An apparatus and method for generating electricity using natural gas pressure energy

Abstract

The present invention relates to a device and method for generating electricity using natural gas pressure energy, belonging to the fields of natural gas pressure regulation and hydraulic pneumatics. The device of the present invention includes a pneumatic unit and a hydraulic unit; the pneumatic unit includes a pneumatic reversing valve I, a cylinder I, a one-way throttle valve I, an air capacitor I, a pneumatic reversing valve II, a cylinder II, a one-way throttle valve II, an air capacitor II, a pneumatic reversing valve III, etc.; the hydraulic unit includes a double-rod double-acting hydraulic cylinder, an accumulator, a bypass type speed control valve, a hydraulic motor, a generator, etc. The device of the present invention has a simple structure, and there are no electrical devices in the whole device, which is safe and reliable.

Description

Technical Field

[0001] The present invention relates to a device and method for generating electricity by using the pressure energy of natural gas, and belongs to the fields of natural gas pressure regulation and hydraulic and pneumatic Background Art

[0002] At present, China is in a period of rapid development of clean energy construction. As a clean energy, natural gas has become an energy widely used in industry and life. In the collection and transportation of natural gas, it is necessary to regulate the pressure of natural gas. For example, for general urban civil natural gas, before entering the urban natural gas pipeline network, it needs to enter a natural gas pressure regulating station first to reduce the pressure of natural gas with an input pressure of 3 MPa to 1.5 MPa for use by natural gas stoves in residents' homes. The main natural gas pressure reducing equipment currently used in China is a pressure reducing valve. Since the pressure reducing valve realizes pressure reduction through throttling, a considerable part of the pressure energy is wasted without being reasonably utilized during the pressure reduction process, resulting in energy waste. With the continuous advancement of the construction of natural gas pipeline networks, under the goal requirements of energy conservation and emission reduction, carbon peak, and carbon neutrality, how to reasonably utilize the wasted energy, improve the utilization rate of natural gas, and reduce unnecessary energy waste is an important issue that cannot be ignored. Summary of the Invention

[0003] The present invention solves the above problems through a gas-liquid conversion device with a new structure, which not only completes the pressure reduction of high-pressure natural gas but also utilizes the pressure energy during the pressure reduction process of high-pressure natural gas.

[0004] The present invention provides a device for generating electricity by using the pressure energy of natural gas. The device includes pneumatic directional control valve I, pneumatic directional control valve II, and pneumatic directional control valve III; the air inlets of pneumatic directional control valve I, pneumatic directional control valve II, and pneumatic directional control valve III are connected to a high-pressure natural gas supply unit; the working port I of pneumatic directional control valve I is connected to cylinder I and one-way throttle valve I, and one-way throttle valve I is connected to air chamber I and the control port of pneumatic directional control valve II; the working port II of pneumatic directional control valve I is connected to cylinder II and one-way throttle valve II, and one-way throttle valve II is connected to air chamber II and the control port of pneumatic directional control valve III; the working port of pneumatic directional control valve II is connected to the control port I of pneumatic directional control valve I; the working port of pneumatic directional control valve III is connected to the control port II of pneumatic directional control valve I; the piston rods of cylinder I and cylinder II are respectively connected to piston rod I and piston rod II of a double-rod double-acting hydraulic cylinder; the oil chambers I and II of the double-rod double-acting hydraulic cylinder are connected to an oil supply unit during oil suction; the oil chambers I and II of the double-rod double-acting hydraulic cylinder are sequentially connected to the inlet of a hydraulic motor through an accumulator and a bypass type flow control valve during oil pressure; the output shaft of the hydraulic motor is connected to the generator shaft.

[0005] The function of the one-way throttle valve in the present invention is: it can adjust the time required for the piston rod of the cylinder to reciprocate for one stroke.

[0006] The function of the accumulator in the present invention is: when the pneumatic directional valve I changes direction, it supplies oil to the hydraulic motor to stabilize the rotational speed of the hydraulic motor.

[0007] The function of the bypass type speed control valve in the present invention is: used to adjust the rotational speed of the hydraulic motor and act as a safety valve.

[0008] Preferably, in the present invention, the exhaust port of the pneumatic directional valve I is connected to the pneumatic sequence valve.

[0009] The function of the pneumatic sequence valve in the present invention is: to act as a back pressure to maintain the pressure in the outlet pipeline at the regulated pressure value.

