeline networks primarily consists of waste heat (high-temperature flue gas) from gas compressors and the pressure differential during pressure regulation. Current waste energy utilization in natural gas pipeline networks primarily focuses on the pressure differential, while the waste heat from gas compressors is not effectively utilized. Pressure differentials are typically used to generate electricity or generate cooling energy, as exemplified by patents CN 110118305, "A Comprehensive Utilization System for Excess Pressure at a Natural Gas Pressure Regulating Station," and CN 105927491B, "A Coupled System and Method for Natural Gas Pressure Differential Power Generation and Cascade Energy Utilization." However, natural gas pressure regulating or boosting stations are often located in relatively remote locations. This power generation or cooling energy generated from pressure differentials is typically limited to internal use within the station and is difficult to dissipate externally. Commercialization is significantly impacted by external environmental factors, making it challenging to implement. Therefore, converting surplus energy into other easily stored energy sources is a promising solution. Hydrogen is an energy carrier and energy storage method, and hydrogen energy is one of the most ideal clean energy sources. Therefore, it is a more feasible way to convert the surplus energy of natural gas into hydrogen energy first, and then use natural gas pipelines for storage and transportation. Patent CN 220287155 U introduces a system for hydrogen production and hydrogen blending using the surplus energy of differential pressure. The technical route is to first generate electricity using the pressure difference of the pressure regulation, and then use the low-temperature natural gas after the pressure reduction to exchange heat with the hydrogen purification device to increase the temperature of the natural gas and reduce the temperature of the hydrogen. However, when the temperature before the pressure regulation is not high enough, the temperature drop after the pressure regulation may cause ice blockage, etc., which will have an adverse effect on the safety of the pipeline network, especially in winter; if the adverse effects are to be avoided, the temperature drop needs to be reduced, and the available pressure difference will be reduced. Therefore, the technical solution of this patent is subject to certain conditions in actual application.

[0003] Therefore, in order to solve the shortcomings of the existing technology, it is necessary to design a new technical solution that can comprehensively utilize the waste energy (waste heat and pressure difference) of the natural gas pipeline network and solve the defects of the existing technology. Utility Model Content

[0004] In order to overcome the deficiencies of the existing technology, the utility model provides a system for comprehensive utilization of surplus energy in natural gas pipeline stations, which solves the problems existing in the existing technology such as difficulty in fully utilizing the surplus energy of the natural gas pipeline network.

[0005] The technical solution adopted by the present invention to solve the above problems is:

[0006] A system for comprehensive utilization of surplus energy in a natural gas pipeline station comprises a waste heat power generation subsystem and a hydrogen production and blending subsystem which are electrically connected to each other.

[0007] As a preferred technical solution, it includes a residual pressure generating subsystem and a hydrogen production and hydrogen doping subsystem that are electrically connected to each other.

[0008] As a preferred technical solution, the waste heat power generation subsystem includes a waste heat power generation unit electrically connected to the hydrogen production and hydrogen blending subsystem.

[0009] As a preferred technical solution, it includes a waste heat heat exchange device connected to the waste heat generator set.

[0010] As a preferred technical solution, the waste heat exchange device is a waste heat boiler or a heat exchanger.

[0011] As a preferred technical solution, the waste heat power generation unit is a steam power generation unit or an organic Rankine cycle power generation unit.

[0012] As a preferred technical solution, the excess pressure power generation subsystem includes an excess pressure power generation unit electrically connected to the hydrogen production and hydrogen blending subsystem.

[0013] As a preferred technical solution, the excess pressure generator subsystem includes a preheater connected to the excess pressure generator set.

[0014] As a preferred technical solution, the hydrogen production and hydrogen blending subsystem includes a hydrogen production device, a hydrogen compressor, and a hydrogen blending device that are connected in sequence.

[0015] As a preferred technical solution, the hydrogen production device is an alkaline electrolyzer or a proton exchange membrane electrolyzer.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The utility model makes full use of the waste heat of the fuel gas compressor to generate electricity and produce hydrogen, and uses a hydrogen blending device to directly mix hydrogen into the natural gas pipeline for transportation;

[0018] (2) The utility model optimizes and improves the problems existing in utilizing waste pressure for power generation and hydrogen production. It utilizes the waste heat of flue gas discharged from the waste heat boiler to increase the temperature of natural gas before pressure regulation, thus avoiding the frost heave temperature caused by the temperature drop after pressure regulation, thereby improving the safety and stability of the turbine expansion generator set and realizing the cascade utilization of waste heat, so that the waste heat of the natural gas pipeline station can be fully utilized, which has the effect of energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the present utility model.

