ES2868001T3 - Transport vehicle with an air conditioning system using an absorption cooler - Google Patents

Abstract

Transport vehicle (2), in particular a railway vehicle for the transport of passengers, comprising: an air conditioning system (12) for conditioning the air inside the transport vehicle, said air conditioning system having a machine (32) absorption cooling to cool the air inside the transport vehicle; an internal combustion engine (4) for propelling the transport vehicle, said internal combustion engine being equipped with a fuel injection system (6); an exhaust line (8) connected to the internal combustion engine to discharge hot exhaust gases from the internal combustion engine; wherein the absorption refrigeration machine (32) is thermally connected to said exhaust line to utilize the heat of said hot exhaust gases for said cooling; and a heat measuring device (10) for measuring the amount of heat in the exhaust gases; characterized by an engine fuel post-injection controller (13) for controlling fuel post-injection in said engine (4), said engine fuel post-injection controller being adapted to: - receive a heat signal of said heat measuring device (10); - if the heat signal is below a predetermined threshold, which indicates that the heat of the exhaust gases is insufficient for the cooling needs of the absorption refrigeration machine (32), control said injection system (6) of fuel to post-inject an additional amount of fuel into the internal combustion engine (4), that is, at the end of a combustion phase, thus increasing the heat of the exhaust gases above said predetermined threshold.

Description

DESCRIPTION

Transport vehicle with an air conditioning system using an absorption cooler

The present invention relates to a transport vehicle, in particular a railway vehicle for the transport of passengers, comprising:

an air conditioning system for conditioning the air within the transportation vehicle, said air conditioning system having an absorption refrigeration machine for cooling the air within the transportation vehicle;

an internal combustion engine for propelling the transport vehicle, said internal combustion engine being equipped with a fuel injection system;

an exhaust line connected to the internal combustion engine to discharge hot exhaust gases from the internal combustion engine;

wherein the absorption refrigeration machine is thermally connected to said exhaust line to utilize the heat of said hot exhaust gases for said cooling; and

a heat measuring device to measure the amount of heat in the exhaust gases.

Such a transport vehicle is known from US 2006/0021332 A1. This document describes a motor vehicle having, as shown in Fig. 2, a diesel engine 1 equipped with an exhaust system 2. The exhaust system 2 is equipped with an exhaust heat exchanger 16, which makes it possible to extract heat from the hot exhaust gases. The extracted heat can be used in an absorption refrigeration machine 26. The absorption refrigeration machine 26 uses the extracted heat to generate cold, which is used to cool the interior 20 of the motor vehicle through an air conditioning heat exchanger 27.

When the exhaust gas of the diesel engine 1 does not contain enough heat for said cooling operation, a pre-oxidation unit 5 located in the exhaust line 3 of the exhaust system 2 is used to inject fuel into the exhaust line 3. This fuel is burned in exhaust line 3 so that there is enough heat available for the cooling operation.

In this way, cooling of the interior 20 of the vehicle with the absorption cooling machine 26 is possible even when the diesel engine 1 is idling or running with little load.

However, this known solution requires a complicated pre-oxidation unit 5 in the exhaust line 3. Another vehicle is known, for example, from US 1985636 A1.

Consequently, it is an object of the present invention to provide a transport vehicle with an internal combustion engine wherein the cooling of the interior of the vehicle through an absorption cooling machine using the heat of the engine's exhaust gases It is guaranteed in a simple way even when the engine is idling or running with little load.

According to the invention, this objective is achieved with the transport vehicle defined above, which is characterized by

an engine fuel post-injection controller for controlling fuel post-injection in said engine, said engine fuel post-injection controller being adapted to:

- receiving a heat signal from said heat measuring device;

- if the heat signal is below a predetermined threshold, which indicates that the heat of the exhaust gases is insufficient for the cooling needs of the absorption refrigeration machine, control said fuel injection system for post-injection an additional quantity of fuel in the internal combustion engine, that is, at the end of its combustion phase, thus increasing the heat of the exhaust gases above said predetermined threshold.

