WO2006018216A1

WO2006018216A1 - Absorption-type refrigerating machine

Info

Publication number: WO2006018216A1
Application number: PCT/EP2005/008717
Authority: WO
Inventors: Raoul Von Der Heydt; Andrea Costa; Paul Kohlenbach; Stefan Petersen; Christian Schweigler; Felix Ziegler; Franz Storkenmaier; Mario Harm; Christoph Kren; Martin Högenauer-Lego; Peter Lamp
Original assignee: Phönix Sonnenwärme AG
Priority date: 2004-08-12
Filing date: 2005-08-11
Publication date: 2006-02-23
Also published as: DE102004039327A1

Abstract

The invention relates to an absorption-type refrigerating machine (10) containing: an evaporator (22) provided in the form of a heat exchanger (104), which is connected to an air-conditioning cold water circuit and which serves to evaporate a refrigerant at low pressure; an absorber (20) for absorbing the refrigerant vapor, which is produced in the evaporator (22), by means of a solvent containing a low content of refrigerant at low pressure and housed in the same housing (14) as the evaporator (22); a solvent pump (86) for delivering the solvent containing a high content of refrigerant at a higher pressure; means for supplying hot water from a hot water source; a generator (16), through which hot water flows and which serves to evaporate the refrigerant out of the solvent, and; a condenser (18), which serves to liquefy the refrigerant vapor at the higher pressure and which is provided in the form of a heat exchanger (38) flowed through by refrigerant and housed in the same housing (12) as the generator (16). The invention is characterized in that the generator (16) is designed in such a manner that refrigerant working substance solution collects in a first area (46) at the bottom of the housing, and means (50; 60) are provided for thermally insulating this area from an area (48) in which the refrigerant liquefied in the condenser (18) collects.

Description

Patent application

Absorption chiller

Technical area

The invention relates to an absorption refrigerating machine containing

(a) an evaporator in the form of a heat exchanger connected to an air conditioning circuit for evaporating a refrigerant at low pressure,

(b) an absorber _. poor refrigerant to absorb the refrigerant vapor generated in ^'the evaporator by a solvent at low pressure, which as the evaporator is arranged in the same housing,

(c) a solvent pump to deliver the refrigerant-rich solvent to a higher pressure,

(d) means for supplying hot water from a hot water source,

(e) an expeller run through by the hot water, to evaporate the

Refrigerant from the solvent, and (F) a condenser for liquefying the refrigerant vapor at the higher pressure in the form of a flowing through coolant heat exchanger, which is arranged in the same housing as the expeller.

With absorption refrigerators, refrigeration is generally used to operate e.g.

Building air conditioners generated. Absorption refrigerators use heat at different temperature levels depending on the application, as drive energy for thermally compressing a refrigerant, e.g. Solar heat or waste heat. It is up to the small energy for pumping and control no electrical energy required. As a result, a high efficiency in the provision of cold can be achieved.

An absorption chiller essentially comprises four components: evaporator, absorber, expeller (also referred to as generator) and condenser. In the evaporator, the refrigerant, eg water, is evaporated to a low pressure level. In the process, the refrigerant extracts energy from an air conditioning circuit, ie the cooling capacity is provided. This is done, for example, in the form that water of a building-Klimakaltwasser cycle flows through the evaporator designed as a heat exchanger and is cooled there. In an absorber, the refrigerant vapor is absorbed by an absorbent, for example, concentrated LiBr solution. As a result, the refrigerant is now present in the solution in liquid form. The refrigerant dissolved in the Li-Br solution by the absorption process is pumped to a higher pressure level in an expeller. The absorber comprises a heat exchanger, which is traversed by cooling liquid at a medium temperature level. The generator comprises a heat exchanger through which hot water flows. The hot water is generated, for example, by solar energy. In the expeller, the refrigerant is evaporated from the refrigerant-rich solution and thereby absorbs energy. The low-refrigerant solution, ie, for example, the concentrated LiBr solution is then available again for the absorption process. The vaporized refrigerant is liquefied in a condenser and then brought back by means of = a throttle device to a lower level Drack. It is then available again in the evaporator. The capacitor also includes a heat exchanger, which is traversed by cooling liquid at a medium temperature level, for example ambient temperature.

