Abstract:
The invention relates to a heating and air-conditioning system ( 10 ) for a motor vehicle, in particular a utility vehicle, in order to heat or cool the inside of a motor vehicle during a journey and when the motor vehicle is stationary. The inside of the motor vehicle is divided into a front region and a back region, which can be heated and cooled separately, and comprises a front system ( 12 ) which is used to heat and cool the front region during a journey of the motor vehicle, a rear system ( 14 ) which is used to heat and cool the rear region during a journey of the motor vehicle and a stationary system ( 16 ) which is used to heat and to cool at least the rear region when the motor vehicle is stationary. According to the invention, the stationary system is integrated into the rear system. The invention further relates to a method for heating and air-conditioning a motor vehicle by means of a heating and air-conditioning system ( 10 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a 35 U.S.C. §371 National Stage entry of PCT/EP2005/003973, filed Apr. 15, 2005, which claims priority from German Patent Application No. 102004019 607.9, filed Apr. 22, 2004, the contents of which are herein incorporated by reference to the extent allowed by law. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a heating and air-conditioning system for a motor vehicle, in particular a utility vehicle, in order to heat and cool the inside of a motor vehicle during a running-state and a stop-state of the motor vehicle, wherein the inside of the motor vehicle is divided into a front region and a rear region, which can be heated and cooled separately. The heating and air-conditioning system comprises a front system for heating and cooling the front region during the running-state of the motor vehicle, a rear system for heating and cooling the rear region during the running-state of the motor vehicle and a stop-state system which is used to heat and cool at least the rear region when the motor vehicle is in the stop-state. 
     The invention further relates to a method for heating and air-conditioning a motor vehicle. 
     Furthermore, the invention relates to a motor vehicle having a heating and air-conditioning system. 
     BRIEF SUMMARY OF THE INVENTION 
     In utility vehicles, in particular in trucks, specific requirements are made on heating and cooling, that is, generally speaking, air-conditioning the inside of the vehicle. The inside of the vehicle is generally divided into a front region and a rear region, wherein the front region includes driver and co-driver seats, which are occupied during the running-state of the vehicle, and wherein the rear region comprises a sleeper-cab which is used when the vehicle is in the stop-state. In order to provide the driver during rest, which he spends within the sleeper-cab, with a comfortable climate, it is helpful to be able to heat and cool the rear region as needed, when the vehicle is in the stop-state. 
     For this purpose, state of the art concepts propose to combine the front system with the rear system, and, in particular, to drive a common compressor of the air-conditioning system also when the vehicle is in the stop-state, in order to cool the rear region of the vehicle. Disadvantages of this concept are high fuel consumption, wear and tear of the engine when the vehicle is in the stop-state, and additional emissions such as pollutants and noise due to the operation of the engine. 
     These disadvantages had been confronted in part by allowing the operation of the front system and the rear system exclusively during the running-state of the vehicle and by providing an additional self-sufficient stop-state air-conditioning system. The stop-state system operates with, for example, an electrically or mechanically driveable compressor which is supplied with power by an auxiliary motor or an auxiliary battery. Even if this concept lowers fuel consumption, it causes decreased engine wear and results in fewer emissions, it has the drawback that due to the self-sufficient stop-state air-conditioning system extensive complexity is required. 
     Within the scope of the present disclosure, operating states of the motor vehicle are indicated by the terms “running-state” and “stop-state”. In this context, it should be borne in mind that “running-state” indicates operating states that do not necessarily require the vehicle to be in transit or motion. On the contrary, it is sufficient that the power supplying aggregate, that is generally the engine of the vehicle, is running. 
     The present invention provides a heating and air-conditioning system having a very rational arrangement. 
     This objective is solved with the features of the independent claims. 
     Advantageous implementation formats of the invention are defined in the dependent claims. 
     The invention is established beyond the generic heating and air-conditioning system in that the stop-state system is integrated into the rear system. Thus, the overall arrangement of the system is more rational since the stop-state system and the rear system may present common components. 
