JP4701147B2 - 2-stage absorption refrigerator - Google Patents

Description

  The present invention relates to a two-stage absorption refrigerator having two sets of evaporators and absorbers and configured to cool a low-pressure side absorber by a high-pressure side evaporator.

  As a background art relating to the present invention, for example, a known technique of Patent Document 1 is cited. In Patent Document 1, in a two-stage absorption heat pump having two sets of evaporators and absorbers and heating the high temperature side (second) evaporator with the absorption heat of the low temperature side (first) absorber, A vertical inner cylinder with closed end faces is provided, and the interior is divided into upper and lower ends by an upper end plate, a solution dispersion end plate, and a lower end plate, and the upper chamber is provided above the upper end plate and below the lower end plate. The lower chamber is connected by a plurality of vertical heat transfer tubes to form a high temperature side evaporator.

  In addition, a low-temperature side absorber is formed between the solution dispersion end plate and the lower end plate with the outside of the vertical heat transfer tube group as an absorption heat transfer surface, and is formed between the upper end plate and the solution dispersion end plate. The solution is allowed to flow down in the form of a film along the outer surface of the vertical heat transfer tube group from the intermediate chamber.

  Furthermore, in this known example, the refrigerant liquid supplied into the tubes of the vertical heat transfer tube group is provided in the lower chamber, that is, the lower portion of the tube group.

  Further, as another background technique related to the present invention, a known technique of Patent Document 2 is cited. In this publicly known example, there are two sets of evaporators and absorbers, and the low temperature side (second) evaporator, the low temperature side absorber, the high temperature side (first) evaporator, and the high temperature side absorber are adjacent to each other in the same order. It is composed of a can body, the high temperature side evaporator and the low temperature side absorber are adjacent to each other via the heat transfer surface, and a liquid refrigerant spraying means for spraying liquid refrigerant in the vicinity of the heat transfer surface of the high temperature side evaporator, Solution spraying means for spraying the solution is disposed in the vicinity of the heat transfer surface of the low temperature side absorber, and the liquid refrigerant spraying means is positioned above the solution spraying means.

  And by the above configuration, the absorption heat of the low-temperature side absorber is directly transmitted through the heat transfer surface to the refrigerant flowing on the heat transfer surface of the high-temperature side evaporator, thereby using an intermediate medium such as circulating water. Compared with this, the temperature difference in heat transport is reduced and the cycle performance is improved.

Japanese Patent Publication No. 63-37301 Fig. 3 Japanese Patent No. 3591356 FIG.

  In the prior art of Patent Document 1, the refrigerant liquid is supplied from the lower part of each heat transfer tube of the vertical tube group, and the recirculation path for guiding the refrigerant vapor evaporated in the pipe from the upper opening of the heat transfer tube to the absorber is omitted. It is configured like a once-through boiler. In this configuration, the refrigerant inlet at the lower part of the heat transfer tube becomes a single-phase flow of the refrigerant liquid, and the supplied refrigerant liquid is heated in the heat transfer pipe and rises in the pipe while evaporating to the boil. For this reason, a bubble flow and slag flow region with large pressure loss due to friction is generated in the heat transfer tube, and in this region, the mass of the refrigerant that is two-phase in the tube is added to generate a large pressure distribution. On the other hand, a distribution also occurs in the evaporation temperature determined. In this case, since the pressure inside the pipe and the evaporation temperature are high on the upstream side, that is, the lower part of the heat transfer pipe, there is a problem that the temperature difference from the absorption temperature outside the pipe becomes small and the heat transfer surface does not work effectively.

  Moreover, in this prior art, since the refrigerant is boiled in the pipe, there is a problem that the temperature difference in heat transport is large, and the cycle performance such as operating temperature and COP is lowered.

  Furthermore, in this prior art, when the absorption temperature is high and the amount of heat transfer is large, there is also a problem that the heat transfer surface tends not to function effectively due to dry out of the refrigerant in the heat transfer tube. In Patent Document 1, the liquid level is formed inside the upper chamber and it is difficult for dry out to occur. In this case, the heat transfer tube is in a full-liquid evaporator, and the pressure loss and The subject that the pressure distribution by the mass of a refrigerant | coolant becomes remarkable arises.

  It is an object of the present invention to provide a two-stage absorption refrigerator that operates at a good operating temperature and COP by effectively operating a heat transfer surface.

  In order to achieve the above object, the first feature of the present invention is that a high-temperature evaporator and a low-temperature absorber are composed of a group of vertical tubes, and the inside of the tube is a high-temperature evaporator and the outside of the tube is a low-temperature absorber. The refrigerant liquid to be supplied is caused to flow from a refrigerant distribution chamber provided in the upper part of the tube group, and the refrigerant distribution chamber is divided into a plurality of regions.