State of the art

Usually absorption chillers are operated in a power range above 200 kW. These systems are large, expensive for small applications and operate at relatively high drive temperatures. But there is also one. Need for small, cost-effective systems.

From the publication "Further development and field test of a compact 10 kW H ₂ O-LiBr absorption refrigeration system" by P. Kohlbach, S. Medel y Molero, C. Schweigler, M. Harm, J. Albers, A. Kühn and S. Petersen at the 3rd Symposium Solares Kühlen, FH Stuttgart, 26./27.04.2004, and the publication "Absorption cold water replacement for solar cooling with 10 kW cooling capacity" by C.

Schweigler, A. Costa, M. Högenauer-Lego, M.Harm and F. Ziegler, published at the annual meeting of the German Refrigeration and Air Conditioning Association (DKV), Ulm, Nov. 2001, is a solar-powered absorption refrigeration system in the lower power range known. The system can be supplied with hot water on the drive side at a low temperature level using conventional flat collectors. The arrangement has in each case a common container arranged pairs of apparatus evaporator / absorber and expeller / condenser. The container with the evaporator and the absorber is arranged below the container with the ejector and the condenser. As a result, a compact arrangement is achieved, which is transportable and z. B. also fits through doors. The manufacture and final assembly of such an arrangement is completely possible at the factory. The arrangement allows hot water temperatures up to a minimum temperature in the range of 56 ° C.

Disclosure of the invention

It is an object of the invention to provide an absorption chiller in the lower power range of the type mentioned, which is compact and a improved ratio of cooling capacity "and this required drive thermal power (Coefficient of Performance COP) also in part-load operation.

According to the invention, the object is achieved in that the expeller is designed such that refrigerant working fluid solution collects in a first region on the housing bottom and means for thermal insulation of this region of a region in which the refrigerant liquefied in the condenser collects. The invention is based on the surprising finding that even in the area of very small cooling capacities, refrigeration systems with a very low temperature can reach a high heat ratio. This applies not only in full load operation, but especially in partial load operation. The prevention of heat leakage from the generator to the condenser and / or from the absorber to the evaporator makes it possible to achieve low outputs.

The thermal insulation can be effected in that the lateral housing wall in the transition areas between the condenser and expeller has a reduced thermal conductivity, for example a reduced thickness. As a result, the heat transfer between the areas also referred to as "swamps" on the housing bottom and the housing interior above these areas along the housing wall is substantially reduced.

Furthermore, the separation of the liquefied refrigerant in the condenser from the non-evaporated refrigerant in the expeller can be effected by a thermally insulated partition wall. This thermally insulated partition can double-walled with an intermediate, thermally insulating medium, in particular air or

Vacuum, be trained. This further reduces the heat transfer between the swamps.

The partition may be welded to the housing bottom and the housing bottom along the wall with holes to further reduce the

Be provided heat transfer. Alternatively, the partition can be integrated by suitable shaping of the housing bottom in this. In a particularly preferred embodiment of the invention, the evaporator is also designed as a trickle-bed heat exchanger in which unevaporated refrigerant collects in a first region on the housing bottom and means for thermal insulation of this region from a region in which the solvent present in the absorber collects. The thermal insulation can be done with the same measures as the thermal insulation of the sumps of expeller and condenser.

Preferably, one or more of the trickle-bed heat exchangers comprise a bundle of raw materials, which is sprayed with liquid from a distributor trough via feed tubes, the feed troughs projecting downwardly from the underside of the distributor trough

Extend direction of the tube bundle. Due to the uniform, well-dosed sprinkling of the tube bundles, a particularly high heat transfer in the heat exchanger can be achieved. This is made possible by the feed tubes. A convergence of the drops is avoided by them.

In a further embodiment of the invention, the vacuum system is connected via suction lances in the absorber with the housing interior of the evaporator / absorber housing comprising a provided on the bottom with holes in the tube, which extends substantially horizontally. The suction lances can additionally be provided with drop baffles, which deflect liquid flowing down the suction lances downwards away from the bores. The drop deflectors may be formed by a cover extending substantially straight down from the top of the suction lance. The downwardly directed holes and the drop deflector prevents liquid from the

Suction lances is sucked, which trickles down on this.

