DE102005012926B4 - Device for expanding the scope of use of a vehicle retrofitted for research purposes - Google Patents

Abstract

cooling device for cooling in largely closed areas of movable and / or stationary Vehicles, such as aircraft, vehicles, containers, etc. accommodated Measuring and other special equipment with heat exchanger and pump, characterized in that in the coolant circuit between the heat exchanger (1) and pump (2) an additional on a consumption coolant (5) based cooling module (4) is involved.

Description

The The invention relates to a cooling device for cooling in largely closed areas of movable and / or stationary Vehicles, such as aircraft, vehicles, containers, etc. accommodated Measuring and other special equipment with heat exchanger and pump.

In DE 34 42 001 For example, there is provided a method of conditioning parked aircraft in which air having a temperature below the freezing point of water is introduced into the aircraft under pressure. This can be compared to conventional cooling devices with the same cooling performance with smaller air flow rates more efficient and thus more pleasant cooling can be created.

In WO 2004/045987 describes an air freight container in which a container is provided with dry ice to the cooling during loading and unloading of the plane as well as during To ensure stopovers. This is a supplementary Device which is decoupled from the actual cooling system.

In EP 1 601 899 describes a dry ice cooling machine for transport containers, wherein the low temperatures generated by the dry ice are used to liquefy the coolant in the condenser, so that the cooling machine can do without a mechanical compressor. This is a closed, self-contained cooling system that has no interaction with other cooling circuits and on top of that only serves to cool the air.

In AT 248 408 a self-contained dry ice cooling machine is described, which is a pure condensation-evaporation unit in a closed circuit arrangement without a pump.

In DE 19 45 957 describes a cooling system for an air freight container, in which dry ice is used. Here, two different cooling mechanisms are proposed for the container, which function completely independently of each other. In one of the cooling mechanisms, an air circulation takes place in the container, wherein a portion of the air is directed via a dry ice cooled surface of a dry ice vessel

At the Operation of complex measuring technology often generates a lot of waste heat. Radar transmitters, high power lasers or large pumps make a significant difference heat sources which cooled efficiently Need to become, so that they function optimally and the working conditions for the person Caregiver bearable stay.

Under Laboratory conditions can be this heat usually, for example, by using a liquid cooler efficiently dissipated be, since here the necessary Conditions regarding water and energy supply given are. However, problems occur when using such devices extreme conditions, such as cooling water, the space required or the required electrical power is not sufficient Measurements to disposal stand. As possible Scenarios here are, for example, research aircraft or measurement containers called in the field, where the operation of such devices therefore with limitations connected is.

below the state of the art will be explained using the example of aircraft. These Let executions but also on the scenario of measurement containers in the field or other vehicles. Research aircraft, or more generally, special purpose aircraft in the field Research, military etc., place in principle, a flying laboratory serving scientific Working and to allow a measuring operation in the air. This means that devices are operated on this platform which, usually developed on the ground in the laboratory, for the use on an aircraft have been adjusted accordingly. Also The aircraft is usually modified to, for example, a ensure adequate energy supply.

The Instrumentation of a fully equipped special aircraft means An additional Demand for electrical energy, often of the order of magnitude of 10kW. Size Consumers are, for example, radar transmitters, high-power lasers or big Pump. The resulting waste heat becomes common directly dissipated in the cabin of the aircraft, in some special cases, where Instruments have the appropriate interface, or the instrumentation housed in closed measuring frames with heat exchanger, However, liquid chillers are also used Use that heat to the passing ones Release air.

This happens through simple heat transfer on the outer skin, such as by the applicant DLR in the case of high power lasers was realized or by using an appropriately designed Air inlet with integrated heat exchanger, as for example in military Radar applications common is. If the aircraft moves sufficiently high, in which the air accordingly is cold, make these cooling methods an efficient and robust process.

This does not work under all operating conditions. issues occur especially on the ground, for example in aircraft Rolling, during a stopover with operation of the equipment or at Low altitude flight in a warm environment. In both cases, the energy can not efficiently dissipated In the first case, sufficient air exchange at the cooling surface will not occur There is more, in the other case, the passing air is too warm.

Based A low-level flight can be shown to be such a system even Heat in the cabin conducts, rather than dissipate. This plays in particular in an otherwise very effective air-inlet solution, because here the air is additionally heated by the congestion effect in the inlet. An additional cooling stage (vapor cycle booster), which works with higher waste heat, is among these Conditions do not make sense, because they require a lot more Space and electrical energy means and under these conditions works inefficiently.

