DE102008028066A1 - Independent air conditioning system i.e. vehicle independent air conditioning system, operating method, involves providing air conditioning cold at fluid/air-heat exchanger when cold memory is charged in still stand phases of vehicle drive - Google Patents

Abstract

The method involves providing a heat exchanger with an evaporator (6) of a coolant circuit (1) for receiving cold, and providing a fluid/air-heat exchanger for delivering air conditioning cold. A cooling medium-compressor (3) is electrically operated by low voltage independent of a vehicle-drive motor in a drive-mechanical manner to charge a cold memory by supplying electrical energy. The air conditioning cold is provided at a fluid/air-heat exchanger (9) when the cold memory is charged in still stand phases of a vehicle drive. An independent claim is also included for a vehicle independent air conditioning system comprising a coolant circuit.

Description

FIELD OF THE INVENTION

The The invention relates to a method for operating a stationary air conditioning system in a vehicle according to the preamble of claim 1 and a stationary vehicle air conditioner according to the The preamble of claim 7. Accordingly, the invention of a known mode of operation of stationary air conditioners, in the two coolant circuits connected by heat exchange means and at least one on and in vehicle standstill phases dischargeable cold storage is used and in which a first coolant circuit at least one coolant compressor, a condenser, an expansion valve and an evaporator and a second coolant circuit at least one the evaporator of the first coolant circuit including heat exchanger for cold absorption and a liquid / air heat exchanger for Delivery of air conditioning refrigeration and, if necessary, a Includes coolant pump.

TECHNOLOGICAL BACKGROUND

at Vehicle air conditioners exist the problem while Driving interruptions, z. B. for rest breaks, also in Situations of relatively warm and / or humid climates sufficient cool air (air conditioning air) available to deliver. It is the one for the operation of such vehicle stationary air conditioners required energy requirement not insignificant. He is in all Usually between 1 and 5 kWh.

When available on the market stationary vehicle air conditioners, it is known to build the stationary air conditioner so that it can be used while driving to adjust and maintain a comfortable climate in the cab, ie to combine the two systems together and the energy required for cooling the drive of the Refrigeration compressor to provide a coolant circuit by mechanical coupling to the vehicle engine. When the vehicle engine is running, the refrigeration compressor is thus mechanically driven by the vehicle engine. In order to be able to bridge longer breaks in the air conditioning system when the vehicle engine is at a standstill, cold generated during the driving periods is stored in order to be able to call it during standstill periods. This is done in detail as follows:
A known integrated driving and stationary air conditioning system consists of two circuits, namely a conventional refrigeration cycle for cooling and a refrigeration transport circuit, for cooling distribution. The conventional refrigeration cycle is z. B. designed for the refrigerant R134a; Its components include a refrigerant compressor, a refrigerant condenser, a refrigerant expansion valve and an evaporator. In this evaporator but not air, as in a conventional (driving) air conditioning for vehicles - but cooled a refrigerant, such as a water-glysantin mixture. The evaporator is the interface between the two coolant circuits. The second coolant circuit is composed of the aforementioned evaporator interface and a cold storage, an air conditioner and a distribution and control unit for the brine. The so-called air conditioner is placed at any point remote from the evaporator to deliver air conditioning refrigeration to the air to be cooled from the circulating second refrigerant circuit. For this purpose, a liquid / air exchanger is used. The distribution and control unit for the circulation medium of the second coolant circuit can be optionally connected to the liquid / air heat exchanger or with a cold storage. The cold storage consists of an insulated housing and a number of storage elements with the intermediate flow channels for brines. The brine can be a mixture of water and z. B. be glysantin. Due to the good heat transfer properties between the existing storage elements and intermediate flow channels for refrigerant cold storage and the evaporator of the first coolant circuit, a capacity of 5 kWh cooling capacity can be charged in a relatively short time in the cold storage. If at the same time to such a charging the cabin air conditioning is done or continued, the cold storage charge takes longer, z. For example, three times the time. In this known stationary vehicle air conditioner circulates in air conditioning while driving the refrigerant of the second coolant circuit between evaporator and air conditioner. In the liquid / air heat exchanger of the air conditioner cabin air (fresh air or circulating air) is cooled and dehumidified. In this mode of operation, also referred to as maintenance air conditioning (without the cab "cooling down"), the continuous evaporator typically provides more cooling energy than is required for cabin air conditioning. The unneeded part of the cooling capacity is used to charge the cold storage. In extreme climate control requirements, the cold storage can also be used to increase the cooling capacity. The brine is then further cooled after the evaporator in the cold storage and then passed to the air conditioner in the vehicle cabin. - Such a combined driving and stationary air conditioning system for vehicles is extremely complex, also as far as the control and the refrigerant distribution.