Preferably, in the transition region between the evaporator and the absorber and / or in the transition region between the expeller and capacitor superimposed, horizontally extending slats are provided, which in the direction of the steam-generating

Area are inclined downwards. These fins function as a mist eliminator for retaining liquid droplets in the vapor stream. Then flows prematurely condensing vapor and other liquid droplets back into the Äustreϊber or evaporator and can be evaporated there in a new "trial".

When switching off the device, the crystallization in the solvent circuit must be avoided. In the case of the known large systems, this is initially cooled before the system is completely switched off. Initially, the hot water supply is switched off and continue to operate the cooling and the solvent pump for a certain time. This follow-up time is in the range of about half an hour and is fixed. At the same time, the solvent is diluted with liquid refrigerant from the evaporator.

In a further embodiment of the absorption refrigeration machine according to the invention means are provided for determining the concentration of the low-refrigerant solvent and means for determining the minimum required to avoid crystallization dilution of the working / refrigerant solution before switching off the

Machine out of this concentration. The determination of the minimum dilution required avoids unnecessarily high dilution of the working / refrigerant solution before the machine is switched off, thus minimizing the drive heat requirement when the system is restarted.

The means for determining the concentration of the low-refrigerant solvent may include:

(a) means for determining the temperature of the solvent exiting the expeller,

(b) means for determining the operating pressure prevailing in the expeller and condenser,

(C) means for determining the temperature of the emerging from the condenser

Refrigerant condensate, (d) means for determining the temperatures of the cooling water entering and leaving the condenser,

(e) recloning means for determining the concentration from the values determined according to (a) to (d).

Through the use of temperature sensors, the regulation of the Abfahrroutine can be made particularly simple in this way. Of course, other means are also suitable for determining the concentration.

For dilution of the solvent can be connected via a valve between a region in which in the. Evaporating refrigerant collects, and be produced to the absorber. Furthermore, means may be provided for cyclically opening the valve at a fixed clock interval, and means for calculating the minimum number of opening operations corresponding to the calculated minimum

Dilution time. By calculating the optimal number of cycles at a fixed cycle interval and fixed volume flow both the dilution time and the dilution degree are set and optimized. There is no excessive dilution which prolongs the restart.

Preferably, the refrigerant is feedable only above a concentration of 55% of the solvent for dilution. A particularly preferred value is 57%. Below this concentration dilution is no longer required. On the contrary. A higher dilution will increase the time required for the restart, because then it must be concentrated again with energy expenditure. Above this concentration, there is a risk of crystallization. Here, the dilution routine described ensures a dilution of the solution adapted to the last prevailing concentration, in order to set a specific state determined for the standstill of the system, regardless of the operating state before the shutdown of the system.

For further utilization of the solar energy, a further heat exchanger may be provided, in which heat from the through the absorber and / or condenser flowing coolant. the water of a swimming pool is released. The cooling liquid has a temperature in the middle range of about 30 °, and is generally above the temperatures, which has an unheated swimming pool. The heat exchanger can use the heat from the cooling liquid and a cooling tower is superfluous. Alternatively, the cooling liquid can also be cooled in other waters, such as lakes, rivers or the ocean. Thus, the expenditure on equipment and the energy consumption for the recooling is reduced and thus increases the efficiency.

A special use of the absorption chiller results with a

Cooling arrangement for cooling ambient air and means for collecting condensed air humidity. The cooling arrangement may be separated from a free-standing heat exchanger, e.g. a tube bundle or the like. The temperature gradient condenses moisture in the air and is collected by means of a collecting means. In this way can be used in arid regions with

Solar energy water can be obtained.

The absorption chiller can be operated with all common solvents and refrigerants, such as LiBr / water or water / NH ₃ .

Embodiments of the invention are the subject of the dependent claims. An embodiment is explained below with reference to the accompanying drawings.

Brief description of the drawings

Fig.l shows a cross section through an absorption chiller

Fig. 2 is an external view of the absorption chiller of Fig. 1 with the water box open 3 is a schematic of the circuits required in the absorption refrigerating machine of FIG

Description of the embodiment

1, a single-stage absorption chiller, generally designated 10, is shown. The absorption chiller 10, comprises two housings 12 and 14. The housing 12 is disposed above the housing 14. In your housing 12 is a generally designated 16 expeller and next to a capacitor 18 is arranged.