[0010] Preferably, in the present invention, the device further includes a manual directional valve; the air inlet of the manual directional valve is connected to the high-pressure natural gas supply unit; the working port of the manual directional valve is connected to the air inlets of the pneumatic directional valve II and the pneumatic directional valve III.

[0011] Preferably, in the present invention, a flow meter is provided between the bypass type speed control valve and the oil inlet of the hydraulic motor.

[0012] Another object of the present invention is to provide a method for generating electricity using the above device. The method includes the following steps: ① High-pressure natural gas enters the cylinder I through the pneumatic directional valve I. The piston rod of the cylinder I extends and pushes the piston rod I of the double-rod double-acting hydraulic cylinder, causing the oil chamber I of the double-rod double-acting hydraulic cylinder to generate a vacuum and suck in hydraulic oil, and at the same time inflating the air chamber I. After the air chamber I is filled, control the pneumatic directional valve II to change direction; ② After the pneumatic directional valve II changes direction, control the pneumatic directional valve I to change direction. The cylinder I and the air chamber I exhaust. High-pressure natural gas enters the cylinder II through the pneumatic directional valve I. The piston rod of the cylinder II extends and pushes the piston rod II of the double-rod double-acting hydraulic cylinder, causing the oil chamber II of the double-rod double-acting hydraulic cylinder to generate a vacuum and suck in hydraulic oil. The hydraulic oil in the oil chamber I of the double-rod double-acting hydraulic cylinder is pressed out. Part of the hydraulic oil is stored in the accumulator, and the remaining hydraulic oil pushes the hydraulic motor to rotate, thereby driving the generator to rotate and generate electricity. At the same time, the air chamber II is inflated. After the air chamber I deflates, the pneumatic directional valve II resets. After the air chamber II is filled, control the pneumatic directional valve III to change direction; ③ After the pneumatic directional valve III changes direction, control the pneumatic directional valve I to change direction. The cylinder II and the air chamber II exhaust. High-pressure natural gas enters the cylinder I through the pneumatic directional valve I. The piston rod of the cylinder I extends and pushes the piston rod I of the double-rod double-acting hydraulic cylinder, causing the oil chamber I of the double-rod double-acting hydraulic cylinder to generate a vacuum and suck in hydraulic oil. The hydraulic oil in the oil chamber II of the double-rod double-acting hydraulic cylinder is pressed out. Part of the hydraulic oil is stored in the accumulator, and the remaining hydraulic oil pushes the hydraulic motor to rotate, thereby driving the generator to rotate and generate electricity. At the same time, the air chamber I is inflated. After the air chamber II deflates, the pneumatic directional valve III resets. After the air chamber I is filled, control the pneumatic directional valve II to change direction; ④ Automatically repeat steps ② and ③ to achieve continuous power generation.

[0013] The beneficial effects of the present invention are:

[0014] The device described in the present invention utilizes the pressure energy of natural gas to generate electricity, improving the utilization rate of natural gas and avoiding energy waste.

[0015] The high-pressure natural gas input into the device described in the present invention does not need to be decompressed and is directly input into the device to do work, and the pressure of the output natural gas also meets the requirements.

[0016] The device described in the present invention has a simple structure, low construction cost and small occupied space, and there is no electrical equipment in the whole device, so the safety and reliability are relatively good.

[0017] The cylinder of the device described in the present invention is directly connected to the high-pressure natural gas supply unit, and the energy conversion efficiency can be increased to more than 60%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The attached Figure 1 drawings

[0019] Figure 1 are schematic structural diagrams of the device described in Embodiment 1;

[0020] Wherein: 1. High-pressure natural gas storage tank, 2. Pneumatic directional control valve I, 3. Cylinder I, 4. One-way throttle valve I, 5. Air capacitor I, 6. Pneumatic directional control valve II, 7. Cylinder II, 8. One-way throttle valve II, 9. Air capacitor II, 10. Pneumatic directional control valve III, 11. Pneumatic sequence valve, 12. Manual directional control valve, 13. Double-rod double-acting hydraulic cylinder, 14. Check valve I, 15. Check valve II, 16. Oil tank, 17. Check valve III, 18. Check valve IV, 19. Accumulator, 20. Bypass type flow control valve, 21. Flowmeter, 22. Hydraulic motor, 23. Generator. DETAILED DESCRIPTION OF THE INVENTION

[0021] The following non-limiting embodiments can enable those of ordinary skill in the art to more comprehensively understand the present invention, but do not limit the present invention in any way.

