DE102006061436B3 - Cooling system e.g. vapor stream cooling system, operating method for e.g. passenger car, involves discharging cooling agent fluid in cooling agent evaporator, and cooling surrounding air in evaporator, where passenger compartment is loaded - Google Patents

Abstract

The method involves feeding mixed vapor from vapor stream-injector (8) of a condenser (9), in which a cooling agent-solvent-mixture is condensed and extracted back to a generator (4) via cooling agent-/solvent line and supply pipe (20, 21). Exhaust gases from a dehumidifier (3) is discharged into the generator, such that the mixture is vaporized. A cooling agent-/solvent vapor is fed to a rectifier (6). A cooling agent fluid is discharged in a cooling agent evaporator (7), and the surrounding air is cooled in the evaporator, where a passenger compartment is loaded.

Description

The The invention relates to a method for operating a refrigeration system in vehicles with internal combustion engine and a refrigeration system for vehicles with internal combustion engine.

since heard in a few years a powerful Air conditioning, which is capable of the increasingly frequent hot days in the passenger compartment of motor vehicles to create a pleasant climate already standard equipment.

It become more powerful and offered smarter systems that are largely automatic the temperature level either according to seating areas even at extreme changing outside temperatures and keep strong sunlight at a predetermined level can.

The hitherto widespread systems all have a decisive disadvantage which, among other things, leads to that air conditioning systems are not yet available in all vehicles. They strain the internal combustion engine of the drive and consume additional energy. in the form of increased fuel consumption, which is no longer driving to Available. They make driving more expensive and increase pollutant emissions in the combustion process of the drive motor.

Generally It is assumed that depending on driving style today's modern air conditioning systems an additional consumption compared the same driving style without air conditioning from one to two liters and can cause more fuel per 100 km and a power loss of about 10 hp occurs.

The Cause for it is due to the widespread operating principle of today's air conditioning systems. It become compressor refrigerators used, the compressor for the compression of the refrigerant usually sitting directly on the crankshaft and so drive energy and drive power consumed. On the other hand, falls during operation of a motor vehicle in considerable Scope of unused energy in the form of heat.

One modern internal combustion engine uses, as is well known, the him only about 26% (petrol engine) and 33, respectively % (Diesel engine) off. 34 percent are released to the environment as exhaust gas, 32% of the energy is lost through engine cooling and about 8% are other losses, exemplified by the internal friction. The available Waste heat potentials currently remain almost unused.

Absorption chillers, the heat for the production of cold use (thermal compressor) have long been known and become e.g. used for "Absorberkühlschränke." For the camping area there it also has refrigerators that Thermal energy for the Expeller next to electric vehicle batteries also from propane gas Respectively. Such systems have the advantage of almost noiseless to run, but consume far more energy than cooling systems with mechanical compressor.

It Systems are also offered and operated, the heat generated, such as e.g. Solar energy, or waste heat from biomass combustion. But there are more complex procedures required because the waste heat only indirectly via further heat exchangers supplied can be.

For air conditioners in motor vehicles are currently no corresponding systems for the practical Offered, which the heat loss from the exhaust system or the muffler system can use directly.

Out The literature is known to deal with such technology. As far as known, such systems use the cooling circuit as an energy source for one Cooling.

US 2,783,622 A describes for automobiles with an internal combustion engine, an air conditioning system on the principle of an absorption refrigeration system (with lithium bromide), the expeller of said plant is in a heat exchange with the exhaust system. Here, an exhaust pipe from the main system is branched from the exhaust system and equipped this branch with a complex heat exchanger. Other components of the exhaust system for heat transfer are not used.

The DE 23 49 346 A1 Provides air conditioning for a vehicle. The system is characterized in that it is connected to the cooling circuit or to the exhaust system of the vehicle as an energy source. It further describes that it has a connected to the cooling circuit and the exhaust system of the vehicle engine generator for heating and evaporation of the coolant flowing through it by utilizing the heat of the vehicle engine, which is connected upstream of the condenser. Further claims detail the known principle of Absorpti onsanlage. Information for the use of the heat exchanger in the exhaust system, the font can not be found.

The utility model application DE 19 86 946 U describes a device for cooling the interiors of motor vehicles according to the absorption principle. It is characterized in that a boiling of the absorption cooling device is connected to the hot line of the liquid cooling device of the drive motor.

