JP2008202859A - Absorption type refrigerating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently spray a refrigerant to a heat transfer face of a plate-type evaporator. <P>SOLUTION: In this absorption type refrigerating device, dispersion plates 45 for allowing a refrigerant jetted from refrigerant spray ports 43 formed on a header 42 to be dispersed and flow down onto the heat transfer faces of heat transfer plates 41 are mounted on the header 42 of the evaporator 4 in a state of covering the refrigerant spray ports 43, and the refrigerant supplied from a condenser 3 and jetted from the refrigerant spray ports 43 of the header 42 is guided by the dispersion plates 45 mounted in a state of covering the refrigerant spray ports 43 to be dispersed and flow down to the heat transfer faces of the heat transfer plates 41, thus the refrigerant can be uniformly and efficiently dispersed and supplied to the heat transfer faces of the heat transfer plates 41 of the evaporator 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an absorption refrigeration apparatus, and more particularly to an evaporator structure in an absorption refrigeration apparatus.

  In the case of an absorption refrigeration system, the evaporator cools the fluid to be cooled by spraying the refrigerant on the heat transfer surface, but the refrigerant in the refrigerant pool provided in the lower part of the evaporator is circulated by a refrigerant pump, and the evaporator A refrigerant pump system is used to spray the heat transfer surface.

  To reduce the size and cost of the evaporator, a plate-type evaporator is considered to be more optimal than a heat-transfer-tube evaporator. However, when a plate-type evaporator is used, it is evenly distributed over the entire heat transfer surface. It is important to ensure wettability.

  In a plate-type evaporator, as a means of ensuring uniform wettability to the heat transfer surface, a porous layer (such as a net, woven wire mesh, or expanded metal) is attached to the heat transfer surface of the evaporator (Patent Document) 1) or a lateral groove on the plate surface of the evaporator (see Patent Document 2) has been known.

JP-A-6-11209 Japanese Patent Laid-Open No. 10-220914

  However, in the technology as disclosed in the above-mentioned patent document, in addition to the problem of cost, when the refrigerant partially accumulates, the heat flow rate on the heat transfer surface is fixed or the amount of the refrigerant is not enough. Had the problem of generating drift and the like.

  This invention is made | formed in view of said point, and it aims at enabling it to perform refrigerant | coolant dispersion | distribution to the heat-transfer surface in a plate type evaporator efficiently.

  In the present invention, as a first means for solving the above problems, the generator 1 that generates the refrigerant vapor Rs and the absorption concentrated solution Lc by heating the absorption diluted solution Ld, and the refrigerant vapor from the generator 1 The condenser 3 that condenses Rs into a liquefied liquid and the refrigerant liquid Rw from the condenser 3 is sprayed on the heat transfer surfaces of the heat transfer plates 41 and 41 through the refrigerant spray ports 43, 43,. The evaporator 4 to be evaporated, the absorber 5 that absorbs the refrigerant vapor Rs evaporated by the evaporator 4 with respect to the absorption concentrated solution Lc, and the absorption dilute solution Ld that has absorbed the refrigerant vapor Rs by the absorber 5. In the absorption refrigeration apparatus including the solution pump 7 that supplies the heat to the generator 1, the refrigerant ejected from the refrigerant spray ports 43, 43. Minutes to disperse flow down to the surface It is attached a plate 45, 45 so as to cover the coolant distribution opening 43, 43 ....

  With the configuration described above, the refrigerant supplied from the condenser 3 and ejected from the refrigerant spray ports 43, 43,... Of the header 42 is attached so as to cover the refrigerant spray ports 43, 43,. It will be guided to 45 and 45, and will be distributed and flowed down to the heat-transfer surface of the heat-transfer plates 41 and 41. FIG. Therefore, the refrigerant can be uniformly and efficiently distributed and supplied to the heat transfer surfaces of the heat transfer plates 41 and 41 of the evaporator 4.

