EP2342127A1

EP2342127A1 - Adsorption cooling system and adsorption cooling method for an aircraft

Info

Publication number: EP2342127A1
Application number: EP09743878A
Authority: EP
Inventors: Mehmet Altay
Original assignee: Airbus Operations GmbH
Current assignee: Airbus Operations GmbH
Priority date: 2008-10-30
Filing date: 2009-10-28
Publication date: 2011-07-13
Also published as: WO2010049147A1; JP2012506817A; CN102202969A; CA2742321A1; US20120000220A1; RU2011118855A; CN102202969B; DE102008053828A1

Abstract

An adsorption cooling system (1) for an aircraft, comprises an evaporator (18), a first adsorber (2), with a first adsorbent for adsorbing an adsorbent coolant evaporated in the evaporator (18) and an second adsorber (4), containing a second adsorbent for adsorbing an adsorbent coolant evaporated in the evaporator (18), wherein the first and the second adsorber (2, 4) may be alternately operated in an adsorption mode and a desorption mode such that one adsorber (2, 4) adsorbs adsorption coolant ad the other adsorber (2, 4) can be regenerated. A heat transfer system in the adsorption cooling system (1) is designed to transmit heat from the adsorber (2, 4) going from desorption mode into absorption mode to the adsorber (2, 4) going from adsorption mode to desorption mode by means of a heat transfer fluid during a transition phase in which one adsorber (2, 4) goes from adsorption mode to desorption mode and the other adsorber (2, 4) goes from desorption mode to adsorption mode.

Description

ADSORPTION COOLING SYSTEM AND ADSORPTION COOLING PROCEDURE FOR ONE

AIRCRAFT

The present invention relates to an improved adsorption cooling system and an improved adsorption cooling method for cooling at least one device and / or area of an aircraft.

In an aircraft, for example, the cabin, the galleys, the dining cars in the galleys, electronic equipment and the like must be cooled. For this purpose, a compression refrigeration machine is usually used, in which a refrigerant is compressed by means of a compressor, condensed in a condenser and expanded in an evaporator with release of cooling energy. A compression refrigeration machine has the disadvantage that in particular the compressor causes a considerable noise. Furthermore, a compression refrigeration requires relatively much drive energy and it must be discharged a relatively high amount of waste heat. The use of a compression refrigerating machine is required in aircraft of the prior art, in particular on the ground, where the outside temperatures can reach relatively high levels. Furthermore, fluorocarbon-containing refrigerants are frequently used, the use of which is controversial with regard to environmental protection.

To overcome the aforementioned problems, it is attempted to use adsorption cooling systems in future aircraft. An exemplary adsorption cooling system is described in DE 10 2006 054 560 A1. The central device of the adsorption cooling system is an adsorber containing an adsorption medium. The adsorption medium is adsorbed by gaseous adsorption coolant, which is evaporated in an evaporator providing cooling energy. The adsorption medium is preferably a finely porous material, for example activated carbon, zeolite, silica gel or the like. As the adsorption coolant, water or alcohol can be used. The adsorption coolant can accumulate on the adsorption medium only in several molecule layers. If the adsorption medium is completely wetted with adsorption coolant, so that no further adsorption coolant can accumulate, the adsorber is saturated and must be regenerated. For this purpose, the adsorption medium is heated so that the adsorbed coolant adsorbed on the adsorption medium is desorbed. The desorbed adsorption refrigerant is condensed, fed to an optional reservoir as a liquid adsorption refrigerant and then returned via an expansion valve to the evaporator described above. Thus, in the adsorption mode of the adsorption cooling system, it is possible to generate cooling energy, while in the desorption mode or regeneration mode of the adsorption cooling system not only no cooling energy can be generated but even regeneration energy in the form of thermal energy has to be supplied. The adsorption cooling system known from DE 10 2006 054 560 A1 therefore has two adsorbers which are used or regenerated alternately for adsorption of adsorption coolant, so that quasi-continuous cooling is possible.

Adsorption cooling systems have the advantage that no compressor is required, which reduces the energy required for cooling and system reliability can be increased. Furthermore, an adsorption cooling system is relatively quiet operation. Finally, an adsorption cooling system does not require a fluorocarbon-containing coolant, but can be run in an environmentally friendly manner with water. However, known adsorption cooling systems still have deficits in terms of their energy efficiency.

The object of the invention is to provide an adsorption cooling system which is suitable for use on board an aircraft and which can be operated in an energy-efficient manner. Furthermore, the invention is directed to the object of specifying a method for operating such an adsorption cooling system.

