DE102011014712B4 - Vehicle, in particular electric vehicle - Google Patents

Abstract

Vehicle, in particular electric vehicle, with an air conditioner (15) having a in a refrigerant circuit (N, H) connected to the heat exchanger (13), which operates in a cooling operation as a refrigerant evaporator, in which under cooling one in the vehicle interior (37) guided air flow (L) evaporates the refrigerant and which heat exchanger (13) operates in a heating operation as a refrigerant condenser, in which the refrigerant condenses while heating the air flow (L), the refrigerant circuit a main circuit (H) and a secondary circuit (N), in which an additional heat exchanger (31) is arranged, which operates in the heating operation as a refrigerant evaporator and which can be heated directly / indirectly by means of fossil fuel, characterized in that in the secondary circuit (N) a Compressor unit (29), in particular a flow pump, is arranged, which in the heating operation instead of the compressor (1) in the main circuit (H) the Kältemit Compresses, and that in the main circuit (H) arranged compressor (1) is flowed through in the heating operation and works as an expansion machine, in which the refrigerant under expansion to the air conditioner heat exchanger (13) can be guided, which operates as a refrigerant condenser.

Description

The invention relates to a vehicle, in particular an electric vehicle, with an air conditioner according to the preamble of claim 1.

In vehicles with modern internal combustion engines, the waste heat available in the cooling water for heating the vehicle interior is available only to a limited extent. This problem is exacerbated in vehicles with partial or complete electric drive, since as heat sources in addition to the electric machines only the power electronics are available, the heat loss is also severely limited for reasons of efficiency.

A generic vehicle has an air conditioner comprising a heat exchanger connected in a refrigerant circuit. This works in the cooling mode as a refrigerant evaporator, in which evaporates with simultaneous cooling of the guided into the vehicle interior airflow, the refrigerant. At the same time, the air conditioner heat exchanger can operate in the heating mode as a refrigerant condenser, in which the refrigerant is condensed while heating the guided into the vehicle interior air flow. Optionally, an electric heater may be provided in the air conditioner, which is arranged in the guided to the vehicle interior air flow in series with the above-mentioned air conditioner heat exchanger. In the event that the heat demand in the vehicle interior can not be covered solely by the working as a condenser refrigeration unit heat exchanger, the electric heater is activated. However, even in moderate ambient conditions, to cover the heat demand in the vehicle interior, power in the range of 1 to 4 KW apply, all of which must be provided by the on-board vehicle battery. The removed from the battery electrical energy is therefore no longer available for drive purposes, which in turn can greatly reduce the range in electric vehicles.

From the DE 10 2007 006 963 A1 a vehicle is known in which a heating heat exchanger is provided in a coolant circuit for heating the vehicle interior, which is externally heated at least partially by means of a burner. From the DE 102 59 071 B4 a vehicle is known with an air conditioner in which a Stirling engine is provided for compressing a working medium of the air conditioning, which is associated with a fuel-fired heater.

The DE 100 06 513 A1 discloses an air conditioning system for a motor vehicle, which is designed for an air conditioning mode and at least one further operating mode in the form of a heat pump mode and / or Reheatbetriebsart. The air conditioning system has a refrigerant circuit with a compressor, a refrigerant radiator and a supply air / refrigerant heat exchanger arranged in an air supply duct and functioning as an evaporator in the air conditioning mode. Furthermore, the air conditioning system has a coolant circuit for cooling a heat-generating vehicle component and a refrigerant / coolant heat exchanger coupling the refrigerant circuit and the coolant circuit in a heat-transmitting manner. According to the DE 100 06 513 A1 is the refrigerant / coolant heat exchanger in the coolant circuit upstream of an engine exhaust / coolant heat exchanger.

The object of the invention is to provide a vehicle with an air conditioner, in which the electrical energy consumption for heating the vehicle interior is reduced.