PRESENTATION OF THE INVENTION

On this basis, the invention is the Task based on simplifying the construction of stationary vehicle air conditioners and to improve the energy resources for Fahrenkinenklimatisierung at standstill of the vehicle drive motor. Corresponding stationary vehicle air conditioners can, of course, cool the most diverse spaces of a vehicle, ie not just the driver's cab.

to Solution to this problem is a method with the features of claim 1 and a device having the feature of the claim 7 proposed. Accordingly, it is provided that the refrigerant compressor the first coolant circuit drive mechanical from Vehicle drive motor independently, namely by means of Low voltage is electrically operated to the cold storage with sufficient supply of electrical energy to charge and for air-conditioning refrigeration on the liquid / air exchanger provide when the cold storage in standstill phases of the vehicle drive is discharged. Furthermore, it can be provided that an approximately used refrigerant pump of the second refrigerant circuit by means of low voltage, in particular with a stationary refrigerant compressor, electrically is operated to the cold storage over the Liquid / air heat exchanger to discharge and - provided desired to air conditioning refrigeration from the first Coolant circuit at the liquid / air heat exchanger provide. The invention is therefore based on the basic idea Provide two energy reservoirs to provide refrigeration at standstill namely the rechargeable cold storage on the one hand and on the other hand, the onboard accumulator for electric Voltage from the vehicle, through which at discharged cold storage despite vehicle standstill via the refrigerant compressor electric Energy for air conditioning refrigeration continues provides.

By the invention, the cold storage can be significantly reduced in comparison to the known stationary vehicle air conditioners without a lower air conditioning capacity must be accepted at the only occasional long stand cooling phases. Such a memory reduction also reduces the weight of the cold accumulator Ge and allows its arrangement directly at the location of the air conditioning air delivery, which improves the compactness, in particular in the manner described below. Cold storage capacities of about 2 kWh are already sufficient in a large number of applications. The accumulator batteries are, as is common practice against deep discharge protected by suitable, known per se battery monitor. The use of purely electrical drive energy for refrigerant compressors is from the WO 85/03603 Although basically known. The local solution is, however, provided for the cooling of coolers with eutectic storage plates, which are operated after discharging the cold storage at a much higher temperature level, as in charged cold storage. Such temperature differences are to be rejected in principle for air conditioning. In addition, eutectic storage plates are unsuitable for delivering the cold air to the air conditioning air at liquid / air heat exchanger for a vehicle stationary air conditioner.

The Invention can now be carried out in various ways. According to a first preferred mode of operation the second, powered by a refrigerant pump Coolant circuit stored and / or immediate Cooling emission in situ generated air conditioning cold over one of the first cycle medium of the first coolant circuit and independent of the refrigerant storage second circulation medium to the liquid / air heat exchanger from. - Different, as in the generic mentioned above Vehicle stationary air conditioners, so is the cold storage content from the circulation medium of the second coolant circuit kept separate. This allows the operating volume of the second coolant circuit to keep extremely small and the (second) circulation medium to the peculiarities of this cycle and in particular to favorable material pairings in the field the liquid / air heat exchanger optimally adapt. As a cold storage medium can therefore any, also solid, cold storage material can be used and in particular The amount and weight of storage material can be optimized. Also, a distribution and control unit for the second Circulation medium omitted or significantly simplified. - One Such method for operating a stationary vehicle air conditioner and a corresponding vehicle parking conditioner is also without the Characteristics of claim 1 of independent inventive meaning. - Nevertheless, a separate Heat exchanger, namely for charging and discharge of the cold storage, omitted when the cold storage with the evaporator of the first coolant circuit and with the containing the evaporator for cold absorption Heat exchanger of the second coolant circuit to a heat exchange unit to be described in more detail below is summarized.