In the housing 14, an absorber 20 and an evaporator 22 is arranged.

In the expeller 16, a heat exchanger 24 is provided. The heat exchanger 24 comprises a bundle of Rob 100 of horizontally extending copper tubes 26. Copper tubes are inexpensive and have a high WameleitfäHgkeitskoeffizienten. They ensure good heat transfer. The copper tubes 26 are arranged in 20 superimposed rows of five tubes side by side in a plane. The distances to each lying in the same plane adjacent pipe correspond to the distances of the rows. The pipe diameter is 12 mm. The tubes are held in holes in two tube plates 28 (Fig.2). The tube plates 28 are arranged parallel to the plane of representation in Fig.l. With them, the housing 12 is completed. The tubes 26 protrude slightly beyond the tube plates 28 and open on the outside of the housing 12 on each side in a water tank 30 and 32. The water tank 30 and 32 is via leads 34 and 36 (Figure 2) with a solar thermal flat collector (not shown) connected. Instead of a solar thermal flat collector, another source of energy can be used. In the collector water is heated by solar heat to a weather and Tageszeit¬ dependent temperature and pumped through a control system through the tubes 26 of Austreib er s 16

In the housing 12, the capacitor 18 is further arranged. The housing height of the housing 12 is reduced along the condenser 18 from the height along the expeller 16. In the condenser 18 is also a heat exchanger 38th intended. The heat exchanger 38 is similar to the heat exchanger 24 made of copper pipes. For the heat exchanger 24, the copper rotors are arranged in 10 rows of 5 horizontally extending tubes 40. However, the tubes are each offset from each other. Also, here open the tubes 40 behind the tube plate 28 in a water tank 42 with inlet 44 (Figure 2). Through the tubes 40 cooling water is passed. About the cooling water, the resulting heat in the condenser via a cooling tower or a heat exchanger (not shown) at a swimming pool, a lake, river or the like discharged into the environment.

The lower housing portions 46 and 48 of the housing 12 are through a partition

50 and a Trenriblech 52 separated from each other. The partition wall 50 consists of one. the base plate 54 welded U-profile 56, with a cavity 58. The U-profile 56 causes thermal isolation of the regions 46 and 48 from each other. The base plate 54 is provided along the U-profile with holes. As a result, the heat transfer between the regions 46 and 48 is also reduced. The tube plates 28 have in the transition region 60 between expeller 16 and capacitor 18 has a smaller thickness. The resulting edges are designated 62 and 64 in FIG. 1.

Both lower housing portions are provided with a strainer 66 in the form of a screen, which extends parallel to the base plate 54 and slightly above. About a U

Tube 68 and a shut-off valve 70 (Figure 3), the condenser 18 is connected to the evaporator 22. The U-tube 68 acts as a throttle due to the pressure difference. This will be a. Pressure difference between the condenser 18 and the evaporator 22 realized.

Between the expeller 16 and, the capacitor 18 is a "steam jalousie" of three lamellar droplet traps 72. The droplet traps 72 consist of horizontally extending, flat sheets, which are inclined in the direction of Austreib ers down.

The expeller 16 is provided with a feed trough 74. The tundish 74 is located just above the tubes 26. The tundish 74 has tundish 76. The dispensing tubes 76 extend on the underside of the Feed tray 74 down. They are located exactly above the center of the tube of the respective underlying tube. Refrigerant-rich LiBr solution, which is located in the hopper, then drips through the feed tube 76 very evenly on the tubes 26. The good distribution, a particularly good heat transfer between the hot water flowed through pipes 26 and the solution is achieved.

The poor, i. concentrated LiBr solution arriving at the lower end of the expeller 18 is first passed to a solution heat exchanger 77. This is shown in FIG. The solvent heat exchanger 77 is of the warmer, low-refrigerant solvent on the one hand and the countercurrent of the slightly colder,

On the other hand, refrigerant-rich solvents flow through. This is illustrated by arrows 79 corresponding to the poor solvent and 81 corresponding to the rich solvent. In the solution heat exchanger 77, the refrigerant-rich solvent is preheated and requires less energy in the expeller. Conversely, the low-refrigerant solvent coming from the expeller into the absorber has already cooled down a bit.