DE 27 56 348 A1 discloses a combustion engine motor vehicle with a system for controlling the temperature of a passenger or utility room open. It contains a cooling system and is characterized in that it is formed with a circulating binary mixture of solvent and refrigerant and with a heatable expeller, wherein the expeller is fed by the waste heat from waste heat generating drive units of the vehicle. By arranging a heat exchanger in the exhaust pipes and the waste heat of the exhaust gases could be utilized.

DE 28 54 937 A1 , an addition to the above application describes a powered by a waste heat generating liquid-cooled internal combustion engine Absorbtionskälteanlage with a powered by the heat of the internal combustion engine expeller. In this document, the arrangement for heat transfer of waste heat in the exhaust system is not solved.

DE 32 07 383 A1 describes a cooling device for an internal combustion engine of vehicles, which consists of an absorption cooling unit, the heater is used as a heat exchanger and is applied to the heat generated by the internal combustion engine, wherein he Absorbtionskühlein belonging capacitor and evaporator via a ventilation system with either the interior of the vehicle or the environment is connected. Here, claim 6 describes a cooling device, characterized in that the heater with the hot exhaust gases of the internal combustion engine is acted upon directly or indirectly via a built-in exhaust pipe gas water or gas-oil heat exchanger. This system has the disadvantage that this gas-water or gas-oil heat exchanger requires a further fluid circuit and thereby only provides an indirect heat transfer of the waste heat of the exhaust pipe to the heater.

So far are not yet known systems that are suitable for retrofitting and / or the exhaust heat directly without further heat transfer for the expeller a chiller to be able to use.

task The invention is a method for direct use of heat loss use the vehicle exhaust system as an energy source for refrigeration and thereby reducing energy consumption. The to be developed refrigeration plant should also be for a subsequent one Installation in vehicles be suitable.

According to the invention Problem solved by the features of claim 1 and 8. Ausgestaltende Features are in the subclaims 2 to 7 and 9 to 12 described.

The inventive method for operating a refrigeration system in vehicles with internal combustion engine is characterized that at least part of the exhaust fumes as a direct source of energy for one Steam jet cooling be used. These are coming from the internal combustion engine Exhaust gases are fed to a dehumidifier, in the motive steam is dehumidified from an expeller or a rectifier. This Driving steam is supplied to a steam jet injector, in which the motive steam at supersonic speed is accelerated. As a result, a negative pressure for a refrigerant evaporator is generated by which the refrigerant from the refrigerant evaporator is sucked off. The mixed steam from the steam jet injector becomes one Condenser fed, in which condenses the refrigerant-solvent mixture and over a refrigerant / solvent line is promoted back to the exporter.

The Exhaust gases from the dehumidifier are introduced into the expeller, causing there the refrigerant-solvent mixture is evaporated. The exhaust gases from the expeller are derived. Of the Refrigerant / solvent vapor is fed to the rectifier, in which the refrigerant is condensed or the refrigerant from the solvent separated by their different boiling / condensation temperatures if different refrigerants and solvent be used. When using only one substance as cold or Solvent, for example, only water would the rectification also work. The measure of the Rectifier to condensing refrigerant is in the case on the Cross section of the openings determined at the intermediate bottom of the rectifier.

The Refrigerant liquid is in the refrigerant evaporator initiated here the ambient air cooled and a passenger compartment fed. When using methanol or ethanol, however, these substances take over at the same time the function of frost protection. Other conventional refrigerants or Refrigerant-solvent pairings are also possible.

in the Dehumidifiers can not only dehumidify the motive steam, but also be heated. You can set the intensity of dehumidification and possibly the additional overheating through the supplied exhaust gas flow. Conceivable would be a throttle, the Controlling the amount of exhaust gases introduced and possibly automated can.

In order to achieve cooling even before departure, when the engine is off or on long downhill runs, the dehumidifier with egg nem additional, independent of the exhaust exhausts hot air flow are fed. The exhaust gases from the expeller are introduced into the exhaust or discharged via a silencer directly to the environment.

The from the condenser by means of a pump to the expeller promoted refrigerant-solvent mixture can over directed to the rectifier and heated there. In the rectifier this stream of cooling serves whereby the separation of the refrigerant-solvent mixture being affected.

One Part of the generated cold air stream can be diverted and for cooling the Combustion air for the Engine for a charge air cooling be used.

