Arrangement for Ventilating a Rail Vehicle Compartment

The invention relates to an arrangement for ventilating a compartment in a rail vehicle in order to reduce a possibly harmful concentration of a gas in said compartment.

It is known to ventilate a compartment of a rail vehicle in a targeted way in order to reduce a gas concentration which is present there or arises there and which could be hazardous for the rail vehicle, for the vehicle driver, etc. until a permissible limit value is reached.

A multiplicity of use scenarios are conceivable here, of which some are mentioned below by way of example, but not restrictively:

The refrigerant example will be described in more detail by way of example usingwith reference to a driver's cab FR of a rail vehicle.

The driver's cab FR is cooled using a refrigeration machine on the basis of what is referred to as a “cold vapor process”. The refrigeration machine has, as annularly interconnected components, a compressor VERDI, an evaporator VERDA, a tension relief valve ENTSP, a liquefier VERFL and a refrigerant KM which flows through the components in different states of aggregation via a duct system.

In order to extract heat from the driver's cab FR, the evaporator VERDA is coupled to the latter—i.e. it is either arranged in the driver's cab or it is arranged externally to the driver's cab FR and is connected to the latter via an intermediate circuit ZWK, which is designed, for example, as a heat exchanger.

The driver's cab FR is connected to the surroundings of the rail vehicle via a ventilation system such that fresh air FRIL passes from the surroundings into the driver's cab FR and is mixed there with circulating air UML of the driver's cab FR.

Preferably, the supply of air and the mixing are supported by a first fan VENTwhich is arranged in the driver's cab FR. Alternatively or to support this, a second fan VENTis provided for the same purpose.

The mixed air is cooled via the coupling to the evaporator VERDA, i.e. heat is extracted from the mixed air with the aid of the intermediate circuit ZWK and/or the evaporator VERDA and supplied to the coolant KM. By means of the absorption of heat, the coolant KM evaporates and passes from the evaporator VERDA to the compressor VERDI.

In the compressor VERDI, the gaseous refrigerant KM is brought to a higher pressure level and to a higher temperature level. The gaseous refrigerant KM then passes from the compressor VERDI to the liquefier VERFL which is arranged in a dedicated compartment RA.

In the liquefier VERFL, the gaseous refrigerant KM is condensed. In the process, heat which is released is transmitted to compartment air in the compartment RA and passes via exhaust air ABL of the compartment RA into the surroundings of the rail vehicle.

For example, the compartment RA is arranged in the front region of the rail vehicle.

The liquefied refrigerant KM passes from the liquefier VERFL to the tension relief valve ENTSP. The liquid refrigerant KM is “relieved of tension” there, i.e. pressure is reduced and therefore the temperature level of the refrigerant KM lowered.

The liquid refrigerant KM subsequently passes from the tension relief valve ENTSP to the evaporator VERDA and the described cooling circuit begins again.

The mixed air cooled in the driver's cab FR is referred to as supply air ZUL and distributed in the driver's cab FR. A portion of the supply air ZUL passes as so-called outgoing air FOL back out of the driver's cab FR via a venting system into the surroundings.

The compartment RA with the liquefier VERFL is structurally separated from the driver's cab FR and connected to the surroundings of the rail vehicle via a ventilation system. Said ventilation system is designed in such a way that intake air ANSL originating from the surroundings is conducted via the liquefier VERFL and passes back again as exhaust air ABL to the surroundings of the rail vehicle.

Preferably, this air conduction is supported by a first fan VENTwhich is arranged in the compartment RE. Alternatively or to support this, a further fan VENTis provided in the compartment RE for the same purpose.

Due to operational stipulations and requirements, individual components of the refrigeration machine may be arranged at different locations or compartments of the rail vehicle that may not coincide either with the driver's cab FR or with the compartment RA.

It is known to use what is referred to as “HFO-1234yf” as a refrigerant in the refrigeration machine. This refrigerant in the gaseous state is a combustible, colorless gas with a weak odor and accordingly has the disadvantage that a leakage may not be noticed. Furthermore, in the (air) atmosphere of a compartment, it forms a persistent, environmentally harmful acid, namely trifluoroacetic acid.

It is also known to use propane as a refrigerant. Propane burns cleanly and does not form a persistent acid when it leaks, but does form a highly explosive mixture with air.