From the solvent heat exchanger 77, the low-refrigerant solvent is passed into the feed trough 82 of the absorber 20. The U-tube 78 and the shut-off valve 80 allow for the PaIl occurring in the solution heat exchanger 77 crystallization of the solution an overflow of the solution directly from the expeller in the absorber. Crystallization blocks the flow of solution in path 79. The solvent heat exchanger 77 throttles the pressure at the absorption level. The absorber 20 is constructed substantially identical, as the expeller 16. The poor solution trickles through a heat exchanger 84 and is thereby cooled by the cooling water to dissipate the heat of absorption. It absorbs the refrigerant vapor generated in the evaporator. Then, the rich solution is pumped by means of a solvent pump 86 (Figure 3) back into the feed trough 74 of the expeller 16.

The absorber 20 and the evaporator 22 are operated at about 10 mbar internal operating pressure, which is determined by the vapor pressure of the refrigerant. To remove interfering residual gases, two "suction lances" 88 and 90, to which a vacuum system is connected, are provided The suction lances 88 and 90 consist of a tube with holes on the bottom 92. Above the tube is a drop deflector in the form of a sheet, which extends from the top of the tube from straight down, down. As a result, no coming from above drops in the Rohröffhungen. Such an arrangement 89 in the condenser 18 - also in conjunction with a vacuum system - is used to remove residual gases from the

Capacitor 18 and evaporator 22 are used.

Also, the absorber 20 and the vaporized ^* 22 are equipped in the lower part with a strainer 94 and a thermally insulating partition 96 with partition plate 98. Also liier is the tube plates are tapered in the transition region between absorber and evaporator. The tubes of the heat exchangers 102 and 104 in the absorber and evaporator open, as in the expeller 16 in water tanks and therefore need not be further described here. The heat exchanger 102 of the absorber has 18 rows of five tubes each. The heat exchanger 104 of the evaporator has 16 rows of four tubes each. He is one with the climate cycle, for example

Building air conditioning connected. Again, a Aufgabewanne 106 is provided with Aufgaberöhrchen 108.

The water passing into the evaporator via pipe 68 refrigerant is pumped by the pump 112 in the task tray 106 and flows through the heat exchanger 104. In this case, it evaporates due to external Wännemfuhi ^* from the Nutzkältekreislauf at a low pressure level. The refrigerant vapor is absorbed in the absorber by a concentrated, low-refrigerant LiBr solution. In the transition region between the evaporator and the absorber four lamellar droplet traps 110 are provided. This have a roof shape. The droplets flow back into their area of origin. to

Ensuring a good wetting, the liquid, non-evaporated refrigerant is pumped by means of a pump 112 from below the heat exchanger 104 back into the task ewanne 106.

The described arrangement uses gravity to transfer refrigerant from the condenser 18 into the evaporator 22, as well as from the expeller 16 to the absorber 20. It therefore only requires two circulation pumps 86 and 112 and is particularly compact. The throttling of the pressure from condenser to evaporator level takes place via a U-Rolir 68 and the height difference of the water columns, the throttling of the pressure of Austrreiber- on absorber level via the solution heat exchanger 77 in conjunction with a U-tube 180. By a suitable control of the flow rates, it is possible to keep the COP in the TeiUastbereich to a high value , As a result, the arrangement works very economically ..

With the described, compact arrangement, a separate Abfahrroutine can be used. For this purpose, the internal operating temperatures at the condenser and expeller outlet are determined. From the measurements, prior to initiating the shutdown routine, the concentration of the working / refrigerant solution, i. the current

Operating point of the system, calculated. These data only give a reliable statement about the currently prevailing Lösungskonzenttation when expelled in the expeller refrigerant vapor by supplying drive heat from the solution and the refrigerant vapor is condensed with heat release to the cooling water in the condenser. This is due to a corresponding increase in temperature of the

Cooling water when passing through the condenser occupied. The detection of these temperatures by means of TemperaturFillers 116 and 120 is also part of the Abfahrroutine.