     In particular, it is intended that the stop-state system comprises a cooling heat exchanger and a cold accumulator, and in so doing that the cooling heat exchanger, a heating heat exchanger of the rear system, and an evaporator of the rear system are supplied with an air flow by the same blower. The cold accumulator of the stop-state system is charged by an evaporation process in the region of the cold accumulator during the running-state of the motor vehicle. The integration of the stop-state system into the rear system is realizable in this case by supplying a cooling heat exchanger which communicates with the cold accumulator with air from the same blower as the evaporator and the heating heat exchanger of the rear system. 
     With this solution, it is further especially beneficial that the cooling heat exchanger of the stop-state system and the cold accumulator of the stop-state system are arranged in a heat carrier circuit, through which a heat carrier is conveyed by a pump. The heat carrier medium can thus withdraw cold stored in the cold accumulator and transport the cool heat carrier medium to the cooling heat exchanger through power of an electrically driven pump. There, air coming from the blower acts upon the cool heat carrier medium, which is then enabled to flow into the rear region of the vehicle as cooled air. 
     Further, it is especially beneficial that an evaporator of the front system, an evaporator of the rear system, and a cold accumulator of the stop-state system communicate with the same condenser and that a compressor is provided for the entire heating and air-conditioning system. It is thus sufficient to provide a single condenser and a single compressor for operating the entire system. The cooling agent that is liquidized within the condenserican reach the evaporator of the front system, the evaporator of the rear system and the cold accumulator of the stop-state system in a valve controlled manner. From these components, the cooling agent is returned to the solitary compressor of the arrangement. 
     However, it is also possible that an evaporator of the front system and an evaporator of the rear system communicate with the same condenser and that the stop-state system comprises its own condenser and its own compressor. By doing so, the adaptive complexity compared to the implementation format having only a single compressor and only a single condenser is increased, but there is, however, a benefit in flexibility when integrating the stop-state air-conditioning system. By equipping the stop-state air-conditioning system with a separate condenser and a separate compressor, it is possible to fill the stop-state air-conditioning system separately with cooling agent and add it to the entire system. 
     Further, it can be set up such that an evaporator of the rear system and a cold accumulator of the stop-state system communicate with the same condenser and that the front system comprises its own condenser and its own compressor. By doing so, the front system is decoupled from the combined rear stop-state air-conditioning system. The load of the front system is thereby reduced, no long cooling agent conduits are necessary between the front region and the rear region, and the rear stop-state air-conditioning system can be integrated in a flexible manner without considering the front system. The compressor of the combined rear stop-state system can be driven mechanically or electrically. In the stop-state of the motor vehicle generally no operation of the compressor is required, since the cold accumulator provides the necessary cold for the stop-state air-conditioning. 
     However, it may be beneficial that the rear system and the stop-state system comprise a common compressor which is operable in the stop-state. In this implementation format a cold accumulator is dispensable. In the stop-state, the compressor is operable mechanically or electrically. The power required for this can, for example, is derived from a sufficiently charged auxiliary battery or a fuel cell. 
     The invention is, moreover, beneficially further developed in that the stop-state system comprises a cold accumulator and in that the stop-state system and the rear system comprise a common cooling heat exchanger which is communicating with the cold accumulator via a pump. By this means a separate evaporator for the running-state air-conditioning assigned to the rear system is dispensable. Rather than having air-conditioning of the rear region be conducted during the running-state by interposition of the cold accumulator. 
     Furthermore, it may be set up such that that the stop-state system and the rear system comprise a common accumulator-evaporator-heat-exchanger-unit. The cold accumulator thus serves for storing cold, as a heat exchanger supplied with air from the blower during the stop-state and as a heat exchanger supplied with air from the blower during the running-state. 
     The invention further concerns a method for heating and air-conditioning of a motor vehicle with the heating and air-conditioning system according to the present invention, and a motor vehicle with the heating and air-conditioning system according to the present invention. By this means, the advantages and special features of the heating and air-conditioning system according to the present invention are also implemented within the scope of a method and a motor vehicle. 
