DE1751375B - Absorption refrigeration system - Google Patents

Description

via a line for liquid refrigerant with The letters HD represent an abbreviation for

connected to the primary evaporator, because high pressure and the letters ND are an abbreviation

characterized in that the heat represents low pressure.

stage of an LP auxiliary absorber (27 to 30) 25 Two-stage absorption refrigeration systems are formed is that the cooling stage is known from an LP, in which the HP generator or Ausrei auxiliary evaporator (90, 92 to 94) and is connected downstream via an LP generator. The ND-that a refrigerant vapor line (33 to 36) between the generator has a condensation part in the see the LP auxiliary evaporator (90, 92 to 94) the refrigerant expelled from the HP generator and the LP auxiliary absorber (27 to 30) pre-medium steam slides and at least partially liquefies is. is sigt. The heat given off serves to

2. Absorption refrigeration system according to claim 1, expelling of enriched absorption solution, characterized in that the LP auxiliary ver- which is also passed from the HP generator to the LP gene steamer of two or more one behind the other gerator. The stages (90, 92 to 94) which are switched on in the LP generator consist of ₃₅ enriched concentrated absorption solution, the pressure gradually drops from stage to stage, so that the LP auxiliary absorber consists of two or more via a heat exchanger in which it is cooled fed to the system behind the absorber. Consists of the Abeinandergeschalteten stages (27 to 30), üorber the weak absorbing solution passes through the pressure from stage to stage gradually Toggle _e i _ne n heat exchanger in the ND generator back increases, and that the refrigerant vapor line corresponds ₄₀ wherein in the second Heat exchanger which is weak according to the number of stages of the LP auxiliary evaporator sorption solution is heated.

fers or the LP auxiliary absorber from two or with such absorption refrigeration systems

more refrigerant vapor lines (33 to 36) compared with single-stage loading facilities a better effect, where each _gra d obtained at least one steam. The well-known two-stage absorption line a pressure stage of the _{LP auxiliary evaporator 45} refrigeration systems, however, make high solution temperature with the corresponding pressure stage of the LP doors and concentrations of the absorbent connecting auxiliary absorber. required in the HD generator if you have the best

Will receive 3. absorption refrigeration system according to claim 2, _ser s efficiency. High solution characterized in that the stages (90, 92 temperatures and concentrations call, for example up to 94) of the LP auxiliary evaporator in the flow ₅₀ Use of lithium bromide as absorption direction from the HP generator (7) to the primary solution a stronger Corrosion of the metal parts her-absorber (11) from stage to stage one before, so that relatively expensive materials have a lower level that are necessary in the. It is therefore known that in the high-pressure stages (27 to 30) of the low-pressure auxiliary absorber, the generator relatively low concentrations drop from level to level. _{55 of} the absorption solution to be used to

4. absorption refrigeration system according to claim 3 to reduce the risk of corrosion. However, one must be characterized in that successive larger heat exchange surface and a lower stage (90, 92 to 94) of the LP auxiliary evaporator efficiency must be accepted, so that they are connected to one another by U-tubes (89) _{at s} i _{cn m} i _t two-stage plants recoverable Vordurch which liquid absorbent solution 60 parts partially canceled again.

flows from one to the next stage, the relatively large heat exchange whereby the vertical legs of the U-tubes min- surfaces in the known two-stage absorption nozzle have such a length that the refrigeration systems also require a relative pressure difference of the LP auxiliary evaporator stages moderately high effort. The heat exchange surfaces (90, 92 to 94) with one another or with adjacent ones must therefore be made so large because the th auxiliary absorber stages (27 to 30), the amount of heat _{to be transferred in a balanced manner is greater.}
and at the same time a vapor barrier is set up. The invention has therefore set itself the task of creating a multi-stage absorption refrigeration system,

with dor a relatively high degree of efficiency is achieved can be without reducing the concentration of the absorption solvent, high generator temperatures provided or large heat exchange surfaces must be available,

In a system of the type mentioned at the outset, this object is achieved in that the heating stage is formed by an LP auxiliary absorber that the cooling stage is formed by an LP auxiliary evaporator and that a refrigerant vapor line between the LP auxiliary evaporator and the LP auxiliary absorber is provided.