The object is solved by the features of claim 1. Preferred embodiments of the invention are disclosed in the subclaims.

The invention is based on a refrigerant flow-through heat exchanger of an air conditioner, which operates in the cooling mode as a refrigerant evaporator, in which the refrigerant is evaporated while cooling the guided into the vehicle interior air flow. The air conditioner heat exchanger also operates in heating mode as a refrigerant condenser, in which the refrigerant condenses while heating the air flow. According to the invention, the refrigerant circuit has an additional heat exchanger, which operates in the heating mode as a refrigerant evaporator. The additional heat exchanger is not heated by means of electrical energy, but directly or indirectly by means of fossil fuel. In this way, the electrical energy consumption for tempering the vehicle interior can be reduced while the range of the vehicle can be increased. The preconditioning of the vehicle interior can also take place independently of an electrical energy supply.

According to one embodiment, the additional heat exchanger can be flowed through directly by exhaust gas of an internal combustion engine and / or by flue gas. Alternatively, the additional heat exchanger may be a fuel-fired burner, in whose flame or flue gas, for example, a coiled tubing heat exchanger is arranged, which is flowed through by refrigerant.

For safety reasons, it may be advantageous if the flue gas or the Flame of the burner is not directly in thermal coupling with the refrigerant, but only indirectly via an intermediate heating circuit in which, for example, cooling water transfers the heat from the exhaust / flue gas flow to the refrigerant through-flow additional heat exchanger.

According to the refrigerant cycle of the air conditioner is divided into a main circuit and a secondary circuit. In the main circuit of working as evaporator / condenser refrigerator heat exchanger and also in a conventional manner, a refrigerant compressor, a condenser and an expansion device may be arranged to accomplish a refrigeration cycle. Accordingly, in the cooling operation, the refrigerant compressed in the compressor is led to a condenser in which the refrigerant condenses to release waste heat. The refrigerant liquefied in the condenser is further passed under expansion through an expansion valve to the air conditioner heat exchanger in which it evaporates while cooling the air flow guided into the vehicle interior. Subsequently, the evaporated refrigerant is returned to the compressor.

In contrast, can be arranged in the secondary circuit of the additional heat exchanger, which operates in the heating mode as an evaporator. The secondary circuit can be shut down by driving control valves in the above-mentioned cooling mode and activated only for the heating mode. In cooling mode, therefore, the additional heat exchanger is not flowed through by refrigerant. According to the invention, the refrigeration appliance heat exchanger can work both as a condenser and as an evaporator, provided that the refrigerant circuit is operated in the reverse direction, that is to say in the heat pump process or in the refrigeration process. In order to enable such a dual function of the refrigeration appliance heat exchanger, a large number of refrigerant lines are to be laid in montage technically complex manner and with great space expenditure in the refrigeration cycle. The bypass or bypass lines provided in this way can also be unlocked or blocked only with great effort for the respective heating or cooling operation. Alternatively, with regard to a simple and space-saving design of the refrigerant circuit, the main circuit on the high-pressure side of the compressor connection points / branch points have over which the secondary circuit can be connected to the main circuit.

In the secondary circuit, a compressor unit, in particular a flow pump, and the aforementioned additional heat exchanger is arranged. To carry out the heating operation, the compressor unit is activated instead of the compressor arranged in the main circuit, while the main circuit compressor remains functionless. The resultant in heating refrigerant circuit is particularly easy to reach in this way. The main circuit compressor operates according to the invention in a dual function as an expansion or expansion machine. In this case, the refrigerant can first be compressed by the secondary circuit compressor unit and then evaporated in the additional heat exchanger, which works as an evaporator. The vaporized refrigerant is further guided under expansion by an expansion element, according to the invention of the main circuit compressor, and from there through the operating as a condenser air conditioner heat exchanger in which the evaporated refrigerant can at least partially condense. The arranged in the main circuit expansion valve can be switched in heating mode in an open position, that is, without function. The also arranged in the main circuit heat exchanger, which works as a condenser in the cooling mode, serves as a further subcooling, to condense optionally still vaporous refrigerant.