     The invention is based on the conclusion that, due to integration of the stop-state system into the rear system, additional possibilities for rationalization with regard to the overall system can be accomplished. Furthermore, this integration provides the prerequisite for lowering energy consumption and emissions as well as for reducing wear and tear of the components that are involved in comparison with systems with the present state of technology. 
    
    
     
       The invention is now to be explained in an exemplary fashion by referring to the accompanying drawings of specifically selected implementation formats. In so doing, there are shown: 
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  a schematic diagram of a first implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 2  an explanatory illustration of possible geometric arrangements of components of a heating and air-conditioning system according to the present invention; 
         FIG. 3  a schematic diagram of a second implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 4  a schematic diagram of a third implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 5  a schematic diagram of a fourth implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 6  a schematic diagram of a fifth implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 7  a schematic diagram of a sixth implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 8  a schematic diagram of a seventh implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 9  a schematic diagram of an eight implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 10  a schematic diagram of a ninth implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 11  a schematic diagram of a tenth implementation format of a heating and air-conditioning system according to the present invention; 
         FIG. 12  is a schematic diagram of an eleventh implementation format of a heating and air-conditioning system according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description of the preferred implementation format of the present invention, identical reference numerals (modulo  100 ) identify identical or similar components. It will be understood that those components in  FIGS. 3-12  that are similar to components described in  FIG. 1  are numbered the same except for the Figure number placed in front of the reference number. Thus, for example, common condenser  334  in  FIGS. 3 and 434  in  FIG. 4  both refer to a condenser similar and analogous to common condenser  34  in  FIG. 1 . 
       FIG. 1  shows a schematic diagram of a first implementation format of a heating and air-conditioning system according to the present invention.  FIG. 2  shows two explanatory illustrations of possible geometric arrangements of components of the heating and air-conditioning system according to the present invention. The heating and air-conditioning system  10  comprises a front system  12 , a rear system  14  and a stop-state system  16 , wherein the mentioned systems are combined with each other. This shows in particular in that a common compressor  36 , a common condenser  34  and a common accumulator  42  communicate with the evaporator  32  of the front system  12 , the evaporator  24  of the rear system  14  and the cold accumulator  20  of the stop-state system  16 , and in that an air flow of the same blower  26  acts upon the heating heat exchanger  22  of the rear system  14 , the cooling heat exchanger  18  of the stop-state system  16  and the evaporator  24  of the rear system  14  which acts as a cooling heat exchanger of the rear system  14 , as shown in  FIG. 2 . Besides the already mentioned components, the heating and air-conditioning system  10  comprises, a heating heat exchanger  44  for the front system  12 , which can be supplied with cooling water  47 , an expansion element  46  assigned to an evaporator  32  of the front system  12 , an expansion element  48  assigned to the evaporator  24  of the rear system  14  and an expansion element  50  assigned to a cold accumulator  20 . Besides the already mentioned blower  26 , an additional blower  52  is provided which is able to supply an air flow to the evaporator  32  of the front system  12  and the heating heat exchanger  44  of the front system  12 . Further, a blower  54  is provided for supplying the condenser  34  with an air flow. Moreover, electrically operable magnetic valves  56 ,  58 ,  60  are provided. In an opened state of the magnetic valves  56 , the evaporator  32  of the front system  12  is supplied with cooling agent, whereas this is prohibited in a closed state of the magnetic valve  56 . In an opened state of the magnetic valve  58 , the evaporator  24  of the rear system  14  is supplied with cooling agent, whereas this is prohibited in a closed state of the magnetic valve  58 . In an opened state of the magnetic valve  60 , the cold accumulator  20  is supplied with cooling agent, whereas this is prohibited in a closed state of the magnetic valve  60 . Further, a check valve  62  is provided which prevents reverse flow of cooling agent in the direction towards the cold accumulator  20 . The cold accumulator  20  and the cooling heat exchanger  18  are connected with each other via a heat carrier circuit  28 , wherein a pump  30  for conveying a heat carrier medium through the components is provided. Further, a water heater  64  is provided which is able to heat cooling water  66  streaming into the heating heat exchanger  22  of the rear system  14 , in order to enable a stop-state heating operation. 
