DE1751375C - Absorption refrigeration system - Google Patents

Description

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with which a relatively high degree of efficiency heat exchanges are within the primary absor-

j aims can be arranged without reducing the concentration of the superchamber 12 to a cooling medium such as

Absorption solvent reduced, high genes - e.g. water, a suitable cooler, e.g. a

ι ratortemperaturen provided or large heat conventional cooling tower to supply.

Exchange areas must be available. 5 The liquid refrigerant is well distributed over the

] In a system of the type mentioned above, evaporator tubes 14 are passed and evaporated there,

This object is achieved in that the heating stage is the liquid refrigerated goods, which by «äe

j is formed by an LP H3fsabsorber that flows through the evaporator tubes, cools the unevaporated,

j Cooling stage formed by an LP auxiliary evaporator Liquid refrigerant escapes from the sump of the

is and that a refrigerant vapor line between xo steam chamber 13 with the help of an evaporator

the LP auxiliary evaporator and the LP auxiliary absorber return pump 17 through a return line 18

is provided forth. and is finally returned to the evaporator

The LP auxiliary evaporator is expediently made up of pipes 14 routed.

For example, the absorber tubes 15 are made up of several tubes connected in series, and are cold, concentrated and at the same time are used for concentrating. ation and 15 trated, strong absorption solution passed, whereby j cooling of the strong solution, after this the flowing medium due to heat dissipation! NB generator has left. Which is cooled in the auxiliary evaporator exchange. Part of the refrigerant vapor generated by the LP auxiliary solution, which collects in the sump of the absorber chamber from the absorber flowing to the HP generator, is absorbed with the aid of an absorber return - weak solution, see above The weak pump 19 ate back through the return line 20 solution is diluted and heated at the same time. The lead; and passed through the absorber tubes 15 again. Heating and dilution of the weak solution Both pumps 17 and 19 can be driven by a low-pressure electric motor 21,
The absorption solution in the primary absorber 11 results in a higher required generator temperature, »5 more refrigerant vapor is evaporated at a lower temperature from the diluted solution through the absorption of refrigerant vapor evaporates. From the sump of the absorber chamber 12, i.e. from the LP auxiliary absorber also expediently consists of the LP housing 16, cold, moderately weak absorption solutions from two or more consecutive absorption solutions pass through a line 25 into the first switched stage, the pressure of which is gradual 30 Stage 27 of an LP auxiliary absorber. From there it rises and the level gradually falls. Each reaches the solution in a second stage 28, the third stage of the auxiliary absorber is with a corresponding 29 and fourth stage 30 of the LP auxiliary absorber. Each pressure stage of the LP auxiliary evaporator is connected. The stages of these stages can basically be constructed in the same way. Stages of the low-pressure auxiliary evaporator are expediently and contain expediently one or besgerweise also arranged in such a way that from level to level 35 several perforated trays 31 reach a different height level to the liquid distribution level, so as to divide the liquid in a cascade manner from the floor The steps can be led through each step through U-tubes to the floor. One connected. Connecting line 32 leads the solution from the An exemplary embodiment of the invention is to be explained in more detail at the first stage 27 to the second stage 28. Corresponding hand of a drawing. 40 connections are between the following In the drawing, a multi-stage Abscrp- stages is provided. A refrigerant vapor line 33 represents a two-stage process, allowing the refrigerant vapor to be placed in the first. A ¹ S refrigerant, for example, water level 27 will get absorbed. Corresponding and as an absorbent, for example, an aqueous vapor lines 34, 35 and 36 conduct refrigerant solution a:> hygroscopic salt, such as. B. 45 steam in each of the following LP auxiliary absorber stage. Lithium bromide. used. A pump 40 for low-pressure solution pumps rich additives can be added to the solution, e.g. B. 2-ethyl warm, weak solution from the last stage 30 hexanol to improve the heat transfer and the LP auxiliary absorber through a line 41 for lithium hydroxide to prevent corrosion. weak solution to the first stage 5C of a HD-The designation of a solution as weak refers to 50 auxiliary absorbers. The first stage 50 of the HD auxiliary relies on a solution that is poor in absorbed salt absorber, can be structurally similar in structure and is weak in absorption power; corresponding to the first stage 27 of the ND-HiKsabsorber. It is said to be a strong solution if it has a refrigerant vapor line 51 which allows the refrigerant vapor rich in absorbed salt and high in absorbent refrigerant vapor to be in the absorption force. 55 solution of the pressure-related absorber stage The system contains a high-pressure generator 7, one to be absorbed. A connecting line 52 LP generator 8 with a HP condensate part conducts the solution from the first stage 50 to an 83, a LP condenser 9, a primary absorber, second stage 53 of the HP auxiliary absorber. The second 11 and a primary evaporator 10. Stage 53 also has a refrigerant-vapor primary evaporator 10 and primary absorber 11 60 line 54, which absorbs the refrigerant vapor, expediently within a low-pressure housing in each solution of the pressure level assigned ses 16 arranged. Within this housing 16 makes possible an absorption stage. The resulting form an inner part 12 the primary absorber chamber - very weak, very warm absorption solution is mer and an inner part 13 the primary evaporator through a line 55 and a pump 60 for very chamber. Numerous tubes 14 for heat exchange 65 weak solution conveyed into the HP generator 7 are inside the primary evaporation chamber 13 to be concentrated there. The pumps 40 arranged to convey a liquid medium, such as 1. B. and 60, can be supplied by a common l-.lcktm-Wasscr. to cool off. Numerous tubes 15 are driven to the engine.