When Consequence of the loss of cooling capacity the cabin air is overheated, which usually results in a cancellation of the mission in question Has. The longtime ones Experience in the operation of meteorological measurement technology on research aircraft the applicant DLR has repeatedly shown these limits, in whose Achieve working in the aircraft was no longer possible. Sufficient cooling defined by electrical consumers on a research aircraft thus decisive the operating limits of the platform.

• • Wenn die vorbeiströmende Außenluft so warm ist, dass kein Wärmeaustausch stattfinden kann, werden als Ergänzung zur Kühlung mobile Zusatzkühleinheiten in Form von Flüssigkeitskühlern am Boden angeboten, da ein Wärmeaustausch mit der Außenluft in diesem Fall nicht funktioniert.
• • Eine zweite Möglichkeit besteht darin, Wärme an die Kabinenluft abzugeben und in der Kabine zusätzliche entsprechende Klimaanlagen einzubauen.

The problem of the cooling of fair installations applies to the scenarios "stopover with operation of the equipment" or "low flying in warm environment" as unresolved. As a method, two methods are currently being discussed:

• • If the passing outside air is so warm that no heat exchange can take place, additional mobile cooling units in the form of liquid coolers are offered on the ground as a supplement to the cooling, since a heat exchange with the outside air does not work in this case.
• • A second option is to give heat to the cabin air and install additional air conditioners in the cabin.

Classical Liquid cooler too Use is an effective under appropriate environmental conditions and robust method. However, this method fails in the above described low-flying scenario. For measurements on the ground must be before Place an additional cooling unit, For example, an air conditioner that replaces the outdoor air heat exchanger, managed become; In turn, this is usually not possible in the case of external landings. These Method also works when taxiing the aircraft and possibly Waiting times, for example on the start release, also not. On top of that, the entire instrumentation must be in closed measuring frames be accommodated, which over heat exchangers with the cooling circuit are connected.

At the Giving off heat To the cabin air can be cooled very comfortably by means of an air conditioner. However, in general, an air conditioner for such a thermal Load not designed; here are only small reserves available. The heat transfer for cooling over the Cabin air is as well very inefficient and leads often for overheating of devices.

Of the Installation additional Air conditioning systems is structurally complex, since in the plane only a small amount of space to disposal stands. For this reason, the waste heat problem requires accommodation such air conditioning outside the cabin.

at Fixed installation of air conditioning suggests the installation as additional weight at the expense of the scientific payload. In addition, arises additionally a large Energy demand. In hotter Environment on the ground and with reduced engine power at low altitude goes the supply of electrical energy or to be tapped air back; The air conditioner works in such a case with a reduced Efficiency.

Of the The invention is therefore based on the object, in a cooling device according to the preamble of claim 1 whose applications and operating limits for complex measurements with for research purposes designed, in particular low-flying aircraft, at Messcontainern in the field and the like to expand.

to Extension of application possibilities or operating limits is according to the invention in the coolant circuit between a heat exchanger and an additional pump on a consumption coolant, like dry ice, based cooling module involved. The use of such an additional cooling module is a pronounced Robust, efficient and space-saving solution, which on top of that for certain Application scenarios can be optimized. On top of that, the inventively provided additional Cooling module too be used in facilities that none of the conventional cooling equipment having.

According to the invention is thus the solution the cooling problem in the integration of an additional cooling module in the circuit of a heat exchanger in the form of a classic liquid or air cooler. The on a consumption coolant in the form of dry ice based cooling module consumed on top of that no significant electrical energy resources, which in turn plays an essential role on an airplane. Further is the cooling capacity such a cooling module adjustable, so that the existing cooling resources are optimally used can be. On top of that, such a system is modularly expandable at any time and can be removed from the cooling circuit at any time. This means it can be integrated on a case-by-case basis for appropriate scenarios become.

Various embodiments will be explained with reference to the drawings. Show it,

1 a schematic representation of a conventional cooling system;

2 a schematic representation of interfaces for the integration of an additional cooling unit in the conventional cooling system;

3 a schematic representation of a cooling unit integrated in a conventional cooling system in the form of a cooling module;

4a to 4c a functional principle for a conventional cooling system with additional cooling module in different operating modes and in 4a with air cooling, in 4b with a supported air cooling and in 4c only with a consumption coolant cooling;

5 a schematic structure of one of the described cooling systems in the case of installation in an aircraft, and

6 an integration of one of the cooling systems described in a measuring rack as part of a scientific payload in an aircraft.