This object is achieved by an adsorption cooling system for an aircraft with the features of claim 1 and a method for operating an adsorption cooling system for an aircraft with the features of claim 7.

The adsorption cooling system according to the invention for an aircraft comprises an evaporator designed, for example, in the form of a heat exchanger. The evaporator serves to convert a liquid adsorption coolant, for example water, into the gaseous state of matter. The adsorption refrigeration system further comprises a first adsorber containing a first adsorption medium for adsorbing the adsorption refrigerant evaporated in the evaporator. A second adsorber of the adsorption cooling system according to the invention contains a second adsorption medium for adsorption of the adsorption coolant evaporated in the evaporator. Activated carbon, zeolite or silica gel can be used as the adsorption medium, wherein in the first and in the second adsorber the same adsorption medium or different adsorption media can / can be used. The first and second adsorbers of the adsorption refrigeration system of the present invention are operable alternately in an adsorption operation in which adsorption refrigerant is adsorbed on the adsorption medium of the adsorber, and a desorption operation in which adsorbent refrigerant attached to the adsorption medium of the adsorbent is sorbed. Consequently, the adsorption cooling system can be operated quasi-continuously, since in each case one adsorber can adsorb adsorption coolant and the other adsorber can be regenerated.

The adsorption refrigeration system of the present invention further comprises a heat transfer system configured to transfer thermal energy from that from the desorbing operation to the adsorbing operation during a transient operation phase during which an adsorber is transferred from the adsorption operation to the desorption operation and the other adsorber is transferred from the desorption operation to the adsorption operation Adsorption to transfer adsorber transferred to the adsorption from the operation in the desorption mode adsorber. In other words, the heat transfer system of the adsorption cooling system according to the invention is capable of heat energy stored in an adsorber operated in the desorption mode due to the supply of regeneration energy in the adsorber, in the adsorption in the adsorption

Desorption to transfer to transfer adsorber and use there as regeneration energy. The adsorption cooling system according to the invention is therefore particularly energy-efficient operable. In addition, the transient operating phase can be shortened and consequently an improved quasi-continuous operation of the adsorption cooling system can be realized.

The heat transfer system may include a conduit network and a plurality of valves disposed in the conduit network which may be switched to transfer thermal energy from the adsorber transferred from the desorption operation to the adsorption operation to the adsorber transferred from the adsorption operation to the desorption operation by the heat transfer fluid.

The heat transfer system may further comprise a heating device and be adapted to supply thermal energy to an adsorber operated in the desorption mode for the regeneration of the adsorber or of the adsorption medium contained in the adsorber. The heating device can be designed, for example, in the form of a heat exchanger, but also any other heating device, for example, be an electric heater. The heater is preferably for heating the heat transfer fluid to an elevated temperature. With the aid of the heat transfer fluid, the heat energy provided by the heater can then be supplied to the adsorber to be regenerated.

A further increase in the energy efficiency of the adsorption cooling system according to the invention is possible if the heating device is thermally coupled to a device emitting waste heat emitting device of the aircraft. The loss-heat-emitting device can be, for example, an air conditioning system, a drive device or an energy store of the aircraft. For example, engine bleed air or the waste heat generated when the engine bleed air is cooled in the aircraft air conditioning system may be used as the heat energy source for the heater. It is also conceivable to use the waste heat generated by an auxiliary turbine, the so-called auxiliary power unit, as a heat energy source for the heating device. This reduces the total energy requirements of the aircraft. Further, the weight of the aircraft is reduced because the electric generator can be made smaller due to the fact that no electrically driven compressor of a compression refrigeration system or an electrically operated heater of an adsorption cooling system needs to be supplied with electrical energy.

The heat transfer system of the adsorption cooling system according to the invention may further comprise a cooling device and be adapted to supply cooling energy to an adsorber operated in the adsorption mode for cooling the adsorber or the adsorption medium contained in the adsorber. By cooling the adsorption medium of an adsorber operated in the adsorption mode, it is ensured that the adsorption medium retains its electrostatic attraction for the gaseous adsorption coolant. Preferably, the cooling device is designed such that it cools the heat transfer fluid to a desired low temperature, so that the adsorptive operated in the adsorber via the heat transfer fluid, the cooling energy generated by the cooling device can be supplied. For example, the cooling device may be designed in the form of a heat exchanger in which ambient air is used as a source of cooling energy. Preferably, the cooling device has a fan which conducts an ambient air flow over cooling fins of the cooling device through which heat transfer fluid flows. The adsorption cooling system according to the invention may further comprise a condenser for condensing adsorption coolant discharged from an adsorber operated in desorption operation. The condenser can be connected to the evaporator _. 5 connected to the evaporator Adsorptionskühlmittel in the liquid state to re-evaporate. An expansion valve may also be arranged between the condenser and the evaporator.