  In the present invention, as a second means for solving the above problems, in the absorption refrigeration apparatus provided with the first means, the heat transfer surfaces of the heat transfer plates 41 and 41 are annealed so as to be wettable. In such a case, the water repellency of the heat transfer surfaces of the heat transfer plates 41 and 41 is reduced, and the wettability is greatly improved, which contributes to the improvement of the heat transmissivity. .

  In the present invention, as a third means for solving the above-described problem, in the absorption refrigeration apparatus provided with the first or second means, each of the dispersion plates 45 is connected to the refrigerant spray ports 43, 43. The vertical part 45a facing the vertical part 45a and the guide part 45b inclined from the lower end of the vertical part 45a toward the heat transfer surface of the heat transfer plate 41 can be configured. The refrigerant supplied from the vessel 3 and ejected from the refrigerant spray ports 43, 43,... Of the header 42 collides with the vertical portion 45a facing the refrigerant spray ports 43, 43,. Accordingly, the refrigerant flows down along the guide portion 45b that inclines toward the heat exchanger, and the refrigerant can be uniformly and efficiently supplied to the heat transfer plate 41 of the evaporator 4.

  In the present invention, as a fourth means for solving the above-described problem, in the absorption refrigeration apparatus including the first, second, or third means, the refrigerant that has not evaporated in the evaporator 4 is A refrigerant pump 8 that circulates and pressure-feeds to the header 42 can also be provided. In such a configuration, the refrigerant that has not evaporated in the evaporator 4 is circulated and pressure-fed to the header 42 by the refrigerant pump 8 and is evaporated again in the evaporator 4. As a result, the refrigerant can be used efficiently.

  According to the first means of the present invention, the refrigerant 1 Rs and the concentrated concentrated solution Lc are generated by heating the diluted absorption solution Ld, and the refrigerant vapor Rs from the generator 1 is condensed and cooled. The condenser 3 to be liquefied, and the evaporator 4 for spraying and evaporating the refrigerant liquid Rw from the condenser 3 on the heat transfer surfaces of the heat transfer plates 41 and 41 through the refrigerant spray ports 43, 43,. An absorber 5 that absorbs the refrigerant vapor Rs evaporated by the evaporator 4 with respect to the absorption concentrated solution Lc, and an absorption dilute solution Ld that has absorbed the refrigerant vapor Rs by the absorber 5 to the generator 1. In the absorption refrigeration apparatus including the solution pump 7 to be supplied, the refrigerant ejected from the refrigerant spray ports 43, 43... Is distributed to the header 42 to the heat transfer surfaces of the heat transfer plates 41, 41. The dispersion plates 45, 45 are .. Are attached so as to cover the openings 43, 43... So that the refrigerant supplied from the condenser 3 and ejected from the refrigerant distribution openings 43, 43... Of the header 42 covers the refrigerant distribution openings 43, 43. Since it is guided by the dispersed plates 45, 45 so as to be dispersed and flowed down to the heat transfer surfaces of the heat transfer plates 41, 41, the refrigerant is uniformly distributed to the heat transfer surfaces of the heat transfer plates 41, 41 of the evaporator 4. There is an effect that it can be efficiently distributed and supplied.

  As in the second means of the present invention, in the absorption refrigeration apparatus provided with the first means, the heat transfer surfaces of the heat transfer plates 41 and 41 can be annealed to improve wettability, When comprised in this way, the water repellency of the heat-transfer surface of the heat-transfer plates 41 and 41 will fall, wettability will improve significantly, and it contributes to the improvement of a heat-transfer rate.

  As in the third means of the present invention, in the absorption refrigeration apparatus provided with the first or second means, each dispersion plate 45 is provided with a vertical portion 45a facing the refrigerant spray ports 43, 43,. And a guide portion 45b inclined from the lower end of the vertical portion 45a toward the heat transfer surface of the heat transfer plate 41. In such a case, the header 42 is supplied from the condenser 3 and supplied from the condenser 42. .. The guide part 45b which inclines toward the heat transfer surface of the heat transfer plate 41 after the refrigerant jetted from the refrigerant spray holes 43, 43... Collides with the vertical part 45a facing the refrigerant spray holes 43, 43. Thus, the refrigerant can be uniformly and efficiently distributed and supplied to the heat transfer plates 41 and 41 of the evaporator 4.

