DE102005001231A1 - Air conditioning for motor vehicles - Google Patents

Abstract

The present invention discloses an air conditioner for heating and cooling a Innenraumzuluftstroms of a motor vehicle having a refrigerant circuit (1), a refrigerant compressor (4) for compression of substantially gaseous refrigerant to a high pressure and temperature level, a refrigerant compressor (4) downstream of the first Heat exchanger (5) for removing heat from the refrigerant, a first valve unit (20, 21) and a high-pressure side of a second heat exchanger (10) for transferring heat to the refrigerant, on which the refrigerant is cooled below ambient temperature, a second valve unit (7, 22) capable of relaxing the refrigerant, having an indoor heat exchanger (8) for bringing the refrigerant to ambient temperature and a low pressure side of the second heat exchanger (10) for energy exchange with the high pressure side of the second heat exchanger (10). The first heat exchanger (5) is designed as a refrigerant / heat transfer fluid heat exchanger, wherein the heat transfer fluid in a second circuit (2) is guided over the heat from the refrigerant circuit to Innenraumzuluftstrom transferable or deliverable to the environment (35, 36). All components of the refrigerant circuit (1) are always flowed through in one direction.

Description

The The invention relates to an air conditioning system for motor vehicles.

From the EP 0 823 344 B1 a vehicle air conditioning system with continuous refrigerant flow is known, are formed in the heat exchanger for cooling and heating in a special air conditioner. The temperature control and ventilation of the vehicle cabin is done with this air conditioner. In the embodiment, in particular, a vehicle without conventional engine coolant (electric vehicle) is considered. On a 4/2-way valve for reversing the flow direction in the refrigeration cycle is omitted here. The switching between cooling and heating is done by appropriate deflection and barriers in a likewise disclosed, provided for this purpose air conditioner.

Especially This prior art discloses a vehicle air conditioner continuous refrigerant flow, in the cool Air through a face-side air outlet even under the condition supplied that can be a refrigerant continuously flows through a refrigerant condenser, without that the cold air through the refrigerant liquefier again heated becomes. The air conditioning system has a duct with a face-side air outlet for blowing air towards an upper body of a Passenger, a defroster air outlet for blowing air in Direction to a windshield and a foot-side air outlet for blowing out the air towards the passenger's feet on. Furthermore, a refrigeration cycle with a refrigerant evaporator, in the channel for cooling the air through heat exchange with a low temperature refrigerant is arranged, which flows in it, and with a refrigerant liquefier, in the channel on a downstream side of the refrigerant evaporator is arranged to heat the air by heat exchange with a high temperature refrigerant to warm, that flows in it, educated. The refrigerant circuit is formed such that the refrigerant to the refrigerant condenser continuously stream is left, with the face-side air outlet on an upstream side of the refrigerant liquefier is arranged. This is an opening / closing flap on the air inlet side of the refrigerant condenser trained in the cooling mode is closed, so that prevents the cooled by the refrigerant evaporator air flows into the refrigerant condenser. So will prevents continuous flow of the refrigerant through the refrigerant condenser warm air with the cool Air mixes. In heating mode, the outside air is heated by the refrigerant condenser.

Farther is from WO 03/064194 A1 an air conditioner for cooling and Heating provided, with a channel system, by means of a switching valve the optional operation of two having a common compressor System areas allows. In this case, the first system area including one arranged in a ventilation housing Vaporizer's for a cooling operation required components, while intended for a Zuheizbetriebe second system area in addition to the compressor essentially only an expansion valve and a a heater serving heating heat exchanger having.

Especially This document describes an air conditioner with a simplified Circuit of a heat pump, a "hot Gas Cycle "as a cost effective way the auxiliary heating with an AC system. Only the heat of compression becomes Heating used and no heat from the environment or other source. However, for that reason the efficiency is poor and the extra consumption for a comfort increasing Zuheizung high.

Furthermore, the disclosure DE 101 63 607 A1 an air conditioning system for a motor vehicle with an integrated heat pump for cooling and heating, is circulated in the refrigerant and which allows heat exchange with the Innenraumzuluft of the motor vehicle. The heat transfer takes place either directly by means of a refrigerant / air heat exchanger through which the interior air can flow, or by means of a secondary refrigerant circuit. In the refrigerant circuit of the heat pump two expansion devices and three heat exchangers are provided.