Furthermore, the adsorption cooling system according to the invention preferably comprises a lo first pressure sensor for measuring the Adsorptionskühlmitteldrucks in the condenser, a second pressure sensor for measuring the Adsorptionskühlmitteldrucks in an adsorber and an electronic control unit, which is adapted to detect signals provided by the pressure sensors. In the adsorption cooling system according to the invention, each adsorber is preferably equipped with a second pressure sensor for measuring the adsorption coolant pressure in the adsorber.

Preferably, the electronic control unit controls the heat transfer system of the adsorption refrigeration system of the present invention such that during the transient operating phase, the supply of heat energy to the adsorber transferred from the adsorption operation to the desorption operation is terminated when the adsorption refrigerant pressure in the adsorber corresponds to the adsorption refrigerant pressure in the condenser. This prevents adsorption refrigerant from flowing into the adsorber from the condenser when fluid communication between the condenser and the adsorber is opened at the beginning of the desorption operation of the adsorber. 5 In a method according to the invention for operating an adsorption cooling system for an aircraft having an evaporator, a first adsorber containing a first adsorption medium for adsorbing an adsorption refrigerant evaporated in the evaporator, and a second adsorbent having a second adsorption medium for adsorbing the vaporized in the evaporator Adsorptionskühl- o means, wherein the first and the second adsorber alternately in a

Adsorption and a desorption are operable so that each adsorber adsorb adsorbent and the other adsorber can be regenerated, during a transitional operating phase during which an adsorber is transferred from the adsorption to the desorption and the other adsorber 5 is transferred from the desorption into the adsorption , By means of a heat transfer fluid heat energy from that of the desorption in transferred to the adsorption adsorber transferred to the transferred from Adsorptionsbetrieb in the desorption mode adsorber.

The heat transfer system of the Adsorptionskühlsystems preferably comprises a conduit network and a plurality of arranged in the conduit network valves which can be switched accordingly, and during the transitional operating phase by means of the heat transfer fluid heat energy from the desorption transferred to the adsorption mode adsorber on the transferred from Adsorptionsbetrieb in the desorption mode adsorber transferred to.

A heating device of the heat transfer system preferably supplies heat energy to an adsorber operated in the desorption mode for the regeneration of the adsorber or the adsorption medium contained in the adsorber.

Preferably, the heater is supplied from a loss-heat-emitting device of the aircraft loss heat.

In a preferred embodiment of the method according to the invention, a cooling device of the heat transfer system supplies an adsorber operated in the adsorption mode for cooling the adsorber or the adsorption medium contained in the adsorber to cold energy.

Preferably, adsorption coolant removed from an adsorber operated in the desorption mode is condensed in a condenser. An electronic control unit may detect signals from a first pressure sensor for measuring the adsorption refrigerant pressure in the condenser and a second pressure sensor for measuring the adsorption refrigerant pressure in an adsorber and control the heat transfer system of the adsorption refrigeration system according to the present invention so that during the transient operating phase, the supply of heat energy to that from the adsorption operation in the Desorptionsbetrieb transferred adsorber is terminated when the adsorption refrigerant pressure in the adsorber corresponds to the adsorption refrigerant pressure in the condenser. The invention will now be described in more detail with the aid of the attached figures. Show it:

FIG. 1 shows an adsorption cooling system in an operating state in which adsorption coolant is desorbed in a first adsorber and in a second adsorber

Adsorber adsorption coolant is adsorbed;

FIG. 2 shows the adsorption cooling system according to FIG. 1 in an operating state in which the adsorber is switched over between an adsorption mode and a desorption mode;

FIG. 3 shows the adsorption cooling system according to FIG. 1 in an operating state in which adsorption coolant is adsorbed in the first adsorber and desorption coolant is adsorbed in the second adsorber; and

FIG. 4 shows the adsorption cooling system according to FIG. 1 in an operating state in which the adsorber is again switched between an adsorption mode and a desorption mode.

An aircraft adsorption refrigeration system 1 shown in the figures has a first adsorber 2 with a first adsorption medium, a second adsorber 4 with a second adsorption medium, a condenser 8, an expansion valve 6 and an evaporator 18. The adsorption medium (not shown) in the adsorbers 2, 4 may be, for example, activated carbon, zeolite, silica gel. The adsorption cooling system 1 further comprises an adsorption coolant circuit 9 in which an adsorption coolant is recirculated and in which a first adsorption control valve 10, a second adsorption control valve 12, a third adsorption control valve 14, and a fourth adsorption control valve 16 are arranged. As the adsorption coolant, for example, water and / or alcohol can be used.