  As in the fourth means of the present invention, in the absorption refrigeration apparatus provided with the first, second or third means, a refrigerant pump for circulating and pumping unevaporated refrigerant to the header 42 in the evaporator 4 8, the refrigerant not yet evaporated in the evaporator 4 is circulated and pumped to the header 42 by the refrigerant pump 8 and evaporated again in the evaporator 4. Use is possible.

  Hereinafter, some preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First Embodiment FIGS. 1 to 4 show an absorption refrigeration apparatus according to a first embodiment of the present invention and a main part of an evaporator in the absorption refrigeration apparatus.

In this absorption refrigeration apparatus, for example, water (H ₂ O) is employed as a refrigerant, and lithium bromide (LiBr) is employed as an absorbent.

  As shown in FIG. 1, the absorption refrigeration apparatus includes a generator 1 that generates refrigerant vapor Rs and an absorption concentrated solution Lc by heating an absorption diluted solution Ld from an absorber 5 with an exhaust hot water heat exchanger 1a. The solution heat exchanger 2 that exchanges heat between the absorption diluted solution Ld from the absorber 5 and the absorption concentrated solution Lc from the generator 1 and the refrigerant vapor Rs from the generator 1 are condensed by the cold water heat exchanger 3a. The condenser 3 that is liquefied to make the refrigerant liquid Rw, and the refrigerant liquid Rw supplied from the condenser 3 through the refrigerant spray ports 43, 43,... Of the header 42 as shown in FIGS. The evaporator 4 that sprays the refrigerant vapor Rs by spraying it on the heat transfer plate surfaces of the pair of heat transfer plates 41 and 41 in which a fluid to be cooled (for example, hot water) Wc is flowed in 47, and the generator 1 Is absorbed by the evaporator 4 with respect to the absorbed concentrated solution Lc from That absorbs the refrigerant vapor Rs by absorbing the refrigerant vapor Rs with the cold water heat exchanger 5a while absorbing the absorption heat, and the absorption diluted solution obtained by absorbing the refrigerant vapor Rs with the absorber 5. And a solution pump 7 for supplying Ld to the generator 1 via the solution heat exchanger 2. Reference numeral 4b is a refrigerant spraying device, and 5b is a concentrated solution spraying device.

And the said evaporator 4 and the absorber 5 are arranged in parallel compactly in each installation chamber 6a, 6b in the same casing 6, for example, The un-evaporated refrigerant | coolant liquid Rw which accumulates in the lower part of the evaporator 4 is It flows into the dilute solution pool 6b ₁ at the bottom of the absorber installation chamber 6b through the bottom surface of the casing 6, and is supplied to the generator 1 together with the dilute solution Ld by the solution pump 7. That is, a refrigerant pump that circulates the non-evaporated refrigerant liquid Rw to the evaporator 4 is unnecessary (in other words, a refrigerant pump-less system is used).

  By the way, in the plate type evaporator 4 of the refrigerant pumpless type as described above, if the refrigerant evaporates from the heat transfer surface as non-evaporated refrigerant without evaporating on the heat transfer plate surface, a large refrigerant loss is caused and the performance is greatly reduced. End up. Therefore, ensuring wettability uniformly over the entire surface of the heat transfer plate of the plate evaporator 4 as described above is extremely important for improving performance.

  Therefore, in the present embodiment, the condenser 3 is used on the surfaces of the heat transfer plates 41 and 41 of the evaporator 4 through the absorption diluted solution reflux pipe 15 using the absorption diluted solution Ld from the solution pump 7. By spraying together with the refrigerant liquid Rw from the heat transfer plate 41, the heat transfer plates 41, 41 of the evaporator 4 are configured to ensure as much wettability as possible.