In 1 is a schematic representation of a conventional cooling system reproduced, the essential parts of a consumer 1 , a pump 2 and an external heat exchanger 3 ₁ For example, in the form of an air cooler, the latter may have a fan to perform a forced ventilation. Furthermore, a temperature scale divided into six stages from hot to cold is shown, wherein the individual stages are characterized by different hatchings. The corresponding hatches are also in the connecting lines between the three parts schematized by blocks 1 to 3 entered.

The consumer 1 has a coolant inlet 10 for cold and a coolant outlet 11 for warm up. Likewise, the heat exchanger 3 ₁ Also, an indicated by the left arrow air intake for cool air. Hereby, a forced ventilation by means of the aforementioned fan or by ram air on the aircraft can be achieved. With the heat exchanger 3 ₁ right-going arrow indicates an outlet for air.

In the schematic representation in 2 is between the parts 1 . 2 and 3 an extra coolness in the form of a cooling module 4 indicated with the appropriate interfaces. In 3 is also a schematic representation of an embodiment of the cooling module 4 reproduced in detail.

In the cooling module 4 is another heat exchanger 3 ₃ provided, in direct contact with a consumer coolant 5 in the form of CO ₂ dry ice. In the exhaust gas stream at a temperature of about -70 ° C is still a heat exchanger 3 ₂ provided by which the CO ₂ exhaust gas stream is heated to a temperature in the order of 0 ° C or higher. An important aspect of this cooling process is also that the gas leaves, for example, an aircraft with such a high temperature that icing problems at an outlet provided in the aircraft can not occur.

About the heat exchanger 3 ₃ the greatest part of the cooling capacity is realized. About the heat exchanger 3 ₃ It may also be just part of the pump 2 directed to the consumer funded coolant. Through a valve V ₂ , the proportion of the consumption of coolant 5 cooled coolant flow regulated. For controlling the valve V ₂ , a temperature measuring unit T _{2 is} provided in the coolant flow.

By means of a second valve V ₁ , the heat exchanger 3 ₁ be bridged in the form of an air cooler, if a high air temperature does not allow cooling. The valve V ₁ is via a in the air inlet flow of the heat exchanger 3 ₁ provided measuring unit T ₁ is controlled.

• • Trockeneis hat eine hohe Verdampfungswärme
• • Trockeneis ist ein Festkörper, welcher sublimiert und damit unmittelbar in eine gasförmige Phase übergeht. Da durch ist die Handhabung sowie Lagerung in einem Flugzeug einfacher als beispielsweise die Handhabung und Unterbringung von flüssigem Stickstoff.
• • Trockeneis ist obendrein als Standardkühlmittel im Luftfahrtbereich gut verfügbar, leicht zu transportieren und gut zu lagern.

The use of dry ice is advantageous for several reasons:

• • Dry ice has a high heat of vaporization
• • Dry ice is a solid that sublimes and thus immediately goes into a gaseous phase. As a result, handling and storage in an aircraft is easier than, for example, the handling and storage of liquid nitrogen.
• • Dry ice is also readily available as a standard aerospace coolant, easy to transport and store well.

The essential material properties of CO ₂ dry ice are listed below: Energy balance for dry ice: Heat of vaporization: 573 kJ / kg Density: 1566 kg / m ³ Temperature: -78.3 ° C CO ₂ specific heat: 0.64 kJ / (kg · K)

A Evaporation and heating of the gas at 0 ° C gives a cooling performance of 0.16kW / (h · kg). A cooling capacity of 10kW thus requires a dry ice consumption of 62kg / h (= 40l / h)

Consumption of a few 10 kg of dry ice per hour means that the additional cooling blocks space and weight resources at the expense of the payload. For a measuring instrument with a power consumption of 1kW and a flight time of 5h, for example, in the worst case, a requirement of about 31kg. However, this requirement is reduced by the fact that a complete dry ice cooling takes place only under the worst conditions. (See, for example 4c ). Otherwise, always the existing air cooling is used as much as possible.

