Condition-based frost removal for a rail vehicle

Abstract

The invention relates to a method for emptying a liquid container for a rail vehicle from freezing and to a rail vehicle equipped for carrying out the method, wherein the method comprises the following process steps: - Recording and storing measured values ​​of the temperature of a liquid in at least one liquid container at predetermined time intervals over a predetermined period; a. Determining a future temperature profile of the liquid in at least one liquid container, at least on the basis of the stored measured values ​​of the temperature of the liquid in at least one liquid container; b. Determining a time point in time when a predetermined limit temperature of the liquid in at least one liquid container is reached, based on the determined future temperature profile of the liquid in at least one liquid container; c. Emptying the liquid from the at least one liquid container if the determined time of reaching the specified limit temperature is before a specified upgrade time.

Description

[0001] The invention relates to a method for emptying a liquid container for a rail vehicle from freezing and to a rail vehicle equipped for carrying out the method.

[0002] Passenger rail vehicles typically include freshwater tanks to supply toilets or galleys with drinking water. If the vehicle is stationary for an extended period in cold weather, there is a risk that the drinking water in the freshwater tanks will freeze. This can damage the freshwater tanks themselves, as well as other systems of the rail vehicle, such as water pipes or valves. Furthermore, the vehicle cannot be used because the freshwater system is inoperable and must first be heated.

[0003] This danger generally does not exist during operation of the vehicle, as the tanks are usually located in the heated interior, typically in the area of ​​the ceiling above the sanitary compartment or the galley.

[0004] Accordingly, when rail vehicles are parked for extended periods without a power supply at sub-zero temperatures, the fresh water tanks and, if applicable, the wastewater tanks, which are susceptible to freezing, are completely emptied. However, the fresh water must then be refilled before the vehicle can be put back into passenger service. This draining is usually carried out by personnel when sufficiently low temperatures are expected to cause freezing. Refilling the tanks is also time-consuming and requires significant manpower.

[0005] Alternatively, the water in the tanks is kept constantly above a predetermined temperature, primarily by means of interior or tank heaters, to prevent freezing. However, this requires an energy supply, especially an external one for overhead line vehicles, which is difficult to implement when the vehicles are dismantled. Another option is to store the rail vehicles in heated depots. Both of these methods involve high energy consumption.

[0006] A generic tank draining device for a fresh water tank of a rail vehicle is disclosed in WO 2014 / 056 768 A1. A thermal switch is connected to the fresh water supply, and when a predetermined temperature limit is reached, for example 2°C, a frost drain valve on a frost drain line opens, thereby emptying the fresh water tank. This eliminates the need for personnel to drain the tank. However, personnel are required for refilling. Furthermore, the temperature at which the water is drained must be sufficiently above freezing to reliably prevent freezing.

[0007] The patent application DE 10 2008 032 651 A1 concerns a rail vehicle with a wastewater tank that can be emptied from the vehicle side.

[0008] The invention is based on the objective of proposing an improved method for frost drainage that saves energy and time and requires less personnel.

[0009] The problem is solved by the subject matter of independent patent claims 1 and 8. Further developments and embodiments of the invention are found in the features of the dependent patent claims.

[0010] A method according to the invention for emptying a liquid container for a rail vehicle, in particular a dismantled one, comprises the following process steps: - Recording and storing measured values ​​of the temperature of a liquid in at least one liquid container at predetermined time intervals over a predetermined period; a. Determining a future temperature profile of the liquid, at least in at least one liquid container, at least on the basis of the stored measured values ​​of the temperature of the liquid in at least one liquid container; b. Determining a time point in time at which a predetermined limit temperature of at least the liquid in at least one liquid container is reached, based on the determined future temperature profile of the liquid in at least one liquid container; c. Emptying the liquid from at least one liquid container, if at least the determined time of reaching the specified limit temperature is before a specified upgrade time.

[0011] Temperature measurements of the liquid in at least one liquid container are recorded at predetermined time intervals from each other, at least over a predetermined period of time, in particular by means of a suitably designed temperature sensor arranged in or on the at least one liquid container.

