KR101033702B1 - CNG refueling system and method with remaining gas compress apparatus - Google Patents

Abstract

The present invention relates to a gas filling system and a method for compressing the residual gas provided with a residual gas compression device for minimizing the amount of residual gas remaining in the tube trailer. In particular, the residual gas remaining in the tube trailer 110 is hydraulically compressed. By reusing, by minimizing the amount of residual gas remaining in the tube trailer 110, there is an effect that can be expected to maximize the filling efficiency and reduce the distribution cost.

To this end, in the present invention, a plurality of high-pressure gas containers 111 into which oil and CNG entry tubes 113 are inserted at both ends are connected in series in a horizontally laid state, and the first container 111a and the last container 111b in series connection. A tube trailer 110 having an oil inlet 111aa and a gas inlet 111bb formed at the upper and lower ends thereof; A charger 120 equipped with a charging gun 121 for charging the vehicle with the CNG; A gas supply pipe 160 connecting the gas inlet 111 bb and the charger 120; An oil tank 140 storing residual gas compression oil; An oil injection pipe having a pump 141 connected between the oil tank 140 and the oil inlet 111aa and providing a pressure for injecting the oil stored in the oil tank 140 into the high pressure gas container 111 ( 170); An oil return pipe 180 connected between the oil inlet 111aa and the oil tank 140 to recover the oil injected into the high pressure gas container 111 into the oil tank 140; A pressure sensor 133 provided on the gas supply pipe 160 to measure a pressure of the residual gas filled in the high-pressure gas container 111; An oil position detecting sensor 131 provided at one side of the high pressure gas container 111 or the oil tank 140 to measure the amount of oil injected into the high pressure gas container; Valves (v161) (v171) (v181) installed in the gas supply pipe (160), the oil injection pipe (170) and the oil return pipe (180); And a controller 150 for controlling the valves v161, v171, v181, and the pump 141 according to signals input from the pressure sensor 133 and the oil position sensor 131. When the residual gas compression command is input from the valve, the supply valve v161 and the recovery valve v181 are closed until the residual gas of the high pressure gas container 111 is compressed to a predetermined value, and then the injection valve v171 is opened. A residual gas compression step of driving the pump 141; A residual gas compression stop step of closing the injection valve v171 and stopping the driving of the pump 141 when it is confirmed that the compression is completed by a predetermined value through the pressure sensor 133; A charging step of charging the vehicle by opening the supply valve v161 when the vehicle is connected to the charger 120 and a charging command is input; And when the residual gas in the high pressure gas container 111 is exhausted or the oil in the high pressure gas container 111 rises up to a prescribed value, the supply valve v161 is closed and the recovery valve v181 is opened to open the high pressure gas container 111. It comprises a; oil recovery step of recovering the oil in the oil tank 140.

CNG residual gas, recovery, feeding tank, oil, high pressure gas filling

Description

CNG refueling system and method with remaining gas compress apparatus

The present invention relates to a gas filling system equipped with a residual gas compression device and a residual gas compression method. In particular, after filling a CNG stored in a tube trailer into a vehicle, the tube trailer is made full use of the residual gas remaining at a low pressure in the tube trailer. It relates to a gas filling system and a residual gas compression method having a residual gas compression device to leave a minimum amount of gas in the.

In recent years, with the rapid progress of industrialization, the increase of national income, the improvement of convenience life and living standards, along with the exponential increase in the consumption of fossil fuels have caused environmental pollution to become a serious social problem. In particular, automobiles, which are the flowers of modern civilization, are the main culprit of air pollution due to their exhaust gas. Accordingly, many countries around the world are making great efforts to reduce air pollution caused by automobile exhaust gas.

As a method for preventing air pollution caused by automobile exhaust gas as described above, a natural gas vehicle using natural gas (NG), which is one of clean fuels having little influence on environmental pollution instead of petroleum, as a fuel Is spreading, and trucks and buses powered by natural gas can reduce carbon monoxide emissions by about 25% and nitrogen oxide emissions by about 50% compared to conventional diesel vehicles. It is known by research.

