Liquid gas system

Abstract

A liquid gas system for mobile applications includes at least one remote gas switch that is mountable to a bottle of liquid gas and a gas pressure regulator. The high-pressure input of the gas pressure regulator is connected to the remote gas switch. A distribution block is provided, the input of which is connected to the low-pressure output of the gas pressure regulator. A filter unit is arranged between the low-pressure output of the gas pressure regulator and the distribution block. Further, an electronic controller is provided which is connected to the remote gas switch.

Claims

1. A liquid gas system for mobile applications comprising at least one remote gas switch that is mountable to a bottle of liquid gas, a gas pressure regulator, where the high-pressure input thereof is connected to the remote gas switch, a distribution block, where the input thereof is connected to the low-pressure output of the gas pressure regulator, a filter unit arranged between the low-pressure output of the gas pressure regulator and the distribution block, and an electronic controller which is connected to the remote gas switch.

2. The liquid gas system of claim 1 wherein the filter unit comprises a disposable filter.

3. The liquid gas system of claim 2 wherein the disposable filter is a filter cartridge.

4. The liquid gas system of claim 2 wherein a sensor for detecting the contamination of the disposable filter is provided.

5. The liquid gas system of claim 4 wherein the contamination sensor comprises a RFID chip which is integrated with the disposable filter.

6. The liquid gas system of claim 4 wherein the contamination sensor is connected to the controller.

7. The liquid gas system of claim 1 wherein the filter unit is integrated with the distribution block.

8. The liquid gas system of claim 1 wherein a second high-pressure tube leading to the second remote gas switch is connected on the high-pressure side of the liquid gas system.

9. The liquid gas system of claim 8 wherein the two high-pressure tubes are connected to both inputs of the tee-piece, where the output thereof is connected to the high-pressure input of the gas pressure regulator.

10. The liquid gas system of claim 1 wherein an electronic crash sensor is provided, which is connected to the controller.

11. The liquid gas system of claim 1 wherein a crash signal interface is provided by means of which the liquid gas system is adapted to access the crash signal of vehicle-side crash sensor.

12. The liquid gas system of claim 1 wherein a heating element and a sensor are provided on the low-pressure side of the liquid gas system.

13. The liquid gas system of claim 12 wherein the sensor is a temperature sensor.

14. The liquid gas system of claim 13 wherein different cooling curves are stored in the controller and that the controller is adapted to compare a measured cooling curve with the stored cooling curves.

15. The liquid gas system of claim 1 wherein a filling level meter is provided.

16. The liquid gas system of claim 15 wherein the filling level meter is connected to the controller.

17. The liquid gas system of claim 1 wherein a heating device which is connected to the controller is provided at the gas pressure regulator.

18. The liquid gas system of claim 17 wherein a temperature sensor which is connected to the controller is associated with the heating device.

19. The liquid gas system of claim 1 wherein the filter unit comprises a near field communications interface.

20. The liquid gas system of claim 1 wherein the controller comprises a remote communications interface.

21. The liquid gas system of claim 1 wherein the remote gas switch is directly connected to the input of the gas pressure regulator.

22. The liquid gas system of claim 1 wherein the remote gas switch is connected to the input of the gas pressure regulator by means of a high-pressure tube.

23. The liquid gas system of claim 22 wherein the high-pressure tube contains a tube break protector.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in the following by using different exemplary embodiments which are explained in the appended drawings. In the figures:

(2) FIG. 1 shows schematically a liquid gas system according to a first embodiment of the invention;

(3) FIG. 2 shows schematically a liquid gas system according to a second embodiment of the invention;

(4) FIG. 3 shows schematically a liquid gas system according to a third embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(5) The liquid gas system comprises two remote gas switches 10 to which a bottle of liquid gas 12 is connected, respectively. Liquid gas bottles are pressure containers filled with pressurized liquid petrol gas (LPG), for example with propane and butane. These are common bottles of liquid gas (in most cases bottles of propane/butane gas), which a user may carry and exchange.

(6) The remote gas switches 10 are solenoid valves which are closed in a currentless state. In order to open them, a solenoid (not shown here) has to be energized. This is performed by the schematically shown control lines 14 which are coupled to a controller 16.