  The evaporator 4 and the absorber 5 are installed side by side in the evaporator installation chamber 6a and the absorber installation chamber 6b in the evaporator and absorber casing 6 as described above, and are evaporated on the evaporator 4 side. The refrigerant vapor Rs is supplied to the absorber 5 in the absorber installation chamber 6b and is absorbed by the absorption concentrated solution Lc supplied from the generator 1.

  In the case of the present embodiment, the absorbed diluted solution Ld obtained by absorbing the refrigerant vapor Rs is supplied to the generator 1 via the solution pump 7, the solution heat exchanger 2, and the diluted solution pipe 11. It is supposed to be.

  At the downstream side of the solution pump 7 of the dilute solution pipe 11 and at the upstream side of the solution heat exchanger 2, an absorbing dilute solution reflux pipe 15 is branched from the dilute solution pipe 11, and this absorbed dilute solution reflux pipe. 15 is connected to and communicated with the refrigerant supply pipe 14 extending from the bottom of the condenser 3 to the header 42 above the evaporator 4 via an open / close control valve 16 made of, for example, an electromagnetic open / close valve.

  The open / close control valve 16 in the middle of the absorption diluted solution reflux pipe 15 is controlled to close in a steady operation state with good wettability after a predetermined time has elapsed after the start of operation, while in a poor wettability state such as at the start of operation, For example, the valve opening control is performed until a predetermined time elapses after the operation start switch is turned on, and the absorption diluted solution Ld from the solution pump 7 is combined with the refrigerant liquid Rw from the condenser 3 and the header of the evaporator 4. 42.

  As a result, until a predetermined time elapses after the operation is started, a large amount of the diluted diluted solution Ld is supplied onto the heat transfer plates 41 and 41 of the evaporator 4, and the heat transfer plate 41 of the evaporator 4. , 41 is secured on the surface.

  Then, after the predetermined time has elapsed, when the wettability is improved, the refrigerant liquid amount is switched to the steady operation amount thereafter.

  The opening / closing control of the opening / closing control valve 16 at the above timing and time is performed, for example, by a timer control via a relay or the like by a microcomputer control unit (not shown).

  By the way, the header 42 of the refrigerant | coolant spraying apparatus 4b of the said evaporator 4 and the heat-transfer plates 41 and 41 which comprise the heat-transfer plate part 4a of the evaporator 4 are made, for example, as shown in detail in FIGS. From a general viewpoint, a configuration that can improve sufficient wettability is employed.

  That is, in the case of the present embodiment, the header 42 and the heat transfer plates 41, 41 are bent into an oblique crank shape through the tapered portion 44b when the upper portion of one heat transfer plate plate is viewed from the side. Are formed in the tapered portion 44b, and the refrigerant storage chamber 42a of the header 42 is formed by a vertical wall portion 44a having a predetermined height above the tapered portion 44b. Yes.

  On the other hand, the vertical wall portions having a considerable length below the tapered portion 44b are used as the heat transfer plates 41, 41, and two plate members having such a configuration are arranged in parallel in the opposite direction as shown in the figure. Then, the both end portions and the bottom portion are joined and sealed as a side wall and a bottom wall with another plate material, and the lower end of the tapered portions 44b and 44b is sealed through a spacer member 46 having a predetermined width, so that FIG. As shown in FIG. 4, an evaporator 4 having a funnel-shaped header 42 at the top, two heat transfer plates 41, 41 facing each other at the bottom, and a cooled fluid passage 47 between the heat transfer plates 41, 41. Is configured.