In line with this global trend, research on natural gas vehicles (NGV) is very active in Korea, including public corporations such as Korea Gas Corporation, and various industry, academia, and research institutes. The Ministry of Environment has promoted the pilot operation of natural gas buses and passenger cars to replace buses in the metropolitan area and major metropolitan areas with natural gas buses.

However, despite the continued efforts of the government, the actual dissemination of natural gas vehicles has not spread further, and one of the biggest causes is not only due to the lack of fueling stations and delayed installation of natural gas stations. In the case of the stationary charging station, a lot of time and money are required for the construction of the pipeline and the construction of the filling station, and in the downtown area, various complaints are being raised due to the public's recognition that it is dangerous when constructing the pipeline for the high pressure gas.

In order to solve the above problems, a storage tank capable of filling a certain amount of gas is installed in a storage box of a compact automobile having excellent maneuverability, and the storage tank is configured to supply gas injection means and stored gas to a fuel tank of a vehicle, etc. Refueling means are installed, and the injection means and the fueling means are equipped with various safety mechanisms, so that the gas-powered vehicle to move to the site, the mobile gas-filled car that can immediately fill the gas in the field is registered in Korea It is known from Shin-an publication No. 20-0265435 (registration date: February 07, 2002).

However, since the conventional mobile gas-filled vehicle as described above is required to perform the filling operation required by a natural differential pressure (差 押) method, the storage tank of the compressed natural gas installed in the gas transport vehicle and the vehicle that needs to be charged. When the pressure between the installed fuel tank is the same level, there was a problem that can no longer be filled with natural gas from the storage tank of compressed natural gas to the fuel tank of the vehicle.

For example, a 1000 L (liter) compressed natural gas is stored in a storage tank at a CNG mother station, and then the gas transport vehicle is moved to recharge the fuel in a natural differential pressure method such as a vehicle that needs to be charged. About 40 to 50% of the compressed natural gas remains in the tank, and the filling efficiency of the compressed natural gas is 50% to 60%, which lowers the economic efficiency, and part of the compressed natural gas is stored in the storage tank for a long time. There was a problem of remaining fuel quality.

Applicant has proposed a mobile tube trailer for filling a compressed natural gas vehicle (Korean Registered Utility Model Publication No. 20-0290054, registered date: September 10, 2002) in order to solve the conventional problems as described above. The proposed mobile tube trailer applies the natural differential pressure method as in the conventional case, and divides the storage tube of compressed natural gas into high pressure, medium pressure and low pressure tube, respectively, and then in the order of low pressure, medium pressure and high pressure when filling gas. The charging efficiency is improved by making the charging step by step.

However, the above-mentioned mobile tube trailers also have a filling efficiency of the compressed natural gas is about 65-75%, and eventually 25-35% of the compressed natural gas is returned to the mortgage while stored in the tube of the trailer. Therefore, there is a problem to be supplemented in terms of further maximizing the filling efficiency and economy of compressed natural gas.

The present invention has been made to solve the above problems, and an object thereof is to provide a gas filling system and a residual gas compression method equipped with a residual gas compression device to minimize the residual gas remaining in the tube trailer.