The HP generator 7 contains generator heat ends in the steam space of the first stage 90 of the LP

exchange tubes 65, which carry steam and with auxiliary evaporator, around the in the first stage 90

the passing absorption solution heat standing refrigerant vapor to the last stage 30 zi

change. Other heating means can also be demonstrated. The strong absorption solution flows from the dei

be seen; alternatively, the generator 5 can first stage 90 of the LP auxiliary evaporator via eir

firing directly with gas, for example. The Absorp- siphon tube 89 in the second stage 92, in which white

tion solution in generator 7 is heated to evaporate cooler refrigerant from the solution. After that

To evaporate medium and to concentrate the solution, the solution reaches the subsequent stages 92

tricrcn. From the HP generator 7 flows hot, enriched and 94, where there is still further evaporation

There is a real absorption solution by the float refrigerant. The second stage 92 of the ND

valve 66 in a line 70 for enriched Lö auxiliary evaporator has a steam line 35 zui

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 consist of a hollow body, for example, as a step 93 or a fourth step 94 with the second step

stand, in which the fed-in solution so against 15 28 or the first stage 27 by you; Refrigerant

the walls is guided so 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 Hebcrrohi

within the high-pressure auxiliary evaporator stage 71. This enters line 95 and is distributed from there via

Line carries refrigerant vapor, which in the ao the absorber heat exchanger 15 of the primary exhaust

crstcn stage 71 of the high-pressure auxiliary evaporator generates sorbers 11 passed.

became the last stage 53 of the HD auxiliary absorber. The low-pressure refrigerant vapor flows out of a low-pressure 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 gecig- and a line 75 to the second stage 78 of the HD- »5 n- 'cn refrigerant, which flows through the tubes of the auxiliary evaporator, which flows structurally similar to the condenser heat exchanger 97, vcriquid the first stage 71 can be carried out. One will. The coolant is withdrawn from the LP condensate refrigerant vapor line 51 conducts the refrigerant gate 9 heat and removes it from the system in a suitable vapor from the second stage 78 of the high-pressure auxiliary location, such as a cooling tower, dampl'ers to the first stage 50 of the HD auxiliary absorber. 30 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 Entspanglcichzcitig 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

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

The various siphon tubes, such as B. 74 u: .J LP refrigerant line 99 and is from there

80. Have such a vertical length that the 40 is distributed as well as possible over the heat exchanger 14

Liquid level of the solution of the limb that is directed to the primary vaporizer 10,

to the next stage with the lower pressure.

is arranged, the level difference of the solution and line 85 a high-pressure refrigerant economizer 100 a

to build up the pressure difference to the previous stage. This economizer 100 can contain a

higher pressure compensates to contain a steam flow 45 which is structurally similar or identical

to prevent movement 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 through

Condenser unit. It is evaporated with a pipe that flows through the high-pressure refrigerant

Heat exchanger 83 equipped, which has an HD-Kon and cools the remaining refrigerant liquid,

densatortcil 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

Medium steam line 67 and the heat exchanger steam line 102 into the refrigerant steam line 51

83, in order to heat the solution in the LP generator, and is used in the first stage 50 of the HP auxiliary absorber

the vapor being absorbed within the tubes of the heater. This way the warm

exchanger 83 condenses The refrigerant fluid from the HP condenser in LP generator 55

The resulting refrigerant vapor passes through a cools before it reaches the LP condenser, and

Line 84 for LP refrigerant vapor to LP condenser refrigerant created in the HP economizer

capacitor9. 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 crown of the HP refrigerant economizer 100,