Subsequently, the condensed refrigerant is returned to the sub-circuit compressor unit.

As mentioned above, the main cycle compressor according to the invention operates in the heating operation as an expansion machine, through which the compressed refrigerant can flow under expansion, the compressor generated in the refrigerant expansion wave work of the compressor can be preferably converted into electrical energy and fed into the vehicle electrical system. For this purpose, the drive unit of the compressor is preferably a working also in the generator mode electric machine.

A refrigerant compressor operating in this way can be, for example, a so-called scroll compressor.

Space is favorable, if the additional heat exchanger and / or the entire secondary circuit are combined in a separate add-on module, which is arranged removable for a summer operation of the vehicle. The attachment module may preferably have a fuel tank, the compressor unit, the burner and the additional heat exchanger. The so-designed add-on module can, if necessary, be connected to the main circuit, for example by means of a quick coupling.

Hereinafter, embodiments of the invention are described with reference to the accompanying figures.

Show it:

1 a block diagram of a used in a vehicle refrigerant circuit operating in the cooling mode;

2 a ph diagram in which the process control is shown in the cooling mode;

3 in a view corresponding to 1 the heating operation of the refrigerant circuit;

4 a ph diagram illustrating the heating operation;

5 an auxiliary heat exchanger according to the first embodiment;

6 a rough schematic representation in which a sequence of movements is illustrated in a scroll compressor; and

7 a refrigerant circuit according to the second embodiment.

In the 1 For example, the air conditioning system of a vehicle has a refrigerant circuit which is divided into a main circuit H and a secondary circuit N. In the main circuit H is a refrigerant compressor 1 arranged, via a high-pressure line 3 with a refrigerant condenser 5 connected is. The refrigerant condenser 5 can be arranged on the radiator side in the front-end module of an electric vehicle, whereby the waste heat can be dissipated. Downstream of the refrigerant condenser 5 leads a second high pressure line 7 the refrigerant up to an expansion valve 9 and then via a low pressure line 11 continue to a heat exchanger 13 working in an air conditioner 15 of the vehicle is arranged. The air conditioner heat exchanger 13 is via a second low-pressure line 17 with the suction side of the compressor 1 connected by an electric machine 19 is driven.

In the first high pressure line 3 between the compressor 1 and the capacitor 5 are two branch points 21 . 23 provided at which the secondary circuit N via sub-lines 25 . 27 is connected to the main circuit H. In the sub-line 25 the secondary circuit N is a pump 29 and a downstream additional heat exchanger 31 arranged. The additional heat exchanger is via the second part line 27 at the branching point 21 with the first high pressure line 3 connected to the main circuit H. In the second sub-line 27 is also a check valve 33 and a control valve 35 arranged.

In the 1 a circuit variant is shown in which the air conditioner operates in a cooling mode. The flow path of the refrigerant is highlighted by thick lines, while the drawn only with thin lines lines are shut down. As a result, the refrigerant flows from the compressor 1 over the capacitor 5 and the expansion valve to the air conditioner heat exchanger 13 in which the expanded refrigerant is cooled while in the vehicle interior 37 guided air flow L evaporates and to the compressor 1 is returned.

The process control of the cooling operation is in the ph diagram of 2 explained by the refrigerant R 134a.

In the 3 is shown a further circuit variant in which the air conditioner operates in heating mode. The flow path of the refrigerant is again highlighted by thick lines. As a result, this is between the two connection points 21 . 23 the high pressure line 3 arranged control valve 39 locked while the control valve 35 in the secondary circuit N is open. In addition, the flow pump is also 29 activated, causing the refrigerant in the sub-line 25 is compressed and to the additional heat exchanger 31 to be led. The additional heat exchanger 31 is in the 5 shown in isolation. Consequently, the auxiliary heat exchanger 31 a coiled tubing heat exchanger in direct thermal contact with flue gas or flue gas. Alternatively, the additional heat exchanger 31 be fired with a flame of a fuel-powered burner.