Gas filling system and residual gas compression method provided with a residual gas compression device according to the present invention for achieving the above object is a plurality of high-pressure gas container 111 is inserted into the oil and CNG entry tube 113 at both ends of the horizontal A tube trailer 110 which is connected in series in a lying state, and has an oil outlet 111aa and a gas outlet 111bb formed in the first container 111a and the last container 111b of the series connection; A charger 120 equipped with a charging gun 121 for charging the vehicle with the CNG; A gas supply pipe 160 connecting the gas inlet 111 bb and the charger 120; An oil tank 140 storing residual gas compression oil; An oil injection pipe having a pump 141 connected between the oil tank 140 and the oil inlet 111aa and providing a pressure for injecting the oil stored in the oil tank 140 into the high pressure gas container 111 ( 170); An oil return pipe 180 connected between the oil inlet 111aa and the oil tank 140 to recover the oil injected into the high pressure gas container 111 into the oil tank 140; A pressure sensor 133 provided on the gas supply pipe 160 to measure a pressure of the residual gas filled in the high-pressure gas container 111; An oil position detecting sensor 131 provided at one side of the high pressure gas container 111 or the oil tank 140 to measure the amount of oil injected into the high pressure gas container; Valves (v161) (v171) (v181) installed in the gas supply pipe (160), the oil injection pipe (170) and the oil return pipe (180); And a controller 150 for controlling the valves v161, v171, v181 and the pump 141 according to the signals input from the pressure sensor 133 and the oil position sensor 131. When the gas compression command is input, the supply valve v161 and the recovery valve v181 are closed until the residual gas of the high pressure gas container 111 is compressed to a predetermined value, and then the injection valve v171 is opened and the pump ( A residual gas compression step of driving 141; A residual gas compression stop step of closing the injection valve v171 and stopping the driving of the pump 141 when it is confirmed that the compression is completed by a predetermined value through the pressure sensor 133; A charging step of charging the vehicle by opening the supply valve v161 when the vehicle is connected to the charger 120 and a charging command is input; And when the residual gas in the high pressure gas container 111 is exhausted or the oil in the high pressure gas container 111 rises up to a prescribed value, the supply valve v161 is closed and the recovery valve v181 is opened to open the high pressure gas container 111. It comprises a; oil recovery step of recovering the oil in the oil tank 140.

According to the gas filling system and residual gas compression method equipped with the residual gas compression device of the present invention as described above, by maximizing the amount of residual gas remaining in the tube trailer to maximize the filling efficiency and reduce the distribution cost There is an expected effect.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the gas filling system and residual gas compression method provided with a residual gas compression apparatus of the present invention.

As shown in FIG. 1, a gas filling system equipped with a residual gas compression device according to the present invention includes a tube trailer 110, a charger 120, an oil tank 140, a controller 150, and a gas supply pipe 160. , The oil injection pipe 170 and the oil recovery pipe 180 and the like.

First, the tube trailer 110 is a CNG movement means mounted so that a plurality of high-pressure gas vessels 111 storing CNG are laid down in a horizontally laid down state, and both ends of each high-pressure gas vessel 111 are for oil and CNG entry and exit. The tube 113 is inserted and connected to each other in series by the tube, and the oil outlet 111aa and the gas outlet 111bb are formed in the first vessel 111a and the last vessel 111b of the series connection.

Next, the charger 120 is a charging means equipped with a filling gun 121 for charging the CNG in the vehicle, and is connected to the tube trailer 110 through the gas supply pipe 160 to gas the CNG stored in the tube trailer 110. Received through the supply pipe 160 is supplied to the vehicle that needs to be charged through the filling gun 121.

At this time, the gas supply pipe 160 is a pipe connecting the gas inlet 111bb and the charger 120, in order to circulate the various tube trailers 111, the end of the gas inlet 111bb and the gas supply pipe 160 It is preferable to adopt a structure in which the male and female connectors connected to each other at the ends are convenient for coupling and detachment.

Next, the oil tank 140 is a container for storing the residual gas compression oil for compressing the residual gas stored in the high-pressure gas container 111, wherein the residual gas compression oil is not mixed with CNG already known in the art. Use oil.

Next, the oil injection pipe 170 and the oil recovery pipe 180 may move the oil gas 140 and the oil inlet 111aa to move the above-mentioned residual gas compression oil between the high pressure gas container 111 and the oil tank 140. In the present embodiment, the oil injection pipe 170 is provided with a pump 141 which is a means for providing a pressure for moving oil.

However, the gas filling system equipped with the residual gas compression device according to the present invention may add a pump, a booster compressor, or a bypass structure to facilitate the movement of oil. First, a method of adding a pump may include an oil recovery pipe. The pump 180 is further provided with a pump for supplying a pressure required for oil recovery to smoothly recover oil, and a method of adding a booster compressor is based on a supply valve v161 of the gas supply pipe 160. (v161) By connecting the pipes branched at both ends to both ends of the booster compressor, the CNG present at the charger 120 side instantaneously flows into the gas inlet 111bb to recover the oil to the oil tank 140 during oil recovery. It is a way to provide pressure.

