Firefighting System with Two-Stage Heating Installation

Abstract

Firefighting system 2, comprising a pressure-resistant extinguishing agent container 4, and a heating means arranged in or on the extinguishing agent container. The operational readiness is enhanced in that the heating means has at least two heating circuits which can be connected independently of one another.

Claims

1. Firefighting system comprising a pressure-resistant extinguishing agent container, and a heating means arranged in or on the extinguishing agent container, characterised in that the heating means has at least two heating circuits which can be connected independently of one another.

2. Firefighting system according to claim 1, characterised in that the heating circuits each have at least one heating resistor.

3. Firefighting system according to claim 2, characterised in that a first heating resistor has a lower specific resistance compared to a second heating resistor.

4. Firefighting system according to claim 2 or 3, characterised in that a first heating resistor has a lower melting point compared to a second heating resistor.

5. Firefighting system according to any of the preceding claims, characterised in that a first heating resistor is connected to a first voltage source and a second heating resistor is connected to a second voltage source, the voltage sources charging the heating resistors with electrical voltages which are different from one another.

6. System according to any of the preceding claims, characterised in that an energy supply feeds a direct voltage to the heating circuits, in particular in that a first direct voltage is a 24 V, preferably a 110 V direct voltage, and in that the second direct voltage is a 380 V, preferably a 400 V direct voltage.

7. Firefighting system according to any of the preceding claims, characterised in that the heating circuits are enclosed in a common housing of the heating means.

8. Firefighting system according to any of the preceding claims, characterised in that the heating means is arranged in particular as a heating sleeve on a riser pipe inside the extinguishing agent container and/or as a heating sleeve on the extinguishing agent container.

9. Firefighting system according to any of the preceding claims, characterised in that at least one temperature sensor is arranged in or on the extinguishing agent container.

10. Firefighting system according to any of the preceding claims, characterised in that a control means controls the charging of the heating resistors with electrical voltage, subject to a temperature detected by at least one temperature sensor.

11. Firefighting system according to any of the preceding claims, characterised in that the extinguishing agent container is a composite container, in particular it is formed from a plastics composite material, preferably from a plastics fibre composite material, or in that the extinguishing agent container is a metal container, consisting in particular of a steel material.

12. Firefighting system according to any of the preceding claims, characterised in that the extinguishing agent container is pressure-resistant, in particular it is permanently pressure-resistant, in particular at a continuous pressure of more than 5 bar, preferably more than 20 bar.

13. Method for operating a firefighting system according to any of the preceding claims, wherein a temperature of the extinguishing agent container and/or of the extinguishing agent in the extinguishing agent container is recorded, wherein, upon falling below a first limiting temperature, only the first heating circuit is activated, and wherein, upon falling below a second limiting temperature which is lower than the first limiting temperature, the second heating circuit is activated.

14. Method according to claim 13, characterised in that the heating circuits are respectively charged with an electrical voltage, in particular in that at least one of the heating circuits is fed by an electrical system voltage of a rail vehicle.

15. Method according to claim 13 or 14, characterised in that the first heating circuit is operated with a lower heating power than the second heating circuit.

Description

[0048] In the following, the subject-matter will be described in more detail with reference to drawings showing embodiments, in which drawings:

[0049] FIG. 1 shows a firefighting system;

[0050] FIG. 2 is a schematic view of a pipe with a heating sleeve;

[0051] FIG. 3a is a schematic plan view of a heating sleeve;

[0052] FIG. 3b is a sectional view of a heating sleeve;

[0053] FIG. 4 is a sectional view of a further embodiment of a heating means;

[0054] FIG. 5 shows the winding of a heating means around a pipe;

[0055] FIG. 6 shows an arrangement of a heating means on an extinguishing agent container;

[0056] FIG. 7 shows a schematic arrangement of an electrical heating means with a voltage supply;

[0057] FIG. 8 is a schematic view of an outlet together with temperature sensors and riser pipe;

[0058] FIG. 9 shows a mode of operation of a firefighting system according to the subject-matter;

[0059] FIG. 10 is a schematic view of a rail vehicle with a firefighting installation according to the subject-matter.

[0060] FIG. 1 shows a firefighting system 2 with an extinguishing agent container 4. Provided in the extinguishing agent container 4 is a riser pipe 6 which leads into a valve 10 via an adapter piece 8. The adapter piece 8 is arranged in the region of an outlet opening 12 of the extinguishing agent container 4 and is screwed therein preferably in a sealing manner.