The LP auxiliary evaporator expediently consists of several stages connected in series and at the same time serves to concentrate and cool the strong solution after this ND generator has left. The refrigerant vapor generated in the auxiliary evaporator is used by the LP auxiliary absorber absorbed by the weak solution flowing to the HD generator, so that the weak Solution is diluted and heated at the same time. The warming and dilution of the weak solution brings less heat to be supplied to the HP generator and thus has a lower heat required generator temperature, since more refrigerant vapor at a lower one Temperature evaporated from the dilute solution.

The LP auxiliary absorber also expediently consists of two or more series-connected Stages, the pressure of which rises in stages and the level falls in stages. Every Stage of the auxiliary absorber is connected to a corresponding pressure stage of the LP auxiliary evaporator. the Stages of the LP auxiliary evaporator are also expediently arranged in such a way that from stage to Level a different height level is reached. The steps are connected by U-tubes connected.

An embodiment of the invention will be explained in more detail with reference to a drawing.

The drawing shows a multi-stage absorption refrigeration system for a two-stage process. The refrigerant used is, for example, water and the absorbent used is, for example, an aqueous one Solution of a hygroscopic salt, such as. B. lithium bromide is used. The solution can be numerous Additives are added, e.g. B. 2-ethylhexanol to improve heat transfer and Lithium hydroxide to prevent corrosion. The designation of a solution as weak relates relying on a solution that is poor in absorbed salt and weak in absorptive power; accordingly A solution is said to be strong if it is rich in absorbed salt and strong in absorptive power is.

The system contains a high-pressure generator 7, a low-pressure generator 8 with a high-pressure condensation section 83, an LP condenser 9, a primary absorber 11 and a primary evaporator 10.

The primary evaporator 10 and the primary absorber 11 are expediently located within an LP housing 16 arranged. Inside this housing 16, an inner part 12 forms the primary absorber chamber and an inner part 13 the primary evaporator chamber. Numerous tubes 14 for heat exchange are arranged within the primary evaporator chamber 13 to a liquid medium, such as. B. Water to cool. Numerous tubes 15 for heat exchange are within the primary absorber chamber 12 arranged to a cooling medium, such as, B, water, a suitable cooler, z, B, a conventional cooling tower,

S The liquid refrigerant is well distributed over the Evaporator tubes 14 passed and evaporated there, where it is the liquid refrigerated material, which by the Evaporator tubes flows, cools. The unevaporated, liquid refrigerant escapes from the sump of the

clampferkammer 13 with the help of an evaporator return pump 17 through a return line 18 and is finally passed again via the evaporator tubes 14,
Cold, concentrated, strong absorption solution is passed through the absorber pipes IS, whereby the medium flowing through is cooled as a result of heat exchange. The part of the absorption solution that collects in the sump of the absorber chamber is removed with the help of an absorber return flow

pump 19 returned through the return line 20 and passed through the absorber tubes 15 again. Both pumps 17 and 19 can be driven by a single electric motor 21.
The absorption solution in the primary absorber 11

is diluted by absorption of refrigerant vapor originating from the primary evaporator 10. From the sump of the absorber chamber 12, that is to say from the LP housing 16, cold, moderately weak ones come out Absorbent solution through a line 25 into the first

Stage 27 of an LP auxiliary absorber. Got from there the solution in a second stage 28, third stage 29 and fourth stage 30 of the LP auxiliary absorber. Every of these stages can in principle have the same structure and expediently contains one or more

ser still several perforated trays 31 for liquid distribution to the liquid in a cascade from the bottom to be able to guide the ground through each step. A connecting line 32 leads the solution from the first stage 27 to the second stage 28. Corresponding connections are between the following Stages provided. A refrigerant vapor line 33 allows the refrigerant vapor in the first Level 27 to be absorbed. Corresponding steam lines 34, 35 and 36 conduct refrigerant

steam into the respective following LP auxiliary absorber stage.

