Device and method for filling a liquefied gas vehicle with liquefied gas

Abstract

Device for filling a liquefied petroleum gas (LPG) vehicle with liquefied petroleum gas, comprising: an auxiliary chamber (20) arranged in an LPG tank (10) of the LPG vehicle; an auxiliary injection line (30) branching off from a fuel line (15) extending from a fuel inlet opening (14) to the LPG tank (10) for connection with the auxiliary chamber (20); a solenoid valve (32) mounted in the auxiliary injection line (30) to selectively allow or block the flow of LPG to the auxiliary chamber (20); a temperature sensor (36) to detect a temperature in the LPG tank (10); and a control device (34) to control the solenoid valve (32) such that it opens when the temperature detected by the temperature sensor (36) is equal to or greater than a critical temperature.

Description

The invention relates to a device and a method for filling a liquefied petroleum gas (LPG) vehicle with liquefied petroleum gas, and in particular a device and a method for filling an LPG vehicle with LPG, which are suitable for easily filling a container with LPG by reducing the temperature and pressure in the container by means of an auxiliary chamber which can be temporarily filled with cold fuel, when the pressure in the container for storing LPG is higher than a filling pressure. As shown in Fig. 1, a process for refueling an LPG vehicle generally comprises a step of operating a refueling pump 2 of a filling station, a step of transferring LPG from an LPG storage tank 1 of the filling station to a dispensing nozzle 3 by operating the refueling pump 2, and a step of filling an LPG tank of the vehicle with LPG by the LPG filling pressure of the dispensing nozzle 3. With reference to Fig. 2, an overflow valve 16, which is connected to a fuel inlet opening 14 of the vehicle via a fuel line 15, is mounted at the inlet of the LPG container 10, and a fuel pump module 18 for transferring fuel to an engine (e.g. internal combustion engine) is arranged in the container 10. Accordingly, the container 10 is filled with LPG from the fuel nozzle 3 via the fuel inlet opening 14 and the overflow valve 16. However, filling with LPG may be impossible if, during the hot season when the outside temperature rises rapidly, the pressure in the vehicle's LPG tank is higher than the LPG filling pressure. This means that if the pressure in the vehicle's LPG tank is higher than the LPG filling pressure, a check valve contained in the overflow valve will not open. For this reason, it is impossible to fill the LPG tank with LPG from the pump nozzle. For example, if during the hot season, when the air temperature is equal to or higher than approximately 40°C, the pressure in the vehicle's LPG tank (e.g., 16.5 bar) is higher than the LPG filling pressure of the pump nozzle (8.3 bar, which is the pressure in the gas station's LPG storage tank, + 8.0 bar, which is the LPG pump pressure dependent on the operation of the filling pump, = 16.3 bar), the check valve in the overflow valve will not open. For this reason, it is impossible to fill the LPG tank with LPG from the pump nozzle. DE 10 2012 102 840 A1 describes a device and a method for filling a liquefied petroleum gas (LPG) vehicle with liquefied petroleum gas, comprising an auxiliary injection line branched off from a fuel line, a solenoid valve to selectively allow or block an inflow of LPG, a temperature sensor to detect a temperature in an LPG container, and a control device to control the solenoid valve. Another method for filling an LPG vehicle with liquefied petroleum gas is known from US 2015 / 0 330 572 A1. The invention provides a device and a method for filling an LPG vehicle with LPG, which are suitable for easily filling a vehicle's LPG tank with LPG by installing an auxiliary chamber, which can be temporarily filled with cold fuel, in the LPG tank and reducing the temperature and pressure in the tank by means of heat exchange between the auxiliary chamber and the LPG tank, when the pressure in the LPG tank is higher than the LPG filling pressure of a dispensing nozzle. According to various aspects of the invention, a device for filling a liquefied petroleum gas (LPG) vehicle with liquefied petroleum gas comprises: an auxiliary chamber arranged in an LPG tank of the LPG vehicle, an auxiliary injection line branching off from a fuel line extending from a fuel inlet opening to the LPG tank for connection with the auxiliary chamber, a solenoid valve mounted in the auxiliary injection line to selectively allow or block an inflow of LPG to the auxiliary chamber, a temperature sensor to detect a temperature in the LPG tank, and a control device to control