Thanks to the post-fuel injection of the invention in the internal combustion engine, the heat of the exhaust gases can be increased when it would otherwise be insufficient to cool the interior of the transport vehicle. By using the fuel injection system already present in the engine to keep the heat of the exhaust gases high enough, the additional fuel injection device in the exhaust line of US 2006/0021332 can be dispensed with, thus reducing the complexity and saving costs. According to preferred embodiments, the transport vehicle of the invention can include one, several or all of the following characteristics, in all technically feasible combinations:

- the engine fuel post-injection controller is adapted for:

- receiving a cooling mode signal from the air conditioning system indicating that it is in a cooling mode;

- if the heat signal is below a predetermined threshold, indicating that the heat from the exhaust gases is insufficient for the cooling needs of the absorption refrigeration machine, and if at the same time a mode signal is received cooling system from the air conditioning system, controlling said fuel injection system to post-inject the additional amount of fuel into the internal combustion engine, that is, at the end of its combustion phase, thus increasing the heat of the gases escape above said predetermined threshold;

- the engine fuel post-injection controller is adapted to control said fuel injection system to perform two subsequent post-injections;

- the engine fuel post-injection controller is adapted to control said fuel injection system to start the post-injection of the first fuel post-injection at the end of a first time interval that is defined by an angle of sweep of the crankshaft of the internal combustion engine between 1 ° and 5 °;

- the time interval between said two subsequent post-injections is a period in which the angle of the crankshaft of the internal combustion engine covers an angle comprised between 90 ° and 180 °;

- the heat measuring device is a temperature sensor located in the exhaust line;

- the default threshold is 252 ° C;

- the absorption refrigeration machine is installed on the roof or under the body of the transport vehicle;

- the internal combustion engine is a diesel engine; and

- the transport vehicle is a rail vehicle in the form of a diesel multiple unit for regional passenger transport.

Illustrative embodiments of the invention will now be described in detail with reference to the drawings, in which:

Figure 1 is a schematic drawing of a transport vehicle according to the invention; and

Figure 2 is a diagram of the fuel injections injected into the internal combustion engine of the transport vehicle according to the invention.

Referring to Figure 1, a schematic diagram of a transport vehicle 2 is shown. The transport vehicle comprises an internal combustion engine 4, a fuel injection system 6, an exhaust line 8 connected to the internal combustion engine, a heat measurement device 10 arranged in the exhaust line 8, a system 12 air conditioning and a post-injection controller 13. Whenever the term "downstream" or "upstream" is used in this description, it refers to a flow direction of a gas stream. "Downstream" defines a direction that is the same as the flow direction of the gas stream. "Upstream" defines a direction opposite to the flow direction of the gas stream.

The transport vehicle 2 is preferably a rail vehicle in the form of a diesel multiple unit for regional passenger transport. Alternatively, the transport vehicle is a bus or truck.

The internal combustion engine 4 is preferably a diesel engine adapted to propel the transport vehicle 2. The diesel engine is equipped with a fuel injection system 6 to inject fuel in a controllable manner into the diesel engine. The diesel engine 4 has one or more combustion chambers 14 to burn the fuel injected during a combustion phase shown in figure 2. Although the diagram in figure 2 shows the time in [ms] on the abscissa axis, it is Of course, for a given speed of revolution, the abscissa axis also corresponds to the sweep angle of the crankshaft of the combustion engine 4. The crankshaft angle and time therefore correspond to each other for a given speed of revolution.

The diesel engine 4 has an exhaust manifold 16 for expelling burnt fuel, or hot exhaust gases, from the combustion chambers 14. The fuel injection system 6 is equipped with fuel injectors (not shown), for example piezoelectric elements (not shown) adapted to oscillate in order to inject fuel into the combustion chambers 14 of the diesel engine 4.

The fuel injectors are adapted to bend about a distance D in order to inject fuel into the combustion chambers 14. The amount of fuel injected into the combustion chambers 14 depends on the distance D and the opening time. The greater the distance D and the opening time, the greater the amount of fuel injected into the combustion chambers 14 (see figure 2).

The fuel injection system 6 is configured to inject zero, one or more fuel pre-injections PI, a main fuel injection MI and at least one first fuel post-injection LI1 into the combustion chambers 14.