A pump 40 for poor LP solution pumps

warm weak solution from the last stage 30

of the LP auxiliary absorber through a line 41 for weak solution to the first stage 50 of a HP

Auxiliary absorber. The first stage 50 of the HD auxiliary absorber can be constructed similarly to the first stage 27 of the LP auxiliary absorber. she has a refrigerant vapor line 51, which enables the refrigerant vapor in the absorption

Solution of the absorber stage associated with pressure to be absorbed. A connecting line 52 directs the solution from the first stage 50 to a second stage 53 of the HP auxiliary absorber. The second Stage 53 also has a refrigerant vapor line 54 which absorbs the refrigerant vapor makes possible in the solution of the pressure-related absorption stage. The resulting very weak, very warm absorption solution is through a line 55 and a pump 60 for very weak solution promoted in the HD generator 7 to be concentrated there. The pumps 40 and 60 can be driven by a common electric motor.

The HP generator 7 contains generator heat ends in the vapor space of the first stage 90 of the LP exchange pipes 65, which lead to steam and with auxiliary evaporator to the entder in the first stage 90 The absorption solution heat flowing past the refrigerant vapor to the last stage 30 change. Other heating means can also be demonstrated. The strong absorption solution flows from the be seen; alternatively, the generator 5 can be connected to the first stage 90 of the LP auxiliary evaporator via a firing directly with gas, for example. The Absorp- siphon tube 89 in the second stage 92, in which Weitionslösung The generator 7 is heated in order to evaporate the cooler refrigerant from the solution. After that To evaporate medium and to concentrate the solution, the solution reaches the subsequent stages 93 trier. From the high-pressure generator 7 flows hot, enriched and 94, where still further evaporation of Secure absorption solution takes place through the float coolant. The second stage 92 of the LP valve 66 in a line 70 for enriched Lö- auxiliary evaporator has a steam line 35 for Solution and then to the first stage 71 of an HD third stage 29 of the LP auxiliary absorber. Corresponding auxiliary evaporator. Similar connections exist between the third

The step 71 can, for example, consist of a hollow body. Step 93 or fourth step 94 with the second step stand, in which the solution fed in so against 15 28 or the first stage 27 by the refrigerant die Walls is passed that no liquid vapor lines 34 or 33.

drips get into the steam outlet pipe. The concentrated, strong absorption solution

Refrigerant vapor line 54 ends in the vapor space and reaches from the last stage 94 through a siphon pipe within the HP auxiliary evaporator stage 71. This into line 95 and is distributed from there via line carries refrigerant vapor, which in 20 the absorber heat exchanger 15 of the primary primary stage 71 of the HP auxiliary evaporator generates sorbers 11 directed,
became the last stage 53 of the HD auxiliary absorber. The LP refrigerant vapor flows out of a LP

From the first stage 71 of the HP auxiliary evaporator, refrigerant vapor line 84 reaches the LP condensate enriched solution via a siphon tube 74 tor 9, where it is exchanged with a suitable and a line 75 to the second stage 78 of the high-pressure »5 neten refrigerant, which flows through the tubes of the auxiliary evaporator, which flows structurally similar to the condenser heat exchanger 97, liquefies the first stage 71 can be carried out. One will. The coolant is withdrawn from the LP condensate refrigerant vapor line 51 leads the refrigerant gate 9 heat and leads it to a suitable one Steam from the second stage 78 of the HP auxiliary site, such as a cooling tower, from the system. steamer to the first stage 50 of the HD auxiliary absorber. 3 ° In addition, liquid refrigerant flows under high

In the stages of the HP auxiliary evaporator, pressure evaporates through a line 85 into the LP condenser refrigerant vapor from the enriched solution; Sator 9 and partially evaporates there by relaxation the hot, enriched solution is cooled, cooling the rest of the remainder at the same time, concentrated and cooled to an enriched by distributing it in the LP condenser. The redemption The vapor remaining at medium temperature and concentration is retained in the condenser 9 again. The concentrated enriched solution becomes liquid.

flows through a line 79 and a siphon pipe 80 The condensed refrigerant comes from the LP

in the LP generator 8. Capacitor 9 through a throttle point 98 into a

The various siphon tubes, such as B. 74 and LP refrigerant line 99 and is from there 80, have such a vertical length that the 40 as well as possible distributed over the heat exchanger 14 liquid level of the solution of the leg that is passed to the primary evaporator 10,
It is advisable, in which HP refrigerant is arranged, to build the level difference of the solution and line 85 of a HP refrigerant economizer 100 into the pressure difference to the previous stage. This economizer 100 can equalize a higher pressure vessel to contain a steam stream 45 that is structurally similar or identical to prevent between the stages. is constructed like those in the auxiliary evaporator