the solenoid valve such that it opens when the temperature detected by the temperature sensor is equal to or greater than a critical temperature. The auxiliary chamber may include a flange section placed in a mounting opening formed in the LPG container, a heat exchange chamber extending from the flange section into the LPG container, and an airtight cover fitted in the mounting opening of the LPG container in which the flange section is located. A check valve can be mounted at one end of the heat exchange chamber in such a way that the LPG can optionally flow from the heat exchange chamber into the LPG container. The auxiliary chamber can be made of an aluminum material with thermal conductivity. The temperature sensor can be mounted on a fuel pump module located inside the LPG tank. According to various aspects of the invention, a method for filling a liquefied petroleum gas (LPG) vehicle with liquefied petroleum gas comprises: i) detecting a temperature in an LPG tank by means of a temperature sensor, ii) supplying LPG from a fuel line to the LPG tank by means of a control device when the temperature in the LPG tank is less than a critical temperature, iii) supplying the LPG from the fuel line via an auxiliary injection line to an auxiliary chamber arranged in the LPG tank by means of the control device when the temperature in the LPG tank is equal to or greater than the critical temperature, iv) carrying out a heat exchange between the auxiliary chamber filled with LPG and an inner surface of the LPG tank, and v) supplying the LPG from the fuel line to the LPG tank by means of the control device when the temperature in the LPG tank is reduced below the critical temperature by the heat exchange. In step ii) supplying LPG from the fuel line to the LPG container, a solenoid valve mounted in the auxiliary injection line can be controlled in such a way that it is closed. In step iii) supplying the LPG from the fuel line via the auxiliary injection line to the auxiliary chamber, a solenoid valve mounted in the auxiliary injection line can be controlled in such a way that it is opened. In step iii) supplying the LPG from the fuel line via the auxiliary injection line to the auxiliary chamber, the LPG supplied to the auxiliary chamber can be a fuel with a lower temperature than the temperature in the LPG tank and can be supplied from an underground LPG storage tank at a filling station. In step v) supplying the LPG from the fuel line to the LPG tank, the LPG tank can be filled with the LPG in the auxiliary chamber. It is understood that the term "vehicle" or "vehicle-" or any other similar term as used herein includes general motor vehicles, such as passenger cars, including SUVs, buses, trucks, various commercial vehicles, watercraft, including a variety of boats and ships, aircraft, and the like, as well as hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other vehicles using alternative fuels (e.g., fuels derived from raw materials other than petroleum). As referenced herein, a hybrid vehicle is a vehicle that has two or more sources of propulsion, for example, both a gasoline engine and an electric engine. The invention is explained in more detail below with reference to the drawings. The drawings show: Fig. 1 a schematic of a process for filling a liquefied petroleum gas (LPG) vehicle according to the prior art; Fig. 2 a view of a filling device for an LPG vehicle according to the prior art; Fig. 3 a view of a filling device for an LPG vehicle according to an embodiment of the invention; Fig. 4 a perspective view of an auxiliary chamber of the filling device according to an embodiment of the invention; Fig. 5 a perspective view of the auxiliary chamber of the filling device according to an embodiment of the invention, which is installed in an LPG tank; Figs. 6 and 7 views illustrating the operation of the filling device for an LPG vehicle according to an embodiment of the invention; and Fig. 8 a flowchart of a filling process for an LPG vehicle according to an embodiment of the invention. It is understood that the attached drawings are not necessarily to scale and represent a somewhat simplified depiction of various features that illustrate the basic principles of the invention. The specific design features of the present invention, which include, for example, specific dimensions, orientations, positions, and shapes as disclosed herein, are partly determined by the intended application and environment of use. Various embodiments of the present invention will now be discussed in detail, examples of which are illustrated in the accompanying drawings and described below. Although the invention is described in connection with exemplary