During the evaporation of the adsorption coolant in the evaporator 18, cooling energy is released in the form of evaporative cooling, which can be conducted to an application site, for example, by means of an airflow generated by an evaporator fan 20. The evaporator 18, which is designed as a heat exchanger, does not necessarily have to cool air, but can cool any cooling medium, for example any fluid or any solid. The cooling energy generated by the evaporator 18 may be used to cool a portion of a cabin, a portion a galley, a dining car in the galley, an electronic device, such as a flight control device, an electronic entertainment system, etc. are used.

.5 Adsorption coolant evaporated in the evaporator 18 deposits on the adsorption medium of an adsorber 2, 4 operated in the adsorption mode. By adsorbing the gaseous adsorption coolant, the partial pressure of the adsorption coolant in the evaporator 18 is reduced. As a result, further liquid adsorption coolant evaporates in the evaporator 18. By contrast, adsorption coolant in the gaseous state of matter is removed from an adsorber 2, 4 operated in the desorptive or regeneration mode and passed into the condenser 8. In the condenser 8 or downstream of the condenser 8 may be a reservoir (not shown). After condensation in the condenser 8, the adsorption refrigerant is returned to the evaporator 18 via the expansion valve 6 for re-evaporation.

In the operating state of the adsorption cooling system 1 shown in FIG. 1, the second adsorber 4 is operated in the adsorption mode, while the first adsorber 2 or the first adsorption medium in the first adsorber 4 is regenerated. The first adsorption control valve 10 and the fourth adsorption control valve 16 are opened, whereas the second adsorption control valve 12 and the third adsorption control valve 14 are closed.

In the following, a heat transfer system of the Adsorptionskühlsystems 1 5 is explained in more detail, which serves to supply the adsorbers 2, 4 and the capacitor 8, as needed, cooling energy or thermal energy. A heating system 50, a cooling device 52, a first supply valve 60, a second supply valve 62, a third supply valve 64, a fourth supply valve 66, a fifth supply valve 68, a sixth are provided in a heat-transfer system network through which a heat transfer fluid flows Supply valve 70, a seventh supply valve 72, an eighth supply valve 74 and a ninth supply valve 76 arranged. The heat transfer fluid may be delivered through the conduit network due to natural convection or due to forced convection generated by a first pump 54 and a second pump 56. The heat transfer fluid may be both gaseous and liquid, with a liquid heat transfer fluid being preferred. The heat transfer fluid may be, for example, water, a mixture of water and glycol or a Perfluoropolyethers, eg the perfluoropolyethers sold by Solvay Solexis under the trade name Galden HT-135.

The heater 50 is supplied with waste heat which is generated in another device .5 of the aircraft as waste heat. The heat loss can be, for example, the heat loss generated by a turbine, an internal combustion engine, an electric motor, an auxiliary unit or an energy storage of the aircraft. It is also possible to use the waste heat created when cooling engine bleed air. This heat loss is delivered in the current aircraft via lo stauluftwärmetauscher to the environment of the aircraft. But it is also possible that the heater 50 is supplied directly with hot engine bleed air or is in the form of an electric heater.

1, the first supply valve 60, the fourth supply valve 66, the fifth supply valve 68 and the eighth supply valve 74 are open, whereas the second supply valve 62, the third supply valve 64, the sixth supply valve 70 and the seventh supply valve 72 are closed. The heat transfer fluid heated in the heater 50 is pumped from the first pump 54 to the first adsorber 2 through the first supply valve 60 opened. In the first adsorber 2, the heat transfer fluid provides heat to the first adsorption medium of the first adsorber 2. As a result, the first adsorption medium of the first adsorber 2 can be regenerated. The heat transfer fluid exits the first adsorber 2 and flows through the open eighth supply valve 74 to the heater 25, where it is reheated.