  Preferably, the vertical heat transfer tube group protrudes upward from the bottom surface of the refrigerant distribution chamber, and a notch for inflow of refrigerant is provided at the upper end of each heat transfer tube. Further, the vertical tube group constituting the high temperature evaporator and the low temperature absorber is constituted by a heat transfer tube provided with concentric or spiral grooves on the outer surface or the inner surface.

  In order to achieve the above object, the second feature of the present invention is that a low-temperature evaporator, a low-temperature absorber, a high-temperature evaporator, and a high-temperature absorber are configured in the same container, and a dividing wall is provided vertically in the container. In addition to providing a low temperature evaporator on one side and a high temperature absorber on the opposite side, the low temperature absorber and the high temperature evaporator are composed of a plurality of flat tubes, and this flat tube group is arranged on the low temperature evaporator side of the dividing wall. Set the side of the cross-section perpendicular to the direction of the low-temperature evaporator and the other side in the direction of the high-temperature absorber, and close the end face on the low-temperature evaporator side of each flat tube. The opposite end face is connected to the dividing wall, and the dividing wall is provided with an opening corresponding to the cross-sectional shape of the flat tube at the connecting portion of each flat tube, thereby reducing the internal space of the flat tube group. It is in opening to the high temperature absorber side of the dividing wall.

  Preferably, a dropping tray whose bottom is divided by a partition perpendicular to the long side is provided at the top of the flat tube group, and a solution dropping hole corresponding to the position of each flat tube is provided at the bottom of the dropping tray. Is.

  Since the refrigerant liquid is supplied into the heat transfer tube from the upper part of the plurality of heat transfer tube groups constituting the integrated evaporator 5, the two-phase flow in the heat transfer tube becomes a void flow or slag flow with a large pressure loss. First, a falling liquid film of the refrigerant is formed around the cross section in the tube, and an annular flow in which the refrigerant vapor flows inside thereof. Accordingly, the pressure loss is reduced, the pressure distribution in the flow direction and the change in the evaporation temperature are reduced, and the entire heat transfer tube works effectively, whereby the heat transfer area can be reduced.

  Also, the flat heat transfer tube is oriented so that the long direction of the cross section is vertical, both ends are horizontal, the end surface on the low-temperature evaporator side is sealed, and the outer surface of the tube is used as a low-temperature absorber, and the end surface on the high-temperature absorber side Is opened to the high-temperature absorber side of the partition wall to make the inner surface of the pipe a high-temperature evaporator. Therefore, it is possible to flow the steam from the low temperature evaporator to the low temperature absorber and the steam from the high temperature evaporator to the high temperature absorber without changing the direction. As a result, energy loss due to flow pressure loss is reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a system diagram of a two-stage absorption refrigerator according to the present invention. The two-stage absorption refrigerator is composed of a high-temperature regenerator 1, a low-temperature regenerator 2, a condenser 3, a high-temperature absorber 4, a high-temperature evaporator and a low-temperature absorber integrated with each other, a low-temperature evaporator 6, a solution Heat exchangers 71, 72, 73, a refrigerant pump 51, a dilute solution pump 61, solution pumps 43, 52, a concentrated solution pump 21, and the like are provided.

  More specifically, the upper part of the high temperature regenerator 1 and the low temperature regenerator 2 are connected via a steam pipe 11. The low-temperature regenerator 2 and the condenser 3 are composed of the same container, and a solution dropping device 25 is arranged at the upper part on the low-temperature regenerator side, and a heat transfer tube 22 is arranged inside, and one end side of the heat transfer tube 22 Is communicated with the condenser 3 through the throttle 23 and connected to the steam pipe 11 at the other end. A heat transfer tube 31 is disposed inside the condenser 3, and the lower part of the container constituting the condenser is connected to the high-temperature absorber 4 side of the integrated evaporation absorber 5 through a pipe having a throttle 32.

  The integrated evaporator 5 includes a plurality of vertical heat transfer tubes 53. The outside of the heat transfer tubes 53 (the left side in the figure) communicates with the low temperature evaporator 6 as a low temperature absorber, and the inside of the tubes is heated at high temperature. As a heat exchanger, it communicates with the high-temperature absorber 4 outside the heat transfer tube 53 (on the right side in the figure) through an opening at the bottom of the heat transfer tube. Further, these spaces are divided by a partition wall 58. The high-temperature absorber 4, the integrated evaporation absorber 5, and the low-temperature evaporator 6 are configured by the same container 100, and the bottom of the container 100 corresponds to each component device, and is a solution tank 42, a refrigerant tank 55, and a solution tank 54. , The dilute solution tank 62 is divided.

