Refrigeration circuit for a motor vehicle

Abstract

Refrigeration circuit (1) for a motor vehicle, comprising a compressor (5), a condenser (3), an expansion valve (9), and an evaporator (7), wherein the compressor (5), the condenser (3), the expansion valve (9), and the evaporator (7) are interconnected by means of lines (4, 6, 8) through which coolant (10) flows in a closed loop, and with a drain valve (14) integrated into one of the lines (4, 6, 8) in the refrigeration circuit (1) for draining coolant (10), characterized in that the refrigeration circuit (1) has a container (11) integrated into the refrigeration circuit (1) in one of the lines (4, 6, 8) containing an extinguishing agent (12), and wherein the container (11) has an explosive element (13) for opening, wherein the explosive element (13) is separated from the extinguishing agent (12) by means of a diaphragm (18), so that when the explosive element (13) is triggered, the diaphragm (18) and thus the container (11) is destroyed,so that the extinguishing agent (12) can enter or flow into the first line (4) and thus into the refrigeration circuit (1).

Description

[0001] The invention relates to a refrigeration circuit for a motor vehicle according to the preamble of claim 1.

[0002] Refrigeration circuits for motor vehicles are known. These circuits serve to regulate the temperature of a motor vehicle's air conditioning system to climate-control the vehicle's interior. They generally comprise a compressor, a condenser, an expansion valve, and an evaporator, with the evaporator having a connection to the vehicle's interior.

[0003] Refrigeration circuits for motor vehicles, which prevent the accumulation of potentially flammable refrigerants in the vehicle's interior, are known from the prior art. However, it remains problematic that flammable and / or explosive refrigerant-air mixtures can accumulate in the area of ​​the vehicle's engine and exhaust system.

[0004] German patent application DE 10 2008 010 024 A1 describes a refrigeration circuit for a motor vehicle which includes a safety device filled with a fire-retardant medium. In the event of a fire detection, particularly a leak in the refrigeration circuit, the medium can be directed into the engine compartment of the motor vehicle via a controllable valve.

[0005] German patent application DE 10 2008 059 942 A1 discloses a refrigeration circuit for a motor vehicle that uses the refrigerant of the refrigeration circuit as an extinguishing agent. For extinguishing, emergency openings in the refrigeration circuit are opened, allowing the refrigerant to escape. The emergency openings are located at specific positions within the refrigeration circuit.

[0006] Similarly, patent applications US 5,515,691 A and US 5,934,379 A disclose a refrigeration circuit in which the refrigerant is used as an extinguishing agent in the event of a fire, with the refrigerant flowing through emergency openings or valves provided in the refrigeration circuit.

[0007] German patent application DE 10 2008 059 968 A1 describes a refrigeration circuit for a motor vehicle, which is connected to a battery via flow-through lines for cooling purposes. In the event of a fire, the refrigerant from the refrigeration circuit is directed into an interior space within the battery and serves to extinguish the fire. To allow the refrigerant to enter the battery interior for firefighting, emergency openings are incorporated into the lines, which are opened in a controlled manner as needed.

[0008] The object of the present invention is to provide an improved refrigeration circuit for a motor vehicle.

[0009] The problem is solved according to the invention by a refrigeration circuit for a motor vehicle with the features of claim 1. Advantageous embodiments with expedient and non-trivial further developments of the invention are specified in the respective dependent claims.

[0010] The refrigeration circuit according to the invention for a motor vehicle comprises a compressor, a condenser, an expansion valve, and an evaporator, wherein the compressor, condenser, expansion valve, and evaporator are connected to one another in series by means of lines through which refrigerant flows. Furthermore, a drain valve is integrated into one of the lines in the refrigeration circuit for draining refrigerant. According to the invention, the refrigeration circuit has a container with an extinguishing agent integrated into one of the lines. The advantage is that, due to the integration of the container into one of the lines of the refrigeration circuit, the extinguishing agent can flow into the refrigeration circuit in order to escape at the corresponding damaged point in the refrigeration circuit and extinguish the fire in that area. Thus, the extinguishing agent can perform its fire-extinguishing function precisely at the damaged point in the refrigeration circuit.In other words, this means that the extinguishing agent can be applied specifically to the source of the fire.

[0011] In one embodiment of the refrigeration circuit according to the invention, the extinguishing agent has a composition different from that of the refrigerant. The refrigerant used in the refrigeration circuit does not necessarily have to have a fire-extinguishing effect, or may, for example, have only a weak fire-extinguishing effect. Thus, the advantage of this embodiment is that an extinguishing agent with a high fire-extinguishing effect can be used regardless of the composition of the refrigerant.