In an alternative embodiment, the concentration of the refrigerant-inert solvent will also be determined differently. For this purpose, the temperature of the solvent emerging from the expeller is determined by means of temperature sensor 174. Furthermore, the pressure in the expeller 22 and condenser 18 is determined by means of a pressure gauge 176. Finally, the temperature of the refrigerant condensate leaving the condenser is determined by means of temperature sensor 172. From these

Values then the concentration is calculated

The temperature values vary due to e.g. Changing solar radiation with the time of day and season At low hot water temperatures, the system therefore operates at a different operating point than at high temperatures. Accordingly, there is a lower risk of crystallization.

The temperature difference between the cooling water inlet and outlet at the condenser is determined by temperature sensors 116 and 120. If this difference falls below one given, small value, for example, 0.4K, it is assumed that no more heating power is provided. For this case, the maximum solvent concentration of about 62% for the low-refrigerant solution is assumed. In this case, a solenoid valve 122 opens, via which a connection between the refrigerant circuit 124 and the solvent circuit 126 is established. Refrigerant is then to

Dilution of the LiBr solution mixed. This reduces the solvent concentration.

The solenoid valve 122 opens clocked at a constant clock interval. The degree of dilution and the duration of dilution depend on the number of

Opening operations. By appropriate Beshrirnmung the required number of

Opening operations can thus significantly reduce the dilution time of the plant.

In this way, the desired for the stoppage of the plant concentration of

Solution set without diluting the solution unnecessarily high. In the present case, it is diluted only at concentrations above 57%. This will be a quick one

Restarting possible. It does not have to be concentrated long before restarting, before cold is generated. As a result, the efficiency of the arrangement is increased overall. The system can be flexibly switched on and off in comparatively short time. In contrast to large machines with long follow-up times, the machine can therefore be adjusted very well to the current environmental conditions.

For removing residual gases and generating the pressure levels of about 10 mbar in the evaporator and absorber and about 50 mbar in the expeller and condenser, a generally designated 130 vacuum system is used (Figure 3). The extraction takes place via the suction lances 88, 89 and 90 and supply lines 134, 136 and 138 to the respective components. Ball valves 140 and 142 are provided in the supply lines. In this way, both housings 12 and 14 are connected to the vacuum pump 144. In a first alternative, which is illustrated in FIG. 3, the vacuum pump 144 is formed by a jet pump. In front of the jet pump 144 is designated 132

Flow meter arranged. The rich solvent pumped by the pump 86 is diverted as a drive jet from the solvent circuit 146 toward the pump 144. This is called 148. The jet pump 144 generates at the terminal 150 the desired one. Vacuum. The supply lines 134 and 138 are connected via the common supply line 136 to the terminal 150, in a separator 152 in the form of a bubble separator, the solvent / gas mixture coming from the pump is separated. The solvent flows back into the circuit 146 via a line 154. The gas is collected in a tank 156. The tank 156 is arranged spatially higher than the absorber 20 and connected to it via a tube. The separator 152 is located at the lowest point of this tube. The gases from the separator 152 rise in the riser to the tank and displace thereby standing in the riser liquid. According to the height difference between separator 152 and minimum liquid level in the absorber 20, a relative overpressure in the tank

156 are generated.

The tank 156 above the absorber 20 is freed from the gas at regular intervals of about a few weeks by flooding. The liquid level in the tank is measured with liquid sensor 168. For this purpose, the already existing solvent pump 86 is used. Then, a pressure above the ambient pressure in the tank is established by the solution pump 86. The line between the solution pump and the Lδsungswärmetauscher is closed by means of the valve 160, as are the valves 140 and 142 in the suction lines 138 and 134. The line between separator 152 and absorber 20 is closed by means of valve 162. The pump then promotes solution in the residual gas tank. A valve 164 on

Residual gas tank is opened and the residual gases are expressed against the environment.

Liquid sensor 166 indicates when the tank is filled with solution and the squeezing procedure is completed. In this vacuum system, no separate motor is required, but the power of the pump 86 is shared via the jet pump. Alternatively, an external vacuum pump can be connected.

Since the jet pump 144 is limited in its suction pressure, the driving jet can be cooled during operation of the plant. For this purpose, a double-walled tube is used, in the inner region of the propulsion jet and in its outer region cooling water is passed from a pitch circle 170 of the cooling water circuit parallel to the absorber. - The Solution is subcooled in this way below the level in the absorber 20 and the vapor pressure is reduced.

