CN213235265U

CN213235265U - Gas supply system

Info

Publication number: CN213235265U
Application number: CN202021943101.XU
Authority: CN
Inventors: 沈红光; 高亚南; 刘果; 王丙祥
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2020-09-08
Filing date: 2020-09-08
Publication date: 2021-05-18
Anticipated expiration: 2030-09-08

Abstract

The utility model discloses a gas supply system belongs to engine technical field. The fuel gas supply system comprises an LNG vaporization buffer assembly, a pressure stabilizer, an injection valve, a bypass pipeline and a measurement adjusting assembly, wherein the LNG vaporization buffer assembly is configured to vaporize LNG and buffer vaporized natural gas; the pressure stabilizer is positioned at the downstream of the LNG vaporization buffer assembly and is used for stabilizing the system pressure at the downstream of the pressure stabilizer; the injection valve is arranged at the downstream of the pressure stabilizer and used for injecting natural gas; the bypass pipeline is connected in parallel with two ends of the voltage stabilizer; the measurement adjustment assembly is configured to measure an inlet pressure of the injection valve to adjust the flow or interruption of the bypass line. The fuel gas supply system can ensure the performance of the LNG engine when the LNG engine is in a heavy-load working condition or climbs a slope.

Description

Gas supply system

Technical Field

The utility model relates to the technical field of engines, especially, relate to a gas feed system.

Background

Petroleum is a non-renewable resource, and with the wide application of petroleum energy and the increasingly tightening supply of energy, the application occasions of clean energy natural gas are increasing. With the continuous upgrading of emission regulations, more and more host plants begin to vigorously popularize natural gas engines; and the price of natural gas is lower than that of petroleum, and the natural gas engine is a main factor for selecting natural gas engines for customers.

The ignition mode of the natural gas engine is different from that of a diesel engine, and the diesel engine is ignited by compressing mixed gas to reach the ignition point of diesel oil and is compression ignition; natural gas engines utilize a set of ignition systems to ignite the mixture with a spark plug before top dead center compression. LNG (Liquefied Natural Gas) is cleaner and has longer driving distance than CNG (Compressed Natural Gas). LNG is widely used for natural gas engines for roads. The LNG engine has a single gas supply system, as shown in fig. 1, and is mainly composed of a gas cylinder 1 ', a vaporizer 2', a buffer tank 3 ', a pressure stabilizer 4' (or a pressure reducer), a filter 5 ', an injection valve 6', and the like. The LNG engine uses a pressurizer 4 'to provide a stable inlet pressure to a downstream injection valve 6', and the typical pressurizer 4 'is mounted on the frame and connected to a downstream filter 5' via a gas line. However, when the LNG engine is in a heavy-load working condition or climbs a slope, the conventional gas supply system has a problem that the power of the LNG engine is insufficient due to low transient gas pressure.

Therefore, there is a need for a fuel gas supply system capable of ensuring the performance of an LNG engine when the LNG engine is in a heavy load condition or climbing a slope, so as to solve the above technical problems in the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a gas supply system, this gas supply system can guarantee LNG engine performance when the LNG engine is in heavy load operating mode or climbing.

To achieve the purpose, the utility model adopts the following technical proposal:

a gas supply system comprising:

an LNG vaporization buffer assembly configured to vaporize LNG and buffer vaporized natural gas;

a pressurizer downstream of the LNG vaporization buffer assembly, the pressurizer to stabilize a system pressure downstream of the pressurizer;

the injection valve is arranged at the downstream of the pressure stabilizer and used for injecting natural gas;

the bypass pipeline is connected in parallel to two ends of the voltage stabilizer;

a measurement adjustment assembly configured to measure an inlet pressure of the injection valve to adjust the flow or interruption of the bypass line.

As a preferable mode of the gas supply system, the gas supply system further includes a filter provided between the injection valve and the regulator.

As a preferred technical solution of the gas supply system, the measurement and adjustment assembly includes a first pressure measurement element for measuring an inlet pressure of the injection valve, and a switching valve disposed on the bypass line or a line where the pressure stabilizer is located and connected in parallel with the bypass line, and the first pressure measurement element is electrically connected to the switching valve.

As a preferred embodiment of the gas supply system, the first pressure measuring element is a pressure sensor.

As a preferable technical solution of the gas supply system, the on-off valve is an electromagnetic valve.

As a preferable technical solution of the gas supply system, the gas supply system further includes a second pressure measuring part for measuring an inlet pressure of the pressurizer.

As a preferred technical scheme of a gas feed system, the LNG vaporization buffer assembly comprises a gas cylinder, a vaporizer and a buffer tank which are connected in sequence, and the buffer tank is connected with the pressure stabilizer.