The first adsorber 2 can be supplied with warm heat transfer fluid until the first adsorption medium contained in the first adsorber 2 is completely regenerated. It is understood that the heat supply to the first adsorber 0 2 can also be interrupted before it is completely regenerated. This may be necessary, for example, if the second adsorption medium in the second adsorber 4 is completely saturated before the first adsorption medium in the first adsorber 2 is completely regenerated. The cooling device 52 serves to cool heat transfer fluid for cooling the second adsorber 4 located in the adsorption mode to a desired low temperature. In the cooling device 52, heat transfer fluid can be added. For example, be cooled by an air stream taken from the environment, which is directed by a Kϋhleinrichtungsgebläses 58 on fins of the cooling device 52 through which the heat transfer fluid flows. The second pump 56 pumps the cooled heat transfer fluid from the cooling device 52 through the opened fourth supply valve 66 to the second adsorber 4. In the second adsorber 4, the heat transfer fluid cools the second adsorption medium of the second adsorber 4. Thus, the adsorption performance of the second adsorber 4 is improved. since the electrostatic attraction of the adsorption medium for the adsorption refrigerant is more pronounced at a lower temperature. The heat transfer fluid flows back from the second adsorber 4 through the opened fifth supply valve 68 to the cooler 52 where it is recooled.

Further, the heat transfer fluid is pumped from the cooling device 52 by means of the second pump 56 to the condenser 8, where it is used to dissipate the heat of condensation generated by the condensation of the Adsorptionskühlmittels in the condenser 8. After flowing through the condenser 8, the heat transfer fluid heated when flowing through the condenser 8 is returned to the cooling device 52 for renewed cooling.

In the following, the following symbols are used to calculate the required cooling and heating capacities of the individual components of the adsorption cooling system 1:

A area at the dead mass ratio

Cp [kJ / (kgK)] specific heat capacity

COP coefficient of performance / heat balance

Q [J] amount of heat

Q [W] heat flow

Q [W] mean heat flux h [kJ / kg] specific enthalpy k [W / (m ² K)] heat transfer coefficient m [kg] mass m [kg / s] mass flow

V [mV s] volumetric flow

P [W] electrical power

P [Pa] pressure r [kJ / kg] Evaporation enthalpy t [S] Time

T [K] Temperature q [kg _w / kg _z ] load

X proportionality factor

Δ difference

3 [ ⁰ C] Temperature λ [W / (mK)] Thermal conductivity

P [kg / m ³ ] density

indices:

0 evaporator, evaporation

1 initial state

2 Final condition required hr heat recovery htf heat transfer fluid hx heat exchanger (heat exchanger) in input out output

A adsorption beginning

Abk cooling

On heating

Ads adsorption

Adsl Adsorberl

Ads2 Adsorber2

D desorption beginning

Desorption

Kond capacitor, condensation

Cooling cooling max. Min. Min. Min regeneration

S saturation

W water

Z zeolite The power required to desorb the first adsorber 2 to be regenerated is:

* Z Des ~ " ¹ IiIf ^c p K ¹ De _W It ^λ Des, m> \ i-)

The cooling capacity required for cooling the condenser 8 and the adsorbent adsorber 4 can be calculated as follows:

Q ii KuIiI _ ~ QϊiKond ^L p '" ^f - ^A TK ^ll o ^lf nd, m ~>\' + ^" m ^ι A '" ^J ds - c ^c p'" ^f - - ^A TA ^lu d ^f s.in λ)

where: rhf _ds + rhf _ond = ™ L "and τχ" = T ^ _{ld m} ;

10

As soon as the second adsorption medium of the second adsorber 4 is saturated, it must be regenerated. An adsorption medium is then saturated if it can no longer adsorb another adsorption coolant.

FIG. 2 shows a transitional operating state in which the first adsorber 2 for the adsorption operation and the second adsorber 4 for the desorption operation are prepared. For this purpose, it is necessary for the first adsorber 2 or the first adsorption medium to be cooled and the second adsorber 4 or the second adsorption medium to be heated. During the transitional operation phase, the first, the second,

20, the third and fourth adsorption control valves 10, 12, 14, 16 are closed, and the blower 20 of the evaporator is turned off, so that the adsorption refrigeration system 1 does not provide cooling performance during the transient operation phase.

In the transmission system of the heat transfer system, the second supply valve 62, the third supply valve 64, the fifth supply valve 68 and the eighth supply valve 74 are opened during the transitional operating state. The first supply valve 60, the fourth supply valve 66, the sixth supply valve 70, the seventh supply valve 72 and the ninth supply valve 76 are closed, however. In addition, the cooling device 52, the cooling device fan 58 and the heating device 50 can be switched off. The second pump 56 thus pumps relatively cool heat transfer fluid from the second adsorber 4 via the fifth supply valve 68, the cooler 52 and the second supply valve 62 to the first adsorber 2. The heat transfer fluid in the second Adsorber 4 has a relatively low temperature because the second adsorber 4 was cooled by the heat transfer fluid during the adsorption operation.