The ND generator 8 consists of a generator stage. Part of the liquid refrigerant that passes through Condenser unit. He is flowing with a pipe, the high-pressure refrigerant economizer, evaporated Heat exchanger 83 equipped, which has an HD-Kon and cools the remaining refrigerant liquid, capacitor part forms. The 50 formed in the high-pressure generator 7 The resulting in the high-pressure refrigerant economiser hot refrigerant vapor flows through a high pressure refrigerant refrigerant vapor passes through a refrigerant vapor line 67 and the heat exchanger vapor line 102 in the refrigerant vapor line 51 83 to heat the solution in the LP generator, and is in the first stage 50 of the HP auxiliary absorber the steam is absorbed within the tubes of the heater. This way the warm exchanger 83 condenses The refrigerant liquid produced in the LP generator 55 from the HP condenser Refrigerant vapor passes through a cools before it enters the LP condenser, and Line 84 for LP refrigerant vapor to the LP condenser in the HP Ekouomiser refrigerant condenser9. The strong steam generated in the LP generator 8 is absorbed in the weak solution, Absorbent solution passes through a siphon tube 86 where it heats and dilutes it at the same time, and a line 87 to the first stage 90 of an LP-60. The cooled HP refrigerant liquid flows through Auxiliary evaporator. That in the high-pressure condenser a throttle point 101 to the low-pressure condenser 9. One Tubes 83 condensed refrigerant passes through vapor flap 96 and the throttle point 101 include a vapor flap 96 to the LP condenser 9. the pressure zone of the HP refrigerant economizer 100,

The first stage 90 can, like the following ones, the pressure of which lies between the pressure in the HP condenser stages of the LP auxiliary evaporator, similar to the 65 sator 8 and the LP condenser 9,
first stage 71 of the HP auxiliary evaporator designed It is also advisable to use a LP refrigeration

will. The refrigerant vapor line 36 begins Mittelekonomiser 110 in the LP line 99 for To be provided in the last stage 30 of the LP auxiliary absorber and liquid LP refrigerant. The low-pressure refrigeration

7 "8

Mittelekonomiser 110 is structurally similar or the HD generator is run through

constructed in the same way as the economizer 100. The one in the high-pressure auxiliary evaporator through the one taking place there

Steam generated by the economizer 110 flows further concentrated by the evaporation of refrigerant.

Steam lines 112 and 33 in the first stage 27 of the It not only increases the concentration of

ND auxiliary absorber. Throttle points 111 and 98 for 5 solution, but at the same time their temperature

LP refrigerants are reduced in the inlet and distribution temperature so that they are only moderately hot (220 ° F

line attached and with the LP refrigerant - corresponding to 104.4 ° C), but concentrated (60.7 ° / n),

Economizer 110 connected to a pressure zone-enriched solution reaches the LP generator.

Pressure between the pressures in the LP generator becomes the absorption solution

¹ and further cooled in the primary evaporator 10 io by evaporation of refrigerant

(190 ° F corresponding to 87.8 ° C),

well distributed over the water jets ^C her 14 f ^ _{c 1} ^^ ' _rimary . _Absorber . In the ND aid agency

mär evaporator is passed. The resulting ^. ^ _{refrigerant vapor from the}

Refrigerant vapor is absorbed and the cold, P ^ _{l evaporates.} The solution becomes

enriched solution of the first mare Li in the evaporation of refrigerant further

Auxiliary absorber diluted and heated ^ _{450 F} corresponding to 62.8 ° C),

During operation, the pressure increases derm ^ ^ _{(645 § / |) solution becomes} to

Series connected stages 27, 28 29 and 30 ^ _primary . _Absorber led to there refrigerant vapor

Auxiliary ^{absorbers gradually absorb into S} ™ " ⁿ _r f2 absorbers.