At standstill of the arrangement, a thermal equilibrium is formed between the system and the environment. At the time of thermal equilibrium, the

Solvent in the absorber strongly undercooled and the vapor pressure decreases compared to the operating condition. Since there is usually still refrigerant in the evaporator sump, which has a much higher vapor pressure than the solvent, an equilibrium pressure builds up. There is a Dampfbewegtmg from the evaporator sump to the absorber sump. Now, if the solvent is passed through the jet pump 144, as the maximum negative pressure of the vapor pressure of the solvent to reach. This results in a continuous Voluinenstrom through the suction lances 88, 89 and 90. The residual gases are entrained.

In alternative embodiments, an auxiliary absorber or a spray absorber may be used instead of the jet pump.

The poor solution is continuously withdrawn from the circuit 146 as in the use of the jet pump. In the auxiliary absorber, this solution is passed through cooling coils, in which cooling water flows before / or parallel to the actual main cooling water flow. The solution is undercooled more than in the absorber 20. Via a pipe, the vapor space of the absorber 20 is connected to the vapor space of the auxiliary absorber. The strong subcooling in the auxiliary absorber leads to a continuous steam mass flow through this line. This also non-condensable gases are taken. The water vapor is absorbed in the auxiliary absorber.

In a downpipe, the solvent is supplied to the separator. Over a slight Krürnniung at the inlet to this downpipe uncondensable gases are entrained.

Instead of the auxiliary absorber we used in a third exemplary embodiment, a spray absorber. At standstill of the system is as described above with reference to the first embodiment to generate a relative negative pressure. By means of a spray nozzle, a solution mist is generated. The fog is at plant stop strongly undercooled and therefore acts hygroscopic. It generates a vapor stream from the absorber 20 and condenser 18 through the suction lances 88, 89 and 90 to the spray absorber. Again, the solvent is passed to the separator as in the auxiliary absorber through a curved in the inlet fair pipe.

Claims

claims

1. Absorption chiller (10) containing

(a) an evaporator (22) in the form of a heat exchanger (104) connected to an air conditioning circuit for evaporating a refrigerant at low pressure,

(B) an absorber (20) for absorbing the refrigerant vapor generated in the evaporator (22) by a low-refrigerant solvent at low

Pressure, which is arranged in the same housing (14) as the evaporator (22),

(c) a solvent pump (86) for delivering the refrigerant-rich solvent to a higher pressure,

(d) means for producing hot water,

(e) an expeller (16) through which the hot water flows, for evaporating the refrigerant from the solvent, and

(t) a condenser (18) for liquefying the refrigerant vapor at the higher pressure in the form of a heat exchanger (38) through which cooling fluid passes, arranged in the same housing (12) as the expeller (16),

characterized in that (g) the expeller (16) is configured to collect residual refrigerant working fluid solution after expulsion in a first region (46) at the bottom of the housing and means (50; 60) for fluidly isolating that portion from a region (48); in which the refrigerant liquefied in the condenser (18) collects.

2. absorption refrigeration machine according to claim 1, characterized in that the thermal insulation is effected in that the lateral housing wall (28) in the transition regions (60) between the condenser (18) and expeller (16) has a reduced thermal conductivity.

3. absorption refrigeration machine according to claim 2, characterized in that the lateral housing wall (28) in the transition regions (60) between the condenser (18) and expeller (16) has a reduced thickness.

4. absorption refrigeration machine according to one of the preceding claims, characterized in that the separation of the liquefied refrigerant in the condenser (18) from the non-evaporated refrigerant in the expeller (16) by a thermally insulated partition wall (50).

5. absorption chiller according to one of the preceding claims, characterized in that the thermally insulated partition (50) is double-walled with an intermediate, thermally insulating medium, in particular air or vacuum, is formed.

6. Absorptionskältemascliine according to claim 5, characterized in that the Trennwandυng (50) on the housing bottom (54) is welded and the housing bottom (54) along the wall (50) is provided with holes or designed as open at the bottom U-profile and with the housing bottom (54) is welded.

7. Absorption cold machine according to one of the preceding claims, characterized in that the evaporator (22) is formed such that non-evaporated refrigerant collects in a first region on the housing bottom and means (96, 100) for the thermal insulation of this area of a region in which collects the solvent in the absorber (20).