[0012] The recorded measurements are stored for further processing, in particular by a suitably designed control unit, for example in a memory of the control unit. The control unit is at least configured to determine a future temperature profile of the liquid in the at least one liquid container, at least initially based on the stored temperature measurements of the liquid in the at least one liquid container. From the temperature measurements of the liquid in the at least one liquid container, recorded and stored over the specified period, the future temperature profile of the liquid in the at least one liquid container is first determined, in particular by means of the control unit. This is done, for example, by means of a regression analysis. Since this is a future temperature profile, it could also be described as a forecast based on known parameters.

[0013] Advantageously, the control unit is further equipped to determine the future point in time at which a predetermined limit temperature of the liquid in at least one liquid container will be reached, based on the determined future temperature profile of the liquid in the liquid container.

[0014] The specified limit temperature of the liquid in at least one liquid container can be significantly lower than a switching temperature for a prior art thermal switch and represent a very high probability of the liquid in at least one liquid container freezing. For example, the limit temperature is set to 0°C.

[0015] By comparing the determined time of reaching the specified limit temperature with a specified start-up time for the rail vehicle, the control unit determines, in particular, whether the liquid must be emptied from the at least one liquid container in order to avoid critical icing.

[0016] Furthermore, the control unit is designed to control the emptying of the at least one liquid container, in particular to control at least one frost-free emptying device for the at least one liquid container, if the determined time of reaching the specified limit temperature is before a specified start-up time for the rail vehicle. Additional criteria for emptying the liquid from the at least one liquid container, in particular by the at least one control unit, could be used (see below).

[0017] The specified setup time for the rail vehicle can be derived from a service plan for the rail vehicle and / or from a timetable for the rail vehicle. It can be entered manually during a dismantling process, particularly in the control unit.

[0018] Furthermore, the control unit can be configured to record or determine the predetermined restart time of the dismantled rail vehicle. For example, the control unit is configured to read a timetable for the rail vehicle and to derive a restart time for the rail vehicle from the read timetable.

[0019] A rail vehicle according to the invention, in particular a passenger rail vehicle, is equipped to carry out the method according to the invention. For this purpose, it comprises the aforementioned means suitable for carrying out the respective method step: at least one liquid container, at least one temperature sensor for detecting the temperature of the liquid in the at least one liquid container, at least one frost drainage device for the at least one liquid container, and at least one control unit.

[0020] The at least one liquid container is in particular a drinking water tank in the rail vehicle, for supplying sanitary facilities or a galley with drinking water. It could equally well be a grey water or wastewater tank.

[0021] The at least one frost draining device for the at least one liquid container comprises in particular a frost draining line connected to the at least one liquid container and a shut-off device, in particular a controllable valve, in the frost draining line, in particular at the inlet or outlet of the frost draining line.

[0022] The at least one temperature sensor for detecting the temperature of the liquid in the at least one liquid container is arranged in or on the at least one liquid container and is configured to detect several measured values ​​of the temperature of the liquid in the at least one liquid container, in particular at predetermined time intervals.

[0023] The at least one temperature sensor for detecting the temperature of the liquid in the at least one liquid container is connected to the at least one control unit, for example via a data bus, by means of a signal. The at least one control unit is configured to receive and store the measured values ​​of the liquid temperature in the at least one liquid container, as detected by the at least one temperature sensor, over a predetermined period of time.

[0024] Furthermore, the at least one control unit is connected to the at least one frost draining device, in particular to the at least one shut-off device of the at least one frost draining device, via a signal connection, for example via a data bus connection, and is designed to control and / or regulate the at least one frost draining device, i.e. in particular to control the opening and closing of the shut-off device, and thus to control the emptying of the liquid from the at least one liquid container by the at least one frost draining device.