Such a cooling module can be accommodated in an aircraft measuring rack whose capacity is between 100 and 180 kg, depending on the aircraft. Such an installation is thus easy to implement and on this scale quite acceptable. It is important, however, that the interior of the cooling module is pressure-tight and thermally insulated and the spent gas can be passed through an exhaust to the outside. (See for example 6 )

• • Wegen der einfachen bzw. schnellen Montage/Demontage auf Grund des modularen Charakters des Kühlmoduls 4 kann dieses fallweise für entsprechende Missionsszenarien integriert werden.
• • Im Hinblick auf die Skalierbarkeit eines solchen Systems können problemlos auch mehrere Module hintereinander verwendet werden, um dadurch die Gesamtkühlleistung zu erhöhen. In einem solchen Fall steuert nur das erste Modul den externen als Kühler dienenden Wärmetauscher 3₁ an. Die weiteren Module dienen nur noch zur Vorkühlung am Wärmetauscher 3₂ und zur geregelten Kühlung am Wärmetauscher 3₃ . Das Ventil 1 überbrückt bzw. die Anschlüsse zum externen Wärmetauscher 3₁ sind kurzgeschlossen.
• • Auch ist eine universelle Einsatzmöglichkeit bei nahezu jedem Flüssigkeitskühler gegeben, da lediglich die entsprechenden Arbeitspunkte (Messstellen) für die Tempera turmesseinheiten T₁ bzw. T₂ in jedem einzelnen Fall festgelegt werden müssen.

Like a comparison with 1 shows is the cooling module 4 to integrate only a few interfaces in an existing cooling circuit. This results directly in the following advantages:

• • Because of the quick and easy assembly / disassembly due to the modular nature of the cooling module 4 this can be integrated case by case for appropriate mission scenarios.
• • In view of the scalability of such a system, it is also easy to use several modules one behind the other to increase overall cooling performance. In such a case, only the first module controls the external radiator serving as a radiator 3 ₁ at. The other modules are only used for pre-cooling on the heat exchanger 3 ₂ and for controlled cooling at the heat exchanger 3 ₃ , The valve 1 bridged or the connections to the external heat exchanger 3 ₁ are shorted.
• • Also, a universal application is possible in almost every liquid cooler, since only the corresponding operating points (measuring points) for the tempera ture meter units T ₁ and T ₂ must be set in each case.

On The reason of using a consuming refrigerant is the cooling capacity finite; over one integrated rule or Control circuit can control the cooling capacity however, be used optimally.

For a system expanded in the manner described above, the in 4a to 4c schematically indicated operating scenarios.

In 4a is in the presence of sufficient air cooling, only the heat exchanger 3 ₁ in operation and the lock-up valve V ₁ is in the 4a brought removable position. The valve V ₂ , via which coolant can be fed, is closed, so that no mixing of coolant from the dry ice cycle takes place.

In 4b is the over the heat exchanger 1 supporting air cooling. The bypass valve V ₁ is located in the same position as in the based on 4a described case. However, via the valve V ₂ follows a regulated admixture of coolant from the dry ice cycle. Here, the activation of the valve V ₂ takes place via the temperature measuring unit T ₂ accommodated in the control circuit.

In the in 4c The case shown is a pure dry ice cooling. As indicated by the position of the lock-up valve V ₁ , the heat exchanger is 3 ₁ not in use. In this case, a controlled admixture of coolant from the dry ice cycle takes place via the valve V ₂ again. Both valves V ₁ and V ₂ are _connected via their associated temperature sensing units T ₁ and T ₂ is activated.

• • Durch die Einbindung eines gemäß 3 ausgeführten Kühlmoduls kann eine ausreichende Kühlung sowohl bei einem Tiefflug in warmer Umgebungsluft als auch beim Rollen eines Flugzeugs problemlos durchgeführt werden, während bei derartigen Umgebungsbedingungen eine herkömmliche Kühlung nicht durchgeführt werden könnte.
• • Ein weiterer großer Vorteil bei Einsatz der erfindungsgemäßen Einrichtung besteht darin, dass am Boden und somit beim Rollen eines Flugzeugs oder auch beim Einsatz eines Messcontainers im Feld keine zusätzliche Infrastruktur benötigt wird.
• • Ein gemäß 3 ausgeführtes System benötigt praktisch keine zusätzliche elektrische Energie.
• • Das System kann fallweise integriert werden, so dass bei anderen Anwendungsszenarien keine Platz- und Gewichtsressourcen verbraucht werden.
• • Zusätzlich ist das System skalierbar; es kann also, so angepasst, um die benötigte Kühlleistung entsprechend erweitert werden.