8. absorption refrigeration machine according to claim 7, characterized in that the thermal insulation is effected in that the lateral housing wall (28) in the transition regions (100) between the evaporator (22) and absorber (20) has a reduced thermal conductivity.

9. absorption refrigeration machine according to claim 8, characterized in that the lateral housing wall (28) in the transition regions (100) between the evaporator (22) and absorber (20) has a reduced thickness.

10. absorption refrigeration machine according to one of the preceding claims, characterized in that the absorber, the evaporator and / or the expeller comprise a trickle-film heat exchanger.

11. An absorption chiller according to claim 10, characterized in that one or more of the trickle-film heat exchangers (24, 102, 104) comprise a tube bundle, which via feed tubes (76, 108) with liquid from a distributor trough (74, 82, 106) sprinkles with the feed tubes extending downwardly from the bottom of the distributor pan towards the tube bundle.

12. Absorption chiller according to one of the preceding claims, characterized in that the vacuum system via suction lances (88, 90) in the absorber (20) with the housing interior of the evaporator / absorber housing (14) and / or suction lances (89) in the condenser (18) is connected to the housing interior of the expeller / condenser housing comprising a bottom provided with a bore tube which extends substantially horizontally.

13. absorption refrigerating machine according to claim 9, characterized in that the

Suction lances (88, 90) are provided with drop baffles, which deflect the liquid flowing down the suction lances downwards away from the bores.

14. absorption refrigeration machine according to claim 12, characterized in that the droplet deflector are formed by a cover, which extend from the top of the suction lance (88, 90) substantially straight down.

15, absorption chiller according to one of the preceding claims, characterized in that in the transition region (100) between the evaporator and absorber and / or in the transition region (60) between the expeller and condenser stacked, horizontally extending slats (72, 110) are provided which in Direction of the steam generating area are inclined downwards.

16. absorption chiller according to one of the preceding claims, characterized in that a further heat exchanger is provided, in which heat from the through the condenser (18) flowing Kühlfiüssigkeit is delivered to the water of a swimming pool.

17, absorption chiller according to one of the preceding claims characterized by a cooling arrangement for cooling ambient air and means for collecting condensed air humidity.

18. absorption chiller according to one of the preceding claims, characterized in that the means for generating hot water solar thermal collectors comprise.

19. absorption chiller according to one of the preceding claims, characterized by means for determining the concentration of the low-refrigerant solvent (113, 114, 116) and means for determining the minimum required dilution of the working / TC refrigerant solution before shutting down the machine from this concentration.

20. Absorption chill after addressed. 19, characterized in that the means for determining the concentration of the low-refrigerant solvent comprises:

(a) means for determining the temperature of the solvent exiting the expeller,

(c) means for determining the temperature of the refrigerant condensate leaving the condenser,

(d) means for determining the temperatures of the cooling water entering and leaving the condenser,

(e) computer means for determining the concentration from the values determined according to (a) to (d).

21. absorption refrigeration machine according to one of claims 19 or 20, characterized in that via a valve (122) has a connection between a

Area in which collects the refrigerant in the evaporator (22), and the absorber (20), the solution circuit or the expeller for

Dilution of the solvent with refrigerant can be produced.

22. absorption refrigeration machine according to claim 21, characterized in that

Means for ventilated opening of the valve (122) are provided at a fixed clock interval, and means for calculating the minimum number of Opening operations according to the calculated minimum required dilution.

23. Absorption refrigerating machine according to claim 21 or 22, characterized in that the refrigerant can be supplied only above a concentration of 55% of the solvent for dilution.

24. absorption chiller according to one of the preceding claims, characterized in that the low pressure level in. common. Housing (14) of the evaporator and absorber or reduced to ambient pressure

Pressure level in the common housing (12) of the expeller and the condenser by means of a vacuum system (130) can be generated, which is operable by the solvent pump (86).

25. absorption refrigerating machine according to claim 24, characterized in that

Refrigerant-rich solvent between the solvent pump (86) ^" and the expeller (16) is branched off and applied to a vacuum pump (144) in the form of a jet pump or a spray absorber.

26. Absorption chiller according to claim 24, characterized in that

Refrigerant-poor solvent is diverted between the solution heat exchanger (77) and absorber (20) and applied to a vacuum pump (144) in the form of an auxiliary absorber.