(7) The output of the remote gas switch 10 is connected to a high-pressure tube 18, respectively, which is provided with a tube break protector 20. The tube break protector 20 works mechanically and ensures to prevent any leakage of gas, in case the escaping gas volume exceeds a predefined volume throughput (due to a leakage).

(8) The two high-pressure tubes 18 are coupled to both inputs of a tee-piece 22, the output of which is coupled to the high-pressure input of a gas pressure regulator 24.

(9) The gas pressure regulator 24 reduces the pressure on the high-pressure side of the liquid gas system, this is the pressure of the bottle, to the significantly lower pressure of the low-pressure side, for example to 30 mbar.

(10) It has shown that common gas pressure regulators which are used in an up-to-date gas system comprising a well-maintained bottle of gas are sufficiently protected against eventually occurring contaminations.

(11) A heating device 26 is associated with the gas pressure regulator 24, which may be driven by the controller 16. In addition, a temperature sensor 28 is provided, which is also connected to the controller 16.

(12) On the low-pressure side of the gas pressure regulator 24 a leak test unit 30 is provided directly next to the gas pressure regulator, which comprises a heating element 32 and a sensor 34. In the exemplary embodiment shown, the sensor is a temperature sensor.

(13) Both the heating element 32 and the sensor 34 are connected to the controller 16.

(14) The gas is routed from the leak test unit 30 via the low-pressure line 35 to a distribution block 36, to which the respective electric consumers are coupled via lines 38 which may be shut-off separately, for example a gas cooker, a burner of a heating system, a burner of a refrigerator, etc. A filter unit 40 is integrated with the distribution block 36 which serves to retain contaminations before the gas is forwarded to the electric consumers. In particular, the contaminations may be oil-containing aerosols. In addition, a precipitator may be provided in order to precipitate moisture.

(15) In the filter unit 40 a disposable filter is arranged in the form of a filter cartridge 42. The filter cartridge 42 is accommodated in a filter casing 44, which may be easily opened and closed again by a user (in particular with any tools). Here, to this end, a clamp mechanism 46 is indicated schematically, which similar to a quick-closing-connection automatically shuts-off the connection in case of a break.

(16) An inspection window 48 is present on the side of the filter cartridge 42, thus a user is always able to check the remaining filtering capacity (or, in other words, up to which degree the filter cartridge is already depleted due to the retained contaminations).

(17) Further, the filter cartridge 42 is provided with the contamination sensor 50, which may identify the degree of contamination of the filter and accordingly determine the remaining filtering capacity.

(18) Also, a RFID chip (not shown here) is integrated in the contamination sensor, which may be driven by the controller 16. This is shown by the dashed communication line 52.

(19) In addition, the liquid gas system has an electronic crash sensor 54 which is connected to the controller 16.

(20) A filling level meter 56 is associated with each of the bottles of liquid gas 12 by means of which the filling level of the respective bottle of liquid gas 12 may be determined.

(21) The filling level meters 56 preferably use ultrasound that is generated by a piezo-element and is coupled into the wall of the bottle of liquid gas 12. In the exemplary embodiment shown, the filling level meters 56 are arranged on the lower side of the bottles of liquid gas 12 at the bottom. Based on a measurement of the time the coupled ultrasound signals need to get reflected on the boundary surface in a liquid-gaseous mode and are again received by the piezo-element, the filling level of the respective bottle of liquid gas may be determined in a reliable way. Said filling level may be sent to the controller 16 or retrieved by it. This may be performed wireless by using a suitable communications protocol, for example the Bluetooth standard. The communication link is indicated here schematically with the reference number 58.

(22) The controller 16 comprises a near field communications interface 60 which may support the Bluetooth and/or the WLAN standard, for example. By using the near field communications interface 60, the filling level meters 56 may be retrieved. In addition, they may be used to establish communication with the smartphone of a user, in case his/her a smartphone is located next to the controller 16.

(23) The controller 16 further comprises a remote communications interface 62, which is adapted to communicate via a cellular network and/or an internet connection, for example by SMS, in case the user is not near to the controller 16.

(24) By means of the controller 16 and the further components of the liquid gas system, it may be operated in a safe and uncomplicated way.