Problematic at conventional Air conditioners, however, it is that very high maximum component temperatures occur, a heat pump very complex is itself refrigerant in the air conditioning cycle with changing operation cooling / heating shifts and / or seeped and / or differences in fill with the refrigerant for cooling and Heating operation and heat losses can occur during heating (due to a low heat capacity of the components).

Therefore It is an object of the present invention, an air conditioner such educate that reliable and cost-effective significantly reduced component temperatures are obtained, a robust, efficient heat pump obtained with the least complexity and the cooling and heating operation a high level of operational safety.

According to the invention this object is achieved by an air conditioner with the features of claim 1 solved. In the dependent claims advantageous developments of the invention are given.

at the air conditioning system of the invention heat dissipation takes place from the refrigeration cycle at Cool and an introduction of heat for heating continuously over a motor cooling, without a distinction as to whether the air conditioner is in a heating or cooling mode located. Switching valves for reversing the refrigerant flow direction can be dispensed with become. Avoiding the heating operation is not done by a complicated circuit of the air flow in the air conditioner, so that conventional air conditioners can be used. Due to the continuous flow direction in the circuit, i.e. of flowing through of all components in the same direction, no infiltrations or Displacements of refrigerant or oil out. The high refrigerant outlet temperature on a compressor is significantly reduced in advance, so that the following Components are easier to run due to low component temperature can.

These and other objects, features and advantages of the present invention will become apparent from the following description of a preferred embodiment of the invention.

following the invention will now be described with reference to a preferred embodiment explained in connection with the drawing.

there shows:

1 a block diagram of an air conditioner according to the invention.

The following will now be first with reference to 1 the structure of an air conditioner according to the invention explained in more detail.

In 1 shows a first circuit connected in series successively one behind the other a compressor 4 , a refrigerant / engine coolant heat exchanger 5 , a first valve unit in which a first expansion valve 20 and a first shut-off valve 21 connected in parallel, a gas cooler / condenser 6 , an internal heat exchanger 10 , a second valve unit, in which a second expansion valve 7 and a second shut-off valve 22 are connected in parallel, an evaporator or indoor heat exchanger 8th and an accumulator or (refrigerant) collector 9 includes. The compressor 4 is adjustable with respect to its refrigerant mass flow. Also controllable are the first and the second valve unit 20 . 21 and 7 . 22 ,

In a second circuit, the refrigerant / engine coolant heat exchanger is successively successively in series 5 , a heating pump 30 , a first and a second switching valve and a heating heat exchanger 31 contain. The first and second switching valve 32 . 33 are 3/2-way valves, over which the circuit with the engine 34 connected or the engine 34 can be bypassed.

The in 1 shown first cycle works as indicated below. In the compressor 4 The refrigerant is compressed to a high pressure and a high temperature. When leaving the compressor, the refrigerant is ideally gaseous. As a refrigerant, for example, CO ₂ or R134a can be used. This gaseous refrigerant then enters the refrigerant / engine coolant heat exchanger 5 in which heat is given to the engine coolant, which consists for example of water or a glycol / water mixture, and thereby the refrigerant is cooled.

Subsequently, the cooled refrigerant enters the first valve unit 20 . 21 one.

In the case of refrigeration, the expansion valve 20 and the shut-off valve 21 open, leaving in the expansion valve 20 no throttle effect occurs and the refrigerant is the valve unit 20 . 21 happened without further influence. Then the pre-cooled refrigerant enters the gas cooler / condenser 6 one. The gas cooler / condenser 6 is flowed through, thus forming an ambient heat exchanger, which cools the gaseous refrigerant and condenses to ambient temperature.