Solution, ^and therefore 7 ° ™ £££? rL HD- The use of auxiliary evaporators for con-

11 _cent for HD Hüfsabsorber and "jgj ^ ™ ^ turing the enriched and the strong

Generator? The ND-Hüfsabsorbersta s ^ _{through the Conventiona} ii _e n AN11 to HDHüfsabs jgj ^^ _center turing the enriched and the heavily generator ?. The .ND-Hüfsabsorbersta en ^ _{over the conventional} ii _e n zones of slowly increasing pressure, between 5 considerable advantages. Pressure in the primary absorber 11 and the first siuic \ _TS f Qn & the auxiliary _{evaporators serve to concentrate the high-pressure auxiliary absorber ^ the} ^ enriched and the strong solution,

The pressure is accordingly. rn aer _{faohe concentrations wd eme Hoh} e Gene-stage 53 of the HD auxiliary absorber large "ak d« ^ m _{ratortemperatur no} t are required to cause eme in first in the stage 50. Both he in B ^ gesgmi absorber entering absorbent solution normaten stages A ^ ™haben _s r, _fe30 i _er concentration. This concentration increase between the pressure in the last absorber makes a significant of the ND auxiliary absorber and the ^ ^{e he} ° ^^ reduction of the required absorber Warme- and possible although in Ström ^ tu ⁿ g ^t he ^L ° solution _exchange surface, since for a given heat primary absorber U to the HP generator 7 _{o exchange area e} in lower absorber steam

A typical Betnebsfall f ^ J-fo '^ _Absorp- pressure is achieved.

if enriched (60 /.)_, ^^ uijSdi Second, the hip evaporators cool the solution,

tion solution from the primary absorber evaporate U Auman refrigerant from it and main stages of the ND HII ^ ^ ^ ^ bsorbersjurch Ateorp_ _{konventioneUe heat} exchanger over-

Snnt ^O will, ^a d ^e aß ^^ "" KfSSS ^ thirdly, the auxiliary evaporators produce refrigerant

(68.9 ° C), weak (58.8 <> / ") solution flows, uies _around ^ ^ J 10-06116 ^ _{01 flowing lo-}

warm and weak solution is _heat allm ^ ^p hch wide _and thin, and ermogverdünnt and heated by ^sl * ^ 1 ^ ₄₅ yZZLft i _ic h n! so that the solution at a opposite

through the stages of the high-pressure hip absorber Katomittg_ J _ntionellen process relatively low

steam is absorbed so that it boils at the emtnttmgn ™ ^ _temperature .

Generator? a very warm one. (III W> ^ ^ _{visible) that} the described weak circle (56.7%) absorption solution is present. _ß ^ _{Advantages of a} conventional two-The amount of refrigerant ^ die ^d u ^r ch Kocn, P ^^. ^^^ o ^ process J _n remarkably different

weak solution in the H ^{0 ;, 06} ™ ⁰ ^ :; L _{erhe better} way

correct temperature can be represents is significant "ess ^ ^ ^ _temperature . _H D genes.

borrowed since the through ^ ^ΓΟ ^ ^η ^ Χ | _{rator compared to} comparable conventional an

Contains very little dissolved salt. When applying | ^ _{eUfch are reduced} , because once the «

of the invention is therefore a low * generator _A | _gor ^ _iolldösulIg is diluted before in de, temperature to achieve addition * "V ^ ⁵⁵ g ° _ne S _tor reaches and on the other konzentnei

weak solution to the Korrosionsgeianr _before ^e validity will _they led in the generator ND

for the metal parts of the HD generation; «El wemger vn ^^ ^^ ^ ^ ^ _dem ^ _{0 Q}

aggressive than _strong with stronger solution and gl · Achem J _{solution further} concentrated ^ ui

Temperature level is the case. y «g ££ be7 at 60 to generate a greater absorption force before si

It is necessary to point out that the Mfsabs ° ^ er b «the primary absorber occurs. This is also b <

hernähme both a Verdunnungs- as AuCN m _Conventiona iien two-stage absorption cold "

a heating function these Vorteje enable _n without üen provided.