embodiments, it is understood that the present description is not intended to limit the invention to these exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents, and other embodiments that may be included within the scope and scope of the invention as defined by the accompanying claims. In Fig. 3, reference numeral 10 denotes an LPG tank that is mounted in an LPG vehicle. An overflow valve 16, which is connected to a fuel inlet opening 14 of the vehicle via a fuel line 15, is mounted on the inlet of the LPG tank 10, and a fuel pump module 18 for transferring fuel to an engine is installed in the LPG tank 10. Accordingly, the LPG container 10 is filled with LPG via the fuel inlet opening 14 and the overflow valve 16 from a fuel nozzle of a filling station. However, if, during the hot season when the outside temperature rises rapidly, the temperature and pressure in the vehicle's LPG tank 10 are increased, and the pressure in the LPG tank 10 is higher than the LPG filling pressure of the nozzle, filling with LPG may be impossible. Therefore, in view of the above problem, the invention aims to facilitate the filling of the container with LPG by reducing the temperature and pressure in the container by means of an auxiliary chamber which can be temporarily filled with cold fuel when the pressure in the container for storing LPG is higher than a filling pressure. The auxiliary chamber 20 is arranged in the LPG container 10, which is mounted in the LPG vehicle. In more detail, the auxiliary chamber 20 has a flanged section 22, which is positioned in a mounting opening 12 formed in a stepped shape in the container 10, and a heat exchange chamber 24, which extends from the flanged section 22 to the inside of the container 10, as shown in Figures 4 and 5. The auxiliary chamber 20 is preferably made of an aluminum material with high thermal conductivity. The heat exchange chamber 24 can preferably be designed in various shapes, such as a straight hollow tube or a zigzag tube, to ensure a heat exchange surface area suitable for the internal volume of the LPG container 10. Furthermore, a check valve 26 is mounted at the end of the heat exchange chamber 24 of the auxiliary chamber 20 to allow the LPG to flow only from the heat exchange chamber 24 into the LPG container 10. Accordingly, after the heat exchange chamber 24 is inserted into the LPG container 10 through the mounting opening 12, the flange section 22 is positioned on the outer circumferential section of the mounting opening 12. Subsequently, an airtight cover 28 comes into contact with the flange section 22, and a screw penetrates the cover 28, the flange section 22, and the container 10, thus securing them together. As a result, the installation of the auxiliary chamber 20 on the container 10 is complete. In this case, an auxiliary injection line 30, which branches off from the fuel line 15, penetrates the airtight cover 28, and the end of the penetrated auxiliary injection line 30 is connected to the auxiliary chamber 20 in such a way that the auxiliary injection line 30 is in contact with the auxiliary chamber 20. In more detail, the auxiliary injection line 30 branches off from the fuel line 15, which connects the fuel inlet opening 14 with the overflow valve 16, which is mounted on the inlet of the LPG container 10, and is connected through the airtight cover 28 to the auxiliary chamber 20 in such a way that it is in contact with the auxiliary chamber 20. Furthermore, a solenoid valve 32, which is opened or closed by the switching control of a control device 34, is mounted in the auxiliary injection line 30. Accordingly, the solenoid valve 32 serves to enable or block the flow of LPG from the fuel line 15 via the auxiliary injection line 30 to the auxiliary chamber 20. Meanwhile, a temperature sensor 36 for detecting the temperature in the container 10 is mounted on the fuel pump module 18, which is installed in the container 10. A signal indicating the temperature detected by the temperature sensor 36 in the container 10 is transmitted to the control unit 34, and the control unit 34 controls the solenoid valve 32 such that the solenoid valve 32 is opened when the temperature detected by the temperature sensor 36 is equal to or greater than a critical temperature. The following describes, with reference to Figs. 6, 7 to 8, the operation of the filling device for an LPG vehicle with the above configuration and a filling method for an LPG vehicle according to an embodiment of the invention. First, the temperature in the LPG container 10 is recorded. The temperature in the container 10 is detected by the temperature sensor 36, which is mounted on the fuel pump module 18 in