PI pre-injection makes it possible to reduce the ignition delay of the main combustion within the combustion chambers 14. This translates into lower noise emissions. The actual number of PI pre-injections used depends on the operation of the engine. The main injection MI is adapted to provide sufficient energy to the diesel engine 4 in order to propel the transport vehicle 2. There are two types of post-injections that are commonly used. On the one hand, there are one or more first LI1 post-injections, which take place immediately after the main injection. They are mainly used to oxidize the soot particles from the main combustion process. In addition, this type of post-injection influences the formation of nitrogen oxide and the temperature of the exhaust gases. The number and type of the first LI1 post-injections depend on the operation of the engine. Operation without LI1 is also performed. On the other hand, a subsequent LI2 post-injection may occur. This introduces unburned hydrocarbons into the exhaust tract, which is not burned in the combustion chamber 14, but in a catalytic converter 18 disposed downstream of the exhaust manifold 16 to raise the temperature of the exhaust gases very much. effective. This allows the particle filter to be cleaned. The number and type of subsequent LI2 post-injections depends on the operation of the engine, even operation without LI2 is temporarily possible, for example when the particulate filter is discharged.

The exhaust line 8 is connected to the combustion chambers 14 through the exhaust manifold 16 of the diesel engine 4.

The exhaust line 8 is adapted to discharge the hot exhaust gases from the diesel engine 4 through an exhaust 15. The exhaust line 8 is also adapted to clean the hot exhaust gases and expel them from the transport vehicle 2. The exhaust line 8 is also adapted to extract heat from the hot exhaust gases. The exhaust line 8 may comprise the catalytic converter 18 arranged downstream of the exhaust manifold 16. The catalytic converter 18 is adapted to transform imperfect combustion products (such as hydrocarbons and carbon monoxide) into non-toxic compounds.

The exhaust line 8 may comprise a particulate filter 20 arranged downstream of the catalytic converter 18, adapted to clean hot exhaust gases. The particulate filter 20 could be integrated into the catalytic converter 18 to save available space. The exhaust line 8 may comprise a urea injector 22 arranged downstream of the catalytic converter 18, adapted to inject urea into the exhaust line 8. The urea injector 22 allows urea to be dosed into the exhaust gas. Urea turns into ammonia. Ammonia is used to reduce nitrogen oxides in a selective catalytic reducer 24 disposed downstream of the urea injector 22.

Exhaust line 8 may comprise selective catalytic reducer 24 arranged downstream of urea injector 22. The selective catalytic reducer 24 allows the nitrogen oxides in the exhaust to be deoxidized. Instead of a urea injector 22 and a selective catalytic redactor 24, a nitrogen oxide storage system can be used.

The exhaust line 8 comprises the heat measuring device 10 arranged in the exhaust line 8, for example arranged downstream of the selective catalytic reducer 24. The heat measurement device 10 may be in contact with the hot exhaust gases or the heat is calculated in the heat measurement device 10 based on available sensor data.

The heat measuring device 10 is adapted to determine the amount of heat in the hot exhaust gases.

The heat measuring device 10 is, for example, a temperature sensor adapted to measure the temperature and a flow meter adapted to measure the flow rate of the hot exhaust gases. Alternatively, the heat measurement device 10 can be a computer model where the temperature and flow rate are calculated based on available sensor data. The exhaust line 8 comprises a first heat exchanger 26 arranged downstream with respect to the heat measuring device 10. The first heat exchanger 26 is in contact with the hot exhaust gases.

The first heat exchanger 26 has an inlet 28 that allows a heat transport medium to access the first heat exchanger 26, and an outlet 30 that allows the heat transport medium to exit the first heat exchanger 26.

The first heat exchanger 26 is adapted to bring the heat transport medium in indirect contact with the hot exhaust gases. The heat transport medium is, for example, a liquid, in particular water, ammonia, brine or a combination thereof.

The air conditioning system 12 comprises an absorption refrigeration machine 32 and a second heat exchanger 34. The air conditioning system 12 is adapted to condition air within the transport vehicle 2, for example, the air stream from a ventilation system of a passenger compartment. The air conditioning system 12 has at least one cooling mode in which the air conditioning system 12 cools the air inside the transport vehicle 2, and a non-cooling mode in which the air conditioning system 12 does not cool the air. air inside the transport vehicle 2. The air conditioning system 12 is electrically connected to the post-injection controller 13. The post injection controller 13 will be described later.