The refrigeration system according to the invention consists of a steam jet refrigeration system which is integrated in the vehicle. The structure is as follows:
From the exhaust pipe coming from the engine, an exhaust pipe goes to a dehumidifier and on to an expeller. The branch can be done for example by means of a throttle valve. From the dehumidifier, a motive steam line leads to a steam jet injector into which a vacuum steam line is also introduced from a refrigerant evaporator. From the steam injector, a mixed steam line leads to a condenser and from there via a refrigerant-solvent line to the expeller. From the generator, an exhaust pipe goes to the exhaust or through a silencer directly to the outside. From the expeller, a mixture vapor line leads to a rectifier. From there, a steam connection line goes to the dehumidifier and a refrigerant line to the refrigerant evaporator, in which a cold air flow is generated and fed to a passenger compartment. The dehumidifier, the expeller, the evaporator and the condenser are designed as recuperative heat exchangers.

Of the Dehumidifiers and thus also the expeller can additionally to a heater be connected.

The Refrigerant-solvent mixture can coming from the capacitor also over directed to the rectifier.

Of the Excavator, dehumidifier and rectifier can directly be summarized in an assembly. It is also conceivable that the injector and the capacitor are combined in an assembly are.

With the solution according to the invention is it is possible the first in the considerable Scope incurred otherwise unused, the overall energy balance deteriorating heat loss the exhaust system directly to the refrigeration for a we kungsvolle Air conditioning and further positive influence on the drive and driving system with the effects shown in the objective to use. With the intended goals surpasses the intended solution the state of the art. For the users are mobilized with significant cost-effective effects.

The Essence of the invention consists in the space-saving use of otherwise unused engine waste heat. Absorption chillers are generally applicable, but they are due to their size, the extensive apparatus construction and due to their sensitivity with changing accelerations, such as braking and accelerating, hardly suitable to be used in a small vehicle. The simple one Apparatus construction in a steam jet refrigeration plant, in particular at a single-material steam jet cooling plant, makes the use possible even in small vehicles.

following the invention is based on an embodiment explained in more detail. It shows:

1 Circuit diagram of a steam jet refrigeration system in the vehicle

It should a refrigeration system for passenger cars be used with an internal combustion engine, where the exhaust gases directly for energy production for a refrigeration system be used.

The structure and operation are as follows:
In a diesel engine with a clutch power of up to 81 kW, the loss energy due to exhaust gas losses is approx. 81.5 kW.

The exhaust gas temperature measured at full load can be sufficiently accurate with 530 ° C are assumed.

at a gasoline engine, the losses are even higher. In these engines, the exhaust heat output is that is about 1.4 times the engine power. The exhaust gas temperature, measured directly at the engine outlet, could with 630 ° C be determined.

The Cooling system according to the invention contains three Circuits, an exhaust gas circuit, a steam jet circuit and a refrigerant circuit.

Exhaust circuit:

Part of the engine 1 coming exhaust gases is by throttle 11 branched off the exhaust stream and via an exhaust pipe 13 the dehumidifier 3 and subsequently via an exhaust pipe 14 the exporter 4 fed. The rest of the exhaust gases is about a middle silencer 2 in an exhaust pipe 5 derived to the exhaust. The energy of the exhaust gases used in these components of the thermal compression of the refrigerant-solvent mixture. The cooled exhaust gases are via the exhaust pipe 15 returned to the exhaust.

Steam circuit:

The refrigerant is methanol and the solvent used is water. Also conceivable are ethanol or other commercially available refrigerants. In the expeller 4 the refrigerant / solvent mixture is vaporized, thereby allowing separation by different boiling temperatures. The refrigerant vapor rises via a mixture vapor line 16 to the rectifier 6 up and is condensed there. The propellant vapor also rises above the mixture vapor line 16 in the lower floor of the rectifika sector 6 on and from there via the steam connection line 17 at about 180 ° C to the dehumidifier 3 , This ensures that anhydrous and slightly superheated motive steam via the motive steam line 18 with about 190-200 ° C to the steam jet injector 8th arrives.

The task of the steam jet injector 8th consists in the generation of the negative pressure via the vacuum steam line 23 for the refrigerant evaporator 7 , For this purpose, the motive steam is accelerated to a supersonic speed with the aid of a De-Lavall nozzle, which is at about 1.3 Mach.