[0025] Furthermore, at least one control unit, as already explained above, is set up for: - Receiving and storing the measured values ​​of the temperature of the liquid in the at least one liquid container, as recorded by at least one temperature sensor, over a specified period of time; - Determining a future temperature profile of the liquid in at least one liquid container, at least based on the stored measured values ​​of the temperature of the liquid in at least one liquid container; - Determining the point in time at which a predetermined limit temperature of the liquid in at least one liquid container is reached, based on the determined future temperature profile of the liquid in at least one liquid container; - Determine whether the determined time of reaching the specified limit temperature is before a specified upgrade time; - Controlling the emptying of the liquid from the at least one liquid container by the at least one frost draining device, if the determined time of reaching the specified limit temperature is before a specified upgrade time.

[0026] The control unit can be a central train control device or it can be designed as a commercially available computer on which a computer program product according to the invention is installed and executable in order to carry out at least the aforementioned process steps.

[0027] A computer program product according to the invention comprises commands which, when the computer program product is executed by a suitable terminal device, in particular the control unit, cause it to execute the method according to the invention.

[0028] A provisioning device according to the invention for the computer program product according to the invention stores the computer program product and / or makes it available. The provisioning device is, in particular, a data carrier on which the computer program product according to the invention is stored.

[0029] During the execution of the method, the rail vehicle is typically in a dismantled state. However, it could still be equipped, and the method is executed during the dismantling process. Advantageously, even in the dismantled state, the rail vehicle has sufficient energy available to operate at least one temperature sensor for measuring the temperature of the liquid in the liquid reservoir, as well as to operate at least one control unit, for example, provided by an on-board battery.

[0030] In addition to the measured temperatures of the liquid in at least one liquid container, other parameters can be taken into account when determining the future temperature profile of the liquid in at least one liquid container.

[0031] According to a first embodiment of the invention, the future temperature profile of the liquid in the liquid container according to process step a. can be determined as a further dependence on a future temperature profile of an ambient and / or outside temperature.

[0032] The ambient temperature of the at least one liquid container is the temperature of the air or other medium in which the at least one liquid container is intended to be used and thus located, for example, the temperature in an interior or intermediate space of the rail vehicle, such as under a ceiling and above a ceiling of a sanitary compartment of the rail vehicle, in which intermediate space the at least one liquid container is located. An outside temperature, on the other hand, refers to the temperature of the air in which the dismantled rail vehicle is located. It can be measured in the immediate vicinity of the rail vehicle or taken from a weather forecast for the vehicle's location when parked outdoors.Accordingly, the future temperature profile of an ambient and / or outside temperature can be determined or specified, in particular based on recorded and stored measured values ​​of the ambient and / or outside temperature, for example by land-based meteorological systems or by a model for predicting the temperature profile in a depot, provided the vehicle is parked in a depot.

[0033] Ambient and / or outside temperature are independent of the temperature of the liquid in the at least one liquid container. If the ambient and / or outside temperature rises or falls, this also affects the temperature of the liquid in the at least one liquid container. Conversely, an increase or decrease in the temperature of the liquid in the at least one liquid container has only a negligible effect on the ambient and / or outside temperature and is therefore considered to have no effect and can be disregarded.

[0034] The system is further developed by means of at least one temperature sensor for detecting the outside temperature of the rail vehicle. The rail vehicle can accordingly include at least one ambient temperature sensor for detecting the ambient temperature of the at least one liquid container and / or at least one outside temperature sensor for detecting the outside temperature of the rail vehicle, wherein the at least one ambient and / or outside temperature sensor is connected to the at least one control unit via a signaling system, and wherein the control unit itself can be configured to - Receiving and storing the ambient and / or outdoor temperature measurements recorded by at least one ambient and / or outdoor temperature sensor over a specified period of time; - Determining a future temperature profile of the ambient and / or outdoor temperature, at least based on the stored measured values ​​of the ambient and / or outdoor temperature; - Determining the future point in time at which a predetermined limit temperature of the liquid in at least one liquid container will be reached, depending on the determined future temperature profile of the liquid in the liquid container and depending on the future temperature profile of an ambient and / or outside temperature.

[0035] The prediction of the further temperature profile can be carried out analogously to determining the future temperature profile of the liquid in at least one liquid container, for example by means of a regression analysis.