To need expensive heat exchange surfaces and on the s ^^ quite possible, both the NL

thus a significant economic vwteu _{Hüfsverdampfer ώ also the LP auxiliary absorber}

compared to the conventional heat exchangers 5 ^ to be _carried out in one step, but one more

exhibit. ., "" On medium-stage design of the LP auxiliary evaporator ur

The hot (307 ° F corresponding to 152.8 M, ° J ™ _d LP-HUfsabsorbers - as shown in the drawing, moderately enriched (58.7%) absorption solution

is shown - the single-stage version by far preferable. When using two or more evaporation zones or two or more absorption zones a considerably greater concentration or dilution of the strong or weak solution can be achieved.

Furthermore, the amount of heat that can be transferred between the strong and the weak solution is at Use of two or more stages significantly larger, so that the efficiency of the system this can still be improved.

In addition, each of the auxiliary LP absorber stages provided in the weak solution line should be provided with a sloping height level - as shown in the drawing -, so that the weak solution can flow through the steps by gravity.

It goes without saying that the structural design of the individual stages has to be carried out in such a way that a steam flow between two successive stages is prevented. In this way, the in Series of stages of the LP auxiliary absorber connected in series in the direction of flow of the solution from the primary absorber to the HP generator absorption zones of gradually increasing pressure Temperature and falling solution concentration.

The stages of the LP auxiliary evaporator are corresponding Provided with a sloping height level in the direction of flow of the solution. In this way the stages connected in series form gradually decreasing refrigerant evaporation zones Pressure and falling temperature. This creates a flow of steam between the stages prevents the legs of the U-tubes through which the solution flows from being sufficiently vertical run high so that the liquid column of the solution in the shorter leg the pressure difference between two successive ones Levels off. The difference in height between the individual steps creates a gravity flow the solution to the primary absorber when the system is shut down and started up and supports the steady-state flow.

The auxiliary evaporator stages and the auxiliary absorber stages can, for example, be used as individual containers be carried out as indicated in the drawing; but it is also possible to turn them into one single apparatus, with this apparatus suitable parts and lines for the Must contain flow of solution and steam, as is the case with a multi-stage boiling flask Case is.

It is also possible to use the refrigerant economizer to be arranged in a housing, which the

ao contains auxiliary absorber and auxiliary evaporator. In this case, the refrigerant economizers can open Contain pans that are located near an auxiliary evaporator stage through which the refrigerant flows, to be ordered.

The number of stages of the auxiliary absorber and auxiliary evaporator can also be varied in order to reduce the cost of the Process to adapt to its degree of use in the most suitable way.

Furthermore, modifications of the internal structure of the system can be made in order to for example to simplify the operation of the system, d. H. to improve.

It can e.g. B. an absorption refrigeration system can be provided with more than two stages is working.

1 sheet of drawings

Λ · '

fr

2417

Claims (1)

1 2 Patent claims D'e invention relates to an absorption refrigeration system with a primary absorber, a 1. Absorption refrigeration system with a primary damper that flows through a line for refrigerant vapor absorber, a primary evaporator that is connected to the absorber via an HD-Gene line for refrigerant vapor with the absorber s rator, which is connected via a line for weak absorbers is, a high-pressure generator, the medium solution and a heat level with the Prieine Line for weak absorption medium marabsorber is connected, an LP generator, solution and a heating stage with the primary absorber via a line for enriched absorption sorber is connected, an LP generator, which is medium-solution connected to the HP generator, via a line for enriched absorption and also to the high-pressure generator via a line medium solution is connected to the high-pressure generator for refrigerant vapor, which in one is bound, which is also connected to the high-pressure generator high-pressure condensation part of the low-pressure generator under Erüber At least one line for refrigerant vapor heating of the solution contained therein is that which is partially condensed in a HD condensation section of the, and which is finally over LP generator with heating of the inside 15 a line for strong absorbent solution and holding solution at least partially condenses a cooling stage connected to the primary absorber and which is finally via a line for, an LP capacitor, which is via a line strong solution and a cooling stage with the primary for refrigerant vapor with the low-pressure generator mararabsorber is connected to an LP condenser and via a line for liquid Sator, which is connected to the primary evaporator via a line for refrigerant vapor 20 refrigerant is connected to the ND generator and is.