Subsequently, the condensed refrigerant on the high pressure side enters the inner heat exchanger 10 in which the refrigerant is cooled below ambient temperature. Thereafter, the further cooled refrigerant enters the valve unit 7 . 22 in which the shut-off valve 22 is closed and throttling through the expansion valve 7 takes place so that the refrigerant is released from a high pressure level to a low pressure level and thereby also cooled. Subsequently, the still further cooled refrigerant at a low pressure level to the evaporator or indoor heat exchanger 8th supplied, which is a connection to the space to be cooled, such as the passenger compartment to be cooled. The evaporator or indoor heat exchanger 8th are located in the air-flow box. There, the warm ambient air is cooled and dehumidified. As a result, the refrigerant is heated and reaches the accumulator or (refrigerant) collector 9 which can also contain a dryer. When passing through the accumulator or (refrigerant) collector 9 the refrigerant does not change state. The quality remains unchanged and it is in the accumulator or (Refrigerant) Collectors 9 only not needed liquid refrigerant stored.

Subsequently, the refrigerant reaches the low pressure side of the inner heat exchanger 10 in which an energy exchange takes place with the high-pressure side. This leads to an energy intake and heating of the refrigerant. This also serves to overheat, so that the refrigerant is again gaseous and gaseous again to the compressor 4 is supplied.

In addition, the first cycle is via the refrigerant / engine coolant heat exchanger 5 Heat deprived, over a radiator 35 . 36 in the summer, ie in cooling, is discharged to the environment, or in the off-season on a heating heat exchanger 31 is used for reheating.

In heat pump mode, ie in the heat generation, however, the refrigerant is after passing through the evaporator 5 and the refrigerant / engine coolant heat exchanger 5 the valve unit 20 . 21 fed. In contrast to the operation for cooling is now the valve unit 20 . 21 so controlled that the shut-off valve 21 is closed and the refrigerant is the expansion valve 20 must happen. By means of the expansion valve 20 throttling occurs, so that the refrigerant is brought to a very low pressure and a very low temperature level below the ambient temperature. Subsequently, the refrigerant takes in the gas cooler / condenser or ambient heat exchanger 6 Heat from the environment, so that it is heated to the ambient temperature, and then passes through the inner heat exchanger 10 without, that there is a heat exchange.

Subsequently, the refrigerant of the valve unit 7 . 22 fed in the heat pump operation both the shut-off valve 22 as well as the expansion valve 7 are open so that any throttle function is off and the refrigerant is the valve unit 7 . 22 unaffected happened and the indoor heat exchanger 8th fed, because it also happens without energy exchange, since the temperature of the refrigerant is equal to the ambient temperature. Then the refrigerant passes through the accumulator or (refrigerant) collector 9 as well as the low pressure side of the inner heat exchanger 10 unaffected, ie without change in state of the gaseous refrigerant, and is then returned to the compressor 4 fed.

In addition, the in the refrigerant / engine coolant heat exchanger 5 heat released from the refrigerant to the engine coolant and outside the starting phase, as soon as the engine is warm, through appropriate switching of the two 3/2-way valves engine heat through a heating heat exchanger 31 as well as the interior heat exchanger 8th in the air box 3 is arranged, delivered to the vehicle interior.

Around to achieve a particular good function of the air conditioning system according to the invention, All components are extremely low pressure loss executed.

Consequently can with the inventive air conditioning a reliable one and cost-effective Air conditioning will be maintained, which will switch to switching facilities the flow direction can be dispensed with, since it is always flowed through in one direction, and has significantly reduced component temperatures, so that, for example Berstsicherheit with less material is possible.

moreover is the air conditioner according to the invention robust and efficient while they as low as possible complexity has only three additional components needed become. The remaining Components of an air conditioning cycle can be unchanged or with fewer requirements continue to be used.

Farther can the for the air conditioning necessary sensors and security elements used unchanged become.

The Packaging is for an AC system with or without a heat pump identical except for one component.

The heat loss from the compressor outlet to the entry of heat into the refrigerant / coolant heat exchanger are very small due to the short lines.

Besides that is Operational safety during cooling and / or heating, as the refrigerant circulates continuously and not to a refrigerant and or oil shift comes and the refrigerant not in the e.g. not at heat pump operation used plant parts for the AC operation, so that at the compressor always a sufficient Sauggasdichte present at the compressor inlet.

by virtue of the low-pressure execution of the Components the AC system when cooling over a very high efficiency.

The refrigerant side Additional volumes for the heat pump function are very low, so look for required the AC and WP operation Refrigerant mass practically does not change.