  Further, the tapered portions 44b, 44b and the refrigerant spray ports 43, 43,... Of the evaporator 4 cover the periphery thereof, and absorb the diluted rare solution Ld ejected from the refrigerant spray ports 43, 43,. Dispersion plates 45 and 45 are provided that receive the refrigerant liquid Rw and diffuse it as uniformly as possible on the heat transfer surfaces of the lower heat transfer plates 41 and 41. That is, the header 42 is provided with dispersion plates 45, 45 for distributing and flowing down the refrigerant sprayed from the refrigerant spray ports 43, 43,.・ It is attached to cover.

  The dispersion plates 45 and 45 correspond to the vertical lengths of the taper portions 44b and 44b, and are vertically aligned with the vertical portions 45a and 45a extending slightly below the length, and the lower ends of the vertical portions 45a and 45a. Heat transfer plates 41, guide portions 45b, 45b inclined toward the surface of the surface, and sprayed from refrigerant spray ports 43, 43,... Formed in taper portions 44b, 44b on both lower sides of the header 42. In the case of a large amount of the refrigerant, such as at the start of the operation shown in FIG. 4, for example, at the steady flow rate as shown in FIG. The refrigerant liquid Rw is reliably received by the vertical portions 45a and 45a, and then smoothly guided downward and diffused efficiently.

  As a result, a large amount of the refrigerant liquid Rw within a predetermined time at the start of operation described above is evenly flowed on the heat transfer surfaces of the heat transfer plates 41 and 41 of the evaporator 4, and the wettability of the heat transfer plate surface in the initial operation is improved. It is secured sufficiently and promptly.

  As described above, the absorption liquid Ld and the refrigerant liquid Rw are sprayed in large amounts on the surfaces of the heat transfer plates 41 and 41 of the plate-type evaporator 4, and the refrigerant liquid is obtained after ensuring the wettability of the entire surfaces of the heat transfer plates 41 and 41. By switching to only Rw, the refrigerant liquid Rw is uniformly wetted over the entire surface of the heat transfer plates 41 and 41 of the evaporator 4, and the heat transmissivity is greatly increased, so that a particularly effective action is obtained in the refrigerant pumpless type evaporator 4. be able to.

  Further, once the wettability is ensured, the wettability lasts for a considerable period of time, and when the absorbable diluted solution Ld is sprayed again when the wettability is lowered, the wettability is restored again.

  In the above case, the heat transfer surfaces of the heat transfer plates 41 and 41 of the evaporator 4 are preferably annealed in order to further improve the wettability. In such a case, the water repellency of the heat transfer surfaces of the heat transfer plates 41 and 41 is lowered, so that the wettability is further improved.

(Modification)
In the above configuration, in order to ensure sufficient wettability of the heat transfer surfaces of the heat transfer plates 41 and 41 of the evaporator 4, the absorption diluted solution Ld on the discharge side of the solution pump 7 is used as the heat transfer plate 41 of the evaporator 4. , 41 is supplied using the dispersion plates 45, 45, but the absorbing dilute solution Ld is further returned from the downstream side of the solution heat exchanger 2, for example, as shown in FIG. You may make it make it.

  Further, as a method for ensuring the same wettability, for example, as shown in FIG. 1B, it is also possible to use an absorption concentrated solution Lc from the generator 1.

Second Embodiment FIG. 5 shows an absorption refrigeration apparatus according to a second embodiment of the present invention.

In this case, the absorption diluted solution recirculation pipe 15 in the first embodiment is abolished, and the refrigerant pump 8 that circulates and pressure-feeds the non-evaporated refrigerant liquid Rw to the header 42 in the evaporator 4 is attached. That is, the refrigerant liquid pool 6a _{1 at} the bottom of the evaporator installation chamber 6a in the casing 6 and the refrigerant supply pipe 14 on the outlet side of the condenser 3 are connected by a refrigerant liquid recirculation pipe 17 having a refrigerant pump 8 interposed therebetween. It is. If it does in this way, the refrigerant | coolant which has not evaporated in the evaporator 4 will be circulated and pressure-fed by the refrigerant | coolant pump 8 to the header 42, and will be evaporated again in the evaporator 4, and efficient utilization of a refrigerant | coolant will be attained. Since other configurations and operational effects are the same as those in the first embodiment, the description thereof is omitted.