[0022] Embodiment 1

[0023] A device for generating electricity by using the pressure energy of natural gas, as Figure 1 shown, the device includes a pneumatic directional control valve I 2 and a manual directional control valve 12;

[0024] The air inlet of the pneumatic directional control valve I 2 and the air inlet of the manual directional control valve 12 are connected to the high-pressure natural gas storage tank 1;

[0025] The working port I of the pneumatic directional control valve I 2 is connected to the cylinder I 3 and the one-way throttle valve I 4, and the one-way throttle valve I 4 is connected to the control port of the air capacitor I 5 and the pneumatic directional control valve II 6, so that when the air capacitor I 5 is inflated, it passes through the throttle valve of the one-way throttle valve I 4, and when the air capacitor I 5 exhausts, it passes through the check valve of the one-way throttle valve I 4;

[0026] The working port Ⅱ of the pneumatic directional control valve Ⅰ2 is connected to the cylinder Ⅱ7 and the one-way throttle valve Ⅱ8. The one-way throttle valve Ⅱ8 is connected to the air capacitor Ⅱ9 and the control port of the pneumatic directional control valve Ⅲ10, such that when the air capacitor Ⅱ9 is inflated, it passes through the throttle valve of the one-way throttle valve Ⅱ8, and when the air capacitor Ⅱ9 exhausts, it passes through the check valve of the one-way throttle valve Ⅱ8;

[0027] The exhaust port of the pneumatic directional control valve Ⅰ2 is connected to the pneumatic sequence valve 11;

[0028] The working port of the manual directional control valve 12 is connected to the inlet port of the pneumatic directional control valve Ⅱ6 and the inlet port of the pneumatic directional control valve Ⅲ10;

[0029] The working port of the pneumatic directional control valve Ⅱ6 is connected to the control port Ⅰ of the pneumatic directional control valve Ⅰ2;

[0030] The working port of the pneumatic directional control valve Ⅲ10 is connected to the control port Ⅱ of the pneumatic directional control valve Ⅰ2;

[0031] The piston rod of the cylinder Ⅰ3 and the piston rod of the cylinder Ⅱ7 are rigidly connected to the piston rod Ⅰ and the piston rod Ⅱ of the double-rod double-acting hydraulic cylinder 13 respectively;

[0032] The oil chamber Ⅰ of the double-rod double-acting hydraulic cylinder 13 is connected to the outlet port of the check valve Ⅰ14 and the inlet port of the check valve Ⅲ17;

[0033] The oil chamber Ⅱ of the double-rod double-acting hydraulic cylinder 13 is connected to the outlet port of the check valve Ⅱ15 and the inlet port of the check valve Ⅳ18;

[0034] The inlet port of the check valve Ⅰ14 and the inlet port of the check valve Ⅱ15 are connected to the oil tank 16;

[0035] The outlet port of the check valve Ⅲ17 and the outlet port of the check valve Ⅳ18 are successively connected to the oil tank 16 through the accumulator 19, the bypass type flow control valve 20, the flowmeter 21, and the hydraulic motor 22;

[0036] The output shaft of the hydraulic motor 22 is coupled to the shaft of the generator 23.

[0037] Embodiment 2

[0038] A method for generating electricity using the device described in Embodiment 1, the method comprising the following steps:

[0039] ①Before the device starts, the air inlet of the pneumatic reversing valve Ⅰ2 is connected to its working port Ⅰ, the working port Ⅱ is connected to its exhaust port, and there is no pressure at the control port Ⅰ and the control port Ⅱ. The air inlet of the manual reversing valve 12 is not connected to its working port. The air inlet of the pneumatic reversing valve Ⅱ6 is not connected to its working port, and there is no pressure at the control port. The air inlet of the pneumatic reversing valve Ⅲ10 is not connected to its working port, and there is no pressure at the control port. High-pressure natural gas enters the cylinder Ⅰ3 through the pneumatic reversing valve Ⅰ2. The piston rod of the cylinder Ⅰ3 extends and pushes the piston rod Ⅰ of the double-rod double-acting hydraulic cylinder 13, causing a vacuum in the oil chamber Ⅰ of the double-rod double-acting hydraulic cylinder 13 and sucking in hydraulic oil. At the same time, the air chamber Ⅰ5 is inflated. When the air chamber Ⅰ5 is full, there is pressure at the control port of the pneumatic reversing valve Ⅱ6, causing it to reverse. The air inlet of the pneumatic reversing valve Ⅱ6 is connected to its working port. Pull the manual reversing valve 12 to connect its air inlet to the working port, and the device starts;