The negative pressure in the refrigerant evaporator 7 is 0.08 bar. This can generate a minimum temperature of 13 ° C in the passenger compartment. The risk of icing of the refrigerant evaporator 7 is not given. The heat exchanger surface is more than sufficient due to the much higher specific heat capacity of the methanol used compared to a common refrigerant for refrigeration systems, such as R134a.

About a mixed steam line 19 the mixed steam comes from the steam jet injector 8th to the condenser 9 , Here, the refrigerant-solvent mixture is condensed and at a temperature of about 35 ° C via the refrigerant-solvent line 20 to the pump 10 and via the refrigerant-solvent feed line 21 to the exporter 4 conveyed back.

Refrigerant circuit:

The refrigerant passes over the refrigerant line 22 from the rectifier 6 to the refrigerant evaporator 7 , In the refrigerant evaporator 7 There is a negative pressure, which from the steam jet injector 8th is produced. With the refrigerant vapor is the ambient air flow 24 cooled and fed as cold air flow of the passenger compartment.

at a passenger car occupied by 5 persons, which is full Sun exposure is exposed, the refrigeration system has an output of 1.8 kW to cool the passenger compartment from 35 ° C to 18 ° C.

The exhaust gases leave the engine 1 with a temperature between 450 ° C and 630 ° C. The specific exhaust gas quantity is on average 11.11 kg / l gasoline. In our example, this corresponds to an idling exhaust gas quantity of 0.00216 kg / s and a throttle exhaust gas quantity of 0.022287 kg / s. The exhaust gas power at idle is 2.42 kW, so that a cooling capacity of 1.36 kW can be generated. In order to produce the required cooling capacity even when idling, the system can be equipped with auxiliary heating 12 be combined, which generates the missing heat output of about 0.8 kW. This heater 12 can also be used to cool the vehicle to approximately 22 ° C before the occupants occupy it. Thus, the periods of occupation of the vehicle are avoided or reduced to the complete cooling of the vehicle to the desired interior temperature. To achieve this is a heat output of the auxiliary heater 22 of about 1.1 kW required. This would allow the vehicle to be cooled to 22 ° C even if left exposed to direct sunlight at a temperature of 35 ° C in the shade.

The expeller 4 is a recuperative shell-and-tube heat exchanger that extracts energy from the exhaust gases of the engine. The energy extracted from the exhaust gases serves to thermally compress the refrigerant-propellant mixture. The dehumidifier 3 , the evaporator 7 and the capacitor 9 are also recuperative tube bundle or are also recuperative shell and tube heat exchangers.

The Vehicle exhaust gas will idle to about 10K above ambient temperature cooled. in the Full load range, the cooling takes place of the exhaust gas to about 100 ° C.

After the methanol-water mixture has been evaporated, the constituents in the rectification are separated again. This is possible because of the rectifier 6 is cooled. Conceivable and energetically advantageous is the summary of the rectifier 6 with the expeller 4 and possibly with the dehumidifier 3 ,

About the refrigerant evaporator 7 a cooling capacity of a maximum of approx. 1.8 kW is generated. By way of example, methanol is used here as the refrigerant. This will be 2.25 × 10 ^-3 kg / s of refrigerant evaporated. In countercurrent, the ambient air is cooled from 35 ° C to 18 ° C and blown into the passenger compartment.

The vacuum required for the generation of the cooling power is generated by the steam jet injector 8th , In this steam is expanded with a pressure of maximum 10 bar to about 1 bar, by the resulting suction effect on the injector nozzle, the negative pressure in the refrigerant evaporator 7 generated and kept constant. The resulting methanol-water mixture is in the condenser 9 liquefied and by pump 10 to the exporter 4 conveyed back.

With the refrigeration system according to the invention can a direct use of the heat loss of the vehicle exhaust system as an energy source for the refrigeration used and thereby the energy and fuel consumption be reduced.

The to be developed refrigeration system is both for a new building as well for a subsequent installation suitable for vehicles.

