CN201334967Y - Liquefied natural gas self-pressurization device - Google Patents

Abstract

A self-pressurizing device for liquefied natural gas relates to a supercharging device for maintaining the pressurization of liquefied natural gas for the normal operation of a liquefied natural gas engine. The gas phase space part of the LNG steel cylinder (1) is connected, and the liquid phase space part of the LNG steel cylinder (1) is connected to the water bath vaporizer (12) through the pipeline (6). No special pump is used, and at the same time there is no need to adjust the overall pressure of the liquid in advance, it can be directly filled into the car bottle and used for driving immediately. After gasification and pressurization, fill the gas phase space of the LNG steel cylinder (1) to ensure that the pressure of the gas phase space of the LNG steel cylinder (1) is not less than 0.8MPa, which solves the problem that the LNG itself is too low in pressure and cannot guarantee the LNG fuel required by the vehicle, and is safe and reliable , mature technology, simple structure and low cost.

Description

Liquefied natural gas self-pressurization device

technical field

The utility model relates to a supercharging device for maintaining the supercharging of liquefied natural gas for the normal operation of a natural gas engine, in particular to a self-supercharging device for liquefied natural gas.

Background technique

Currently, the known gas supply systems for natural gas vehicles mainly include compressed natural gas (CNG) and liquefied natural gas (LNG). Compressed natural gas is to compress natural gas in a steel cylinder at a high pressure of 20-25Mpa to supply gas to vehicles. After compression, the volume ratio is about 1:200. Due to the limitation of the cylinder capacity, it is generally 50-60 liters, and the filling volume at one time is only 10-12m ³ . The driving range is low, and it is mostly used in the gas system of small cars. Liquefied natural gas is stored, transported and used by converting natural gas into a liquid state through compression and cooling. The volume ratio is 1:625, which is three times that of compressed natural gas. Alternative fuel use for heavy vehicles. Since the pressure of liquefied natural gas itself is low, generally lower than 0.5MPa, the gas supply system for automobiles requires a relatively stable pressure higher than 0.5MPa in order to continuously and stably supply gas to the engine. The current LNG gas supply system for automobiles is also divided into two methods. One is to use professional pumps for liquid transportation. The advantage is that it is stable and reliable. The disadvantage is that it is costly and there is no mature product at present. Another way is to increase its own pressure to more than 0.5Mpa through overall pressure regulation in the LNG factory or gas filling station, and then fill it into the car bottle for use by the car. The advantage is that the car gas supply system does not require a special The pressure boosting and pressure supply device has a simple and reliable structure. The disadvantage is that it takes a long time to adjust the pressure in the factory or station, and the energy consumption is large, so the cost is high.

A small number of public related technical solutions still cannot meet the requirements for the normal use of engines for supercharging liquefied natural gas (LNG) in reality.

Contents of the invention

The purpose of this utility model is to solve the problem that LNG cannot provide sufficient and continuous fuel supply for vehicle engines due to the fact that LNG itself is atmospheric pressure at -162 degrees Celsius, that is, to propose a self-pressurizing device for liquefied natural gas.

The measures for realizing the purpose of the invention of the utility model include: the liquid phase space of the LNG steel cylinder is connected to the supercharger through a pipeline and then connected to the gas phase space of the LNG steel cylinder, and the liquid phase of the LNG steel cylinder is connected to the water bath vaporizer through a pipeline.

The utility model has the advantages of: no special pump is used, and at the same time, the liquid can be directly filled in the vehicle bottle and immediately used for driving the vehicle without the overall pressure regulation of the liquid in advance. 5. After LNG gasification and pressurization, fill the gas phase space of LNG steel cylinder 1 to ensure that the pressure of the gas phase space of LNG steel cylinder 1 is not less than 0.8Mpa, which solves the problem that the pressure of LNG itself is too low and cannot guarantee the LNG fuel required by the vehicle. The advantages of this system For: safe and reliable, mature technology, simple structure, low cost.

Description of drawings:

Accompanying drawing 1 is the structural representation of the utility model embodiment 1

Reference signs include: LNG cylinder 1, third-stage safety valve 2, second-stage safety valve 3, liquid level gauge 4, supercharger 5, pipeline 6, one-way pressure valve 7, low-temperature cut-off valve A8, low-temperature cut-off valve B 9 , circulating water inlet 10, circulating water outlet 11, water bath vaporizer 12, safety valve 13, buffer tank 14, solenoid valve 15, pressure regulating valve 16, LNG engine 17.

Detailed ways

Embodiment 1: connect the supercharger 5 by the liquid phase space part of the LNG steel cylinder 1 through the pipeline 6 and then connect the gas phase space part of the LNG steel cylinder 1, and connect the water bath vaporizer 12 by the liquid phase space part of the LNG steel cylinder 1 through the pipeline 6.

The LNG steel cylinder 1 is externally connected with a third-stage safety valve 2 and a second-stage safety valve 3 . A liquid level gauge 4 is connected to the LNG steel cylinder 1 .

The liquid space part of the LNG steel cylinder 1 is connected to the low-temperature cut-off valve A8 and the one-way pressure valve 7 in turn through the pipeline 6, and then the supercharger 5 is connected to the gas phase space part of the LNG steel cylinder 1. Supercharger 5 is an air-temperature vaporization device. The one-way pressure valve 7 is to ensure that the LNG liquid moves from the liquid phase to the gas phase device.