[0040] ②High-pressure natural gas enters the control port Ⅰ of the pneumatic reversing valve Ⅰ2 through the pneumatic reversing valve Ⅱ6, causing pressure at the control port Ⅰ, while there is no pressure at the control port Ⅱ of the pneumatic reversing valve Ⅰ2. The pneumatic reversing valve Ⅰ2 reverses, causing its air inlet to be connected to its working port Ⅱ and its working port Ⅰ to be connected to its exhaust port. The cylinder Ⅰ3 and the air chamber Ⅰ5 exhaust. High-pressure natural gas enters the cylinder Ⅱ7 through the pneumatic reversing valve Ⅰ2. The piston rod of the cylinder Ⅱ7 extends and pushes the piston rod Ⅱ of the double-rod double-acting hydraulic cylinder 13, causing a vacuum in the oil chamber Ⅱ of the double-rod double-acting hydraulic cylinder 13 and sucking in hydraulic oil. As the piston rod of the cylinder Ⅱ7 extends, the piston rod of the cylinder Ⅰ3 retracts, and the hydraulic oil in the oil chamber Ⅰ of the double-rod double-acting hydraulic cylinder 13 is pressed out. A small part of the hydraulic oil is stored in the accumulator 19, and the remaining hydraulic oil drives the hydraulic motor 22 to rotate, thereby driving the generator 23 to rotate and generate electricity. At the same time, the air chamber Ⅱ9 is inflated. After the air chamber Ⅰ5 deflates, there is no pressure at the control port of the pneumatic reversing valve Ⅱ6, causing it to reset. The air inlet of the pneumatic reversing valve Ⅱ6 is not connected to its working port, and further, there is no pressure at the control port Ⅰ of the pneumatic reversing valve Ⅰ2. When the air chamber Ⅱ9 is full, there is pressure at the control port of the pneumatic reversing valve Ⅲ10, causing it to reverse. The air inlet of the pneumatic reversing valve Ⅲ10 is connected to its working port;

[0041] ③ High-pressure natural gas enters the control port II of the pneumatic reversing valve I 2 through the pneumatic reversing valve III 10, causing it to have pressure, while the control port I of the pneumatic reversing valve I 2 has no pressure, and the pneumatic reversing valve I 2 reverses, so that the air inlet of the pneumatic reversing valve I 2 is connected to its working port I, and the working port II is connected to its exhaust port. The cylinder II 7 and the air chamber II 9 exhaust. High-pressure natural gas enters the cylinder I 3 through the pneumatic reversing valve I 2. The piston rod of the cylinder I 3 extends and pushes the piston rod I of the double-rod double-acting hydraulic cylinder 13, causing a vacuum to be generated in the oil chamber I of the double-rod double-acting hydraulic cylinder 13 and sucking in hydraulic oil. As the piston rod of the cylinder I 3 extends, the piston rod of the cylinder II 7 retracts, and the hydraulic oil in the oil chamber II of the double-rod double-acting hydraulic cylinder 13 is pressed out. A small part of the hydraulic oil is stored in the accumulator 19, and the remaining hydraulic oil drives the hydraulic motor 22 to rotate, thereby driving the generator 23 to rotate and generate electricity, while inflating the air chamber I 5. After the air chamber II 9 deflates, the control port of the pneumatic reversing valve III 10 has no pressure and it resets. The air inlet of the pneumatic reversing valve III 10 is not connected to its working port, and further, the control port II of the pneumatic reversing valve I 2 has no pressure. After the air chamber I 5 is filled, the control port of the pneumatic reversing valve II 6 has pressure and it reverses. The air inlet of the pneumatic reversing valve II 6 is connected to its working port;

[0042] ④ Automatically repeat steps ② and ③ to achieve continuous power generation.