The heat transfer fluid is heated in the first adsorber 2 by heat transfer .5 from the first adsorbent medium and flows back to the second adsorber 4 via the eighth supply valve 74, the heater 50, the first pump 54 and the third supply valve 64. The heat transfer fluid thus transports thermal energy from the first one Adsorber 2 to the second adsorber 4 and vice versa cooling energy, ie negative heat energy from the second adsorber 4 lo to the first adsorber 2. The closed ninth supply valve 76 prevents heat transfer fluid from flowing through the condenser 8 during the transient operating phase.

Since heat energy is transported from the first adsorber 2 to the second adsorber 4 and, conversely, that cold energy is transported from the second adsorber 4 to the first adsorber 2, the adsorption cooling system 1 requires less energy during the transient operating phase. Further, the switching of the adsorbers 2, 4 from the adsorption to the desorption and vice versa speeds and thus the duration of the transitional operating phase, during which the Adsorptionskühlsys- 20 tem 1 provides no cooling performance can be shortened.

The adsorption cooling system 1 may be considered adiabatic during the transient operating phase since only heat exchange within the adsorption cooling system 1 occurs. The amount of heat transferred from the first adsorber 2 to the second adsorber 4 can be represented as follows:

reg ~) ^m _HLJ ^C p K ¹ ¹ AbKOM AhKm) "* ~) ^m _{/ (/} ^C p V ¹ ^λ ₁ OW on, (m) ^{T Ü} ^j)

The first integral describes the amount of heat extracted from the first adsorber 2, 0, and the second integral describes the amount of heat absorbed by the second adsorber 4.

It will be appreciated that the heater 50 for providing additional thermal energy and the cooler 52 for dissipating thermal energy may be switched on to further reduce the duration of the transient operating phase. In the condenser 8 and in the adsorbers 2, 4 are each pressure sensors (not shown) for measuring the Adsorptionskühlmitteldrucks available. The signals provided by the pressure sensors are detected and processed by an electronic control unit. Depending on the pressure sensor signals, the electronic control unit controls the components of the adsorption cooling system 1, and in particular the valves 60, 62, 64, 66, 68, 70, 72, 74, 76 of the heat transfer system such that during the transient operating phase the supply of heat to that of the adsorption operation the second adsorber 4 to be switched to the desorption mode is ended as soon as the same adsorption coolant pressure prevails therein as in the condenser 8. This prevents adsorption coolant from flowing from the condenser 8 into the second adsorber 4 when the fluid connection between the desorption operation of the second adsorber 4 the capacitor 8 and the second adsorber 4 is opened. The circulation of the heat transfer fluid between the adsorbers 2, 4 can consequently be terminated selectively as soon as the second absorber 4 has reached an operating state in which the regeneration of the second adsorber can be started.

Alternatively or additionally, the electronic control unit may control the components of the adsorption cooling system 1, and in particular the valves 60, 62, 64, 66, 68, 70, 72, 74, 76 of the heat transfer system such that during the transient operating phase, the supply of heat to that of the Adsorption on the desorption to be switched second adsorber 4 is stopped when the temperature in the second adsorber 4 falls after reaching a maximum value again. For this purpose, the electronic control unit can detect and process signals from temperature sensors (not shown) arranged in the adsorbers 2, 4.

FIG. 3 shows an operating state of the adsorption cooling system 1 in which the first adsorber 2 adsorbs adsorption coolant and the second adsorber 4 is regenerated. For this purpose, the second adsorption control valve 12 and the third adsorption control valve 14 are opened, whereas the first adsorption control valve 10 and the fourth adsorption control valve 16 are closed. Thus, adsorption refrigerant evaporates in the second adsorber 4, which flows via the opened second adsorption control valve 12 to the condenser 8, where it condenses. Subsequently, the adsorption refrigerant flows to the expansion valve 6 and to the evaporator 18 where it is evaporated. The gaseous adsorption coolant flows through the open Nete third adsorption control valve 14 in the first adsorber 2, where it is adsorbed by the first adsorption medium.

The first adsorber 2 operated in the absorption mode and the condenser 8 are supplied with cooling energy by the heat transfer system. In contrast, the heat transfer system leads to the second adsorber 4 operated in the desorption mode to heat energy. For this purpose, the second supply valve 62, the third supply valve 64, the sixth supply valve 70, the seventh supply valve 72 and the ninth supply valve 76 are opened. The first supply valve 60, the fourth supply valve 66, the fifth supply valve 68 and the eighth supply valve 74 are closed. Consequently, the first pump 54 pumps heat-transfer fluid heated by the heater 50 through the opened third supply valve 64 to the second adsorber 4, so that the second adsorbent medium is heated. The heat transfer fluid then exits the second adsorber 4 and flows back to the heater 50 via the opened sixth supply valve 70.