[0020] The symbols and their corresponding names in the accompanying drawings are: 1. Waste heat power generation subsystem, 2. Waste pressure power generation subsystem, 3. Hydrogen production and hydrogen blending subsystem, 11. Waste heat heat exchange device, 12. Waste heat power generation unit, 21. Preheater, 22. Waste pressure power generation unit, 31. Hydrogen production device, 32. Hydrogen compressor, 33. Hydrogen blending device. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0022] Example 1

[0023] like Figure 1 As shown, in order to overcome the above-mentioned shortcomings of the prior art, the utility model provides a system for comprehensive utilization of surplus energy in natural gas pipeline stations, which utilizes the flue gas of the gas booster to generate waste heat electricity, utilizes the pressure difference of the pressure regulator to generate pressure difference electricity, converts electrical energy into hydrogen energy through a water electrolysis hydrogen production device, and mixes hydrogen into the natural gas pipeline for transportation through a hydrogen blending skid-mounted device, thereby solving the storage and transportation problems of hydrogen. In the pressure difference power generation subsystem, the waste heat of the flue gas of the waste heat boiler is used to heat the natural gas before pressure regulation, ensuring that the natural gas after pressure regulation still has an appropriate temperature and avoiding the adverse effects caused by temperature drop. At the same time, the waste heat and waste pressure of the natural gas pipeline station are converted into clean energy hydrogen energy for utilization, thereby improving the utilization rate of surplus energy.

[0024] A system for comprehensive utilization of waste energy at natural gas pipeline stations includes three subsystems: a waste heat power generation subsystem, a waste pressure power generation subsystem, and a hydrogen production and blending subsystem. The waste heat power generation subsystem includes a waste heat heat exchanger and a waste heat generator set; the waste pressure power generation subsystem includes a preheater and a waste pressure generator set; and the hydrogen production and blending subsystem includes a hydrogen production device, a hydrogen compressor device, and a hydrogen blending device. The input end of the waste heat exchanger is connected to the flue gas duct of the fuel gas compressor, and the output end is respectively connected to the input end of the waste heat generator set and the input end of the preheater of the waste pressure power generation subsystem; the output end of the preheater is connected to the input end of the waste pressure generator set; the output ends of the waste heat generator set and the waste pressure generator set are connected to the input end of the hydrogen production device; the output end of the hydrogen production device is connected to the input end of the hydrogen compressor, the output end of the hydrogen compressor is connected to the input end of the hydrogen blending device, and the output end of the hydrogen blending device is connected to the gas transmission trunk pipeline.

[0025] The high-temperature flue gas discharged from the combustion-driven compressor is introduced into a waste heat heat exchanger, where water or organic fluid is converted into steam for introduction into the waste heat generator set to generate electricity. The waste heat from the flue gas removed by the waste heat heat exchanger is introduced into the preheater in the waste pressure generator subsystem to preheat the natural gas in the station's distribution pipelines, ensuring that the gas supply temperature to downstream users after pressure regulation meets requirements and does not cause adverse effects such as frost heave. The pressure difference in the distribution pipeline is used to drive the waste pressure generator set to generate electricity. The output ends of the two generator sets are connected to a hydrogen production unit, which is then connected to a hydrogen compressor, which is then connected to a hydrogen blending unit. This utilizes the waste energy of the natural gas station to generate electricity and produce green hydrogen, which is then directly blended into the natural gas transmission network. This fully utilizes the waste heat and excess pressure of the natural gas station, while also solving the storage and transportation issues associated with waste energy conversion.

[0026] As a preferred solution, a preheater is provided at the front end of the residual generator set.

[0027] As a preferred solution, the waste heat power generation system is one of steam power generation and ORC (Organic Rankine Cycle) power generation. If the waste heat power generation system is a steam generator set, the waste heat heat exchange device is a waste heat boiler; if the waste heat power generation system is an ORC generator set, the waste heat heat exchange device is a heat exchanger.

[0028] As a preferred solution, the hydrogen production device in the hydrogen production and hydrogen blending subsystem is one of an alkaline electrolyzer (ALK) and a proton exchange membrane electrolyzer (PEM).

[0029] Example 2

[0030] like Figure 1 As a further optimization of Example 1, based on Example 1, this embodiment also includes the following technical features:

[0031] A system for comprehensively utilizing surplus energy from natural gas pipeline stations includes three subsystems: a waste heat power generation subsystem 1, a waste pressure power generation subsystem 2, and a hydrogen production and blending subsystem 3. Specifically, it includes a waste heat heat exchanger 11, a waste heat generator set 12, a preheater 21, a waste pressure generator set 22, a hydrogen production device 31, a hydrogen compressor 32, and a hydrogen blending device 33.