As an optimal technical scheme of a gas supply system, the vaporizer includes the barrel and sets up the gas pipe in the barrel, the barrel inside with form the cooling water chamber between the gas pipe, barrel one end is provided with engine cooling water import and LNG import, and the other end is provided with engine cooling water export and natural gas export, gas pipe one end with LNG import intercommunication, the other end with natural gas exit linkage, the gas cylinder with LNG import intercommunication, the buffer tank with natural gas export intercommunication, engine cooling water import with engine cooling water export all with cooling water chamber intercommunication.

As a preferred technical scheme of a gas supply system, the vaporizer also comprises a water temperature sensor and an electric heater, the water temperature sensor is arranged on the cylinder, a probe of the water temperature sensor extends into the cooling water cavity, the electric heater is arranged in the cooling water cavity, and the electric heater is in electric signal connection with the water temperature sensor.

As a preferable technical scheme of the fuel gas supply system, the fuel gas pipe is a spiral pipe.

The utility model provides a gas supply system, which comprises an LNG vaporization buffering component, a voltage stabilizer, an injection valve, a bypass pipeline and a measurement adjusting component, wherein LNG enters the voltage stabilizer through the vaporization buffering of the LNG vaporization buffering component to be stabilized, and finally natural gas enters the injection valve to be injected, the pressure characteristic of the voltage stabilizer is that the output pressure must be lower than a certain value of the input pressure to be basically not changed along with the change of the input pressure, thereby playing the role of stabilizing the system pressure at the downstream of the voltage stabilizer, but the transient gas pressure is lower than the preset value when an engine is in a heavy load working condition or climbing, for this purpose, the utility model adopts the measurement adjusting component to measure the inlet pressure of the injection valve, when the measurement adjusting component measures the inlet gas pressure of the injection valve to be lower than the preset value, the measurement adjusting component enables the bypass pipeline to be circulated, the natural gas discharged from the LNG vaporization buffering assembly does not pass through the pressure stabilizing valve for pressure stabilization, and directly enters the injection valve through the bypass pipeline, so that the inlet pressure of the injection valve can be improved to a certain degree, and the inlet pressure of the injection valve is kept within a required range under various working conditions, thereby ensuring sufficient power and stable operation of the LNG engine and ensuring the performance of the LNG engine.

Drawings

FIG. 1 is a schematic diagram of a prior art gas supply system;

fig. 2 is a schematic diagram of a gas supply system according to an embodiment of the present invention.

Reference numerals:

1', a gas cylinder; 2', a vaporizer; 3', a buffer tank; 4', a voltage stabilizer; 5', a filter; 6', an injection valve;

1. a voltage regulator; 2. an injection valve; 3. a first pressure measurement member; 4. an on-off valve; 5. a filter; 6. a gas cylinder; 7. a vaporizer; 8. a buffer tank; 9. a second pressure measurement member.

Detailed Description

In order to make the technical problem solved by the present invention, the technical solution adopted by the present invention and the technical effect achieved by the present invention clearer, the technical solution of the present invention will be further explained by combining the drawings and by means of the specific implementation manner.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used in the orientation or positional relationship shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

As shown in fig. 2, the present embodiment provides a gas supply system comprising an LNG vaporization buffer assembly, a pressurizer 1, an injection valve 2, a bypass line, and a measurement and regulation assembly, wherein the LNG vaporization buffer assembly is configured to vaporize LNG and buffer vaporized natural gas; the pressure stabilizer 1 is positioned at the downstream of the LNG vaporization buffering assembly, and the pressure stabilizer 1 is used for stabilizing the system pressure at the downstream of the pressure stabilizer 1; the injection valve 2 is arranged at the downstream of the pressure stabilizer 1 and is used for injecting natural gas; the bypass pipeline is connected in parallel with two ends of the voltage stabilizer 1; the measurement and regulation assembly is configured to measure the inlet pressure of the injection valve 2 to regulate the passage or interruption of the bypass line.

LNG enters the pressure stabilizer 1 through the vaporization buffer of the LNG vaporization buffer assembly to stabilize the pressure, and finally natural gas enters the injection valve 2 to be injected, the pressure characteristic of the pressure stabilizer 1 is that the output pressure basically does not change along with the change of the input pressure until the output pressure is lower than a certain value of the input pressure, so that the effect of stabilizing the system pressure at the downstream of the pressure stabilizer 1 is achieved, but when an engine is in a heavy load working condition or climbs a slope, the transient gas pressure is low, therefore, the embodiment adopts the measuring and adjusting assembly to measure the inlet pressure of the injection valve 2, when the measuring and adjusting assembly measures that the inlet gas pressure of the injection valve 2 is lower than a preset value, the measuring and adjusting assembly enables a bypass pipeline to circulate, the natural gas discharged from the LNG vaporization buffer assembly does not pass through the pressure stabilizer 1 to stabilize the pressure, and directly enters the injection valve 2 through the, the inlet pressure of the injection valve 2 is kept within a required range under various working conditions, so that the LNG engine is sufficient in power and stable in operation, and the performance of the LNG engine is guaranteed.