The air conditioning system 12 may output a cooling mode signal to the post injection controller 13 indicating a cooling mode or it may output a non-cooling mode signal indicating a non-cooling mode. The absorption cooling machine 32 is thermally connected to the exhaust line 8, in particular to the first heat exchanger 26 arranged in the exhaust line 8, and to the second heat exchanger 34 adapted to cool, for example, the air inside of the transport vehicle 2. The absorption refrigeration machine 32 is adapted to use the heat from the hot exhaust gases to cool the air within the transport vehicle 2.

In particular, the absorption cooling machine 32 is thermally connected to the inlet 28 and the outlet 30 of the first heat exchanger 26 to extract heat from the first heat exchanger 26.

The absorption refrigeration machine 32 is thermally connected to the second heat exchanger 34 to extract heat from the second heat exchanger 34.

The second heat exchanger 34 is adapted to receive an air stream from the ventilation system of a passenger compartment. The air stream is preferably a hot air stream that is cooled through the second heat exchanger 34. This cooled air stream is adapted to cool a passenger compartment of the transport vehicle 2.

The absorption cooling machine 32 is installed, for example, on the roof of the transport vehicle 2 or under the vehicle body. This makes it possible to reduce the space occupied within the transport vehicle 2. Post-injection controller 13 is electrically connected to heat measurement device 10 to receive a heat signal. The heat signal indicates the temperature of the hot exhaust gases.

Advantageously, the post-injection controller 13 is electrically connected to the air conditioning system 12 to receive the cooling mode signal indicating a cooling mode of the air conditioning system 12.

The post-injection controller 13 is adapted to control the fuel injection system 6 in order to inject fuel into the diesel engine 4.

The post-injection controller 13 is adapted to control a post-injection of fuel in the diesel engine 4.

The post-injection controller 13 is adapted to evaluate the heat signal and, advantageously, the cooling mode signal, to control the fuel injection system 6.

The post-injection controller 13 is adapted to initiate a post-injection through the fuel injection system 6 if the heat signal is less than a predetermined threshold and, advantageously, if the cooling mode signal indicates that the system 12 air conditioning is in a cooling mode.

The predetermined threshold indicates a minimum temperature of the hot exhaust gases to supply sufficient heat to the absorption cooling machine 32 through the first heat exchanger 26. The predetermined threshold is between 120 ° C and 280 ° C, in particular, the threshold is approximately 252 ° C.

The post-injection comprises at least a first post-injection LI1 of fuel at the end of the combustion phase of the diesel engine 4 (see figure 2).

The post-injection of the first fuel post-injection LI1 begins at the end of a first interval TI1 of time defined by a sweep angle of the crankshaft of the internal combustion engine 4 comprised between 1 ° and 5 ° of the crankshaft sweep angle at the end of MI main fuel injection. In other words, the engine fuel post-injection controller 13 is adapted to control said fuel injection system 6 to start the post-injection of the first fuel post-injection LI1 at the end of a first time interval TI1. which is defined by an angle of coverage or sweep of the crankshaft of the internal combustion engine 4 comprised between 1 ° and 5 °.

The operation of the air conditioning system and the post-injection controller 13 is described below.

Post-injection controller 13 receives a heat signal from heat measurement device 10.

Next, the post-injection controller 13 analyzes the received heat signal and compares the received heat signal with the predetermined threshold.

If the received heat signal is less than the predetermined threshold and, advantageously, if, at the same time, the post-injection controller 13 receives a cooling mode signal from the air conditioning system 12, the post-injection controller 13 post-inject the first post-injection LI1 into the diesel engine 4.

The first post-injection LI1 is performed for each combustion phase if the received heat signal is less than the predetermined threshold and, advantageously, if, at the same time, the post-injection controller 13 receives a cooling mode signal.

The first post-injection LI1 starts at the end of the first time interval TI1 after the end of the main MI injection. Thanks to the post-fuel injection of the invention, it is possible to use an absorption cooling machine to cool the interior of a railway vehicle. Until now, train air conditioning systems have always used cooling compressors to ensure cooling in all train operating states. However, these compressors consume electricity. By replacing the compressor with an absorption cooler, the residual heat from the diesel engine, which is generated in any case, is used for cooling. Therefore, it is no longer necessary to generate extra power for the air conditioner. The air conditioning solution of the invention thus reduces the energy consumption of the railway vehicle.