  In the high temperature regenerator 1 and the low temperature regenerator 2, the dilute solution is heated and concentrated to generate a concentrated solution. The concentrated solution in the high-temperature regenerator 1 merges with the concentrated solution from the low-temperature regenerator 2 through the solution heat exchanger 71, and a part of the solution in the high-temperature absorber 4 through the concentrated solution pump 21 and the solution heat exchanger 72. Guided to the dropping device 45. A solution pump 43 and a solution heat exchanger 73 are respectively provided in the middle of the pipes that guide the solution collected in the solution tank 42 of the high-temperature absorber 4 to the integrated evaporation absorber 5.

  A refrigerant pump 51 is provided below the refrigerant tank 55 in order to supply the refrigerant liquid accumulated in the refrigerant tank 55 to the inside of the pipe of the integrated evaporator 5. Similarly, a dilute solution pump 61 is provided below the low temperature evaporator in order to drop the dilute solution stored in the dilute solution tank 62 below the low temperature evaporator 6 into the low temperature evaporator. Below the high temperature absorber 4, a solution pump 43 is provided to supply the solution accumulated in the solution tank 42 to the outside of the tube of the integrated evaporation absorber 5. A solution pump 52 for sending the solution to the high-temperature regenerator 1 and the low-temperature regenerator 2 is disposed below the solution tank 54.

  In this embodiment, the refrigerant is water and the absorbent is an aqueous lithium bromide solution.

  The operation of the two-stage absorption refrigerator configured as described above is as follows. The solution is heated by heat input means (not shown) inside the high-temperature regenerator 1 to generate refrigerant vapor. This refrigerant vapor is guided to the heat transfer tube 22 of the low-temperature regenerator 2 through the steam pipe 11, condensed inside the heat transfer tube 22, and flows into the condenser 3 through the throttle 23. Inside the low temperature regenerator 2, the solution is heated by the heat of condensation of the steam generated in the high temperature regenerator 1, and refrigerant vapor is also generated here. This refrigerant vapor is cooled by cooling water flowing in the condenser on the heat transfer pipe 31 of the condenser to become a refrigerant liquid, and together with the refrigerant liquid flowing in from the pipe of the low-temperature regenerator 2, integral evaporation is performed via a pipe provided with a throttle 32. It is guided to the high temperature absorber 4 side, that is, the refrigerant tank 55 divided by the partition wall 58 of the absorber 5.

  The refrigerant liquid in the refrigerant tank 55 is guided to the upper part of the integrated evaporation absorber 5 by the refrigerant pump 51. A refrigerant distribution chamber 56 is provided in the upper part of the integrated evaporation absorber 5. The refrigerant liquid supplied to the refrigerant distribution chamber 56 flows into the respective tubes of the plurality of heat transfer tubes 53 arranged vertically on the bottom side of the refrigerant distribution chamber 56, evaporates by taking heat from the solution outside the tubes, It becomes refrigerant vapor. This refrigerant vapor flows out from the lower part of the heat transfer tube 53 group. And it flows in into the high temperature absorber 4 which is connected with the inside of the heat exchanger tube of the heat exchanger tube 53 group.

  In the high temperature absorber 4, the concentrated solution heated and concentrated in the high temperature regenerator 1 and the low temperature regenerator 2 is supplied to the solution dropping device 45 by the concentrated solution pump 21 via the solution heat exchangers 71 and 72 and transmitted from there. It is dropped on the surface of the heat tube 41 group. Cooling water is passed through the tubes of the heat transfer tubes 41, and the solution supplied to the surface of the heat transfer tubes 41 is supplied from the heat transfer tubes of the integrated evaporator 5 while being cooled by the cooling water. Absorbs refrigerant vapor. The heat transfer tube 41 exits the high-temperature absorber and is connected to the heat transfer tube 31 in the condenser 3, and the cooling water is discharged out of the apparatus through the condenser 3. The solution whose concentration has been reduced by absorbing the refrigerant vapor in the high-temperature absorber 4 passes through the solution pump 43 and the solution heat exchanger 73 and constitutes a portion constituting the low-temperature absorber of the integrated evaporation absorber 5 (solution distribution chamber to be described later) 57).

  In the low temperature absorber portion of the integrated evaporator 5, the solution sent from the high temperature absorber is supplied to the outer surface of the heat transfer tubes 53 arranged vertically, and is cooled by the evaporation heat of the refrigerant in the heat transfer tubes 53. However, the refrigerant vapor generated in the low temperature evaporator 12 is absorbed. The solution further reduced in concentration by absorbing the refrigerant flows down to the solution tank 54 formed in the lower part of the integrated evaporator 5 on the low temperature evaporator side.