The first stage 90, like the following, can have their pressure between the pressure in the high-pressure condenser

Stufcn the LP auxiliary evaporator similar to the 65 sator 8 and the LP condenser 9 is located

first stage 71 of the HP auxiliary evaporator designed It is also advisable to use a LP refrigeration

The refrigerant vapor line 36 begins Mittelekonomiser 110 in the LP line 99 for

to be provided in the last stage 30 of the low-pressure auxiliary absorber and liquid low-pressure refrigerant. The ND-Källe-

The miltclckonomiscr 110 is structurally similar or the same as the economizer 100. The steam generated in the economizer 110 flows through the steam lines 112 and 33 into the first stage 27 of the LP auxiliary absorber. Throttling points 111 and 98 for low pressure coolants are installed in the inlet and distribution line and connected to the low pressure refrigerant component 110 'in order to define a pressure zone, the pressure of which is between the pressures in the

the high-pressure generator, as it passes through the high-pressure auxiliary evaporator, takes place there Evaporation of refrigerant further concentrated. But it is not just the concentration that increases 5 solution, but at the same time its temperature is lowered so that it is only moderately hot (220 ° F corresponding to 104.4 "C), but concentrated (60.7%), enriched solution enters the ND generator. The absorption solution is in the LP generator

LP-Kondcnsator9 and in the primary evaporator 10 io is further cooled by evaporation of refrigerant. Part of the liquid LP refrigerant is concentrated and concentrated.

steams in the ND-Källcmittclckonomiser 110 and cools the moderately cold (190 ° F corresponding to 87.8 ° C),

the rest of the refrigerant before this strongest possible (63.3%) solution is passed through the backcourt distributed over the heat exchanger 14 of the primary switched stages of the LP auxiliary evaporator miir evaporator. The resulting 15 is directed to the primary absorber. In the LP auxiliary supply refrigerant steam is absorbed, taking the cold, more refrigerant vapor from the damper enriched solution of the first stage 27 evaporated in the ND-strong solution. This will be the solution Auxiliary absorber diluted and heated. further reduced by the evaporation of refrigerant

During operation, the pressures in the cools and the cold (145 ° F corresponding to 62.8 ° C) increase, Series connected stages 27, 28, 29 and 30 of the ND λο concentrated, strong (64.5%) solution is used for Auxiliary absorbers are gradually led into the flow direction of the primary absorber in order to generate refrigerant vapor there Solution, and thus also to be absorbed by the primary absorber.

11 on the HD Hitfsabsorber and finally on the HD- The use of auxiliary evaporators for con-

Generator?. The LP auxiliary absorber stages center the enriched and the strong zones of slowly increasing pressure between the »5 Solution offers considerable advantages over the conventional on-pressure in the primary absorber 11 and the first stage.
50 of the HD auxiliary absorber. Firstly, the auxiliary evaporators are used to concentrate

Correspondingly, the pressure in the second concentration of the enriched and the strong solution is Stage 53 of the HD auxiliary absorber is greater than the pressure so that high concentrations and a high level of genein its first stage 50. Both connected in series- 3 "ratorterr.peratur are not required to have an in The tenth stages cause a gradual pressure - the absorption solution entering the absorber is more normal Achieve concentration. This concentration of the absorbent makes a significant one Reduction of the required absorber heat exchange area is possible, as there is a given heat outlet area a lower absorber vapor pressure is achieved.

Second, the auxiliary evaporators cool the solution by evaporating refrigerant from it and mation so diluted by refrigerant vapor and thus overheated conventional heat exchangers that warm liquid through the HD auxiliary absorber.

(68.9 C), weak (58.8%) solution flows. Thirdly, the auxiliary evaporators generate warm refrigerant; the weak solution is gradually further thinned by the vapor flowing to the high-pressure generator and warmed up by heating and diluting them as they pass through, and making it possible the stages of the HP auxiliary absorber refrigerant 45 borrowed so that the solution at one opposite vapor absorbed, so that when entering the HD conventional process relatively low Generator? a very warm (118.3 ° C), very temperature boiling.

weak (56.7 Ve) absorption solution is present. It can be seen that the K-written circular

The refrigerant quantity, which by boiling, process all the advantages of a conventional two-weakness Solution in the high-pressure generator with a 50-stage absorption process in remarkably detuned Temperature can be created, is considerably increased