For a compartment in a rail vehicle, in which a critical gas concentration may occur, a safety assessment or a risk assessment is required. For a positive risk assessment, it has to be ensured that, in the event of relatively small leaks in components of the refrigeration machine, a mean gas concentration in the compartment has only a low level or falls short of a specified gas concentration level.

In the case of the arrangement described according to, this is achieved in that large amounts of intake air ANSL are continuously conducted through the compartment RA irrespective of whether the refrigeration machine is or is not in operation.

A disadvantage of this solution is that components involved in this conduction of air (e.g. filters, fans, duct components, housing parts, etc.) are subject to being operated continuously, which leads to increased wear, soiling and to an increased need for maintenance.

The same analogously applies to each compartment of a rail vehicle if a hazardous gas concentration could occur therein—for example due to the drive system, as described at the beginning.

It is therefore the object of the present invention to specify an improved arrangement for ventilating a compartment in a rail vehicle in order, with little outlay, to reduce a possibly dangerous or hazardous gas concentration in said compartment.

This object is achieved by the features of claim. Advantageous developments are specified in the dependent claims.

The invention relates to an arrangement for ventilating a compartment in a rail vehicle, the rail vehicle additionally having a passenger accommodation area.

In particular, the passenger accommodation area is considered to be a driver's cab of the rail vehicle.

The compartment to be ventilated contains a component which releases a gas concentration in said compartment in the event of a leak.

The passenger accommodation area is connected to the surroundings of the rail vehicle via a ventilation system such that fresh air passes from the surroundings into the passenger accommodation area, is mixed there with circulating air present in the passenger accommodation area and is subsequently distributed as supply air in the passenger accommodation area.

The passenger accommodation area is connected to the compartment via an air duct. The air duct is designed in such a way that a portion of the supply air is removed from the passenger accommodation area as outgoing air and conducted in a unidirectional direction into the compartment in order to reduce the gas concentration there or in order to ensure a specified (possibly minimal) gas concentration in said compartment.

“Unidirectional” is understood here as meaning that the outgoing air is conducted only in one direction, namely from the passenger accommodation area into the compartment.

This is preferably realized using a nonreturn valve which is, for example, an integrated constituent part of the air duct.

By way of example, the component arranged in the compartment is

In a preferred development, the refrigeration machine carries out cooling using a cold vapor process.

In a preferred development, the refrigeration machine has, as annularly interconnected components, a compressor, an evaporator, a tension relief valve, a liquefier and the refrigerant, the refrigerant flowing through the components in different states of aggregation via a duct system.

In a preferred development, the liquefier of the refrigeration machine forms the component arranged in the compartment.

In a preferred development, further components of the refrigeration machine (the compressor and/or the tension relief valve) are likewise arranged in the compartment.

In a preferred development, the evaporator is likewise arranged in the compartment.

In a preferred development, the evaporator is coupled to the passenger accommodation area—i.e. the evaporator is at least partially arranged in the passenger accommodation area or the evaporator is arranged externally to the passenger accommodation area but is connected to the passenger accommodation area via an intermediate circuit.

In each case, heat is extracted from the circulating air, which is mixed with fresh air, and therefore from the passenger accommodation area and supplied to the refrigeration machine refrigerant which evaporates because of the supply of heat.

In a preferred development, the annularly interconnected components of the refrigeration machine are configured in such a way:

In a preferred development, the compartment is structurally and/or spatially separated from the passenger accommodation area.

In a preferred development, the compartment is arranged in the front region of the rail vehicle.

In a preferred development, the compartment is connected to the surroundings of the rail vehicle via a ventilation system so that the compartment is ventilated.

In a preferred development, the ventilation system of the compartment is designed in such a way that intake air originating from the surroundings is conducted via the component of the compartment.

In a preferred development, the outgoing air passes either on its own or together with the intake air as exhaust air into the surroundings of the rail vehicle.

In a preferred development, the supply of the outgoing air into the compartment is designed as a continuous supply such that, when a ventilation system of the compartment is inactive, the reduction in the gas concentration in the compartment or the maintaining of the specified gas concentration in said compartment is ensured via the outgoing air.

In a preferred development, the ventilation system of the compartment is designed in such a manner that the intake air originating from the surroundings is conducted via the liquefier for heat transfer purposes such that heat from the coolant is transferred via the liquefier to the intake air.

The present invention achieves minimal ventilation of a compartment in a rail vehicle with simple means and with little outlay. This minimal ventilation is sufficient to reduce a critical gas concentration which may be present or arises in said compartment to a negligible extent.