[0012] Preferably, the drain valve is designed to be controllable. Conventional refrigeration circuits typically have a drain valve to prevent pipes and / or components from bursting in the event of a pressure increase within the refrigeration circuit. Previously, drain valves were used that opened uncontrollably. The advantage of a controllable drain valve is the controlled release of refrigerant from the refrigeration circuit, thus preventing bursting in a controlled manner. Another significant advantage is that when the container is opened and extinguishing agent flows into the refrigeration circuit, the drain valve can be opened immediately to direct the flow of the extinguishing agent within the circuit.

[0013] If, for example, the coolant were in the form of 2,3,3,3-tetrafluoropropene, or the coolant known under the trade name R-1234yf, the pressure surge generated by the extinguishing agent could be used to allow a sufficient quantity of the coolant to escape through the drain valve to exceed the concentration of the coolant's upper explosive limit, thus eliminating any risk of explosion. In other words, the controllable drain valve allows the ignition limit of the coolant-air mixture to be deliberately exceeded. By releasing a controlled quantity of coolant through the drain valve, the coolant can no longer accelerate the fire.

[0014] In a further embodiment, the container is located on one side of the condenser, and the drain valve is located on the other side of the condenser, facing away from the first side, within the refrigeration circuit. The advantage is that the condensed refrigerant flows out of the refrigeration circuit via the drain valve, allowing the extinguishing agent to expand freely to the damaged area in order to extinguish the fire.

[0015] In a further embodiment, the container can be opened in a controlled manner. The advantage is that, for example, in the event of sufficiently high impulses acting on the vehicle, which can be measured using acceleration sensors, the container can be opened before a detectable fire has developed, allowing the extinguishing agent to flow into the refrigeration circuit and potentially extinguish the fire at its source.

[0016] According to the invention, the container has an explosive element for opening, which allows the container to open abruptly and thus enables the extinguishing agent to escape quickly from the container into the refrigeration circuit. Furthermore, the explosive element creates an additional pressure surge in the refrigeration circuit, which accelerates the outflow of the refrigerant via the drain valve and also the spread of the extinguishing agent within the refrigeration circuit.

[0017] In another embodiment, the explosive element can be triggered like an airbag. In other words, the explosive element is triggered abruptly, almost like a spring action. As soon as smoke and / or fire is detected in the refrigeration circuit as a result of a refrigerant leak, the explosive element is triggered to open the container.

[0018] In another formulation, the extinguishing agent is carbon dioxide. The advantage of carbon dioxide is that it is non-toxic, not aggressive towards all common materials, and advantageously evaporates without leaving any residue after use.

[0019] Preferably, at least one sensor is provided which initiates control of the container, or the explosive element and / or the drain valve.

[0020] The container is preferably in the form of a capsule, which can be easily integrated into one of the lines of the refrigeration circuit. Capsules typically have a neck that is connected, for example, via a thread on the neck to a complementary threaded fitting in the refrigeration circuit.

[0021] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. Identical or functionally equivalent elements are assigned identical reference numerals. The figures show: Fig. 1 in a perspective schematic representation a refrigeration circuit according to the invention for a motor vehicle with a container in a closed state, and Fig. 2. In a perspective schematic representation, the refrigeration cycle according to... Fig. 1 with the container in an open state.

[0022] A refrigeration circuit 1 according to the invention for a motor vehicle 2 is in accordance with Fig. The refrigeration circuit 1 comprises a condenser 3, which is connected to a compressor 5 via a first flow line 4. The compressor 5 is connected via a second flow line 6 to an evaporator 7, which is connected to the condenser 3 via a third flow line 8 to create a circulation of refrigerant 10 flowing through the refrigeration circuit 1. An expansion valve 9 is provided in the third line 8 between the evaporator 7 and the condenser 3.

[0023] The refrigerant 10, which flows through refrigeration circuit 1, is fed into refrigeration circuit 1 in liquid form via the expansion valve 9. From the expansion valve 9, the refrigerant 10 flows into the evaporator 7, where it evaporates due to the addition of heat and thus enters a gaseous state.

[0024] The coolant 10, which is in a gaseous state, flows into the compressor 5, from which it is drawn in and compressed, whereby, due to the compression, it has a higher pressure and temperature level downstream of the compressor 5, thus in the first line 4, than in the second line 6 upstream of the compressor 5.

[0025] The coolant 10 enters the condenser 3 via the first line 4, where it is brought back into the liquid state from its gaseous state, releasing heat in the process.

[0026] The refrigeration circuit 1 according to the invention additionally comprises a container 11 formed between the condenser 3 and the compressor 5, which is filled with an extinguishing agent 12. The container 11 is arranged on a first side 19 of the condenser 3.

[0027] In this embodiment, the extinguishing agent 12 is gaseous carbon dioxide (CO2). The container 11 is opened as needed, for example, upon detection of a fire, by means of an integrated explosive element 13, allowing the extinguishing agent 12 to flow from the container 11 into the refrigeration circuit 1. The explosive element 13 is separated from the extinguishing agent 12 within the container 11 by a membrane 18.