According to another preferred embodiment, it is provided that, as far as provided, the second coolant circuit is part of the cold storage and flows through an independent of the cooling medium of the first coolant circuit second circulation medium and that in the evaporator of the first coolant circuit and him containing heat exchanger of cold storage cold is discharged directly to the liquid / air heat exchanger. The cold-storing substance can - alternatively - in the Cold storage also rest. In this way, can be dispensed with a special circulation medium for the transport of cold air to the liquid / air heat exchanger for air conditioning. The entire heat exchanger assembly can - as in a known air conditioner - be installed directly at the place of consumption for air conditioning refrigeration. The heat exchanger weight is charged comparatively slightly by the cold storage, because subsets of an approximately circulating cold storage medium can be accommodated in a heat-insulated auxiliary storage also removed from the cold discharge point. Connecting lines between the additional storage and the cold storage can be easily installed and heat insulated. Thus, there is a triple heat exchange and on a distribution and control unit for refrigerants, as is known from the above-mentioned prior art, can be completely dispensed with. In operating phases without charging or discharging the cold accumulator, the approximately existing refrigerant pump of this circuit need only be switched off. The amount of cold storage medium contained in the combined liquid / air heat exchanger acts as a buffer, which evened out the cold absorption of the integrated heat exchanger, but in particular its cooling output in a manner comfortable for the vehicle user. - The second embodiment is independent of the characterizing features of claim 1, of independent inventive importance.

If the refrigerant storage with the evaporator of the first Coolant circuit and with the evaporator in order Cold absorption containing heat exchanger summarized is, as already stated, in terms of thermal engineering and circuit-wise of particular use and permitted also a reduction of the components and a comparatively flexible placement in the vehicle and a compact design. Also this method and a corresponding integrated heat exchanger is also without the characterizing features of claim 1 of independent inventive meaning.

If a tube-in-tube system for the vaporizer and him containing heat exchanger is used, so can in a particularly simple way a highly effective heat exchange between the first coolant circuit, the second coolant circuit and / or the cold storage and the liquid / air heat exchanger take place, because one of the heat exchange media refrigeration between the two remaining heat exchange media inserted is, so that between the media on the shortest path cooling energy optionally can be exchanged, with relatively small quantities on cooling media for effective heat exchange already sufficient. Such an integrated heat exchanger is, even without the characterizing features of claim 1 of independently inventive meaning.

The the aforementioned and the claimed and in the embodiments described to be used according to the invention Components are subject in size, shape design, Material selection and technical conception no special exceptions, so that the selection criteria known in the field of application unrestricted Application can find more details, features and advantages of the subject invention will become apparent from the Subclaims, as well as from the following description the accompanying drawing and table, in the - example - a Embodiment of a stationary vehicle air conditioner shown is.

In show the drawing

BRIEF DESCRIPTION OF THE FIGURES

1 shows a block diagram of the essential elements of a first embodiment of a stationary vehicle air conditioning system;

2 shows a block diagram of the essential elements of a second embodiment of a stationary vehicle air conditioner;

3 shows a vertical sectional view of a schematic diagram of an integrated heat exchanger and cold storage for the embodiment according to 1 such as

4 shows a vertical sectional view of a schematic diagram of an integrated heat exchanger and cold storage for the embodiment according to 2

DETAILED DESCRIPTION THE FIGURES

In the 1 in sections as a schematic diagram illustrated vehicle stationary air conditioning 10 has a first coolant circuit 1 and a refrigeration-related second coolant circuit 2 on. The first, z. B. with the refrigerant R134a filled coolant circuit 1 comprises at least one, preferably controllable, refrigerant compressor 3 , a capacitor 4 , an expansion valve 5 and an evaporator 6 and common piping that closes the circuit. The second, with water and optionally a solidification temperature lowering, known per se filled with tel coolant circuit 2 includes at least one refrigerant pump 7 , one the evaporator 6 of the first coolant circuit 1 containing heat exchanger 8th for cold absorption as well a liquid / air heat exchanger 9 for the delivery of air conditioning refrigeration to the room air by means of an evaporator fan 11 , The arrows inside the two coolant circuits 1 and 2 indicate the flow direction of the first circulation medium (R134a) and the second circulation medium (water). The refrigerant compressor 3 is operated exclusively with 24 volt DC electric, so the drive motor drive-mechanically independent. The electrical drive voltage can basically be 12 or 36 volts or even 48 volts. In this sense, low voltage in the context of the invention is understood to mean an electrical voltage, in particular a DC voltage, between about 10 and 50 volts.

In the first coolant circuit 1 the cold required for the cooling of the air conditioning air is generated and beyond a cold surplus, so that not only a maintenance air conditioning and cooling at least one room in the vehicle even with strong heat radiation is possible, but also sufficient cooling energy for charging a cold storage is available. A corresponding cold storage 12 is also found in the unit, in which also the evaporator 6 and heat exchangers 8th to find oneself. A corresponding integrated arrangement is associated with 3 be explained.