the container 10, and a signal indicating the detected temperature is transmitted to the control unit 34. Next, the control unit 34 compares the current temperature in the container 10 with a critical temperature (S101). If, as a result of the comparison, the current temperature in the container 10 is less than the critical temperature (e.g. 44°C), the control device 34 controls the solenoid valve 32 in such a way that it is closed (S102). This means that if the current temperature in the container 10 is lower than the critical temperature, it is determined that the pressure in the LPG container 10 is lower than the LPG filling pressure of the dispensing nozzle. Therefore, the control unit 34 controls the solenoid valve 32 so that it closes. Accordingly, the container 10 is easily filled with LPG from the filling station nozzle via the fuel inlet opening 14 and the overflow valve 16 (S103), and at the same time the fuel flowing from the fuel line 15 to the auxiliary injection line 30 is blocked by closing the solenoid valve 32, as shown in Fig. 6. Otherwise, if the current temperature in the container 10 is greater than or equal to the critical temperature (e.g. 44°C), the control device 34 controls the solenoid valve 32 so that it is opened (S104). This means that if the current temperature in the container 10 is greater than or equal to the critical temperature, it is determined that the pressure in the LPG container 10 is greater than the LPG filling pressure. Therefore, the control unit 34 controls the solenoid valve 32 so that it opens. In this case, if the pressure in the LPG container 10 is greater than the LPG filling pressure, the check valve contained in the overflow valve 16 will not open, and it is therefore impossible to fill the LPG container 10 with LPG. Therefore, the condition is maintained in which the container 10 is not filled with LPG from the fuel pump nozzle of the filling station via the fuel inlet opening 14 and the overflow valve 16, and the LPG flows from the fuel pump nozzle via the fuel line 15 to the auxiliary injection line 30, while it is directed via the open solenoid valve 32 to the auxiliary chamber 20 (S105), as shown in Fig. 7. In this case, the LPG supplied to the auxiliary chamber 20 remains temporarily in the heat exchange chamber 24, since the pressure in the LPG container 10 is greater than the LPG filling pressure in the heat exchange chamber 24. Meanwhile, since LPG is supplied to auxiliary chamber 20 from the underground LPG storage of the filling station, the LPG has a lower temperature than the current temperature (e.g. 44°C) in the LPG tank 10, and the LPG stored in the underground LPG storage is usually kept at about 20°C even in the hot season. Accordingly, a heat exchange is carried out between the low temperature (about 20°C) of the LPG supplied to the heat exchange chamber 24 of the auxiliary chamber 20 and the heat present in the interior of the LPG container 10, so that the temperature in the LPG container 10 is reduced below a critical temperature after a certain period of time (S106). In this regard, if the temperature in the LPG container 10 is reduced below the critical temperature, the pressure in the container 10 will be reduced below the filling pressure of the LPG dispensing nozzle (S107). Therefore, if the pressure in the container 10 is less than the filling pressure of the LPG nozzle, the container 10 is easily filled with LPG by the nozzle of the filling station via the fuel inlet opening 14 and the overflow valve 16 (S108). Furthermore, if, as a result of the heat exchange through the auxiliary chamber 20, the temperature in the LPG container 10 is lower than the critical temperature, the control device 34 controls the solenoid valve 32 in such a way that it is closed again (S109). As can be seen from the above description, the invention has the following effects. If, during hot weather (summer) or similar periods when the outside temperature rises rapidly, the pressure in an LPG tank exceeds the LPG filling pressure of a pump nozzle, cold LPG (stored in the underground reservoir of an LPG filling station) at a lower temperature than the temperature in the LPG tank is fed to an auxiliary chamber installed within the tank. This reduces the temperature and pressure in the tank through heat exchange between the auxiliary chamber and the LPG tank. As a result, it is always possible to fill the tank with LPG without any problems. To simplify the explanation and precise definition in the attached claims, the terms “top”, “bottom”, “inside”, “outside”, etc. are used to describe features of the exemplary embodiment in relation to the positions of these features in the figures.