1

engine

2

middle silencer

3

dehumidifiers

4

expeller

5

exhaust pipe

6

Rektifikator

7

Refrigerant evaporator

8th

Steam jet injector

9

capacitor

10

pump

11

throttle

12

Auxiliary heating / auxiliary heating

13

exhaust pipe to the dehumidifier

14

exhaust pipe to the exporter

15

exhaust pipe

16

Mixture steam line

17

Steam line connection

18

Blowing steam line

19

Mixing steam line

20

Refrigerant-solvent line

21

Refrigerant-solvent feed line

22

Refrigerant line

23

Steam pipe under pressure

24

Ambient air flow

25

Cold air flow

Claims (12)

Method for operating a refrigeration system in vehicles with an internal combustion engine, characterized in that at least part of the exhaust gases are used as a direct source of energy for a steam jet refrigeration system by - the exhaust gases exhaust a dehumidifier ( 3 ) are supplied in the motive steam from an expeller ( 4 ) or a rectifier ( 6 ) is dehumidified, - this motive steam a steam injector ( 8th ) is supplied, in which the driving steam accelerates to supersonic speed and thereby a negative pressure for a refrigerant evaporator ( 7 ) is generated, through which the refrigerant is sucked from the refrigerant evaporator, - the mixed steam from the steam jet injector ( 8th ) a capacitor ( 9 ), in which the refrigerant-solvent mixture condenses and via a refrigerant / solvent line ( 20 . 21 ) to the exporter ( 4 ), - the exhaust gases from the dehumidifier ( 3 ) in the exporters ( 4 ), thereby evaporating the refrigerant / solvent mixture there, and the exhaust gases from the expeller ( 4 ), - the refrigerant / solvent vapor the rectifier ( 6 ), in which the refrigerant is condensed, - wherein the refrigerant liquid in the refrigerant evaporator ( 7 ) is introduced and in the refrigerant evaporator ( 7 ) Ambient air is cooled and fed to a passenger compartment. A method according to claim 1, characterized in that the motive steam in the dehumidifier ( 3 ) is overheated. Method according to one of claims 1 or 2, characterized in that the dehumidifier ( 3 ) is fed with an additional, independent of the exhaust gases hot air flow. Method according to one of claims 1 to 3, characterized in that the exhaust gases from the expeller ( 4 ) in the exhaust ( 5 ) be initiated. Method according to one of claims 1 to 3, characterized in that the exhaust gases from the expeller ( 4 ) are delivered via a silencer directly to the environment. Method according to one of claims 1 to 5, characterized in that that of the capacitor ( 9 ) coming refrigerant / solvent mixture in the rectifier ( 6 ) and the rectifier ( 6 ) is cooled thereby. Method according to one of claims 1 to 6, characterized in that a part of the generated cold air stream ( 25 ) is used for cooling the combustion air for the engine (charge air cooling). Refrigeration system for vehicles with internal combustion engine, characterized in that in the vehicle, a steam jet refrigeration system is integrated, in which - by the combustion engine ( 1 ) coming Exhaust pipe an exhaust pipe ( 13 ) to a dehumidifier ( 3 ) and on to an exporter ( 4 ), - from the dehumidifier ( 3 ) a motive steam line ( 18 ) to a steam jet injector ( 8th ), in which also a vacuum vapor line ( 23 ) from a refrigerant evaporator ( 7 ), - from the steam jet injector ( 8th ) a mixed steam line ( 19 ) to a capacitor ( 9 ) and from here via a refrigerant-solvent line ( 20 . 21 ) to the exporter ( 4 ), - by the exporter ( 4 ) an exhaust pipe ( 15 ) goes to the exhaust, - from the expeller a mixture vapor line ( 16 ) to a rectifier ( 6 ), - from the rectifier a steam connection line ( 17 ) to the dehumidifier ( 3 ) and a refrigerant line ( 22 ) to the refrigerant evaporator ( 7 ), in which a cold air flow ( 25 ) is generated and fed to a passenger compartment and - the dehumidifier ( 3 ), the exporter ( 4 ), the evaporator ( 7 ) and the capacitor ( 9 ) are designed as recuperative heat exchangers. Refrigeration system according to claim 8, characterized in that the dehumidifier ( 3 ) and the exporter ( 4 ) to a parking heater ( 12 ) are connected. Refrigeration system according to one of claims 8 or 9, characterized in that the refrigerant / solvent mixture from the condenser ( 9 ) coming via the rectifier ( 6 ). Cooling system according to one of claims 8 to 10, characterized in that the expeller ( 4 ) and / or the dehumidifier ( 3 ) and / or the rectifier ( 6 ) are combined in an assembly. Refrigeration system according to one of claims 8 to 11, characterized in that the injector ( 8th ) with the capacitor ( 9 ) are combined in an assembly.