As needed for the air conditioning system according to the invention only a few additional components There are only a few additional connection points. This has an advantageous effect on costs and leakage.

There an introduction of heat for heating in the air conditioner about a heating heat exchanger done, deleted any risk of the disc fitting or even flash fogging.

Finally is the control of the air conditioning very easy. The air conditioning will operated until the cooling water reached the corresponding temperature. The switching off and on the air conditioning is regarding of comfort not noticeable.

Claims (10)

Air conditioning system for heating and cooling an interior airflow of a motor vehicle, comprising: a refrigerant circuit ( 1 ), which is a refrigerant compressor ( 4 ) for the compression of substantially gaseous refrigerant to a high pressure and temperature level, a refrigerant compressor ( 4 ) downstream first heat exchanger ( 5 ) for heat removal from the refrigerant, a first valve unit ( 20 . 21 ) and a high pressure side of a second heat exchanger ( 10 ) for transferring heat to the refrigerant, on which the refrigerant is cooled below ambient temperature, a second valve unit ( 7 . 22 ), which can relax the refrigerant, an indoor heat exchanger ( 8th ) for bringing the refrigerant to ambient temperature and a low pressure side of the second heat exchanger ( 10 ) for energy exchange with the high-pressure side of the second heat exchanger ( 10 ), characterized in that the first heat exchanger ( 5 ) is formed as a refrigerant / heat transfer fluid heat exchanger, wherein the heat transfer fluid in a second circuit ( 2 ) is guided over the heat transferable from the refrigerant circuit to the interior air supply or can be delivered to the environment ( 35 . 36 ), and all components of the refrigerant circuit ( 1 ) are always flowed through in one direction. Air conditioning system according to claim 1, characterized in that the first and second valve units ( 20 . 21 . 7 . 22 ) each have a shut-off valve ( 21 . 22 ) and a parallel connected expansion valve ( 20 . 7 ), wherein in the refrigeration, the first valve unit ( 20 . 21 ) is fully open, so that the refrigerant can pass without interference, and in the second valve unit ( 7 . 22 ) the shut-off valve ( 22 ) is closed and by the expansion valve ( 7 ) a relaxation from a high to a low pressure level, by which the refrigerant is cooled and brought to a lower pressure level, while in the heat generation in the first valve unit ( 20 . 21 ) the shut-off valve ( 21 ) is closed and by the expansion valve ( 20 ) a relaxation of the refrigerant to a very low pressure and temperature level and the second valve unit ( 7 . 22 ) is fully open so that the refrigerant can pass without interference. Air conditioning system according to claim 1 or 2, characterized in that the refrigerant circuit ( 1 ) following the first valve unit ( 20 . 21 ) an ambient heat exchanger ( 6 ), which cools the gaseous refrigerant and condenses to ambient temperature. Air conditioning system according to claim 3, characterized in that the ambient heat exchanger ( 6 ) is a gas cooler, in which the refrigerant is cooled or heated to ambient temperature. Air conditioning system according to one of claims 1 to 4, characterized in that all components of the refrigerant circuit ( 1 ) are executed extremely low pressure loss. Air conditioning system according to one of claims 1 to 5, characterized in that the heat transfer fluid in the second circuit ( 2 ) Is water or a glycol / water mixture. Air conditioning system according to claim 2, characterized in that the first shut-off valve ( 21 ) is actively controlled while the second shut-off valve ( 22 ) is pressure controlled. Air conditioning system according to one of claims 1 to 7, characterized in that the refrigerant compressor ( 4 ) brings the refrigerant to a high pressure and temperature level. Air conditioning system according to one of claims 1 to 8, characterized in that the refrigerant on the high-pressure side of the second heat exchanger ( 10 ) is cooled below ambient temperature, as far as this has not yet done in upstream components. Air conditioning system according to one of claims 1 to 9, characterized in that the second circuit ( 2 ), two 3/2-way valves ( 32 . 33 ) and a heating heat exchanger ( 31 ), so that between a heat transfer to the environment via a radiator ( 35 . 36 ) or a heating of the vehicle interior via the heating heat exchanger ( 31 ) either using only the heat from the refrigerant / engine coolant heat exchanger ( 5 ) or with additional use of engine heat can be switched.