  The solution accumulated in the solution tank 54 is sent to the solution heat exchanger 73 by the solution pump 52 and exchanges heat with the solution sent from the high temperature absorber 4 to the low temperature absorber portion of the integrated evaporation absorber 5, and then the solution It branches into two via the heat exchanger 72, and a part is sent to the high temperature regenerator 1 via the solution heat exchanger 71, and the rest is sent to the solution dropping device 25 of the low temperature regenerator 2.

  Inside the low-temperature evaporator 6, a heat transfer tube 63 through which cold water or brine flows is arranged. The refrigerant pump 51 provided below the refrigerant tank 55 provided on the high-temperature evaporator side of the integrated evaporator 5 is provided in the lower part of the low-temperature evaporator 6 from the middle of the pipe for sending the refrigerant to the refrigerant distribution chamber 56. A pipe 59 for feeding the refrigerant to the dilute solution tank 62 is branched. The leading end of the branched pipe 59 is open to the bottom surface, which is the liquid phase part of the dilute solution tank 62. The refrigerant is sent from the refrigerant tank 55 to the diluted solution tank 62 through this pipe. The flow rate of the refrigerant flowing in the pipe 59 is controlled by a control valve 59 a provided in the middle of the pipe 59.

  A dilute solution tank 62 provided at the lower part of the low-temperature evaporator 6 stores a dilute solution. The dilute solution pump 61 passes the concentration detection means 64 and sends it to a dropping device 65 disposed at the upper part of the low-temperature evaporator 6. It is done. Then, the refrigerant, that is, water in the dilute solution evaporates on the surface of the heat transfer tube 63 from the dropping device 65 onto the heat transfer tube 63, and cool water or brine flowing through the heat transfer tube 63 is cooled by latent heat of evaporation.

  Various control operations in the two-stage absorption refrigerator of the present embodiment are substantially the same as the contents disclosed in Patent Document 2 described above.

  Next, the flow of the working fluid, that is, the refrigerant liquid, the solution, and the refrigerant vapor in the integrated evaporation absorber 5 will be described with reference to FIGS. 2 and 3. FIG. 2 is a detailed view of the refrigerant distribution chamber 56, and FIG. 3 is a view showing the flow of the working fluid around the heat transfer tube in the integrated evaporation absorber. In FIG. 3, one heat transfer tube is taken out for explanation.

  As shown in FIG. 2, the refrigerant distribution chamber 56 divides a box-shaped container into a plurality of regions by a partition plate 56b, and a refrigerant inlet 56a is provided for each region. In addition, a hole for penetrating and connecting the plurality of heat transfer tube 53 groups is opened on the bottom surface of each region, and the heat transfer tube is passed through this hole so that the upper end of the heat transfer tube is higher than the bottom surface of the refrigerant distribution chamber. Connected. A notch 53b is provided at the upper end of each heat transfer tube.

  The refrigerant liquid sent to the refrigerant distribution chamber 56 by the refrigerant pump 51 is distributed to the number of areas partitioned by the partition plate 51b of the refrigerant distribution chamber 56, and each area from the refrigerant inlet 56a provided on the side surface of each area. Flows into the interior. Then, as shown in FIG. 3, a liquid surface is formed in the refrigerant distribution chamber, and overflows from a notch 53 b provided at the upper end of the heat transfer tube 53 and flows into the heat transfer tube 53.

  A part of the partition wall 58 is formed in a U shape, and the lower end side of the plurality of vertical heat transfer tubes 53 is attached to and supported by the U side upper partition wall (low temperature absorption bottom plate 58b), and the bottom side of the U shape The refrigerant liquid is discharged to the (high temperature evaporation bottom plate 58a).

  As shown in FIG. 3, the refrigerant liquid 111 flowing into the heat transfer tube 53 from the notch 53 b forms a falling liquid film 110 on the inner surface of the heat transfer tube 53, and heat is supplied from the falling liquid film 130 of the solution outside the heat transfer tube 63. Part of it is evaporated to become refrigerant vapor, which flows down the falling liquid film in the pipe. At the outlet of the heat transfer tube 53, the refrigerant vapors 122 and 123 flow into the high temperature absorber 4, and the refrigerant liquid 112 that has flowed down without evaporating up to the outlet of the heat transfer tube flows onto the high temperature evaporation bottom plate 58 a that is a part of the partition wall 58. It flows down and further flows into the refrigerant tank 55 shown in FIG. The high temperature evaporation bottom plate 58a is installed with a slight inclination in the direction of flowing down to the refrigerant tank 55.

  The refrigerant liquid flowing into the refrigerant tank 55 is sent again to the refrigerant distribution chamber 56 by the refrigerant pump 51 together with the refrigerant liquid flowing in from the condenser 3.