[0032] The input end of the waste heat heat exchange device 11 is the high-temperature flue gas discharged by the fuel-driven compressor, and the output end is respectively connected to the input end of the waste heat generator set 12 and the input end of the preheater 21 in the waste pressure generator subsystem.

[0033] The input end of the preheater 21 is connected to the natural gas pipeline and the flue gas output end of the waste heat heat exchange device 11 respectively, and the output end of the preheater 21 is connected to the waste pressure generator set 22 and the flue gas discharge chimney respectively. The waste heat of the flue gas is used to increase the temperature of the natural gas in front of the waste pressure generator set 22, fully utilizing the waste heat of the flue gas, and at the same time solving the frost heave problem after the pressure drop of the expander, thereby increasing the safety and stability of the waste pressure generator set.

[0034] The output ends of the waste heat generator set 12 and the waste pressure generator set 22 are connected to the input ends of the hydrogen production device 31, and the electrical energy is converted into hydrogen energy through the hydrogen production device; the output end of the hydrogen production device 31 is connected to the hydrogen compressor 32, the output end of the hydrogen compressor 32 is connected to the hydrogen blending device 33, and the output end of the hydrogen blending device 33 is connected to the natural gas pipeline.

[0035] Taking a natural gas pipeline boosting station as an example, multiple 30MW gas compressors are installed in the station to boost the pressure of the trunk line transmitted from the station to downstream areas; at the same time, the station is also equipped with a pressure regulating and distribution pipeline to provide gas supply to the local area. The surplus energy in the natural gas pipeline boosting station includes the preheating of the gas compressor and the pressure difference of pressure regulating and distribution. The high-temperature flue gas from the fuel gas compressor is introduced into the waste heat boiler (waste heat heat exchange device 11), and the waste heat boiler uses thermal energy to convert desalted water into water vapor, which drives the condensing generator set (waste heat generator set 12) to generate electricity, thereby converting thermal energy into electrical energy; the waste heat of the flue gas from the waste heat boiler is introduced into the preheater 21 to preheat the natural gas, and the heated natural gas is introduced into the turbine expansion generator set (waste pressure generator set 22) to generate electricity using the pressure difference, thereby converting the pressure difference energy into electrical energy. In addition, since the natural gas is heated in advance, the temperature drop after pressure regulation will not cause frost heave problems, thereby avoiding the adverse effects of frost heave on the pressure difference generator set and downstream pipeline facilities; the electricity produced by the generator set (waste heat generator set 12, waste pressure generator set 22) is introduced into the hydrogen production device 31, and the electricity is converted into hydrogen energy (hydrogen gas). The low-pressure hydrogen gas is pressurized to the pressure required by the hydrogen blending device 33 by the hydrogen compressor 32, and the hydrogen is blended into the natural gas pipeline through the hydrogen blending device 33, thereby realizing the transportation of hydrogen gas.

[0036] As described above, the present invention can be implemented well.

[0037] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Based on the technical essence of the present invention and within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement of the above embodiment shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A system for comprehensive utilization of surplus energy in natural gas pipeline stations, characterized in that: It includes a waste heat power generation subsystem (1) and a hydrogen production and hydrogen blending subsystem (3) electrically connected to each other; The hydrogen production and hydrogen blending subsystem (3) is electrically connected to the excess pressure generating subsystem (2); The waste heat power generation subsystem (1) includes a waste heat power generation unit (12) electrically connected to the hydrogen production and hydrogen blending subsystem (3); It includes a waste heat heat exchange device (11) connected to a waste heat generator set (12); The excess pressure generator subsystem (2) includes an excess pressure generator set (22) electrically connected to the hydrogen production and hydrogen blending subsystem (3); The excess pressure generator subsystem (2) includes a preheater (21) connected to the excess pressure generator set (22); The hydrogen production and hydrogen blending subsystem (3) comprises a hydrogen production device (31), a hydrogen compressor (32), and a hydrogen blending device (33) which are connected in sequence.

2. A system for comprehensive utilization of surplus energy in a natural gas pipeline station according to claim 1, characterized in that: The waste heat exchange device (11) is a waste heat boiler or a heat exchanger.

3. The system for comprehensive utilization of surplus energy in a natural gas pipeline station according to claim 1 is characterized in that: The waste heat power generation unit (12) is a steam power generation unit or an organic Rankine cycle power generation unit.

4. A system for comprehensive utilization of surplus energy in a natural gas pipeline station according to claim 1, characterized in that: The hydrogen production device (31) is an alkaline electrolyzer or a proton exchange membrane electrolyzer.

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