The same applies to the pump 29 in the secondary circuit N compressed refrigerant in the additional heat exchanger 31 Continue to heat and over the check valve 33 as well as the branching point 21 in a countercurrent direction through the main circuit compressor 1 guided. The main circuit compressor 1 works in heating mode as an expansion machine, which is flowed through by the refrigerant expansion. The generated wave work in the compressor 1 is in the associated electric machine 19 converted into electrical energy that can be fed into the electrical system. The so expanded refrigerant continues to air conditioner heat exchanger 13 guided. This now works as a refrigerant condenser, in which the refrigerant can condense with release of heat, with which the air flow L is heated. In the further course of the flow follows the expansion valve 9 , which is switched inoperative in heating mode, that is, is switched to an open position without throttle function. The downstream of the expansion valve 9 following capacitor 5 provides in heating mode in addition to the air conditioner condenser another subcooling distance in which the refrigerant can give off heat. Subsequently, the refrigerant is sent via the branching point 23 back to the pump 29 recycled. The litigation of the in the 3 shown heating is in the 4 illustrated in a ph diagram.

In the 6 is roughly schematically a sequence of movements of the operation of the running as a scroll compressor compressor 1 shown. The structure and operation of a scroll compressor is well known, so that only the basic operation in the 6 is illustrated. As a result, the scroll compressor has a pair of turns 43 . 45 which are fitted into each other to define a plurality of compression chambers. The turn 45 is in compressor operation in an orbit relative to the winding 43 driven, whereby the compression chambers reduce in volume, thus compressing the trapped refrigerant. Will the turn 45 In contrast, rotated in a reverse direction, there is no compression of the refrigerant, but rather an expansion of the refrigerant, as required for the heating operation of the present invention.

With a turn of the winding 45 Clockwise (sequence of movements from 1 to 8) results in the compressor operation, while counterclockwise (sequence of movements 1, 8 to 2) results in the expansion mode of operation. The switchover between the two modes of operation thus takes place by changing the direction of rotation.

In the 7 a block diagram is shown according to the second embodiment, which is identical in basic construction with the block diagram of 1 or the 2 is. Unlike the 1 and 2 is the fossil fuel-fired burner 47 does not flow directly with refrigerant, but is the burner 47 with the interposition of a heating circuit 49 with the additional heat exchanger 31 thermally coupled. To activate the heating circuit 49 is a circulation pump 51 provided, for example, cooling water through the burner 47 as well as through the additional heat exchanger 31 promotes.

The compressor 1 is by means of an electric machine 19 driven, whereby a variation of the delivery volume flow is made possible by means of speed variation. At the outlet of the working in the heating operation as an expansion compressor 1 are the already mentioned check valves (not in 7 shown), which prevent a return flow of the refrigerant. A conventional scroll compressor has a valve on the high pressure side. This is usually a so-called flutter valve. When reversing the direction of rotation, ie also reversing the direction of flow, this valve blocks the flow rate and the scroll compressor sucks against the closed valve and creates a negative pressure. Due to the lack of refrigerant flow, lubrication and cooling are not guaranteed and the scroll compressor can be damaged. However, according to the invention, the scroll compressor together with the flutter valve works as an expansion machine. The expansion machine according to the figures has two valves 32 . 33 , which release only one flow path depending on the direction of rotation. This machine can thus independently of the direction of rotation of the scroll compressor suck refrigerant and compress or expand as an expansion element, the refrigerant. Accordingly, the compressor has 1 three refrigerant connections: one low-pressure side and two high-pressure side connections. The control of the valves and the control of the direction of rotation is done electronically. With this type of construction, it is ensured that a refrigerant flow through the scroll compressor is provided for each direction of rotation. Lubrication and cooling are thus ensured regardless of the direction of rotation.