  On the other hand, the solution sent to the low-temperature absorber portion of the integrated evaporation absorber 5 by the solution pump 43 of FIG. 1 is guided to the solution distribution chamber 57 shown in FIG. Although not shown in the drawing, the solution distribution chamber 57 is partitioned into a plurality of regions in the same manner as the refrigerant distribution chamber 56. A vertical heat transfer tube group passes through the solution distribution chamber 57, and the through hole of the heat transfer tube 53 provided in the bottom plate is a circle having a diameter slightly larger than the outer diameter of the heat transfer tube. The solution guided to the solution distribution chamber 57 is supplied to the outer surface of the heat transfer tube 53 through the gap 57 a between the through hole and the outer surface of the heat transfer tube 53.

  The solution supplied to the outside of the heat transfer tube 53 forms a falling liquid film 130 as shown in FIG. 3 and flows from the low temperature evaporator 6 while being cooled by the evaporation heat of the refrigerant evaporating in the heat transfer tube 53. The refrigerant vapors 120 and 121 are absorbed. Then, after flowing down on the low temperature absorption bottom plate 58 b which is a part of the partition wall 58, it flows down to the solution tank 54.

  As described above, in the present embodiment, since the refrigerant liquid is supplied into the heat transfer tubes from the upper part of the plurality of heat transfer tube groups constituting the integrated evaporator 5, the two-phase flow in the heat transfer tubes is generated. Instead of a void flow or slag flow with a large pressure loss, a falling liquid film of the refrigerant is formed around the cross section in the tube, and an annular flow in which the refrigerant vapor flows inside is formed. Accordingly, the pressure loss is reduced, the pressure distribution in the flow direction and the change in the evaporation temperature are reduced, and the entire heat transfer tube works effectively, whereby the heat transfer area can be reduced.

  At this time, the pressure and evaporation temperature distribution in the heat transfer tube tends to gradually decrease from the top to the bottom of the heat transfer tube, and the concentration and equilibrium temperature of the solution flowing outside the tube also move from the top to the bottom. It gradually decreases by absorbing the refrigerant vapor. Therefore, a heat exchange temperature difference can be ensured over the entire length of the heat transfer tube, and the cooling capacity by the refrigerant evaporation in the tube and the heat exchange area of the entire heat transfer tube can be effectively utilized for refrigerant absorption outside the tube.

  Further, in this embodiment, the partition plate 56b is provided in the refrigerant distribution chamber 56 and divided into a plurality of areas, and the refrigerant liquid is distributed and supplied in advance to each area, so that the two-stage absorption refrigerator main body is inclined. Even in this case, it is possible to prevent deterioration of the refrigerant distribution state to the entire tube group.

  Further, in the present embodiment, the upper end of each heat transfer tube 53 protrudes from the bottom surface of the refrigerant distribution chamber 56 so that the refrigerant in the refrigerant distribution chamber flows into the tube by overflow, so that the refrigerant flow is in the vicinity of the refrigerant inlet 56a. It is distributed well to each heat transfer tube without being biased to the heat transfer tube.

  Furthermore, in the present embodiment, the notch 53b for refrigerant inflow is provided at the upper end portion of each heat transfer tube constituting the vertical heat transfer tube 53 group, and therefore heat transfer is performed by appropriately providing the number and width of the notches 53b. The flow rate of the refrigerant liquid flowing into the pipe can be set. Moreover, even if a slight inclination occurs during the installation of the refrigerator body, the distribution of the refrigerant for each heat transfer tube in each region can be maintained satisfactorily by the notch 53b.

In the present embodiment, circumferential or spiral grooves or protrusions may be provided on the inner surface of each heat transfer tube constituting the vertical heat transfer tube 53 group. In this case, the heat transfer tube works effectively by the effect of improving the wettability of the refrigerant liquid in the heat transfer tube and the expansion of the heat transfer surface, and there is an advantage that the integrated evaporation absorber 5 can be downsized. Similarly, circumferential or spiral grooves or protrusions may be provided on the outer surface of the heat transfer tube 53. In this case, there is an advantage that the integral evaporator 5 can be miniaturized because the heat transfer tube 53 acts effectively due to the effect of improving the wettability of the solution outside the heat transfer tube 53 and the effect of expanding the heat transfer surface.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the overall configuration and cycle operation of the entire two-stage absorption refrigerator are the same as those in the first embodiment, and only the configuration of the integrated evaporation absorber 5 is different. Therefore, this part will be described in detail. .