Claims

Device for filling a liquefied petroleum gas (LPG) vehicle with liquefied petroleum gas, comprising: an auxiliary chamber (20) arranged in an LPG tank (10) of the LPG vehicle; an auxiliary injection line (30) branching off from a fuel line (15) extending from a fuel inlet opening (14) to the LPG tank (10) for connection with the auxiliary chamber (20); a solenoid valve (32) mounted in the auxiliary injection line (30) to selectively allow or block the flow of LPG to the auxiliary chamber (20); a temperature sensor (36) to detect a temperature in the LPG tank (10); and a control device (34) to control the solenoid valve (32) such that it opens when the temperature detected by the temperature sensor (36) is equal to or greater than a critical temperature. Device according to claim 1, wherein the auxiliary chamber (20) comprises: a flange section (22) which is placed in a mounting opening (12) which is formed in the LPG container (10); a heat exchange chamber (24) which extends from the flange section (22) into the LPG container (10); and an airtight cover (28) which is attached to the mounting opening (12) of the LPG container (10) in which the flange section (22) is arranged. Device according to claim 2, wherein a check valve (26) is mounted at one end of the heat exchange chamber (24) such that the LPG flows from the heat exchange chamber (24) selectively into the LPG container (10). Device according to one of claims 1 to 3, wherein the auxiliary chamber (20) comprises an aluminum material with thermal conductivity. Device according to one of claims 1 to 4, wherein the temperature sensor (36) is mounted on a fuel pump module (18) which is arranged in the LPG container (10). A method for filling a liquefied petroleum gas (LPG) vehicle with liquefied petroleum gas, comprising: i) detecting a temperature in an LPG tank (10) by means of a temperature sensor (36); ii) supplying LPG from a fuel line (15) to the LPG tank (10) by means of a control device (34) when the temperature in the LPG tank (10) is less than a critical temperature (S103); iii) supplying the LPG from the fuel line (15) via an auxiliary injection line (30) to an auxiliary chamber (20) arranged in the LPG tank (10) by means of the control device (34) when the temperature in the LPG tank (10) is equal to or greater than the critical temperature (S105); iv) carrying out a heat exchange between the LPG-filled auxiliary chamber (20) and an inner surface of the LPG tank (10). (S106);andv) Supplying the LPG from the fuel line (15) to the LPG tank (10) by means of the control device (34) when the temperature in the LPG tank (10) is reduced below the critical temperature by heat exchange (S107).; Method according to claim 6, wherein in ii) supplying LPG from the fuel line (15) to the LPG container (10) a solenoid valve (32) mounted in the auxiliary injection line (30) is controlled such that it is closed (S102). Method according to claim 6, wherein in iii) supplying the LPG from the fuel line (15) via the auxiliary injection line (30) to the auxiliary chamber (20) a solenoid valve (32) mounted in the auxiliary injection line (30) is controlled such that it is opened (S104). Method according to claim 6 or 8, wherein in iii) supplying the LPG from the fuel line (15) via the auxiliary injection line (30) to the auxiliary chamber (20) the LPG supplied to the auxiliary chamber (20) is a fuel with a lower temperature than the temperature in the LPG container (10) and is supplied from an underground LPG storage tank of a filling station. Method according to one of claims 6, 8 and 9, wherein in v) supplying the LPG from the fuel line (15) to the LPG container (10) the LPG container (10) is filled with the LPG in the auxiliary chamber (20).

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