In the 7 is the secondary circuit N together with its components, that is the pump 29 , the additional heat exchanger 31 as well as the components of the heating circuit 49 summarized in a cultivation module 53 that in the 7 only shown by dashed lines. The add-on module 53 is over the two sub-lines 25 . 27 with the branching points 21 . 23 the main circuit H in combination, and preferably via a quick coupling, not shown. In this way, the attachment module 53 be dismantled in the summer mode readily from the air conditioning and only be installed as needed in the vehicle.

Claims (11)

Vehicle, in particular electric vehicle, with an air conditioner ( 15 ), which is a in a refrigerant circuit (N, H) connected heat exchanger ( 13 ), which operates in a cooling operation as a refrigerant evaporator, in which, while cooling one in the vehicle interior ( 37 ), the refrigerant evaporates and which heat exchanger ( 13 ) operates in a heating operation as a refrigerant condenser in which the refrigerant condenses under heating of the air flow (L), the refrigerant circuit having a main circuit (H) and a secondary circuit (N), in which an auxiliary heat exchanger ( 31 ) is arranged, which operates in the heating mode as a refrigerant evaporator and which is directly / indirectly heated by means of fossil fuel, characterized in that in the secondary circuit (N) a compressor unit ( 29 ), in particular a flow pump is arranged, which in the heating mode instead of the compressor ( 1 ) in the main circuit (H) the refrigerant is compressed, and that in the main circuit (H) arranged compressor ( 1 ) is flowed through in heating operation and works as an expansion machine, in which the refrigerant under expansion to Air Conditioner Heat Exchanger ( 13 ), which works as a refrigerant condenser. Vehicle according to claim 1, characterized in that the additional heat exchanger ( 31 ) is traversed by exhaust gas and / or flue gas. Vehicle according to claim 1, characterized in that the additional heat exchanger ( 31 ) a fuel-powered burner ( 47 ), which is traversed by refrigerant. Vehicle according to one of claims 1 to 3, characterized in that the burner ( 47 ) and / or the exhaust gas / flue gas flow via an intermediate circuit ( 49 ) with the additional heat exchanger ( 31 ) is thermally coupled. Vehicle according to one of claims 1 to 4, characterized in that the secondary circuit (N) is shut down in the cooling mode. Vehicle according to claim 5, characterized in that the main circuit (H) on the high pressure side of the compressor ( 1 ) Branching points ( 21 . 23 ), via which the secondary circuit (N) the main circuit (H) is connectable. Vehicle according to one of claims 5 or 6, characterized in that in the main circuit (H) a refrigerant compressor ( 1 ) is arranged, which in the cooling operation, the refrigerant under compression to a capacitor ( 5 ), in which the refrigerant condenses with heat release, and the condensed refrigerant under expansion by an expansion element ( 9 ) to the air conditioner heat exchanger ( 13 ) is feasible, in which it is cooled by the air flow ( 1 ) and to the compressor ( 1 ) is traceable. Vehicle according to one of the preceding claims, characterized in that the electric drive unit ( 19 ) of the compressor ( 1 ) is an electric machine with which the shaft work of the compressor generated in the heating operation ( 1 ) is fed as electrical energy into the vehicle electrical system. Vehicle according to one of the preceding claims, characterized in that the refrigerant compressor ( 1 ) is a scroll compressor. Vehicle according to one of the preceding claims, characterized in that the additional heat exchanger ( 31 ) and / or the secondary circuit (N) as a separate add-on module ( 53 ) are provided removable. Vehicle according to claim 10, characterized in that the add-on module ( 53 ) a fuel tank, the compressor unit ( 29 ), the burner ( 47 ) and the additional heat exchanger ( 31 ), and that in particular the add-on module ( 53 ), via, for example, a quick coupling, to the main circuit (H) can be connected.

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