  The invention of the present application is not limited to the above-described embodiments, and it goes without saying that the design can be changed as appropriate without departing from the scope of the invention.

1 is a refrigeration circuit diagram showing a refrigeration cycle of an absorption refrigeration apparatus according to a first embodiment of the present invention. It is the perspective view which excised a part which shows the structure of the heat exchanger plate and refrigerant | coolant spraying apparatus part of the evaporator in the absorption refrigeration apparatus concerning 1st Embodiment of this invention. It is sectional drawing which shows the refrigerant | coolant spraying state at the time of the steady operation of the heat exchanger plate and refrigerant | coolant spraying apparatus part of the evaporator in the absorption refrigeration apparatus concerning 1st Embodiment of this invention. It is sectional drawing which shows the abundant absorption solution dispersion state at the time of the operation | movement start of the heat-transfer plate and refrigerant | coolant spraying device part of an evaporator in the absorption refrigeration apparatus concerning 1st Embodiment of this invention. It is a refrigeration circuit diagram which shows the refrigerating cycle of the absorption refrigeration apparatus concerning 2nd Embodiment of this invention.

Explanation of symbols

1 is a generator 2 is a solution heat exchanger 3 is a condenser 4 is an evaporator 4a is a heat transfer plate part 4b is a refrigerant spray device 5 is an absorber 6 is a casing 7 is a solution pump 8 is a refrigerant pump 11 is a dilute solution pipe 12 Is a refrigerant vapor pipe 13 is a concentrated solution pipe 14 is a refrigerant supply pipe 15 is an absorption dilute solution reflux pipe 16 is an open / close control valve 17 is a refrigerant liquid reflux pipe 41 is a heat transfer plate 42 is a header 42a is a refrigerant storage chamber 43 is a refrigerant spray port 45 is a dispersion plate 45a is a vertical part 45b is a guide part Lc is an absorbing concentrated solution Ld is an absorbing diluted solution Rs is a refrigerant vapor Rw is a refrigerant liquid

Claims (4)

A generator (1) that generates refrigerant vapor (Rs) and an absorption concentrated solution (Lc) by heating the absorption diluted solution (Ld), and condensing the refrigerant vapor (Rs) from the generator (1) The condenser (3) for cooling and liquefying, and the refrigerant liquid (Rw) from the condenser (3) are transferred to the heat transfer plate (41) via the refrigerant spray ports (43), (43),. , (41) spread on the heat transfer surface and evaporate, and absorption that absorbs the refrigerant vapor (Rs) evaporated in the evaporator (4) with respect to the absorption concentrated solution (Lc). Absorption refrigeration apparatus comprising: a vessel (5); and a solution pump (7) for supplying an absorption dilute solution (Ld) having absorbed refrigerant vapor (Rs) by the absorber (5) to the generator (1) In the header (42), the refrigerant sprayed from the refrigerant spray ports (43), (43),. Dispersion plates (45) and (45) for dispersing and flowing down to the heat transfer surfaces of the heat plates (41) and (41) are attached so as to cover the refrigerant spray ports (43), (43). Absorption refrigeration equipment characterized. The absorption refrigeration apparatus according to claim 1, wherein the heat transfer surfaces of the heat transfer plates (41) and (41) are annealed to improve wettability. Each of the dispersion plates (45) is transferred to the heat transfer plate (41) from the vertical portion (45a) facing the refrigerant spray ports (43), (43), and the lower end of the vertical portion (45a). The absorption refrigeration apparatus according to any one of claims 1 and 2, wherein the absorption refrigeration apparatus includes a guide portion (45b) inclined toward a hot surface. The absorption type according to any one of claims 1, 2, and 3, further comprising a refrigerant pump (8) for circulating and pressure-feeding unvaporized refrigerant to the header (42) in the evaporator (4). Refrigeration equipment.

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