Specifically, the measurement and regulation assembly comprises a first pressure measurement part 3 and a switch valve 4, the first pressure measurement part 3 is used for measuring the inlet pressure of the injection valve 2, the switch valve 4 is arranged on a bypass pipeline or a pipeline where the voltage stabilizer 1 is arranged and connected with the bypass pipeline in parallel, and the first pressure measurement part 3 is in electrical signal connection with the switch valve 4. Preferably, in the present embodiment, the first pressure measuring part 3 is a pressure sensor. Further preferably, the on-off valve 4 is a solenoid valve. It is to be noted that, as a rule, the first pressure measuring part 3 is integrated with the injection valve 2.

The gas supply system further comprises a second pressure measuring member 9, the second pressure measuring member 9 being adapted to measure the inlet pressure of the pressurizer 1. Preferably, in this embodiment, the second pressure measuring member 9 is a pressure sensor. First pressure measurement 3 and second pressure measurement 9 are all connected with ECU, through calculating the pressure loss between first pressure measurement 3 and the second pressure measurement 9, when pressure loss is unusual, for example the condition such as pipeline gas leakage appears, reports to the police through ECU, and then whether inspection stabiliser 1 and relevant pipeline are unusual.

As shown in fig. 2, the gas supply system further includes a filter 5, and the filter 5 is provided between the injection valve 2 and the regulator 1. The filter 5 is used for filtering impurities such as olefins and water in the LNG, the natural gas filtered by the filter 5 is cleaner, and the conditions of blockage and blockage of the nozzle of the injection valve 2 can be avoided.

Specifically, LNG vaporization buffering subassembly is including gas cylinder 6, vaporizer 7 and the buffer tank 8 that connect gradually, and buffer tank 8 is connected with stabiliser 1. It should be noted that the gas cylinder 6 has good thermal insulation performance, and mainly includes: the device comprises a liquid feeding port, a liquid discharging port, a pressure gauge, a safety valve and a pressure release valve; LNG is stored in the gas cylinder 6 at a low temperature of-142 ℃ to-125 ℃ and is in a gas-liquid coexisting state; when the pressure in the gas cylinder 6 is higher than a set value, the safety valve is opened to release the pressure. The vaporizer 7 absorbs heat from the engine cooling water to convert the liquefied LNG to gaseous natural gas. The buffer tank 8 is mainly used for pressure fluctuation of a buffer system in a fuel gas supply system, so that the fuel gas supply system can run more stably.

Further specifically, vaporizer 7 includes the barrel and sets up the gas pipe in the barrel, forms the cooling water chamber between inside and the gas pipe of barrel, and barrel one end is provided with engine cooling water import and LNG import, and the other end is provided with engine cooling water export and natural gas export, and gas pipe one end and LNG import intercommunication, the other end and natural gas exit linkage, gas cylinder 6 and LNG import intercommunication, buffer tank 8 and natural gas export intercommunication, engine cooling water import and engine cooling water export all communicate with the cooling water chamber. High-temperature cooling water in the engine cooling system enters the cooling water cavity through the engine cooling water inlet to heat LNG in the gas pipe, so that liquid LNG is changed into gaseous natural gas, and then low-temperature cooling water is discharged from the engine cooling water outlet and enters the engine cooling system again for cyclic utilization.

Preferably, the vaporizer 7 further comprises a water temperature sensor and an electric heater, the water temperature sensor is arranged on the cylinder, a probe of the water temperature sensor extends into the cooling water cavity to monitor the temperature of the engine cooling water in the cylinder in real time, the electric heater is arranged in the cooling water cavity, and the electric heater and the water temperature sensor are both connected with the ECU. When the water temperature in the cooling water cavity measured by the water temperature sensor is lower than a preset value, the ECU controls the electric heater to heat the cooling water, and the heated water directly heats the LNG in the gas pipe so as to rapidly increase the temperature of the LNG and vaporize the LNG, thereby ensuring the normal operation of the engine.

Optionally, the electric heater comprises a U-shaped heating tube. In other embodiments, other forms of heating structures may be selected.