     In the running-state, the compressor  36  is driven by the engine of the motor vehicle such that the condenser  34  is supplied with compressed cooling agent. This is then supplied to the evaporator  32 ,  24  of the front system  12  and the rear system  14  and to the cold accumulator  20  via the accumulator  42  dependent on the state of the magnetic valves  56 ,  58 ,  60 . In particular, the cold accumulator  20  can be charged in this manner with the magnetic valve  60  being opened. In the stop-state of the vehicle, that is when the engine is at rest, the cooling energy can then be withdrawn from the cold accumulator  20  by operating the pump  30 . This cooling energy can be fed to the rear region of the vehicle in form of a cooled air flow via the cooling heat exchanger  18  through an air flow  26  acting upon the same (see  FIG. 2 ). 
       FIG. 3  shows a schematic diagram of a second implementation format of a heating and air-conditioning system according to the present invention. In this implementation format of the heating and air-conditioning system  10  according to the present invention, the front system  12  and the rear system  14  are designed in a comparable manner, in particular regarding the operation in the running-state, as the heating and air-conditioning system  10  according to  FIG. 1 . Merely no valves are provided for enabling a selective operation of the front system  12  and the rear system  14  during the running-state. Of course, this is possible by arranging magnetic valves prior to the expansion elements  346  and  348 . 
     The stop-state system  16  is integrated in a different manner into the heating and air-conditioning system  10  as described in connection with  FIG. 1 . The stop-state system comprises an additional compressor  340 , which is preferably electrically drivable, by, for example, electric power directly from the generator, from a battery, preferably an auxiliary battery, or by electric power from a fuel cell. Compressed cooling agent is fed into an additional condenser  338  that is cooled by an additional blower  370 . The compressed cooling agent is then fed to the cold accumulator  320  via an additional accumulator  368  and an expansion element  350 . The thus conducted charging process of the cold accumulator  320  is preferably conducted during the running-state of the vehicle, because then sufficient power for operating the compressor  340  is available. However it is also possible to conduct a charging process in the stop-state of the vehicle, if a sufficient amount of electric power is available. The discharging of the cold accumulator  320  is then effected as in the implementation format according to  FIG. 1 . 
     In the present implementation format according to  FIG. 3 , the integration of the stop-state system  16  into the rear system  14  is also characterized in particular in that an air flow from a common blower  326  acts upon the components of the heating heat exchanger  322  of the rear system  14 , the cooling heat exchanger  318  of the stop-state system  16  and the evaporator  324  of the rear system  14 , as illustrated in connection with  FIG. 2 . 
       FIG. 4  shows a schematic diagram of a third implementation format of a heating and air-conditioning system according to the present invention. In this illustrated implementation format of the heating and air-conditioning system  10 , a compressor  436  and a condenser  434  are provided for the operation of the front system  12 , and a compressor  440  and a condenser  438  are provided for the operation of the rear system  14  and the operation of the stop-state system  16 . The front system  12  and the combination of rear system  14  and stop-state system  16  are thus completely decoupled. The compressor  440  which is in particular electrically driven, operates preferably in the running-state, in order to provide a running-state air-conditioning of the rear region through the evaporator  424  and in order to charge the cold accumulator  420 . A discharging is effected again via the heat carrier circuit  428  by operating the pump  430 . Again it is to be noted, as already mentioned in connection with  FIG. 3 , that an operation of the compressor  440  by all means may also be considered during the stop-state. Then, a direct cooling of the rear region via the evaporator  424  with the magnetic valves  458  being opened is possible and/or a charging of the cold accumulator  420  is possible with the magnetic valve  460  being opened, in order to withdraw this cooling energy later on from the cold accumulator  420 . Again, as shown in  FIG. 2 , an air flow from the same blower  426  acts on the heating heat exchanger  422 , the cooling heat exchanger  418  and the evaporator  424 . 