[0036] The outside temperature sensor is, for example, located on the exterior of the rail vehicle, particularly on its outer skin. Alternatively, a stationary, land-based weather station in the vicinity of the rail vehicle can also incorporate the at least one outside temperature sensor. A signal connection to the at least one control unit is then advantageously wireless, for example via a radio link.

[0037] If the rail vehicle is parked in a depot, the at least one outdoor temperature sensor records measurements of the temperature inside the depot. If, however, the rail vehicle is on a track, particularly a siding, in an open-air position, the at least one outdoor temperature sensor records measurements of the open-air temperature.

[0038] The control unit can additionally or alternatively serve to receive and evaluate the future temperature profile of an ambient and / or outdoor temperature or other external data or parameters, and can be configured accordingly. For example, it is configured to receive and evaluate a weather forecast from meteorological systems and to derive the future temperature profile of an outdoor temperature from it.

[0039] The future temperature profile of the liquid in the at least one liquid container can be determined based on the recorded and stored measured values ​​of the liquid temperature in the at least one liquid container and based on the future temperature profile of the ambient and / or outside temperature by correlating a preliminary future temperature profile of the liquid temperature in the at least one liquid container with a future temperature profile of the ambient and / or outside temperature, wherein the preliminary future temperature profile of the liquid temperature in the at least one liquid container is determined independently of the future temperature profile of the ambient and / or outside temperature.Similarly, the measured values ​​for the temperature of the liquid in at least one liquid container and for the ambient and / or outside temperature, recorded at the same times within a given time interval, could be correlated with each other.

[0040] According to a further embodiment, the fill level of the liquid in at least one liquid container is detected, in particular by means of at least one suitably designed level sensor arranged in or on the at least one liquid container. This sensor can in turn be connected via signal technology to the at least one control unit, which is then configured to store the detected measured values ​​of the liquid level in the at least one liquid container for a predetermined period and / or to further process the detected measured values ​​of the liquid level in the at least one liquid container.

[0041] Further training stipulates that the following precedes procedural step c.: - Determining the amount of energy available to heat the liquid in at least one liquid container; where process step a. is followed by process step c.: - Determining the necessary amount of energy to heat the liquid in the at least one liquid container in order to keep the temperature of the liquid in the at least one liquid container always above the specified limit value until the specified setup time for the rail vehicle, in particular depending on the detected fill level of the liquid in the at least one liquid container and the future temperature profile of the liquid in the at least one liquid container determined according to process step a. - Heating the liquid in at least one liquid container to maintain the temperature of the liquid in at least one liquid container above the specified limit until the specified time of setup, - if the time of reaching the specified limit temperature determined according to procedure step b. is before the specified setup time for the rail vehicle and - if the determined available energy quantity is greater than or equal to the determined required energy quantity; wherein the emptying of the liquid from the at least one liquid container is carried out in accordance with process step c. - if the time of reaching the specified limit temperature determined according to procedure step b. is before a specified upgrade time and - if the determined available energy quantity is less than the determined necessary energy quantity.

[0042] Accordingly, a heater can be provided to warm the liquid in at least one liquid container, and this heater can be arranged in or on the at least one liquid container. The amount of energy required to warm the liquid in the at least one liquid container could also be described as the minimum amount of heat to be supplied in order to maintain the temperature of the liquid in the at least one liquid container above the specified limit until the specified time for the rail vehicle's setup. Warming is achieved in particular by supplying thermal energy, colloquially also referred to as heating. The amount of energy required to warm the liquid in the at least one liquid container can be determined as a function of the temperature or temperature profile of the liquid in the at least one liquid container and, furthermore, as a function of the liquid level in the at least one liquid container.Furthermore, additional parameters such as the heat capacity of the liquid in at least one liquid container can be specified and / or assumed.