Preferably, the gas pipe is a spiral pipe. Further preferably, the electric heater is located within the helical ring of the helical tube.

When the switch valve 4 is positioned on the bypass pipeline, the control method of the gas supply system comprises the following steps:

the pressure at the inlet of the injection valve 2 is detected by the first pressure measuring part 3;

when the first pressure measuring part 3 detects that the pressure value at the inlet of the injection valve 2 is smaller than the preset value, the ECU controls the switch valve 4 to be opened, and natural gas crosses the pressure stabilizer 1 through the bypass pipeline and enters the filter 5;

when the first pressure measuring part 3 detects that the pressure value at the inlet of the injection valve 2 reaches a preset value, the switch valve 4 is closed, and natural gas continues to enter from the pressure stabilizer 1;

the ECU distinguishes the pressure loss condition of the middle gas pipeline by detecting the pressure in front of the pressure stabilizer 1 and the pressure at the inlet of the injection valve 2, and alarms when the pressure loss value is larger than the limit value to check whether the pressure stabilizer 1 and the pipeline are abnormal or not.

When the switch valve 4 is positioned on a pipeline where the voltage stabilizer 1 is positioned and is connected with the bypass pipeline in parallel, the control method of the gas supply system comprises the following steps:

when the first pressure measuring part 3 detects that the pressure value at the inlet of the injection valve 2 is smaller than the preset value, the ECU controls the switch valve 4 to be closed, and natural gas crosses the pressure stabilizer 1 through the bypass pipeline and enters the filter 5;

when the first pressure measuring part 3 detects that the pressure value at the inlet of the injection valve 2 reaches a preset value, the switch valve 4 is opened, and natural gas continues to enter from the pressure stabilizer 1;

The above description is only for the preferred embodiment of the present invention, and for those skilled in the art, there are variations on the detailed description and the application scope according to the idea of the present invention, and the content of the description should not be construed as a limitation to the present invention.

Claims

1. A gas supply system, comprising:

a pressurizer (1) downstream of the LNG vaporization buffer assembly, the pressurizer (1) for stabilizing a system pressure downstream of the pressurizer (1);

an injection valve (2) arranged downstream of the pressurizer (1) for injecting natural gas;

the bypass pipeline is connected in parallel to two ends of the voltage stabilizer (1);

a measurement and regulation assembly configured to measure an inlet pressure of the injection valve (2) to regulate the passage or interruption of the bypass line.

2. Gas supply system according to claim 1, characterized in that it further comprises a filter (5), said filter (5) being arranged between said injection valve (2) and said pressurizer (1).

3. Gas supply system according to claim 1, characterised in that the measuring and regulating assembly comprises a first pressure measuring member (3) and a switching valve (4), the first pressure measuring member (3) being intended to measure the inlet pressure of the injection valve (2), the switching valve (4) being arranged on the by-pass line or on a line on which the pressure regulator (1) is arranged and which is connected in parallel with the by-pass line, the first pressure measuring member (3) being electrically connected to the switching valve (4).

4. Gas supply system according to claim 3, characterized in that the first pressure measuring member (3) is a pressure sensor.

5. Gas supply system according to claim 3, characterized in that said on-off valve (4) is a solenoid valve.

6. Gas supply system according to claim 1, characterized in that it further comprises a second pressure measuring member (9), said second pressure measuring member (9) being adapted to measure the inlet pressure of the pressurizer (1).

7. The gas supply system according to any one of claims 1 to 6, wherein the LNG vaporization buffer assembly comprises a gas cylinder (6), a vaporizer (7) and a buffer tank (8) which are connected in sequence, and the buffer tank (8) is connected with the pressure stabilizer (1).

8. The gas supply system according to claim 7, wherein the vaporizer (7) includes a cylinder and a gas pipe disposed in the cylinder, a cooling water chamber is formed between the inside of the cylinder and the gas pipe, the cylinder is provided with an engine cooling water inlet and an LNG inlet at one end and an engine cooling water outlet and a natural gas outlet at the other end, the gas pipe is communicated with the LNG inlet at one end and the natural gas outlet at the other end, the gas cylinder (6) is communicated with the LNG inlet, the buffer tank (8) is communicated with the natural gas outlet, and the engine cooling water inlet and the engine cooling water outlet are both communicated with the cooling water chamber.

9. The gas supply system according to claim 8, wherein said vaporizer (7) further comprises a water temperature sensor provided on said cylinder, a probe of said water temperature sensor extending into said cooling water chamber, and an electric heater provided in said cooling water chamber, said electric heater being in electrical signal connection with said water temperature sensor.

10. The gas supply system of claim 8, wherein the gas tube is a coiled tube.