The advantages of CO ₂ dry ice cooling versus CO air-assisted air cooling are as follows:

• • By incorporating one according to 3 Cooling module is executed, a sufficient cooling both in a low-altitude flight in warm ambient air and when rolling an aircraft can be easily performed, while in such environmental conditions conventional cooling could not be performed.
• • Another great advantage of using the device according to the invention is that no additional infrastructure is needed on the ground and thus when rolling an aircraft or even when using a measuring container in the field.
• • One according to 3 executed system requires virtually no additional electrical energy.
• • The system can be integrated on a case-by-case basis so that no space and weight resources are consumed in other application scenarios.
• • In addition, the system is scalable; So it can be adapted to be expanded to the required cooling capacity accordingly.

The inventive device allows thus an efficient and sufficiently dimensioned cooling under Conditions under which else an operation with the conventional cooling methods not possible yet was. Due to the simple interface is also a universal Use for different devices, but also on different platforms like different planes without significant major modifications possible. additionally offers a modular design, since to increase the overall cooling capacity several individual systems combined to form a large system can be. Even a cooling of large equipment, for example on an airplane under extremely unfavorable cooling conditions Environmental conditions, without consumption of electrical resources and, as already stated, be carried out without the use of a ground-based infrastructure.

The mentioned above are scenarios for special missions known from the operation of research aircraft and have been able to date not solved satisfactorily become.

In 5 is a basic structure in an aircraft reproduced that via a heat exchanger 3 ₁ Contact with the outside air has. At the in 5 It is an efficient heat exchanger in the form of a cooler with air inlet, which, however, by design, as already mentioned, already undergoes some warming due to the adiabatic process due to the back pressure.

In 5 are two heat-producing consumers, each with a coolant inlet 10 (cold) and a coolant outlet 11 (warm). The execution of the cooling module 4 corresponds essentially to that of 3

In 6 is the integration of such a cooling system reproduced in a typical aircraft measuring rack. Are in the frame 6 For example, 150 kg of coolant housed, so is a cooling capacity of about 24kWh available, this in turn is a value that is sufficient for current aircraft mission scenarios, for example in the field of climate research. As the schematic representation in 6 can be seen, the structure of the cooling system is very compact and easy to integrate, since the number of hydraulic and electrical connections to be performed manageable.

For one Operation of measuring instruments with big Energy needs on aircraft, such as research aircraft, as well as for example in military Applications are both for Operators of existing infrastructures as well as manufacturers and outfitters Special purpose aircraft supplemented by one or more cooling modules conventional cooling systems used in an advantageous manner. Furthermore, an operation of measuring instruments is under allows extreme conditions where laboratory-like infrastructure not available stands, for example Vehicles or measuring containers in field use.

1

consumer

10

inlet

11

outlet

2

pump

3 ₁ , 3 ₂ , 3 ₃

heat exchangers

4

cooling module

5

Consumption coolant

6

Aircraft measurement frame

V ₁

bypass valve

V ₂

Valve

T ₁ , T ₂

Temperature measuring unit

Claims (8)

Cooling device for cooling in largely closed areas of mobile and / or stationary vehicles, such as aircraft, vehicles, containers, etc. accommodated measuring and other special equipment with heat exchanger and pump, characterized in that in the coolant circuit between the heat exchanger ( 1 ) and pump ( 2 ) an additional on a consumption coolant ( 5 ) based cooling module ( 4 ) is involved. Cooling device according to claim 1, characterized in that the consumption coolant ( 5 ) Is dry ice. Cooling device according to claim 1, characterized in that the additional cooling module ( 4 ) at least one further heat exchanger ( 3 ₂ ; 3 ₃ ) having. Cooling device according to claim 1, characterized in that the cooling module ( 4 ) one in direct contact with the consumable coolant ( 5 ) standing heat exchanger ( 3 ₃ ), which is used to regulate by means of the consumption coolant ( 5 ) downstream of a cooled coolant flow is a valve (V ₂ ). Cooling device according to claim 4, characterized in that the cooling module ( 4 ) has a temperature measuring unit (T ₂ ) for controlling the valve provided in the coolant flow (V ₂ ). Cooling device according to one of the preceding claims, characterized in that the cooling module ( 4 ) a further heat exchanger ( 3 ₂ ) in the cold exhaust gas stream of the consumer coolant ( 5 ) having. Cooling device according to claim 1, characterized in that for bridging the conventional heat exchanger ( 3 ₁ ) of the cooling system in the form of an air cooler by means of a temperature measuring unit (T ₁ ) controlled valve (V ₁ ) is provided. Device according to one of claims 1 to 6, characterized in that to further increase a cooling capacity, a plurality of cooling modules ( 4 ) are switchable in a row.