In particular, the method using the bypass structure has the advantage that a separate device such as a pump or a booster compressor is not required. The oil return pipe 180 is provided with a bypass pipe connected to the pump 141 and the oil injection pipe 170. And only a bypass valve controlled by the controller 150 in the bypass pipe.

At this time, the bypass pipe should be configured in an X-shape so that the flow of oil in the oil return pipe 180 is opposite to the oil injection pipe 170.

That is, when the valve v171 is opened and the bypass valve is closed, the pressure of the pump 141 is used for oil injection. When the valve v171 is closed and the bypass valve is opened, the pressure of the pump 141 is oil recovery. Since it is used in the opening and closing of the valve and the bypass valve, the pressure of the pump 141 can be used in common for oil injection or oil recovery.

On the other hand, the oil injection pipe 170 and the oil return pipe 180, like the gas supply pipe 160, in order to circulate the various tube trailers 111, the end of the oil inlet 111aa and the oil injection pipe 170 And a male and female connector connected to each other at the end of the oil return pipe 180 to adopt a structure that is easy to engage and disengage, the 3-way valve (v143) controlled by a controller as shown in FIG. 1. ) To control the direction of injection and discharge and at the same time enable separate coupling.

Next, the pressure sensor 133 is provided on the gas supply pipe 160 to measure the pressure of the residual gas filled in the high-pressure gas container 111, the oil gas 140 to the residual gas of the high-pressure gas container 111 In order to stop the compression at the level required for compression with oil stored in the oil, for example, the pressure required to charge the vehicle, stop the driving of the pump 141 at the time when the residual gas of the high-pressure gas container 111 becomes 207 bar. To close the valve (v171) bar controller 150 is a necessary component to detect this point.

The oil position detection sensor 131 is provided on one side of the high pressure gas container 111 or the oil tank 140 to measure the amount of oil injected into the high pressure gas container 111, in the high pressure gas container 111. When the vehicle is charged with the compressed residual gas, the residual gas in the high pressure gas container 111 decreases as much as the amount filled in the vehicle, and the pressure decreases. Thus, the oil level in the high pressure gas container 111 is gradually increased. When it reaches up to the specified height before being discharged from the high-pressure gas container 111 to the gas supply pipe 160, it is necessary to check the height of the oil to stop the filling and recover the oil.

Next, the plurality of valves (v161) (v171) (v181) is installed in the above-described gas supply pipe 160, oil injection pipe 170 and oil recovery pipe 180, according to the signal transmitted from the controller 150 Open or closed, it is provided to control the movement of residual gas and the movement of oil.

The control of the valves (v161) (v171) (v181) may be performed manually, but it is preferable to control the valves automatically. In this embodiment, the controller 150 adopts a structure that is automatically controlled by the controller 150. 150 may be a computer or a PLC in which a control program is installed.

Accordingly, the controller 150 controls the valves v143, v161, v171, v181 and the pump 141 as previously programmed according to the signals input from the pressure sensor 133 and the oil position sensor 131. .

On the other hand, if the automatic pressure control valve 295 is provided between the oil injection pipe 170 and the oil recovery pipe 180 and the pressure reducing device 293 is further provided in the oil recovery pipe, the oil recovery due to the rapid pressure change during oil recovery When the pipe 180 and the oil tank 140 can be prevented from being damaged, and the filter 296 and 297 are further provided on the oil tank 140 side of the oil injection pipe 170 and the oil return pipe 180. When it is turned on, the oil sludge or the like can be prevented from flowing into the oil tank 140 or the high-pressure gas container 111 in advance, thereby extending the life of the system.

In particular, although not shown in the drawing, a backflow prevention valve may be added to the gas supply pipe 160, the oil injection pipe 170, or the oil return pipe 180 as necessary.

In addition, v164 is an exhaust valve when the supply valve v161 is not closed due to the residual gas pressure in the gas supply pipe 160 when the supply valve v161 is to be closed after charging to the charger 120. Valve for forcibly discharging residual pressure gas.

Hereinafter, a residual gas compression method of a gas filling system having a residual gas compression device according to the present invention will be described with reference to FIG. 2.