[0043] Whether the at least one liquid container is emptied depends not only on whether the determined time of reaching the specified limit temperature is before a specified start-up time, but also, according to this design, on whether the available energy, possibly including a corresponding reserve, is sufficient to heat the liquid in the at least one container to maintain its temperature above the specified limit until the specified start-up time of the rail vehicle. Only if both criteria are met is the at least one liquid container emptied. An insufficient amount of available energy for heating could, for example, be due to an inadequate charge level in the vehicle's battery. If the required amount of energy is available, the liquid is heated accordingly.However, if the determined time of reaching the specified limit temperature is after the specified upgrade time, further measures are obsolete, as there is no risk of critical icing.

[0044] Other parameters, such as the temperature of the liquid at critical points, such as pipelines, can also be taken into account.According to a further development, additional temperature measurements of the liquid in at least one or more pipelines of the rail vehicle are recorded at predetermined time intervals and stored for at least a predetermined period, and a point in time at which a predetermined limit temperature of the liquid in the at least one pipeline is reached can be determined based on the determined future temperature profile of the liquid in the at least one pipeline, wherein the emptying of the liquid from the at least one liquid container and / or from the at least one pipeline takes place depending on the further temperature measurements of the liquid in the at least one pipeline and / or depending on a determined temperature profile of the liquid in the at least one pipeline.The future temperature profile of the liquid in the at least one pipeline can also be determined based on the future temperature profile of the ambient and / or outside temperature. The control unit is connected via signal technology to corresponding additional temperature sensors in the pipeline(s) and receives and evaluates their signals accordingly, i.e., to determine a temperature profile for one or more temperature sensors and take this into account when assessing the drainage process. The pipelines are connected to the at least one liquid container, and in particular to the at least one drainage device.

[0045] A heating element can also be provided to warm the liquid in the at least one pipeline, arranged in or on the at least one pipeline, for example in the form of pipe tracing. Similarly, the necessary amount of energy for warming the liquid in the at least one pipeline can be determined in order to maintain the temperature of the liquid in the at least one pipeline above the specified limit until the specified time for the rail vehicle's setup, and the liquid in the at least one pipeline can be warmed to maintain the temperature of the liquid in the at least one liquid container above the specified limit until the specified time for setup.If the determined time of reaching the specified limit temperature is before the specified start-up time for the rail vehicle, and if the determined available energy quantity is greater than or equal to the determined required energy quantity, or if the liquid in the at least one pipeline is emptied, if the determined time of reaching the specified limit temperature is before a specified start-up time, and if the determined available energy quantity is less than the determined required energy quantity, the liquid level in the at least one pipeline can be assumed or also measured using suitable sensors to determine the required energy quantity for heating the liquid in the at least one pipeline so that its temperature is always kept above the specified limit value.

[0046] A further improvement involves limiting the amount of energy required to heat the liquid in at least one liquid container and / or in at least one pipeline. A maximum value could be specified for the amount of energy needed to heat the liquid in at least one liquid container in order to maintain the liquid temperature above the specified limit until the designated time for the rail vehicle's setup. If the calculated required amount of energy exceeds the specified maximum value, the liquid is still drained. This prevents high energy consumption in vehicles that are parked for extended periods, even if they have an "infinite" amount of energy available, for example, because they are connected to an external power supply.

[0047] According to a further development, generating and outputting a message about the successful emptying of at least the liquid from at least one liquid container follows process step c.

[0048] In particular, a message about the emptying of the liquid from the at least one liquid container and / or from the at least one pipeline is generated by the control unit and transmitted to a land-based, for example central, service control center for planning a filling of the at least one liquid container, where it can be processed accordingly.

[0049] The invention allows for numerous embodiments and offers many advantages. For example, the likelihood of needing to drain fluid is significantly reduced. Fluid is only drained when freezing is certain. Besides saving fresh water and potentially preventing environmental contamination from drained grey or wastewater, this has the advantage that the vehicle can be put into operation immediately without having to refill the drained fresh water. This considerably simplifies operations. Likewise, the energy required to heat the fluid – if technically feasible – is reduced, as heating only occurs when absolutely necessary. Therefore, the invention contributes to the economical operation of the vehicle by helping to save personnel, time, water, energy, and thus costs.