The second pump 56 pumps heat transfer fluid cooled by the cooler 52 through the ninth supply valve 76 to the condenser 8. The heat transfer fluid flows back from the condenser 8 to the cooler 52. Further, the second pump 56 pumps the heat transfer fluid cooled by the cooler 52 through the second supply valve 62 to the first adsorber 2, so that the first adsorbent medium is effectively cooled. Subsequently, the adsorption refrigerant flows back to the cooling device 52.

25

As soon as the first adsorber 2 is saturated and / or the second adsorber 4 is regenerated, the adsorbers 2, 4 can be switched over again. This is carried out by means of a second switching operation, which substantially corresponds to the first switching operation shown in FIG. 2, heat energy being transferred from the second adsorber 4 to the first adsorber 2 during the second switching operation. This second switching operation is shown in FIG.

During the transient operating phase illustrated in FIG. 4, the first, second, third and fourth adsorption control valves 10, 12, 14, 16 are closed. Consequently, the evaporator 18 can not provide cooling power during the transient operating phase. Further, the first supply valve 60, the fourth supply valve 66, the sixth supply valve 70 and the seventh supply valve 72 opened. The second supply valve 62, the third supply valve 64, the fifth supply valve 68, the eighth supply valve 74 and the ninth supply valve 76 are closed. The heater 50 and the cooler 52 may be turned off. The first pump 54 and the second pump 56 pump warm heat transfer fluid from the second adsorber 4 via the sixth supply valve 70, the heater 50 and the first supply valve 60 to the first adsorber 2, thereby heating the first adsorption medium. Further, cool heat transfer fluid is supplied from the first adsorber 2 via the seventh supply valve 72, the cooler 52, and the fourth supply valve 66 to the second adsorber 4, thereby extracting heat from the second adsorption medium. The transitional operation is continued until in the first adsorber 4 at least the same adsorbent pressure as in the condenser 8 prevails. Otherwise, the transitional operation takes place as previously described with reference to FIG. After completion of the transitional operating phase, the adsorption cooling system 1 again enters the state described with reference to FIG. The adsorption cooling system cycles through the four operating states described above according to FIGS. 1 to 4 in the order described.

The control unit of the adsorption cooling system 1 may comprise the adsorption control valves 10, 12, 14, 16, the expansion valve 6, the supply valves 60, 62, 64, 66, 68, 70, 72, 74, 76, the evaporator fan 20, the heating device 50, controlling the cooling device 52 and the cooling device fan 58 as previously described with reference to FIGS. 1 to 4. Further, volumetric flow sensors may be provided in the adsorption coolant circuit 9 to determine if an adsorber 2, 4 is saturated. It is also possible to conclude that an adsorber 2, 4 is saturated from an ascending temperature in the evaporator 18 measured by means of a suitable temperature sensor. If it is determined during regeneration of an adsorber 2, 4 that the temperature of the heat transfer fluid does not (substantially) decrease as it flows through the adsorber 2, 4, the adsorber 2, 4 can be completely regenerated. Consequently, a plurality of temperature sensors arranged in the line network of the heat transfer system can be present. The signals of the volumetric flow sensors and of the temperature sensors are detected by the control device and converted into corresponding control signals for controlling the components of the adsorption cooling system 1.

Further, the heater 50 and the cooler 52 need not be turned off if no heating or cooling is desired. Instead, appropriate be provided bypassing valves and / or bypass valves, which ensure that the heat transfer fluid flows past one of these facilities. This may be useful, for example, if the heating device 50 is supplied with heat energy by a device which always gives off heat loss.

Claims

claims

An adsorptive cooling system (1) for an aircraft, comprising:

an evaporator (18),

a first adsorber (2) containing a first adsorption medium for adsorbing an adsorption refrigerant evaporated in the evaporator (18),

a second adsorber (4) containing a second adsorption medium for adsorbing the adsorption refrigerant evaporated in the evaporator (18), the first and second adsorbers (2, 4) being operable alternately in an adsorption mode and a desorption mode, respectively an adsorber (2, 4) adsorbing adsorption coolant and the other adsorber (2, 4) can be regenerated,

a heat transfer system, which is adapted, during a transitional operating phase, during which an adsorber (2, 4) from the adsorption in the

