JP2017122515A - Heat transfer device, filled-liquid type regenerator and evaporator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat transfer device that facilitates liquid ebullition.SOLUTION: A heat transfer device 10 has: a heat transfer member 11 that has a heat transfer face 12 in contact with liquid and transfers heat from the heat transfer face 12 to the liquid; and a punching metal material 13 having a plurality of through holes 13a. The punching metal material 13 faces the heat transfer face 12 with a gap therebetween.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat transfer device that transfers heat to a liquid, a full liquid regenerator that evaporates a refrigerant liquid by heat transferred from a heat transfer surface of the heat transfer device, and an evaporator.

  As an example of the structure of the heat transfer surface of an apparatus for transferring heat to a liquid, for example, an evaporator for evaporating a refrigerant liquid, there is a structure in which a large number of minute spaces such as a conical type, a cylindrical type, and a reentrant type are formed. In particular, when a reentrant-type micro space is formed on the heat transfer surface, the effect that the formed bubble nuclei exist stably in the micro space is increased. However, in order to form the reentrant type structure on the heat transfer surface, complicated processing is required, which increases the cost.

  The following Patent Document 1 and Patent Document 2 describe heat transfer devices aimed at improving boiling heat transfer characteristics without forming a reentrant structure on the heat transfer surface.

  In Patent Document 1 (Japanese Patent Application Laid-Open No. 57-172193), a groove is formed on the surface of the heat transfer surface, and a plate-like member having a plurality of through holes is brought into contact with the heat transfer surface so as to cover the groove. A mounted heat transfer device is described. In addition, as an object of the invention, “a reentrant cavity that has been conventionally said in a very simple manner on the surface of the heat transfer surface, that is, a large number of microspaces with a wide interior and a small opening are formed, so that high-performance boiling is achieved. It is to provide a heat transfer surface easily. "

  Patent Document 2 (Japanese Patent Application Laid-Open No. 64-067591) describes a heat transfer device in which a plurality of layers of metal nets are arranged facing each other with a space from the heat transfer surface. As a function of the wire mesh, “the wire mesh (6), (7) is to maintain an appropriate space where the bubbles (13) can exist between the heat transfer surface (5) and the wire mesh (8) and to trap the bubble nuclei. Will also be fulfilled. " It is also described that the wire mesh (8) alone is not effective and the wire mesh (6) or (7) is necessary.

JP-A-57-172193 Japanese Patent Application Laid-Open No. 64-067591

  The heat transfer device described in Patent Document 1 combines two structures, a groove and a plate-like member, to form a minute space with a wide interior and a small opening (that is, the same structure as a conventional reentrant structure). It is characterized by. In other words, the reentrant structure is only created differently from the conventional method, and the function of stably allowing the bubble nuclei in the minute space to exist is considered to be the same as the reentrant structure.

The heat transfer device described in Patent Document 2 also describes that a multi-layered wire net is provided in order to make bubble nuclei exist stably, and its function is the same as when a reentrant type structure is adopted. it is conceivable that.
In addition, in the heat transfer apparatus described in Patent Document 2, since it is necessary to provide a multi-layered wire mesh, the structure becomes complicated and it takes time to manufacture.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a heat transfer device, a full liquid regenerator, and an evaporator that can easily cause boiling of a liquid.

The characteristic configuration of the heat transfer device according to the present invention for achieving the above object has a heat transfer surface in contact with the liquid, and a heat transfer member that transfers heat from the heat transfer surface to the liquid,
A punching metal material having a plurality of through holes,
The punching metal material is disposed so as to face the heat transfer surface at an interval.

  According to the above characteristic configuration, the punching metal material is disposed facing the heat transfer surface at an interval, so that the flow of liquid in contact with the heat transfer surface is suppressed between the punching metal material and the heat transfer surface. The As a result, the degree of superheat of the liquid in the vicinity of the heat transfer surface can be increased to facilitate boiling. That is, a lower temperature heat source can be used as a heat source for boiling the liquid.

Another characteristic configuration of the heat transfer device according to the present invention is that the heat transfer member is a heat transfer tube in which a heat medium flows,
The heat transfer tube is a smooth tube, a low fin tube having a fin structure on the heat transfer surface, or a reentrant tube having a reentrant structure on the heat transfer surface.

  According to the said characteristic structure, a heat transfer apparatus can be comprised using a smooth tube, a low fin tube, or a reentrant tube as a heat transfer tube (heat transfer member).

A characteristic configuration of the full-liquid regenerator according to the present invention is such that the heat transfer device is disposed in the liquid in which an absorption liquid and a refrigerant liquid are mixed and stored in a container, and the refrigerant liquid is It is in the point of evaporating with the heat transmitted from the heat transfer surface of the heat transfer device.
Here, water may be used as the refrigerant liquid, and an aqueous lithium bromide solution may be used as the absorbing liquid.

  According to the above characteristic configuration, the full liquid regenerator can be used as a regenerator for an absorption refrigerating machine. Further, a lower temperature heat source can be used as a heat source for regenerating the absorbent.