[0050] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

Claims

[1] Method for frost-free emptying of a liquid container for a rail vehicle, wherein several measured values ​​of a temperature of a liquid in the liquid container are recorded at predetermined time intervals from one another and stored for at least a predetermined period of time, characterized by following procedural steps: a. Determining a future temperature profile of the liquid in at least one liquid container at least on the basis of the stored measured values ​​of the temperature of the liquid in at least one liquid container; b. Determining a time at which a predetermined limit temperature of at least the liquid in the at least one liquid container is reached based on the determined future temperature profile of the liquid in at least one liquid container; c. Emptying the liquid from at least one liquid container if at least the determined time at which the predetermined limit temperature is reached is before a predetermined upgrade time for the rail vehicle. [2] Method according to claim 1, characterized by that according to method step a. the future temperature profile of at least the liquid in the liquid container is determined in further dependence on a future temperature profile of an ambient and / or outside temperature. [3] Method according to claim 2, characterized by that the future temperature profile of the ambient and / or outside temperature is determined on the basis of recorded and stored measured values ​​of the ambient and / or outside temperature or is specified by onshore meteorological systems. [4] Method according to one of claims 1 to 3, characterized bythat a fill level of the liquid in at least one liquid container is detected. [5] Method according to one of claims 1 to 4, characterized by that precedes step c.: - determining an available amount of energy for heating the liquid in at least one liquid container; - determining a necessary amount of energy for heating the liquid in the at least one liquid container in order to keep a temperature of the liquid in the at least one liquid container always above the predetermined limit value until the predetermined upgrading time for the rail vehicle; - heating the liquid in the at least one liquid container in order to keep a temperature of the liquid in the at least one liquid container always above the predetermined limit value until the predetermined time of upgrading, if the time at which the predetermined limit temperature is reached, as determined according to method step b., is before the predetermined upgrading time for the rail vehicle and if the determined available energy quantity is greater than or equal to the determined necessary energy quantity; wherein the emptying of the liquid from the at least one liquid container takes place if the time at which the predetermined limit temperature is reached, as determined according to method step b., is before a predetermined upgrading time and if the determined available energy quantity is less than the determined necessary energy quantity. [6] Method according to one of claims 1 to 5, characterized bythat further measured values ​​of a temperature of the liquid in at least one pipeline are recorded, wherein the emptying of the liquid from the at least one liquid container takes place in further dependence on the further measured values ​​of the temperature of the liquid in the at least one pipeline and / or in further dependence on a determined temperature profile of the temperature of the liquid in the at least one pipeline. [7] Method according to one of claims 1 to 6, characterized by that follows process step c.: - Generating and outputting a message about the successful emptying of at least the liquid from the at least one liquid container. [8] Rail vehicle comprising at least one liquid container, at least one frost-removal device for the at least one liquid container, at least one temperature sensor in the at least one liquid container, at least one control unit which is signal-connected to the at least one temperature sensor in the at least one liquid container and to the at least one frost-removal device, wherein the at least one temperature sensor is configured to record measured values ​​of a temperature of a liquid in the at least one liquid container at predetermined time intervals from one another at least over a predetermined period of time, characterized by that at least one control unit is set up to: - receiving and storing the measured values ​​of the temperature of the liquid in the at least one liquid container detected by the at least one temperature sensor over a predetermined period of time; - Determining a future temperature profile of the liquid in the at least one liquid container at least based on the stored measured values ​​of the temperature of the liquid in the at least one liquid container; - Determining a time at which a predetermined limit temperature of the liquid in the at least one liquid container is reached based on the determined future temperature profile of the liquid in the at least one liquid container; - Controlling the at least one frost emptying device for emptying the liquid from the at least one liquid container if the determined time of reaching the predetermined limit temperature is before a predetermined set-up time. [9] Computer program product comprising instructions which, when the computer program product is executed by a suitable mobile terminal, cause the terminal to carry out the method according to one of claims 1 to 7. [10] Provision device for the computer program product according to claim 9, wherein the provision device stores and / or provides the computer program product.