FIG. 4 is a cycle system diagram of the two-stage absorption refrigerator according to the present embodiment. A different point from the embodiment of FIG. 1 is a part of the integrated evaporation absorber 5. The integrated evaporator 5 includes a plurality of flat heat transfer tubes 80, a refrigerant distribution duct 81 that distributes the refrigerant into the tubes of each flat heat transfer tube 80, and a refrigerant distribution duct 81 provided at the uppermost part inside each flat heat transfer tube 80. A refrigerant distribution pipe 82 is provided that distributes the refrigerant flowing in from the axial direction (flat direction) of the flat heat transfer tube 80 and supplies it to the inner surface. That is, the refrigerant distribution pipes 82 are provided as many as the flat heat transfer tubes 80. In place of the solution distribution chamber 57 shown in FIG. 3, a solution dropping device 85 having the same structure as the solution dropping device 45 of the high-temperature absorber 4 is installed so as to supply the solution to the outside of the flat heat transfer tube 80. . As shown in FIG. 4, the flat heat transfer tube 80 is installed so that most of the flat heat transfer tube 80 is located on the low-temperature evaporator side of the partition wall 58 (partition wall).

  Further, the detailed structure of the integrated evaporation absorber 5 will be described with reference to FIGS. FIG. 5 is a detailed view of the refrigerant distribution portion of the integrated evaporator according to this embodiment, and FIG. 6 is a view showing the details of the heat exchange portion in a cross section perpendicular to FIG. As shown in FIG. 5, a plurality of refrigerant distribution pipes 82 are arranged and connected to the side surface of the refrigerant distribution duct 81 along the axial direction of the refrigerant distribution duct 81. As shown in FIG. 6, the refrigerant distribution pipe 82 is inserted and installed at the top of the flat heat transfer tube 80, and the number thereof is the same as the number of flat heat transfer tubes 80. As shown in FIG. 6, each refrigerant distribution pipe 82 is provided with a plurality of refrigerant distribution holes 82a on the left and right as viewed from the tube axis direction. As shown in FIG. 5, a plurality of the refrigerant distribution holes 82 a are arranged and opened in the axial direction of the refrigerant distribution pipe 82.

  As shown in FIG. 6, the plurality of flat heat transfer tubes 80 are arranged side by side so that the long direction of the cross section is vertical and the tube row is horizontal. The installation direction is such that one end of the flat heat transfer tube 80 is directed to the low-temperature evaporator 6 and the opposite end is directed to the high-temperature absorber 4, and is fixed to the partition wall 58 near the end on the high-temperature absorber side. ing. The partition wall 58 is provided with a hole for connecting the flat heat transfer tube based on the cross-sectional shape of the flat heat transfer tube 80, and the flat heat transfer tube is inserted into this hole, and the periphery of the heat transfer tube and the inside of the hole of the partition wall 58 are Sealed to prevent leakage of solution and refrigerant vapor.

  The end surface on the low-temperature evaporator 6 side of each flat heat transfer tube 80 is sealed, and the entire end surface or the lower end of the end surface on the high-temperature absorber 4 side is open. As a result, the outside of each flat heat transfer tube communicates with the low temperature evaporator 6, and the inside of the tube communicates with the high temperature absorber 4.

  A solution dripping device 85 is installed on the top of the flat heat transfer tube 80. A solution distribution duct 85 a for distributing the solution sent from the high-temperature absorber 4 by the solution pump 43 in the row direction of the flat heat transfer tubes 80 is provided at the upper part. The bottom of the solution dropping device 85 is divided into a plurality of regions in the row direction of the flat heat transfer tubes 80 by the partition plate 85c, and a solution distribution hole 85b is opened on the side surface of the solution distribution duct 85a corresponding to each region. is doing. Moreover, 85 d of solution dripping holes are provided in the bottom part of the solution dripping apparatus 85 in the position corresponding to each flat heat exchanger tube.

  Next, the flow of the solution, the refrigerant liquid, and the refrigerant vapor in the integrated evaporation absorber 5 of the present embodiment will be described. The refrigerant liquid sent to the integrated evaporation absorber 5 by the refrigerant pump 51 first flows into the refrigerant distribution duct 81 and is distributed to the refrigerant distribution pipe 82. Then, a plurality of refrigerant distribution holes 82 a provided in the axial direction of the respective refrigerant distribution pipes 82 are supplied into the flat heat transfer pipe 80.

  The refrigerant liquid supplied to the flat heat transfer tube 80 forms a falling liquid film 110 on the surface of the vertical inner wall of the flat heat transfer tube 80, takes heat from the solution outside the flat heat transfer tube 80, and part of it evaporates. It becomes refrigerant vapor. The refrigerant vapor generated in the flat heat transfer tube 80 flows into the high-temperature absorber 4 from an open portion provided on the end face on the partition wall 58 side. On the other hand, the refrigerant liquid that has not completely evaporated and has flowed down to the lowermost part in the flat heat transfer tube flows into the refrigerant tank 55 from the opening provided at the end face on the partition wall 58 side, and together with the refrigerant liquid that has flowed in from the condenser 3 51 is sent again to the refrigerant distribution duct.