A characteristic configuration of the evaporator according to the present invention is that the heat transfer device is disposed in the liquid stored in a container, and the liquid is evaporated by heat transmitted from the heat transfer surface of the heat transfer device. It is in point to let you.
Here, the liquid may be water, chlorofluorocarbon, hydrocarbon, ammonia, carbon dioxide, or a mixture of any two or more of these liquids.

  According to the above characteristic configuration, it is possible to provide an evaporator in which liquid boiling easily occurs using the heat transfer device. Moreover, a lower temperature heat source can be used as a heat source for boiling the liquid.

It is a figure which shows the structure of a full liquid regenerator provided with a heat exchanger. It is sectional drawing of a full liquid regenerator provided with a heat exchanger. It is a perspective view explaining the structure of a heat exchanger. It is a graph which shows the relationship between a heat flux and a heat transfer rate. It is sectional drawing of another heat-transfer apparatus. It is sectional drawing of another heat-transfer apparatus.

A heat transfer device 10 according to an embodiment of the present invention and a full liquid regenerator 1 including the heat transfer device 10 will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration of a full liquid regenerator 1 including a heat transfer device 10. FIG. 2 is a cross-sectional view of the full liquid regenerator 1 including the heat transfer device 10. FIG. 3 is a perspective view illustrating the structure of the heat transfer device 10. As shown in the figure, a full-liquid regenerator 1 has a structure in which a heat transfer device 10 is stored in a liquid (mixed liquid 3) in which an absorbing liquid and a refrigerant liquid are mixed and stored in a container 2. It has become. In the full liquid regenerator 1, the refrigerant liquid is evaporated by the heat transmitted from the heat transfer surface 12 of the heat transfer device 10. The full liquid regenerator 1 includes a condenser that condenses the refrigerant, an evaporator that evaporates the refrigerant liquid condensed in the condenser, an absorber that absorbs the refrigerant evaporated in the evaporator with an absorption liquid, and an absorption It is used as a regenerator that constitutes a part of an absorption refrigerator having a regenerator that regenerates the absorbing liquid and refrigerant by evaporating the refrigerant liquid from the mixed liquid (absorbing liquid + refrigerant liquid) obtained in the apparatus. For example, the refrigerant liquid is water and the absorbing liquid is an aqueous lithium bromide solution.

  The heat transfer device 10 includes a heat transfer member 11 and a punching metal material 13. The punching metal material 13 has a plurality of through holes 13a. The punching metal material 13 is disposed so as to face the heat transfer surface 12 at an interval. The heat transfer member 11 has a heat transfer surface 12 in contact with a liquid (mixed liquid 3 in which an absorption liquid and a refrigerant liquid are mixed in this embodiment), and transfers heat from the heat transfer surface 12 to the liquid. Let In the present embodiment, the heat transfer member 11 is a heat transfer tube through which the heat medium H flows. The heat transfer surface 12 on the surface of the heat transfer tube is formed in a smooth shape without irregularities. That is, the heat transfer tube of this embodiment is a smooth tube.

  Heat is transferred from the heat medium H flowing inside the heat transfer member 11 to the heat transfer surface 12 on the surface of the heat transfer member 11, and the heat is mixed on the heat transfer surface 12 in which the absorption liquid and the refrigerant liquid are mixed. It is transmitted to the liquid 3. In the present embodiment, the punching metal material 13 has a structure in which a plurality of through holes 13a are formed in a cylindrical member made of metal such as stainless steel. By disposing the heat transfer member 11 in the internal space of the cylindrical punching metal material 13, the punching metal material 13 is located facing the heat transfer surface 12 of the heat transfer member 11 with a distance D. That is, the mixed liquid 3 can freely flow in the two-dimensional plane along the heat transfer surface 12 between the punching metal material 13 and the heat transfer surface 12 of the heat transfer member 11. On the other hand, the mixed liquid 3 can flow in the direction perpendicular to the heat transfer surface 12 through the through hole 13a of the punching metal material 13. Thus, the flow of the mixed liquid 3 that receives heat from the heat transfer surface 12 is restricted by the punching metal material 13.

  Inside the container 2, the heat transfer device 10 is immersed in the mixed solution 3. An inlet 4 through which the mixed liquid 3 flows into the container 2 is provided at one end of the container 2, and an outlet 5 through which the mixed liquid 3 flows out of the container 2 is provided at the other end of the container 2. Provided. Inside the container 2, the mixed liquid 3 flows from the inlet 4 toward the outlet 5 while being heated by the heat transfer device 10. That is, inside the container 2, the mixed liquid 3 in which the absorbing liquid and the refrigerant liquid are mixed flows from the inlet 4 to the outlet 5 while being transferred from the heat transfer surface 12 of the heat transfer device 10. As a result, the refrigerant liquid is evaporated. And from the outflow port 5, the liquid mixture 3 after a refrigerant | coolant liquid evaporates flows out.

  In the example shown in FIG.1 and FIG.2, although the full liquid regenerator 1 has shown the example provided with 30 heat exchangers 10, the number of the heat transfer apparatuses 10 with which the full liquid regenerator 1 is provided is set suitably. Is possible. Moreover, although the 30 heat-transfer apparatuses 10 have shown the example arrange | positioned in parallel mutually with 5 vertical rows and 6 horizontal rows, the number of vertical and horizontal rows can also be set suitably. Furthermore, the space | interval with the adjacent heat exchanger 10 can also be set suitably.