       FIG. 5  shows a schematic diagram of a fourth implementation format of a heating and air-conditioning system according to the present invention. Here, too, a complete decoupling of the front system  12  on the one hand and combination of the rear system  14  and the stop-state system  16  on the other hand is present; The front system  12  corresponds to that of  FIG. 5 . In contrast to the solution according to  FIG. 4 , the combination of rear system  14  and stop-state system  16  does not comprise a cold accumulator. Hence, even in the stop-state air-conditioning, the compressor  540  has to be operated in order to be able to generate cold within the evaporator  524 . Therefore, it is recommendable to use a compressor that is electrically or mechanically drivable by an auxiliary motor for the compressor  540 , because this one can be operated by a battery, in particular an auxiliary battery, or by electric power from a fuel cell during the stop-state of the vehicle. The heating heat exchanger  522  is fed with cooling water  566 , so, for example, according to  FIG. 4 ; wherein this can also be achieved for the purpose of heating during the stop-state by a water heater. 
       FIG. 6  shows a schematic diagram of a fifth implementation format of a heating and air-conditioning system according to the present invention. The present example of the heating and air-conditioning system  10  corresponds in a wide extent the one which was described in connection with  FIG. 5 . Differences can be noted only with respect to the heating means of the front system  12  and the combination of rear system  14  and stop-state system  16 . The front system  12  comprises an air heater  672  that is fed with air by the blower  652 , preferably by bypassing the evaporator  632 . 
     Such an air heater can be configured as, for example, a conventional fuel-operated auxiliary air heating device. The combination of rear system  14  and stop-state system  16  comprises an electric heater  674 . This is fed with electric power from a vehicle battery, in particular an auxiliary battery, a fuel cell or a generator. The electrical heater  674  is also preferably supplied with an air flow by the blower  626  by bypassing the evaporator  624 . 
       FIG. 7  shows a schematic diagram of a sixth implementation format of the heating and air-conditioning system according to the present invention. Again, an example is illustrated in which the front system  12  on the one hand and a combination of rear system  14  and stop-state system  16  on the other hand are decoupled completely from each other. The front system  12  is constructed in a conventional manner. In contrast to the implementation format according to  FIG. 4 , the combination of rear system  14  and stop-state system  16  lacks a separate evaporator. On the contrary, only the cold accumulator  720  is provided as an evaporator of the cooling circuit. Consequently, also in the running-state if a cooling of the rear region of the vehicle is desired, the cold required for cooling is withdrawn from the cold accumulator  720  via the cooling heat exchanger  718  by the pump  730  via the heat carrier circuit  728 . 
       FIG. 8  shows a schematic diagram of a seventh implementation format of a heating and air-conditioning system according to the present invention. This corresponds in a large extent to the implementation format according to  FIG. 7 . There are differences with respect to the heater in the combination of the rear system and stop-state system. 
     In the current example, an air heater  876  is provided which is supplied with air by a blower  826 , preferably by bypassing the cooling heat exchanger  818 . Such an air heater can be configured as, for example, a conventional fuel-operated auxiliary air heating device. 
       FIG. 9  shows a schematic diagram of an eighth implementation format of a heating and air-conditioning system according to the present invention. The implementation format illustrated here of the heating and air-conditioning system  10  according to the present invention corresponds to a large extent to the implementation format according to  FIG. 8 . In the combination of rear system  14  and stop-state system  16 , however, a separate cooling heat exchanger is omitted. On the contrary, the cold accumulator is designed as an accumulator-evaporator-heat-exchanger-unit  920 , which can directly be fed with air by the blower  926  for transmitting cold into the interior of the vehicle. A heating device (not shown) can also be provided by, for example, a heating heat exchanger through which cooling water passes, such as, for example, described in connection with  FIG. 7 , an air auxiliary heating device, such as, for example, described in connection with  FIG. 8 , or an electric heater, as for example described in connection with  FIG. 6 . 