2 is a flowchart of a residual gas compression method of a gas filling system equipped with a residual gas compression device according to the present invention.

As shown in FIG. 2, a residual gas compression method of a gas filling system having a residual gas compression device includes a residual gas compression step, a residual gas compression stop step, a filling step, and an oil recovery step. Is performed by.

First, in the residual gas compression step, when a residual gas compression command is input from the outside, the supply valve v161 and the recovery valve v181 are closed until the residual gas of the high-pressure gas container 111 is compressed to a predetermined value. The injection valve v171 is opened and the pump 141 is driven.

That is, the oil in the oil tank 140 is introduced into the high pressure gas container 111 until the residual gas becomes a pressure capable of charging the vehicle by the pressure of the pump 141.

Next, in the pressure stopping step, when it is confirmed that the compressed gas is compressed to a predetermined value through the pressure sensor 133, the injection valve v171 is closed and the pump 141 is stopped.

In the next charging step, after the pressure stop step, the charging gun 121 of the charger 120 is coupled to the charging port of the vehicle and is performed when a charging command is input. The charging is performed in the vehicle by opening the supply valve v161. To be performed.

The next oil recovery step is input from the pressure sensor 133 or the oil position detection sensor 131 when the remaining gas of the high pressure gas container 111 is exhausted or the oil in the high pressure gas container 111 rises up to a prescribed value in the filling step. This is confirmed by the signal, and the supply valve v161 of the gas supply pipe 160 is closed, and then the recovery valve v181 is opened to recover oil in the high pressure gas container 111 to the oil tank 140.

More specifically, for example, assuming that the remaining gas remaining 60bar while charging the tube trailer 110 filled with CNG 200bar, 100bar remaining vehicle is connected to the charger 120 to charge At 60 bar, the residual gas pressure of the tube trailer 110, 100 bar may not be charged to the remaining vehicle.

At this time, if the gas filling system equipped with the residual gas compression device according to the present invention is used, the remaining gas of 60 bar is also available. First, the oil of the oil tank is driven into the high pressure gas container 111 by driving the pump 141. By moving to compress the remaining gas 60bar in the high-pressure gas container 111 to 200bar. After that, the compressed residual gas is charged to the vehicle with 100 bar remaining.

When the filling is completed, the oil injected into the high pressure gas container 111 is recovered to the oil tank 140.

 Therefore, when using the gas filling system equipped with the residual gas compression device as in the present invention, the CNG stored in the tube trailer 110 is directly charged to the vehicle and the remaining gas can also be reused, remaining in the tube trailer 110. By minimizing the amount of residual gas, it is possible to maximize the filling efficiency and reduce the distribution cost.

The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best explain their invention in the best way possible. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

In addition, the configuration shown in the embodiments and drawings described herein are only one of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention, various modifications that can be replaced at the time of the present application Since there may be equivalents and modifications, the present invention is not limited to the above-described embodiments, and various modifications may be made within the range allowed by the technical idea of the present invention.

1 is a conceptual diagram of a gas filling system equipped with a residual gas compression apparatus according to the present invention,

Figure 2 is a flow chart of the filling method of the gas filling system with a residual gas compression apparatus according to the present invention.

<Explanation of symbols for the main parts of the drawings>

110: tube trailer 111: high pressure gas container

120: charger 121: charging gun

131: oil position sensor 133: pressure sensor

140: oil tank 141: pump

150: controller 160: gas supply pipe

170: oil injection pipe 180: oil recovery pipe

293: decompression device 295: automatic pressure control valve

296, 297: filter

Claims (8)