(25) The remote gas switches 10 facilitate switching from one bottle of gas to another bottle of gas. This may be performed automatically by the controller, in case the filling level of the respective bottle of liquid gas 12, which currently operates the liquid gas system, falls under a certain value. The user may be informed in advance or at this point of time at the latest that the current standby bottle of liquid gas 12 is taking over the gas supply, and thus a new bottle of liquid gas 12 has to be bought.

(26) Due to their design, the remote gas switches 10 also ensure that the two bottles of liquid gas 12 are removed from the system in case no electrical power is present, this is, for example, when the camper is temporarily taken off the road, and thus the battery is disconnected.

(27) The heating device 26 prevents the icing up of the gas pressure regulator 24 even in case of low surrounding temperatures, and thus the liquid gas system may also be reliably operated in winter.

(28) The leak test unit 30 enables a user to easily perform an automated leak test. For this purpose, the controller 16 drives the heating element 32 until a predefined temperature is achieved in the leak test unit 30. Then the cooling behavior is detected by the temperature sensor 34. The recorded cooling curve is compared with the cooling curves 60 stored in the controller 16. In case the liquid gas system is a closed system, the temperature will be reduced in a comparatively slow way. In case the liquid gas system is not tight, that is, the gas will flow from a bottle of liquid gas 12 into the system, then the temperature will here sink faster than in a closed liquid gas system. Accordingly, the controller 16 is able to detect that there is apparently a leakage. In this case the user may be adequately informed by the controller 16, and the controller 16 may switch off both bottles of liquid gas 12 by means of the two remote gas switches 10. The switching off will not be suspended until a service technician confirms that the gas system has been repaired. In this case the service technician would perform a leak test again. Hereto the controller 16 activates the remote gas switch and thus releases the gas system such that the measurement may start.

(29) Due to the electric crash sensor 54 it is allowed to operate the liquid gas system also in a camper which is travelling. The controller 16 may directly cut off the gas supply by using the remote gas switches 10, in case the crash sensor 54 detects a delay indicating an accident.

(30) By means of the filter unit 40 it may be ensured that the electric consumers are reliably protected against any contaminations present in the gas. By means of the contamination sensor associated with the filter cartridge 42, the user is able to determine the remaining many filtering capacity at any time, and when a new filter cartridge has to be inserted. Due to the distinctive design of the filter unit 40, it may be inserted without any tool and with little effort, thus after replacing the filter the system becomes immediately operable again.

(31) FIG. 2 shows a liquid gas system according to a second embodiment. For components known from the first embodiment the same reference number will be used, and in this respect reference is made to the description above.

(32) In the second embodiment, the first bottle of gas 12 is directly connected to the remote gas switch 10, to which the gas pressure regulator 24 is connected by using a tee-piece 22.

(33) Downwards of the gas pressure regulator 24 a low-pressure line 35 is connected which is forwarded via a filter unit 40 to the distribution block 36.

(34) The second gas bottle (here, for differentiation, the reference number 12 is used) is connected to the second input of the tee-piece 22 by means of a high-pressure tube 18, which comprises a tube break protector 20 and is connected to an output of a further remote gas switch 10. Also, at the second bottle of gas 12, the remote gas switch 10 is directly mounted to it, without the need of a tube connection between the bottle of gas 12 and the remote gas switch 10.

(35) Depending on the respective safety requirements, the tube break protector may also not be required.

(36) Generally, this results in a liquid gas system providing both a simple design and a high operational reliability.

(37) The further components of the liquid gas system, like the controller etc., are not shown in FIG. 2.

(38) FIG. 3 is a liquid gas system according to a third embodiment. For components known from the preceding embodiments the same reference number will be used, and thus reference is made to the description above.

(39) In a third embodiment, a remote gas switch 10, which is followed by a gas pressure regulator 24, is attached to each bottle of gas 12. The outputs of the two gas pressure regulators 24 are connected to the two inputs of the tee-piece 22 via low-pressure tubes 35, from which a further low-pressure tube 35 is routed to a filter unit (not shown here) and then to the distribution block.

(40) The advantage of the third embodiment is that no high-pressure tube is used.