In the second coolant circuit 2 is a fluid refrigerant, such as water, between the heat exchanger combination 6 . 8th . 12 and the liquid / air heat exchanger 9 in the circuit by means of a designed as a water pump refrigerant pump 7 transported. With sufficient thermal insulation of the circulation lines and the other two units, the loss of cold through the circulation is low. By switching off the also electrically operated water pump, the loss of cold in the second coolant circuit can be lowered to almost zero in case of need. Will now be running water pump room air by means of ansich known evaporator fan 11 through the liquid / air heat exchanger 9 passed, so is the second Kühlmit tel-circuit 2 the refrigeration required for room air conditioning withdrawn. Suitable pipelines, in particular air distribution means 13 for air conditioning air which may already be present in the vehicle, transport the air conditioning refrigeration to the preferred Ausströmorte. However, the air conditioning air can also directly from a known air conditioner 9 . 11 . 13 emerge at the preferred central location for air conditioning air.

A preferred mode of operation of this embodiment is now the following: When there is sufficient electrical power in the vehicle, so preferably when the vehicle drive motor is running z. B. an alternator, not shown in the drawing by means of the current vehicle drive motor enough electrical DC to the in the illustrated and as far preferred embodiment designed as a controllable 24V DC compressor refrigerant compressor 3 drive. This is done by a possible provided by home in the vehicle vehicle air conditioning completely independent and independent of the mechanical vehicle drive, so purely electric. The compressor runs during the journey of the vehicle, in particular a commercial vehicle, and uses the energy provided by the alternator to the refrigerant in the evaporator 6 and the preferably integrated therein cold storage 12 provide. In this phase of refrigeration provision different modes of operation are possible. On the one hand, the cold can immediately via the second coolant circuit to the consumer, the air conditioner 9 . 11 . 13 , to get redirected. If there is particularly high demand for refrigeration, so it may happen in extreme cases, that not only the cold storage is not charged, but in it is still stored residual cold with consumed. The second cooling circuit can also be switched off, so that all cold the cold storage 12 is supplied. Thereafter, the cooling energy is stored in the stored form of the vehicle stationary air conditioning system. If this is now switched on to cool the cab during a break or continue to keep cool, the stored refrigeration energy is first retrieved from the cold storage. Here, only the second coolant circuit operates. The first coolant circuit is not flown through. The electric power consumption is limited to the operation of the water pump 7 and the evaporator blower 11 , If the cold energy is consumed from the cold storage and the vehicle drive motor is still stationary, the refrigerant compressor switches 3 to cover the current cooling demand. The compressor takes over the energy now required from the vehicle battery. The cold storage is not charged during this time because the provided cooling energy through the primary circuit (first coolant circuit) within the combined heat exchanger 6 . 8th . 12 is discharged directly to the secondary circuit (second coolant circuit).

The stationary vehicle air conditioner therefore uses two energy stores in standby mode, for one of the cold storage 12 if it is charged. And secondly from the vehicle battery, which operates the electrically operated refrigerant compressor. The cooling time can thus easily be at least six to eight hours.

Out 3 is one for the embodiment according to 1 particularly suitable integrated heat exchanger shown schematically. It On the one hand is a tube-in-tube cooling coil arrangement 14 and on the other to one with a cold-storing substance 16 filled, preferably outside heat-insulated storage tank 15 into the tube-in-tube cooling coil assembly 14 is immersed. Through an outer tube 14A the circulation medium (R134a) of the primary circuit (first coolant circuit) flows. The outer tube 14A includes the evaporator 6 , Through an inner tube 14B the z. B. consisting of water and antifungal circuit medium of the secondary circuit (second coolant circuit). The cold-storing substance 16 in the storage tank 15 can z. Example, a water / antifungal mixture include, which is not circulated in the rule and is in the preferred temperature range between + 1 ° and -5 ° in liquid form. Semisolid and solid cold-storing substances can also be used. Outside the storage tank 15 is the inner tube 14B from the outer tube 14A led out and arranged separately. Inside the storage tank 15 serves the inner tube 14B as the the evaporator 6 (on its outside) containing heat exchangers 8th between the primary and secondary circuits.

The cooling medium 1A the primary circuit transmits its cooling energy by indirect heat transfer but also on the cold-storing substance 16 - and not just on the cooling medium 2A of the secondary circuit. It uses the outer tube 14A as a heat exchanger. In this way can be discharged with high efficiency cooling both to the secondary circuit and cold storage to its charge.