The temperature in the HD gene in particular can

contains very little dissolved salt. When using rator compared to comparable conventional others Invention is therefore a low generator locations are significantly reduced because once the to achieve temperature. Also, a very 55 absorption solution is diluted before being in the weak solution with regard to the risk of corrosion generator arrives, and concentrate on the other for the metal parts of the high-pressure generator is much less before it is fed into the low-pressure generator aggressive than this with a stronger solution and the same. In a similar way, the one from the ND Generatoi Tcmpcraturnivcau is the case. Furthermore, it is more concentrated, flowing strong solution, urr lig to point out that the auxiliary absorbers at 60 produce a greater absorption force before they Takeover of both a dilution and the primary absorber. This is also be a heating function enable these advantages without the conventional two-stage absorption cooling To need expensive heat exchange surfaces and systems not seen before.

thus a significant economic advantage, while it is entirely possible to use both the ND

compared to the conventional heat exchangers 65 auxiliary evaporators as well as the LP auxiliary absorbers exhibit. to be carried out in one step, jedocii is one more

The hot (307 ° F corresponding to 152.8 C), medium-stage version of the LP auxiliary evaporator moderately enriched (58.7%) absorption solution from the LP auxiliary absorber - as shown in the drawing

increase between the pressure in the last stage 30 of the LP auxiliary absorber and the HP generator 7, specifically in the direction of flow of the solution from the primary absorber 11 to the HP generator 7.

A typical operating case is e.g. B. occurs when enriched (60%), cold (41, Γ C) absorption solution from the primary absorber 11 gradually in the stages of the LP auxiliary absorber by absorption

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

Furthermore, r'ic is the amount of heat that can be transferred between the strong and the weak solution when using two or more levels larger, so that the efficiency of the system 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 Absorption zones in the direction of flow of the solution from the Primür absorber to the HP generator gradually increasing pressure, increasing temperature and decreasing 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 form the stages, which are connected in series, and which gradually decrease in the 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 be carried out high, so that the liquid column of the solution in the shorter leg Compensates the pressure difference between two successive stages. The difference in altitude between the two the individual stages causes a gravity flow of the solution to the primary absorber when stopping and starting up the system and supports the flow when it is chilled.

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 Flow of solution and vapor contain only as is the case with a multi-stage Siedckolhcn Case is.

It is just as 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 law can open Pans that are placed in the vicinity of an auxiliary evaporator stage, through which the refrigerant flows, are arranged.

as The number of stages of the auxiliary absorber and Auxiliary evaporator can be varied to suit the cost of the process to its degree of utilization Adapt the way.

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

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

1 sheet of drawings

Claims (4)

Claim ^: ^ 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, an HD-Gcae line for refrigerant vapor with the absorber 5 rator, which is connected via a line for weak absorbers is, an HD generator, the medium solution and a Wännstufe nut dem Prieins Line for weak absorption medium marabsorber is connected, an LP generator, solution and a heat level with the primary absorber via a line for enriched absorption absorbers is connected to an LP generator, which is connected to the medium solution with the HP generator, via a line for enriched absorption 10 the further with the high-pressure generator via a line tion medium solution is connected to the HD generator vsr- for refrigerant vapor, which in one is bound, which is also nut the HP generator HP condensation part of the LP generator under Erüber at least one line for refrigerant vapor to heat up 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? * Arke 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 ao refrigerant is connected to the ND generator and is. over a line for liquid refrigerant mU Dk 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 N ^ auxiliary evaporator (90.92 to 94) the refrigerant expelled from the high-pressure 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 n? Ch claim 1, expelling enriched absorbing solution, characterized in that oer ND-Hilfsver- which is more hintereinanderge- _ra passed tor also from the HD-generator for ND genes steamer of two or more. The stages (90, 92 to 94) connected in the LP generator are made up 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), sorber reaches the weak absorption solution over the pressure from stage to stage gradually Toggle a heat exchanger in the ND generator back increases, and that the refrigerant vapor line corresponds ₄₀ wherein in the second heat exchanger, the weak Depending on the number of stages, the LP auxiliary evaporation solution is heated fers or the LP auxiliary absorber from two or Mj _t 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 temperatures with the corresponding pressure stage of the LP doors and concentrations of the absorbent connecting auxiliary absorber in the HP generator necessary if 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 (ll) from stage to stage one in each case, so that relatively expensive materials have a lower height 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 level (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} j _c h _m j _t two-stage plants recoverable Vordurch which liquid Absorptionsmittcllösung parts 60 are partially canceled again. flows from one to the next stage, Dj _e 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 vaporization stages moderately high effort. The heat exchange surfaces (90, 92 to 94) with each other or with neighboring 65 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. jjj _c invention has therefore set itself the task of creating a multi-stage absorption refrigeration system,