  The solution sent from the high-temperature absorber 4 to the integrated evaporation absorber 5 by the solution pump 43 is first sent to the solution dropping device 85 and distributed to each region partitioned by the partition plate 85c by the solution distribution duct 85a. The Further, it is dropped from the solution dropping hole 85 d provided at the bottom of the solution dropping device 85 to the outer upper end of each flat heat transfer tube 80.

  The solution dropped on the flat heat transfer tube 80 forms a falling liquid film 130 on the surface of the tube, and is cooled by the flowing liquid film 110 of the refrigerant evaporating in the tube, thereby absorbing the refrigerant vapor evaporated in the low-temperature evaporator. While flowing down. Then, it flows down to the solution tank 54 at the bottom. The solution accumulated in the solution tank 54 is sent to the high temperature regenerator 1 and the low temperature regenerator 2 by the solution pump 52.

  As described above, in this embodiment, the flat heat transfer tube 80 is oriented so that the long direction of the cross section is vertical, both ends are directed in the horizontal direction, the end surface on the low-temperature evaporator side is sealed, and the outer surface of the flat heat transfer tube is A low-temperature absorber is used, and the end surface on the high-temperature absorber side (end surface on the partition wall 58 side) is opened to make the inside of the flat heat transfer tube a high-temperature evaporator. Therefore, it is possible to flow the steam from the low temperature evaporator to the low temperature absorber and the steam from the high temperature evaporator to the high temperature absorber without changing the direction. As a result, energy loss due to flow pressure loss is reduced.

  Further, by ensuring a large flow path cross-sectional area of the refrigerant vapor, the vapor flow velocity can be suppressed, and the separation of the refrigerant liquid scattered in the refrigerant vapor becomes easy. As a result, it is possible to reduce the cycle loss due to the scattering of the refrigerant droplets, and it is possible to reduce the pressure loss associated with the separation of the refrigerant liquid, which causes other losses.

  As a result, in the second embodiment, a more efficient two-stage absorption refrigerator can be obtained as compared with the first embodiment.

The system diagram of the two-stage absorption refrigerator related to Example 1 of this invention. FIG. 2 is a detailed view of a refrigerant distribution chamber of the integrated evaporation absorber in the embodiment of FIG. 1. FIG. 2 is a detailed view of a heat exchange part of the integrated evaporation absorber in the embodiment of FIG. 1. The system diagram of the two-stage absorption refrigerator related to Example 2 of this invention. FIG. 5 is a detailed view of a refrigerant distribution portion of the integrated evaporation absorber in the embodiment of FIG. 4. FIG. 5 is a detailed view of a heat exchange part of the integrated evaporation absorber in the embodiment of FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Low temperature regenerator 3 Condenser 4 High temperature absorber 5 Integrated evaporation absorber 6 Low temperature evaporator 11 Steam piping 21 Concentrated solution pump 22, 31, 41, 53, 63 Heat transfer tube 23, 32 Restriction 43, 52 Solution pumps 42, 54 Solution tanks 45, 85 Solution dripping device 51 Refrigerant pump 53b Notch 55 Refrigerant tank 56 Refrigerant distribution chamber 56a Refrigerant inlet 56b, 85c Partition plate 57 Solution distribution chamber 58 Partition wall 58a High temperature evaporation bottom plate 59b Low temperature absorption bottom plate 59 Piping 59a Control valve 61 Dilute solution pump 62 Dilute solution tank 64 Concentration detection means 65 Dripping device 71, 72, 73 Solution heat exchanger 80 Flat heat transfer tube 81 Refrigerant distribution duct 82 Refrigerant distribution pipe 85a Solution distribution duct 85b Solution distribution hole 85d Solution dripping Hole 100 Container 110 Flowing liquid film 111, 112 Refrigerant liquid 120-123 Refrigerant vapor 1 30 Falling liquid film

Claims (11)