[0028] Furthermore, the refrigeration circuit 1 includes a drain valve 14 arranged between the condenser 3 and the expansion valve 9 in the third line 8 on a second side 20 of the condenser 3 which is designed facing away from the first side 19, through which the coolant 10 can leave the refrigeration circuit 1, in other words, flow out of the refrigeration circuit 1.

[0029] Additionally, refrigeration circuit 1 has a sensor 15, which is connected to the drain valve 14 and the container 11. The sensor 15 detects smoke. If smoke is detected by the sensor 15, the container 11 and / or the drain valve 14 are controlled via the connections to the sensor 15. The explosive element 13 serves to open the container 11 so that the extinguishing agent 12 can escape from the container 11 and enter refrigeration circuit 1. Simultaneously or almost simultaneously, the drain valve 14 is opened so that the refrigerant 10 can escape from refrigeration circuit 1.

[0030] In Fig. Figure 1 shows the refrigeration circuit 1 with the container 11 in a closed state. The third line 8 has a defect 16, which may have resulted from an accident, for example. The refrigerant 10 flows from this defect 16 and ignites due to a nearby hot exhaust unit 17 of the vehicle 2.

[0031] Fig.Figure 2 shows the refrigeration circuit 1 with the container 11 in an open state. As soon as smoke or fire is detected by the sensor 15 from the igniting or combusting refrigerant 10, the drain valve 14 is opened and simultaneously or almost simultaneously the container 11 is opened by the explosive element 13, so that the extinguishing agent 12 can flow from the container 11 into the refrigeration circuit 1. The principle of airbag deployment is essentially employed. According to the invention, the explosive element 13 is separated from the extinguishing agent 12 by means of the membrane 18, so that when the explosive element 13 is triggered, the membrane 18 and thus the container 11 are destroyed, allowing the extinguishing agent 12 to enter the first line 4 and thus into the refrigeration circuit 1.

[0032] The coolant 10 exits via the drain valve 14, while the extinguishing agent 12 flows in refrigeration circuit 1 to the fault location 16 in refrigeration circuit 1 to extinguish the fire there. By controlling the discharge of the coolant 10 via the drain valve 14, a flow direction of the extinguishing agent 12 can be created, so that the extinguishing agent 12 flows to the fault location 16, overflows there, and extinguishes the fire.

[0033] In this embodiment, the container 11 is designed in the form of a capsule. Naturally, it could have any other shape.

[0034] With the aid of the refrigeration circuit 1 according to the invention, fires, especially in an engine compartment of a motor vehicle, can thus be specifically combated and / or prevented.

Claims

[1] Refrigeration circuit (1) for a motor vehicle, comprising a compressor (5), a condenser (3), an expansion valve (9) and an evaporator (7), wherein the compressor (5), the condenser (3), the expansion valve (9) and the evaporator (7) are connected to each other in a circulating manner by means of lines (4, 6, 8) through which coolant (10) flows, and with a drain valve (14) integrated in one of the lines (4, 6, 8) in the refrigeration circuit (1) for draining coolant (10), characterized by, that the refrigeration circuit (1) has a container (11) integrated into the refrigeration circuit (1) in one of the lines (4, 6, 8) containing an extinguishing agent (12), and wherein the container (11) has an explosive element (13) for opening, wherein the explosive element (13) is separated from the extinguishing agent (12) by means of a membrane (18), so that when the explosive element (13) is triggered, the membrane (18) and thus the container (11) is destroyed, so that the extinguishing agent (12) can enter or flow into the first line (4) and thus into the refrigeration circuit (1). [2] Refrigeration circuit (1) according to claim 1, characterized by , that the extinguishing agent (12) has a composition different from that of the coolant (10). [3] Refrigeration circuit (1) according to claim 1 or 2, characterized by , that the drain valve (14) is designed to be controllable. [4] Refrigeration circuit (1) according to claim 3, characterized by, that the container (11) is located in the area of ​​a first side (19) of the condenser (3) and the drain valve (14) is located in the area of ​​a second side (20) of the condenser (3) which is designed to face away from the first side (19). [5] Refrigeration circuit (1) according to any one of the preceding claims, characterized by , that the container (11) can be opened in a controlled manner. [6] Refrigeration circuit (1) according to any one of the preceding claims, characterized by , that the explosive element (13) can be triggered in an airbag-like manner. [7] Refrigeration circuit (1) according to any one of the preceding claims, characterized by , that the extinguishing agent (12) is carbon dioxide. [8] Refrigeration circuit (1) according to any one of the preceding claims, characterized by , that at least one sensor (15) is provided which initiates control of the container (11) and / or the drain valve (14). [9] Refrigeration circuit (1) according to any one of the preceding claims, characterized by, that the container (11) is in the form of a capsule.

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