A plurality of high-pressure gas container 111 with oil and CNG inlet and outlet tube 113 inserted at both ends are connected in series in a horizontally laid state, and the oil inlet (at the first container 111a and the last container 111b of the serial connection) A tube trailer 110 formed with 111aa and a gas inlet 111bb; A charger 120 equipped with a charging gun 121 for charging the vehicle with the CNG; A gas supply pipe 160 connecting the gas inlet 111 bb and the charger 120; An oil tank 140 storing residual gas compression oil; An oil injection pipe having a pump 141 connected between the oil tank 140 and the oil inlet 111aa and providing a pressure for injecting the oil stored in the oil tank 140 into the high pressure gas container 111 ( 170); An oil return pipe 180 connected between the oil inlet 111aa and the oil tank 140 to recover the oil injected into the high pressure gas container 111 into the oil tank 140; A pressure sensor 133 provided on the gas supply pipe 160 to measure a pressure of the residual gas filled in the high-pressure gas container 111; An oil position detecting sensor 131 provided at one side of the high pressure gas container 111 or the oil tank 140 to measure the amount of oil injected into the high pressure gas container; Valves (v161) (v171) (v181) installed in the gas supply pipe (160), the oil injection pipe (170) and the oil return pipe (180); And And a controller 150 for controlling the valves v161, v171, v181 and the pump 141 according to signals input from the pressure sensor 133 and the oil position sensor 131. Gas filling system is provided with a residual gas compression device. The method of claim 1, The oil return pipe (180) is a gas filling system with a residual gas compression device, characterized in that the pump further provides a pressure required for oil recovery. The method of claim 1, The gas supply pipe 160 is a gas filling system with a residual gas compression device, characterized in that the booster compressor for providing a pressure required to recover the oil injected into the high-pressure gas container 111 to the oil tank 140 is connected. The method of claim 1, The oil return pipe 180 is provided with a bypass pipe connected to the pump 141, the oil injection pipe 170 and the bypass pipe is further provided with a bypass valve controlled by the controller 150 valve and Gas filling system with a residual gas compression device, characterized in that the pressure of the pump 141 is used for oil injection or oil recovery in accordance with the opening and closing of the bypass valve. The method according to any one of claims 1 to 4, Gas filling system with a residual gas compression device, characterized in that the automatic pressure control valve (295) is further provided between the oil injection pipe (170) and the oil recovery pipe (180). The method according to any one of claims 1 to 4, The oil return pipe 180 is a gas filling system with a residual gas compression device, characterized in that further provided with a decompression device (293). The method according to any one of claims 1 to 4, Gas filling system with a residual gas compression device, characterized in that the filter 296 (297) is further provided on the oil tank 140 side of the oil injection pipe (170) and oil recovery pipe (180). A plurality of high-pressure gas container 111 with oil and CNG inlet and outlet tube 113 inserted at both ends are connected in series in a horizontally laid state, and the oil inlet (at the first container 111a and the last container 111b of the serial connection) A tube trailer 110 having a 111aa) and a gas inlet 111bb, a charger 120 having a filling gun 121 for charging a CNG in a vehicle, and a gas connecting the gas inlet 111bb and the charger 120 Supply pipe 160, the oil tank 140, the residual gas compression oil is stored, connected between the oil tank 140 and the oil inlet (111aa), the oil inlet pipe 170 with a pump 141, oil inlet An oil position provided at one side of the oil return pipe 180 connected between the 111a and the oil tank 140, the pressure sensor 133 provided on the gas supply pipe 160, the high pressure gas container, or the oil tank 140. The control sensor 131, a plurality of valves (v161) (v171) (v181) and the sensor 133 (131), valves (v161) (v171) (v181) and the pump 141 to control It is performed by the controller 150 of the gas filling system is provided with a residual gas compression device made of a controller 150, When a residual gas compression command is input from the outside, the supply valve v161 and the recovery valve v181 are closed until the residual gas of the high pressure gas container 111 is compressed to a predetermined value, and then the injection valve v171 is opened. And residual gas compression step of driving the pump 141; A residual gas compression stop step of closing the injection valve v171 and stopping the driving of the pump 141 when it is confirmed that the compression is completed by a predetermined value through the pressure sensor 133; A charging step of charging the vehicle by opening the supply valve v161 when the vehicle is connected to the charger 120 and a charging command is input; And When the residual gas in the high pressure gas container 111 is exhausted or the oil in the high pressure gas container 111 rises up to a prescribed value, the supply valve v161 is closed and the recovery valve v181 is opened to open the recovery valve v181 in the high pressure gas container 111. Oil recovery step of recovering the oil to the oil tank 140; a method of driving a gas filling system having a residual gas compression device comprising a.

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