In an alternative embodiment, the post-injection may comprise two separate subsequent post-injections, wherein the first post-injection LI1 and a subsequent post-injection LI2 are temporally separated by a second time interval TI2.

The second time interval TI2 is between 90 ° and 180 ° crank angle. That is, the time interval TI2 between said two subsequent post-injections LI1 and LI2, or between the peaks of these post-injections, is a period in which the crankshaft angle of the internal combustion engine 4 covers or sweeps an angle between 90 ° and 180 °.

Two separate post-injection after-injections allow the exhaust gas temperature to be raised faster than with a single post-injection. In an alternative embodiment, the heat measurement device 10 is arranged in the heat exchanger 26.

It should be noted that the invention is not limited to the above embodiments. Rather, a person skilled in the art will understand that many changes and modifications can be made within the scope of the appended claims.

Claims (10)

1. Transport vehicle (2), in particular a railway vehicle for the transport of passengers, comprising: an air conditioning system (12) for conditioning the air inside the transport vehicle, said air conditioning system having a machine ( 32) absorption cooling to cool the air inside the transport vehicle; an internal combustion engine (4) for propelling the transport vehicle, said internal combustion engine being equipped with a fuel injection system (6); an exhaust line (8) connected to the internal combustion engine to discharge hot exhaust gases from the internal combustion engine; wherein the absorption cooling machine (32) is thermally connected to said exhaust line to utilize the heat from said hot exhaust gases for said cooling; and a heat measuring device (10) for measuring the amount of heat in the exhaust gases; characterized by an engine fuel post-injection controller (13) for controlling fuel post-injection in said engine (4), said engine fuel post-injection controller being adapted to: - receiving a heat signal from said heat measuring device (10); - if the heat signal is below a predetermined threshold, which indicates that the heat of the exhaust gases is insufficient for the cooling needs of the absorption refrigeration machine (32), control said injection system (6) of fuel to post-inject an additional quantity of fuel into the internal combustion engine (4), that is, at the end of a combustion phase, thus increasing the heat of the exhaust gases above said predetermined threshold. Transport vehicle according to claim 1, wherein the engine fuel post-injection controller (13) is adapted to: - receiving a cooling mode signal from the air conditioning system (12) indicating that it is in a cooling mode; - if the heat signal is below a predetermined threshold, which indicates that the heat of the exhaust gases is insufficient for the cooling needs of the absorption refrigeration machine (32), and if at the same time a cooling mode signal from the air conditioning system (12), controlling said fuel injection system (6) to post-inject the additional amount of fuel into the internal combustion engine (4), that is, at the end of its combustion phase, thus increasing the heat of the exhaust gases above said predetermined threshold. Transport vehicle according to claim 1 or 2, wherein the engine fuel post-injection controller (13) is adapted to control said fuel injection system (6) to perform two subsequent post-injections (LI1, LI2). Transport vehicle according to claim 3, wherein the engine fuel post-injection controller (13) is adapted to control said fuel injection system (6) to initiate the post-injection of the first post-injection (LI1) of fuel at the end of a first interval (TI1) of time that is defined by a sweep angle of the crankshaft of the internal combustion engine (4) comprised between 1 ° and 5 °. 5. Transport vehicle according to claim 3 or 4, wherein the time interval (TI2) between said two subsequent post-injections (LI1, LI2) is a period where the crankshaft angle of the internal combustion engine (4) covers an angle between 90 ° and 180 °. Transport vehicle according to any one of the preceding claims, wherein the heat measurement device (10) is a temperature sensor located in the exhaust line (8). Transport vehicle according to any one of the preceding claims, wherein the predetermined threshold is 252 ° C. Transport vehicle according to any one of the preceding claims, wherein the absorption cooling machine (32) is installed on the roof or under the body of the transport vehicle (2). Transport vehicle according to any one of the preceding claims, wherein the internal combustion engine (4) is a diesel engine. Transport vehicle according to any one of the preceding claims, wherein the transport vehicle (2) is a rail vehicle in the form of a diesel multiple unit for regional passenger transport.