Desorption is transferred and the other adsorber (2, 4) is transferred from the desorption into the adsorption, by means of a heat transfer fluid heat energy from the transferred from desorption to adsorption adsorber (2, 4) on the transferred from adsorption to desorption mode adsorber ( 2, 4),

a condenser (8) for condensing adsorption coolant removed from an adsorber (2, 4) operated in the desorption mode, which is fed to the evaporator (18) after condensing,

a first pressure sensor for measuring the adsorption coolant pressure in the condenser (8),

a second pressure sensor for measuring the adsorption coolant pressure in an adsorber (2, 4), and

- An electronic control unit which is adapted to detect signals provided by the pressure sensors and to control the heat transfer system of the adsorption cooling system (1) such that during the

Transitional operating phase, the supply of heat energy to the transferred from the adsorption to the desorption mode adsorber (2, 4) is terminated when the adsorption refrigerant pressure in the adsorber (2, 4) corresponds to the Adsorptionskühlmitteldruck in the condenser (8).

2. adsorption cooling system according to claim 1, characterized in that the heat transfer system comprises a conduit network and a plurality of arranged in the conduit network valves (60, 62, 64, 66, 68, 70, 72, 74, 76)

.5

3. adsorption cooling system according to claim 1 or 2, characterized in that the heat transfer system comprises a heater (50) and is adapted to supply a desorbed operation in the adsorber (2, 4) for regenerating the adsorber (2, 4) thermal energy.

10

4. Adsorptionskühlsystem according to claim 3, characterized in that the heating device (50) is thermally coupled to a loss-heat emitting device of the aircraft.

5. adsorptive cooling system according to one of claims 1 to 4, characterized in that the heat transfer system further comprises a cooling device (52) and is adapted to an adsorber operated adsorber (2, 4) for cooling the adsorber (2, 4) cooling energy supply.

A method of operating an adsorption refrigeration system (1) for an aircraft, the adsorption refrigeration system (1) comprising:

an evaporator (18),

a first adsorber (2) containing a first adsorption medium for adsorbing an adsorption refrigerant evaporated in the evaporator (18), and

25 - a second adsorber (4) containing a second adsorption medium for adsorbing the adsorption refrigerant evaporated in the evaporator (18), the first and second adsorbers (2, 4) being operable alternately in an adsorption operation and a desorption operation, such that one adsorber (2, 4) can adsorb adsorption coolant and the other adsorber (2, 4) can be regenerated,

Wherein in the method of operating an adsorption refrigeration system (1)

- During a transitional operating phase during which an adsorber (2, 4) is transferred from the adsorption to the desorption and the other adsorber (2, 4) is transferred from the desorption into the adsorption, by means of a heat transfer fluid heat energy from that of the Desorptionsbetrieb in

35 adsorber (2, 4) transferred to the adsorption operation is transferred to the adsorber (2, 4) transferred from the adsorption operation to the desorption operation, condensed from a adsorber (2, 4) operated in the desorption mode adsorption in a condenser (8) and the evaporator (18) is fed, and

an electronic control unit sends signals from a first pressure sensor to the measuring

5 senses the adsorption refrigerant pressure in the condenser (8) and a second pressure sensor for measuring the adsorption refrigerant pressure in an adsorber (2, 4) and controls the heat transfer system of the adsorption refrigeration system (1) such that during the transient operating phase the supply of heat energy to that from the adsorption operation in the adsorber (2, 4) transferred to the desorption operation is stopped when the adsorption coolant pressure in the adsorber (2, 4) corresponds to the adsorption coolant pressure in the condenser (8).

7. The method according to claim 6, characterized in that the heat transfer system comprises a line network as i5 a plurality of arranged in the line network valves (60, 62, 64, 66, 68, 70, 72, 74, 76), corresponding to to transfer thermal energy from the adsorber (2, 4) transferred from the desorption mode to the adsorption mode to the adsorber (2, 20 4) transferred from the adsorption mode to the desorption mode during the transitional operating phase by means of the heat transfer fluid.

8. The method according to claim 6 or 7, characterized in that a heating device (50) of the heat transfer system to a desorbed operation adsorber (2, 4) for the regeneration of the adsorber 5 (2, 4) supplies thermal energy.

9. The method according to claim 8, characterized in that the heating device (50) is supplied from a loss of heat-emitting device of the aircraft loss heat. 0

10. The method according to any one of claims 6 to 9, characterized in that a cooling device (52) of the heat transfer system to a powered adsorption in the adsorber (2, 4) for cooling the adsorber (2, 4) supplying cold energy. 5