[0061] In the variant which is shown, the extinguishing agent container 4 is a steel cylinder which has a plastics liner 14 on its inner surface to protect the material of the extinguishing agent container 4 against corrosion. Extinguishing fluid 16, here in the form of water, is stored under pressure in the extinguishing agent container 4. The extinguishing agent container 4 is preferably in standby mode at a resting pressure of more than 5 bar, preferably more than 20 bar, in particular more than 100 bar. By opening the valve 10, the extinguishing fluid 16 is expelled from the extinguishing agent container 4 via the riser pipe 8 and can then be applied, for example via a high-pressure water mist system or via corresponding high-pressure mist nozzles. However, it is also conceivable for the present firefighting system to be used in conventional sprinkler systems, because they also suffer from the problem of freezing. The heating installation according to the subject matter can be used in the firefighting system 2 which is shown.

[0062] FIG. 2 shows the riser pipe 6 which is sheathed by a heating sleeve 18. The heating sleeve 18 is directly connected, for example adhesively bonded, to the outer wall of the pipe 6. The connection between heating sleeve 18 and riser pipe 6 is preferably such that no gap is formed between the outer wall of the pipe 6 and the heating sleeve 8. In particular, the connection between heating sleeve 18 and riser pipe 6 is such that no gas or liquid can flow between the heating sleeve 18 and riser pipe 6.

[0063] As can be seen, at least one heating resistor 20 is provided in the heating sleeve 18. The heating resistor 20 is encased in the heating sleeve 18 and, in the assembled state, is wound around the riser pipe. The material of the heating sleeve 18 is preferably a solid material, in particular it is formed from a non-conductive metal alloy or from a non-conductive metal oxide. At least one heating resistor 20 in the form of a heating wire is guided in the interior of the heating sleeve 18. Due to the insulating characteristic of the material of the heating sleeve 18, the heating resistor/resistors 20 can be guided directly in the material of the heating sleeve 18.

[0064] FIG. 3a is a plan view of a development of a heating sleeve 18. Two heating resistors 20a, 20b which can be connected separately from one another are guided in the heating sleeve 18. It can be seen that the heating resistors 20a, 20b each have two electrical connections 22 (22a, 22a and 22b, 22b). The heating resistors 20a, 20b which can be configured as heating wires can be charged via these two respective electrical connections 22 with a respective electrical voltage, which can also be different. The electrical power fed into the heating resistors 22a, 22b can be different, so that the heating resistors 22a, 22b can have different heating powers.

[0065] The heating sleeve 18 can be wound around the riser pipe 6 if the material of the heating sleeve 18 and of the heating resistors 22a, 22b is plastically deformable. In particular, a minimum bending radius can be preset by the outer radius of the riser pipe 16. The material of the heating sleeve 18 and of the heating resistors 20a, 20b should be plastically deformable without being destroyed up to such a bending radius.

[0066] FIG. 3b shows a cross section through a heating sleeve 18. It can be seen that the conductor cross sections of the heating resistors 20a, 20b can vary in size, which results in different heating powers, in particular in different ampacities. The melting points of the materials of the heating resistors 20a, 20b can also be different.

[0067] FIG. 4 shows a further embodiment of a heating means 24 on a riser pipe 6. It can be seen that the heating means 24 is formed from an outer pipe 24a and filler material 24c arranged in an annular space 24b between the outer pipe 24a and the riser pipe 6, as well as at least one heating resistor 20. The filler material 24 is preferably electrically non-conductive and thus insulates the heating resistor 20. On the other hand, the material preferably has a good thermal conductivity, so that the heating power of the heating resistor 20 can be released to the extinguishing agent 16 via the outer pipe 24a without a significant time delay.

[0068] A heating sleeve 18, as shown in FIG. 3a, can be coiled or wound around the riser pipe 6 in the form shown in FIG. 5.

[0069] The heating means do not necessarily have to be arranged on the riser pipe 6, but they can also be arranged on the adapter piece 8 (not shown) as well as on the outer lateral surface of the extinguishing agent container 6. FIG. 6 shows a heating mat 26 which has two switching resistors 20 (not shown) which can be switched separately from one another. Via electrical connections 22 (not shown) which can be respectively equipped separately from one another, the heating resistors can be operated at different times and with different electrical powers, so that only one heating resistor or alternatively two heating resistors can be operated, depending on a temperature of the extinguishing agent container 6 or of the extinguishing agent 16 stored in the extinguishing agent container 6.

[0070] FIG. 7 shows the connection and disconnection of the electrical supply to the heating resistors 20a, 20b. In FIG. 7, for example a 24 V direct voltage supply 28 is shown as an accumulator battery. Provided next to this is a rectifier 30 which is connected to the voltage supply of the vehicle, for example a rail vehicle, and provides an electrical direct voltage of 380 V or 400 V via its outputs. The accumulator battery 28 and the rectifier 30 are connected to the electrical connections 22 of the heating resistors 20a, 20b (not shown) via respective switches 32, 34.