Claims

1. A device for generating electricity using the pressure energy of natural gas, characterized in that: The device includes pneumatic reversing valve I, pneumatic reversing valve II, and pneumatic reversing valve III; The air inlets of pneumatic reversing valve I, pneumatic reversing valve II, and pneumatic reversing valve III are connected to the high-pressure natural gas supply unit; The working port I of pneumatic reversing valve I is connected to cylinder I and one-way throttle valve I, and one-way throttle valve I is connected to air capacitor I and the control port of pneumatic reversing valve II; The working port II of pneumatic reversing valve I is connected to cylinder II and one-way throttle valve II, and one-way throttle valve II is connected to air capacitor II and the control port of pneumatic reversing valve III; The working port of pneumatic reversing valve II is connected to the control port I of pneumatic reversing valve I; The working port of pneumatic reversing valve III is connected to the control port II of pneumatic reversing valve I; The piston rods of cylinder I and cylinder II are respectively connected to piston rod I and piston rod II of the double-rod double-acting hydraulic cylinder; When the oil chambers I and II of the double-rod double-acting hydraulic cylinder suck oil, they are connected to the oil supply unit; When the oil chambers I and II of the double-rod double-acting hydraulic cylinder press oil, they are successively connected to the hydraulic motor's oil inlet through an accumulator and a bypass type speed control valve; The output shaft of the hydraulic motor is connected to the generator shaft.

2. The device according to claim 1, characterized in that: The exhaust port of pneumatic reversing valve I is connected to the pneumatic sequence valve.

3. The device according to claim 1, characterized in that: The device further includes a manual reversing valve; The air inlet of the manual reversing valve is connected to the high-pressure natural gas supply unit; The working port of the manual reversing valve is connected to the air inlets of pneumatic reversing valve II and pneumatic reversing valve III.

4. The device according to claim 1, characterized in that: A flowmeter is provided between the bypass type speed control valve and the oil inlet of the hydraulic motor.

5. A method for generating electricity using the device according to claim 1, 2, 3 or 4, characterized in that: The method includes the following steps: ① High-pressure natural gas enters cylinder I through pneumatic reversing valve I, the piston rod of cylinder I extends and pushes piston rod I of the double-rod double-acting hydraulic cylinder, causing a vacuum to be generated in oil chamber I of the double-rod double-acting hydraulic cylinder and sucking in hydraulic oil, while inflating air capacitor I. After air capacitor I is full, it controls the reversal of pneumatic reversing valve II; ② After pneumatic reversing valve II reverses, it controls the reversal of pneumatic reversing valve I. Cylinder I and air capacitor I exhaust. High-pressure natural gas enters cylinder II through pneumatic reversing valve I. The piston rod of cylinder II extends and pushes piston rod II of the double-rod double-acting hydraulic cylinder, causing a vacuum to be generated in oil chamber II of the double-rod double-acting hydraulic cylinder and sucking in hydraulic oil. The hydraulic oil in oil chamber I of the double-rod double-acting hydraulic cylinder is pressed out. Part of the hydraulic oil is stored in the accumulator, and the remaining hydraulic oil pushes the hydraulic motor to rotate, thus driving the generator to rotate and generate electricity. At the same time, air capacitor II is inflated. After air capacitor I deflates, pneumatic reversing valve II resets. After air capacitor II is full, it controls the reversal of pneumatic reversing valve III; ③ After pneumatic reversing valve III reverses, it controls the reversal of pneumatic reversing valve I. Cylinder II and air capacitor II exhaust. High-pressure natural gas enters cylinder I through pneumatic reversing valve I. The piston rod of cylinder I extends and pushes piston rod I of the double-rod double-acting hydraulic cylinder, causing a vacuum to be generated in oil chamber I of the double-rod double-acting hydraulic cylinder and sucking in hydraulic oil. The hydraulic oil in oil chamber II of the double-rod double-acting hydraulic cylinder is pressed out. Part of the hydraulic oil is stored in the accumulator, and the remaining hydraulic oil pushes the hydraulic motor to rotate, thus driving the generator to rotate and generate electricity. At the same time, air capacitor I is inflated. After air capacitor II deflates, pneumatic reversing valve III resets. After air capacitor I is full, it controls the reversal of pneumatic reversing valve II; ④ Automatically repeat steps ② and ③ to achieve continuous power generation.

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