When unloading the cold storage acts between the cold accumulating substance 16 and the secondary circuit interposed pipe wall of the outer tube 14A including that of the outer tube 14A included amount of first cooling medium 1A comparatively to the cooling release to the cooling medium 2A the second coolant circuit, but without hindering the discharge of the cold storage.

According to the in 2 illustrated second embodiment and the particular embodiment according to 4 , is the first coolant circuit 1 in essence identical to the first embodiment. Only the one with the evaporator 6 provided integrated heat exchanger 6 . 8th . 9 ' constructed differently, as will be explained below. In the case of the second embodiment, the cold is directly to one in the evaporator and the heat exchanger 8th integrated liquid / air heat exchanger 9 ' delivered as described below. It thus eliminates a pure transport cycle, as in the first embodiment. Optionally, however, a cold storage circuit is provided, as described below:
An integrated heat exchanger preferred for use with the second embodiment will now be described in connection with 4 explained. Its structure agrees with the structure so far 3 agree that an outer tube 14A a tube-in-tube cooling coil arrangement 14 the cooling medium 1A the primary circuit, z. B. R134a leads, wherein in its interior, in particular coaxially extending inner tube 14B is arranged, within which the second cooling medium 2A , z. B. What ser, optionally with a solidification temperature lowering additive, such as anti-cavities, is provided.

Unlike the integrated heat exchanger after 3 is a cooling coil arrangement 14 receiving storage container is not provided. Instead circulates in the inner tube 14B a cold-storing fluid 16 by gravity flow or, as not shown, with the assistance of a fluid pump. Outside the actual heat storage is an additional memory 12 ' , at spaced-apart ends of the inlet and outlet of the inner tube 14B fluid-conducting receives. The second "coolant circuit 2 "Thus includes next to the inner tube 14B Possible connecting lines and the preferably outside lying additional memory 12 ' and possibly a circulation pump. The inner tube 14B is thus at the same time part of a storage container 15 for a cold-storing, preferably but not necessarily, fluid cold storage substance 16 , But it can also be fixed cold storage substances in the inner tube 14B be provided.

The snake arrangement 14 is in a known manner with a variety of closely spaced metal fins 17 provided for heat exchange with the air conditioning air. The slats 17 are part of the heat exchanger 9 ' for cooling the air conditioning air and allow a passage for air conditioning air.

The operation of the integrated heat exchanger after 4 is now the one that the outer tube 14A includes the evaporator of the primary circuit and on its outside cold to the fins 17 for removal by the air conditioning air transmits. Likewise, cold is on the inner tube 14B transferred, which part of the cold storage 12 is and with sufficient supply of cooling energy or lack of cold demand on the slats 17 (an evaporator fan is switched on) Cold to the cold accumulating substance 16 emits.

If the vehicle drive motor is not running, now can be cold in the storage tank 15 be removed until it is completely discharged. If there after the refrigeration demand is still pending, the refrigerant compressor from the on-board battery can be supplied with electric current, as also explained in the first embodiment.

1

first Coolant circulation

1A

cooling medium

2

second Coolant circulation

2A

cooling medium

3

Refrigerant compressor

4

capacitor

5

expansion valve

6

Evaporator

7

Refrigerant pump

8th

heat exchangers

9

Liquid / air heat exchanger

9 '

Liquid / air heat exchanger

10

Vehicle Standklimaanlage

11

Evaporator fan

12

cold storage

12 '

additional memory

13

Air distribution means

14

Cooling coil arrangement

14A

outer tube

14B

inner tube

15

storage container

16

cold retaining substance

17

slats

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 85/03603 [0006]

Claims (15)