       FIG. 10  shows a schematic diagram of a ninth implementation format of a heating and air-conditioning system according to the present invention. Here, two separate cooling circuits,  1084  and  1086 , are provided. Both cooling circuits  1084  and  1086  are connected with the same evaporator  1076 , wherein no mixture of the material flowing separately through the evaporator  1076  occurs within the evaporator  1076 . The cooling circuit  1086  comprises a compressor  1040  which is drivable by an auxiliary motor  1080  or an auxiliary battery  1080 . Operation of the auxiliary motor can be effected as in other implementation formats of the present invention directly mechanically or in that the auxiliary motor directly drives the compressor  1040  via a generator or with interposing a battery that is charged by the generator. The second cooling circuit  1086  is otherwise complete in the sense that it has its own condenser  1038 , its own accumulator  1082  and its own expansion element  1078 . During the running-state of the vehicle the compressor  1036  is generally operated, whereas the compressor  1040  is not operated. In the stop-state of the motor vehicle, stop-state air-conditioning is conducted due to the compressor  1040  being operated. 
       FIG. 11  shows a schematic diagram of a tenth implementation format of a heating and air-conditioning system according to the present invention. This one corresponds to a large extent with the implementation format according to  FIG. 10 . In contrast to  FIG. 10 , no completely separated cooling circuits are provided. The proper operation of the system with the compressor  1136  being operated as well as with the compressor  1140  being operated, is ensured by the arrangement of check valves  1188 ,  1190 ,  1192 . During operation of the compressor  1036  and during stopping of the compressor  1140 , the check valve  1192  ensures that no flow of cooling agent occurs via the conduit which bypasses the expansion element  1148 , but that the entire flow proceeds through the expansion element  1148 . The compressor  1140  prevents the flow of cooling agent towards the condenser  1138 . During stopping of the compressor  1136  and during operating the compressor  1140 , the check valve  1190  ensures that the flow through the expansion element  1178  proceeds towards the evaporator  1176 . The check valve  1188  ensures that no flow occurs through the evaporator  1132 . The compressor  1136  is responsible for avoiding undesired flows of cooling agent occurring in the direction towards the condenser  1134 . 
       FIG. 12  shows a schematic diagram of an eleventh implementation format of a heating and air-conditioning system according to the present invention. This one corresponds to a large extent with the implementation format according to  FIG. 10 . In contrast to  FIG. 10 , however, separate evaporators are provided for the running-state and the stop-state, namely the evaporator  1224  for the running-state and the evaporator  1276  for the stop-state. An integration of the stop-state system  16  into the rear system  14  again shows in particular how the heating heat exchanger  1222  of the rear system  14 , the evaporator  1224  of the rear system  14  and the evaporator  1276  of the stop-state system  16  is supplied with an air flow by the same blower  1226 , thus comprising, for example, an arrangement, as shown in connection with  FIG. 2 , that has already been discussed several times. The cooling heat exchanger  18  according to  FIG. 2  is then merely replaced by the evaporator  1276  according to  FIG. 12 . 
     The features of the present invention disclosed in the preceding description, in the drawings and in the claims can be essential for implementation of the invention individually and in combination. 
     REFERENCE NUMERALS 
     
         
           10  air-conditioning system 
           12  front system 
           14  rear system 
           16  stop-state system 
           18  cooling heat exchanger 
           20  cold accumulator 
           20  accumulator-evaporator-heat-exchanger-unit 
           22  heating heat exchanger 
           24  evaporator 
           26  blower 
           28  heat carrier circuit 
           30  pump 
           32  evaporator 
           34  condenser 
           36  compressor 
           38  condenser 
           40  compressor 
           42  accumulator 
           44  heating heat exchanger 
           46  expansion element 
           47  cooling water 
           48  expansion element 
           50  expansion element 
           52  blower 
           54  blower 
           56  magnetic valve 
           58  magnetic valve 
           60  magnetic valve 
           62  check valve 
           64  water heater 
           66  cooling water 
           70  blower 
           72  air heater 
           74  heater 
           76  evaporator 
           78  expansion element 
           80  auxiliary motor/auxiliary battery 
           82  accumulator 
           84  cooling circuit 
           86  cooling circuit 
           88  check valve 
           90  check valve 
           92  check valve 
       
    
     Reference numerals added with a whole numbered multiple of 100 are indicating identical or similar components.