The liquid space part of the LNG steel cylinder 1 is connected to the low-temperature stop valve B9 through the pipeline 6 and then enters the water bath vaporizer 12. The water-bath vaporizer 12 utilizes the circulating hot water system on the vehicle to quickly vaporize the 0.8Mpa LNG into natural gas to meet the fuel required by the vehicle engine. The water bath vaporizer 12 is externally connected to the vehicle circulating water inlet 10 and the vehicle circulating water outlet 11 . The water bath vaporizer 12 is connected to the buffer tank 14 through the pipeline 6 and then connected to the LNG engine 17 . The buffer tank 14 solves the phenomenon of insufficient fuel supply when the vehicle is accelerating and under heavy load. The safety valve 13 is externally connected to the buffer tank 14 . The safety valve 13 is a safety device for ensuring the buffer tank 13 . The buffer tank 14 is connected to the solenoid valve 15 and the pressure regulating valve 16 through the pipeline 6 and then connected to the LNG engine 17 . Gas circuit electromagnetic valve 15 is the device that can cut off the fuel supply synchronously when guaranteeing that vehicle stops running. The pressure regulating valve 16 ensures the stable pressure of the fuel required by the engine 17 .

The vehicle-mounted LNG steel cylinder 1 generally adopts double-layer metal plus vacuum winding heat insulation technology. Using this technology, the daily evaporation rate can be controlled within 0.2%, so it can ensure that there is basically no evaporation loss in 7 to 14 days. The LNG steel cylinder 1 has a pressure gauge, a two-stage safety valve and a liquid level gauge on the venting pipeline, which can be automatically discharged after the pressure in the tank is kept high.

In order to realize the purpose of the invention of the embodiment of the utility model, the LNG steel cylinder 1 is equipped with an air-temperature type vaporization supercharger 5 on the outlet pipeline in order to solve the above-mentioned problems of the LNG fuel, and the LNG steel cylinder 1 is stored by the supercharger 5. The liquid in the LNG liquid phase space in the tank is heated and vaporized and delivered to the gas phase space in the LNG steel cylinder 1 storage tank, so that the pressure of the LNG steel cylinder 1 storage tank is increased to about 0.8Mpa, and the fuel pressure required by the engine 17 is guaranteed.

After the LNG is gasified and pressurized by the supercharger 5, the gas phase space of the LNG steel cylinder 1 is filled to ensure that the pressure of the gas phase space of the LNG steel cylinder 1 is not less than 0.8Mpa, and the LNG is vaporized from the LNG steel cylinder 1 through the water bath vaporizer 12, and then passed through the buffer tank. 14 feeds into LNG engine 17 and uses.

-162°C LNG increases the pressure in the LNG cylinder to about 0.8Mpa through the additional booster 5, so that the LNG in the cylinder is vaporized into natural gas with a pressure of 0.8Mpa through a water bath vaporizer at a pressure of 0.8Mpa, and stored To the buffer tank 14, the natural gas whose pressure is adjusted to 0.5Mpa supplies fuel for the engine 17.

The advantage of this embodiment is that no special pump is used, and the liquid can be directly filled in the car bottle for immediate use when the car is driven without the need to adjust the overall pressure of the liquid in advance. 5. After LNG gasification and pressurization, fill the gas phase space of LNG steel cylinder 1 to ensure that the pressure of the gas phase space of LNG steel cylinder 1 is not less than 0.8Mpa, which solves the problem that the pressure of LNG itself is too low and cannot guarantee the LNG fuel required by the vehicle. The advantages of this system For: safe and reliable, mature technology, simple structure, low cost.

Claims (6)

1. The liquefied natural gas self-pressurization device is characterized in that, the liquid phase space part of the LNG steel cylinder (1) is connected to the supercharger (5) by the pipeline (6) and then connected to the gas phase space part of the LNG steel cylinder (1), by The liquid phase space of the LNG cylinder (1) is connected to the water bath vaporizer (12) through a pipeline (6). 2. The liquefied natural gas self-pressurizing device according to claim 1, characterized in that, the LNG steel cylinder (1) is externally connected with a third-stage safety valve (2) and a second-stage safety valve (3). 3. The self-pressurizing device for liquefied natural gas as claimed in claim 1, characterized in that, the LNG cylinder (1) is connected to the liquid level gauge (4). 4. The self-pressurizing device for liquefied natural gas as claimed in claim 1, characterized in that, the liquid phase space part of the LNG steel cylinder (1) is connected to the low temperature cut-off valve A (8) and the one-way pressure valve ( 7) The rear supercharger (5) is then connected to the gas phase space of the LNG cylinder (1), and the supercharger (5) is an air-temperature vaporization device. 5. The self-pressurizing device for liquefied natural gas as claimed in claim 1, characterized in that, the liquid phase space part of the LNG steel cylinder (1) enters the water bath vaporizer (12) after being connected with the low temperature cut-off valve B (9) through a pipeline (6) . 6. The self-pressurizing device for liquefied natural gas as claimed in claim 5, characterized in that, the water bath vaporizer (12) is externally connected to the vehicle circulating water inlet (10) and the vehicle circulating water outlet (11), and the water bath vaporizer (12) passes through the pipeline ( 6) After the buffer tank (14) is connected to the LNG engine (17), the buffer tank (14) is externally connected to the safety valve (13), and the buffer tank (14) is connected to the solenoid valve (15) and pressure regulator through the pipeline (6) The valve (16) is connected to the LNG engine (17).

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