[0071] From a temperature sensor (not shown), a control circuit 36 receives a temperature signal 38 which it evaluates. Based on the evaluation of the temperature signal 38, the control circuit 36 opens or closes the switches 32, 34. Thus, upon falling below a first limiting temperature, for example 10 C., the switch 32 can be closed, while the switch 34 remains open. The heating resistor 20a is operated with a relatively low electrical power, and the temperature of the extinguishing agent 16 is merely maintained. However, if the outside temperature falls further, this low heating power will be inadequate. The temperature of the extinguishing agent then falls below a second limiting temperature. Even during a complete disconnection of the two heating systems, for example, during the operational standstill of the vehicle, the temperature of the extinguishing agent 16 can fall below the second limiting temperature which is lower than the first limiting temperature. Such a temperature triggers a corresponding temperature signal 38 which is evaluated by the control circuit 36 so that the switch 34 is closed. The switch 34 can be closed cumulatively to switch 32 or alternatively to switch 32.

[0072] When switch 34 is closed, the heating resistor 20b is provided with electrical power from the rectifier 30, this electrical power being significantly greater than the power from the accumulator 28. This leads to a higher thermal dissipation in the heating resistor 20b, which results in the extinguishing fluid 16 being heated up faster. In particular, if the extinguishing fluid is frozen, for example if the temperature signal 38 registers a temperature value of 0 C., a rapid heating procedure of this type can be activated.

[0073] FIG. 8 shows a detail view of an opening 4a in an extinguishing agent container 4. It can be seen that the adapter piece 8 is screwed with the mouth of the opening 4. A first temperature sensor 40a can be arranged outside the adapter piece 8. A second temperature sensor 40b can be arranged in the interior of the extinguishing agent container 4. The temperature sensors 40a, 40b can transmit a temperature signal 38 to the control means 36.

[0074] Furthermore, it can be seen that the heating sleeve 18 is arranged directly on the riser pipe 6. The riser pipe 6, together with the heating sleeve 18 which is preferably formed from metal at least on its outer surface, is guided through the adapter piece 8. The heating sleeve 18 is received in a sealing manner in the adapter piece 8, which is indicated schematically by the O rings 8a and 8b. The seal is sufficiently well-known and is therefore not described in more detail. Provided outside the extinguishing agent container 4 are the electrical connections 22a and 22b, via which the heating resistors 20a, 20b of the heating sleeve 18 can be electrically contacted.

[0075] To reduce the switching frequency and to allow a frozen extinguishing agent container 4 to be reliably thawed out, the heating resistors 20a, 20b are operated with a hysteresis. In FIG. 9, a temperature value is plotted in C. on the X-axis. Furthermore, the switching states 1 and 2 are plotted on the Y-axis. Switching state 1 means that only one heating resistor is activated and switching state 2 means that both heating resistors are activated, i.e. they are charged with electrical power. When the temperature falls, for example upon reaching a temperature of 5 C., a first heating resistor is activated. For example, this can be the heating resistor which is charged with the lower electrical power.

[0076] As long as the temperature ranges between 0 and 10 C., the first heating resistor will remain activated. Only when the temperature exceeds 10 C. is switching state 1 exited and the first heating resistor is deactivated again.

[0077] However, if the temperature in switching state 1 falls further and reaches 0 C., for example, switching state 2 is activated. In switching state 2, both heating resistors are preferably charged with electrical power, the second heating resistor being charged with a significantly higher electrical power than the first heating resistor. If the temperature falls even further, switching state 2 remains. However, the second heating resistor is only deactivated again when the temperature exceeds 5 C. The switching frequency is reduced by this hysteresis.

[0078] FIG. 10 shows a rail vehicle 42 with a pipeline system 44 and water mist nozzles 46a-c. The pipeline system 44 is coupled to two extinguishing agent containers 4. The extinguishing agent containers 4 are controlled by a central control means 36 which is connected to a fire alarm centre (not shown). In the event of a fire, the valves 10 are opened via the central control 36 and extinguishing agent passes out of the nozzles 46a-c.

[0079] The control means 36 also monitors a temperature of the extinguishing agent container 4 and, based on the temperature, controls an energy supply 50 which is coupled, for example, to the central energy supply of the rail vehicle 42. The extinguishing agent containers or the heating systems therein are controlled as described above.

LIST OF REFERENCE NUMERALS

[0080] 2 firefighting system [0081] 4 extinguishing agent container [0082] 6 riser pipe [0083] 8 adapter [0084] 10 valve [0085] 12 outlet opening [0086] 14 liner [0087] 16 extinguishing fluid [0088] 18 heating sleeve [0089] 20 heating resistor [0090] 22 electrical connections [0091] 24 heating means [0092] 24a outer pipe [0093] 24b annular space [0094] 24c filler material [0095] 28 battery [0096] 30 rectifier [0097] 32, 34 switches [0098] 36 control circuit [0099] 38 temperature signal [0100] 40 temperature sensor [0101] 42 rail vehicle [0102] 44 pipeline system [0103] 46 nozzles [0104] 50 energy supply