A method of operating a stationary air conditioning system in a vehicle using two coolant circuits connected by heat exchange means and at least one cold storage tank, at least in vehicle stoppage phases, wherein a first coolant circuit comprises at least a refrigerant compressor, a condenser, an expansion valve and an evaporator and a second coolant circuit comprises at least one evaporator of the first coolant circuit-containing heat exchanger for cold absorption and a liquid / air heat exchanger for delivery of air conditioning refrigeration and, optionally, a refrigerant pump, characterized in that the refrigerant compressor is drive-electrically independent of the vehicle drive motor by means of low voltage electrically operated to charge the cold storage with sufficient supply of electrical energy and air conditioning cold at the liquid / air heat exchanger provide when the cold storage is discharged in stoppages of the vehicle drive. Method according to the preamble of claim 1, in particular according to claim 1, characterized in that when existing refrigerant pump the second refrigerant circuit stored and / or simultaneously generated by means of this refrigerant refrigerant refrigerant over one of the first cycle medium of the first coolant circuit and independent of the cold storage second Circulation medium to the liquid / air heat exchanger emits. Method according to the preamble of claim 1, in particular according to claim 1, characterized in that the second coolant circuit Part of a cold storage is and of one of the Cooling medium of the first Kühlmit tel-cycle independent flows through the second cooling medium and that both cooling circuits in the area of the evaporator of the first coolant circuit and of it containing Heat exchanger of the second coolant circuit Cold to the liquid / air heat exchanger submit directly. The method of claim 3, wherein the cold storage is not flowed through by a cooling medium, but the cold-storing substance rests. Method according to the preamble of claim 1, in particular according to one of claims 1 to 4, characterized that the cold storage with the evaporator of the first coolant circuit and with the containing the evaporator for cold absorption Heat exchanger of the second coolant circuit is summarized to a heat exchanger unit. Method according to the preamble of claim 1, in particular according to one of claims 1 to 5, characterized by the Use of a tube-in-tube system for the evaporator and the heat exchanger containing it. Two vehicle air conditioner by heat exchange means ( 8th ) connected coolant circuits ( 1 . 2 ) and with at least one charge and discharge cold storage ( 12 ), in which a first coolant circuit ( 1 ) at least one refrigerant compressor ( 3 ), a capacitor ( 4 ), an expansion valve ( 5 ) and an evaporator ( 6 ) and in which a second coolant circuit ( 2 ) at least one the evaporator ( 6 ) of the first coolant circuit ( 1 ) containing heat exchanger ( 8th ) for cold absorption and a liquid / air heat exchanger ( 9 ) for the delivery of air conditioning refrigeration, and optionally a refrigerant pump ( 7 ), characterized in that the refrigerant compressor ( 3 ) is mechanically independent of the drive train drive motor and can be electrically operated by means of low voltage in order to supply the cold storage ( 12 ) to charge with sufficient supply of electrical energy and to provide air conditioning refrigeration at the liquid / air heat exchanger when the cold storage is discharged in stoppages of the vehicle drive. Vehicle air conditioner according to the preamble of claim 7, in particular according to claim 7, characterized in that the second coolant circuit ( 2 ) with one of the cold storage ( 12 ) independent second cycle fluid ( 2A ) is filled. Vehicle air conditioner according to the preamble of claim 7, in particular according to claim 7 or 8, characterized in that the cold storage ( 12 ) with the evaporator ( 6 ) of the first coolant circuit ( 1 ) and with which the evaporator ( 6 ) for the purpose of containing cold heat exchanger ( 8th ) of the second coolant circuit ( 2 ) is combined to a heat exchanger unit. Vehicle air conditioner according to the preamble of claim 7, in particular according to one of claims 7 to 9, characterized by a tube-in-tube system, wherein the one tube the evaporator ( 6 ) of the first coolant circuit ( 1 ) and in which the other tube the cooling medium ( 2A ) of the second coolant circuit ( 2 ) in the area of the heat exchanger ( 8th ) of the second coolant circuit ( 2 ). Vehicle air conditioner according to the preamble of claim 7, in particular according to one of claims 7 to 10, characterized in that the second coolant circuit ( 2 ) Part of the Cold storage ( 12 ) and one of the cooling medium ( 1A ) of the first coolant circuit ( 1 ) receives independent second cooling medium and that both coolant circuits ( 1 and 2 ) in the area of the evaporator ( 6 ) of the first coolant circuit ( 1 ) and the heat exchanger containing it ( 8th ) of the second coolant circuit ( 2 ) Heat exchange means, such as lamellae ( 17 ), for direct delivery of cold air to an air conditioning. Vehicle air conditioner according to claim 11, characterized by an additional memory ( 12 ' ) derived from the second cooling medium ( 2A ) or a cold-storing substance ( 16 ) in the circuit with the cold storage ( 12 ) can be flowed through. Vehicle air conditioner according to one of the claims 10 to 12, characterized in that the cold storage with the evaporator of the first coolant circuit and with the containing the evaporator for cold absorption Heat exchanger of the second coolant circuit is summarized to a heat exchanger unit. Vehicle air conditioner according to claim 10 or 13, characterized in that the evaporator ( 6 ) and the cold storage ( 12 ) in the area of the liquid / air heat exchanger ( 9 ' ) are designed as a tube-in-tube system. Vehicle air conditioner according to one of the claims 7 to 9, characterized in that the cold storage is not flowed through by a cooling medium, but the cold-storing substance rests.