A two-stage configuration comprising a low-temperature evaporator, a low-temperature absorber, a high-temperature evaporator, a high-temperature absorber, a regenerator, a condenser, and a solution circulation pump, wherein the low-temperature absorber is cooled by the evaporation heat of the high-temperature evaporator. In absorption refrigerator,
The low-temperature evaporator, the low-temperature absorber, the high-temperature evaporator, and the high-temperature absorber are configured in the same container, and the high-temperature evaporator is communicated with the high-temperature absorber side as a plurality of vertical heat transfer tubes. A heat exchanger is connected to the low-temperature evaporator outside the plurality of vertical heat transfer tubes, and a refrigerant liquid is supplied into the heat transfer tubes from above the plurality of vertical heat transfer tubes. Two-stage absorption refrigerator.   2. The two-stage absorption refrigerator according to claim 1, wherein a refrigerant distribution chamber is provided in an upper portion of the plurality of vertical heat transfer tube groups, and the plurality of heat transfer tubes are passed through a bottom surface of the refrigerant distribution chamber. A two-stage absorption refrigerator characterized by having an opening.   The two-stage absorption refrigerator according to claim 2, wherein the plurality of heat transfer tubes protrude upward from a bottom surface of the refrigerant distribution chamber, and a notch for inflow of refrigerant is provided at an upper end portion of each heat transfer tube. Two-stage absorption refrigerator. In the two-stage absorption refrigerating machine according to claim 1, the coolant distribution chamber provided at an upper portion of the plurality of vertical tube banks, the coolant distribution chamber and characterized in that the bottom portion is divided into regions of multiple Two-stage absorption refrigerator.   The two-stage absorption refrigerator according to claim 1 or 2, wherein the plurality of vertical heat transfer tubes constituting the high-temperature evaporator and the low-temperature absorber are provided with a circumferential or spiral groove or protrusion on the inner surface thereof. A two-stage absorption refrigerator characterized by comprising a heat tube.   5. The two-stage absorption refrigerator according to claim 3, wherein the plurality of vertical heat transfer tubes constituting the high-temperature evaporator and the low-temperature absorber are provided with circumferential or spiral grooves or protrusions on the inner surface thereof. A two-stage absorption refrigerator characterized by comprising a heat tube.   The two-stage absorption refrigerator according to claim 1 or 2, wherein the plurality of vertical heat transfer tubes constituting the high temperature evaporator and the low temperature absorber are provided with circumferential or spiral grooves or protrusions on an outer surface. The two-stage absorption refrigerator characterized by comprising.   5. The two-stage absorption refrigerator according to claim 3 or 4, wherein the plurality of vertical heat transfer tubes constituting the high temperature evaporator and the low temperature absorber are provided with circumferential or spiral grooves or protrusions on the outer surface. The two-stage absorption refrigerator characterized by comprising. A two-stage configuration comprising a low-temperature evaporator, a low-temperature absorber, a high-temperature evaporator, a high-temperature absorber, a regenerator, a condenser, and a solution circulation pump, wherein the low-temperature absorber is cooled by the evaporation heat of the high-temperature evaporator. In absorption refrigerator,
The low-temperature evaporator, the low-temperature absorber, the high-temperature evaporator, and the high-temperature absorber are configured in the same container, and the high-temperature evaporator is communicated with the high-temperature absorber side as a plurality of vertical heat transfer tubes. A heat exchanger outside the tubes of the plurality of vertical heat transfer tubes and communicating with the low temperature evaporator, supplying a refrigerant liquid into the heat transfer tubes above the plurality of vertical heat transfer tubes, and at the top of the heat transfer tubes. A two-stage absorption refrigerator characterized in that the dilute solution is sprinkled on the outside of the heat transfer tube. A two-stage configuration comprising a low-temperature evaporator, a low-temperature absorber, a high-temperature evaporator, a high-temperature absorber, a regenerator, a condenser, and a solution circulation pump, wherein the low-temperature absorber is cooled by the evaporation heat of the high-temperature evaporator. In absorption refrigerator,
The low-temperature evaporator, the low-temperature absorber, the high-temperature evaporator, and the high-temperature absorber are configured in the same container, the partition is vertically provided in the container, the low-temperature evaporator is provided on one side, and the high-temperature absorber is provided on the opposite side. The low-temperature absorber and the high-temperature evaporator are composed of a plurality of flat heat transfer tubes, and the flat heat transfer tube group is provided on the low-temperature evaporator side of the partition wall, with the long direction of the cross section being vertical, and one side is the low temperature In the direction of the evaporator, the opposite side is installed in the horizontal direction facing the direction of the high-temperature absorber, the end surface of each flat heat transfer tube on the low-temperature evaporator side is closed, and the opposite end surface is connected to the partition wall. The two-stage absorption is characterized in that the partition wall is provided with an opening corresponding to the cross-sectional shape in the connection portion of each flat heat transfer tube, and the internal space of the flat heat transfer tube group is opened to the high-temperature absorber side of the partition wall. refrigerator. The two-stage absorption refrigerator according to claim 10,
A two-stage absorption refrigerator characterized in that the inside of the flat heat transfer tube is the high-temperature evaporator and the outside is a low-temperature absorber.

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