  FIG. 4 is a graph showing the relationship between the heat flux and the heat transfer coefficient, derived from the pool boiling experiment. In this pool boiling experiment, in order to simulate the full liquid regenerator 1, a smooth plate simulating the heat transfer tube (heat transfer member 11) of this embodiment shown in FIG. 3 and punching simulating the punching metal material 13 are used. Plates A to C were arranged with a gap D = 1 mm. In the punching plates A to C, a plurality of through holes are formed in a staggered arrangement. The opening ratio indicating the ratio of the opening area of the through hole per unit area in each punching plate A to C is 40%. As a mixed solution, a lithium bromide aqueous solution (concentration = 55 wt%) was used, and measurement was performed at a pressure = 6 kPa.

The punching plate A is a metal plate in which through holes having a diameter of 3 mm are arranged at a pitch of 4.5 mm (that is, the minimum interval between adjacent through holes is 1.5 mm). The punching plate B is a metal plate in which through holes having a diameter of 1.5 mm are arranged at a pitch of 2.3 mm (that is, the minimum interval between adjacent through holes is 0.8 mm). The punching plate C is a metal plate in which through holes having a diameter of 1 mm are arranged at a pitch of 1.5 mm (that is, the minimum interval between adjacent through holes is 0.5 mm).
Further, as a comparative example, an example in which no punching plate is arranged (that is, only a smooth plate) is shown.

  As shown in FIG. 4, when the punching plates A to C are arranged at a distance from the smooth plate as compared with the comparative example in which no punching plate is arranged, the heat transfer coefficient is within a relatively small range of the heat flux. It can be seen that there has been a significant improvement. In particular, when the punching plate A indicated by a white circle in the figure is arranged, the heat transfer coefficient is greatly improved in most heat flux ranges. Therefore, also in the heat transfer device 10 shown in FIGS. 1 to 3, the flow of the mixed liquid 3 in the vicinity of the heat transfer surface 12 is suppressed by installing the punching metal material 13 at a position slightly away from the heat transfer surface 12. Thus, it is considered that the superheat degree of the mixed liquid 3 in the vicinity of the heat transfer surface 12 is increased and boiling easily occurs. That is, a lower temperature heat source can be used as a heat source for heating the heat medium H supplied to the full liquid regenerator 1.

<Another embodiment>
<1>
In the said embodiment, although the specific example was given and demonstrated about the structure of the heat exchanger 10, the structure can be changed suitably.
For example, regarding the heat transfer device 10, the case where the heat transfer surface 12 of the surface of the heat transfer tube (heat transfer member 11) is formed in a smooth shape without unevenness, that is, the case where the heat transfer tube is a smooth tube has been described. However, the surface shape of the heat transfer tube (heat transfer member 11) may be another shape.
5 and 6 are cross-sectional views of another heat transfer device 10. Specifically, FIG. 5 shows an example in which the heat transfer member 11 is a low fin tube having a fin structure on the heat transfer surface 12 on the surface of the tube. FIG. 6 shows an example in which the heat transfer member 11 is a reentrant tube having a reentrant structure on the heat transfer surface 12 on the surface of the tube. Even if the heat transfer surface 12 having such a structure is employed, the same effect as that of the above embodiment can be obtained, although the degree of the effect of improving the thermal conductivity as described in the above embodiment varies.

  Further, in the above embodiment, when the full liquid regenerator 1 is used as a regenerator for an absorption refrigerator, ammonia may be used as a refrigerant liquid and water may be used as an absorption liquid.

  Furthermore, in the said embodiment, although the case where the heat-transfer member 11 was a heat-transfer pipe | tube with which the heat medium H flows inside was demonstrated, if the heat-transfer member 11 is a member which can transmit the heat from a heat source to a liquid, It does not have to be such a tube.

  In the above embodiment, the example in which the full liquid regenerator 1 including the heat transfer device 10 is used as a regenerator for an absorption chiller has been described. However, the heat transfer device 10 is different from the regenerator for an absorption chiller. You may utilize for the heat exchanger of the use of. Specifically, the heat transfer device 10 is disposed in a liquid stored in a container, and an evaporator of a type that evaporates the liquid by heat transmitted from the heat transfer surface 12 of the heat transfer device 10 ( It can be used for a full liquid evaporator.

  For example, the heat transfer device 10 can be used in the evaporator for the absorption chiller described above. In this case, the evaporator having the heat transfer device 10 functions as an evaporator of the condenser, the evaporator, the absorber, and the regenerator constituting the absorption refrigeration cycle, and evaporates the refrigerant liquid obtained by the condenser. And supply the vapor to the absorber.

  In addition, the heat transfer device 10 can be used in an evaporator for a vapor compression refrigeration cycle. In this case, the evaporator having the heat transfer device 10 functions as an evaporator out of the compressor, the condenser, the decompressor, and the evaporator constituting the vapor compression refrigeration cycle, and after evaporating the refrigerant, Supply. As the refrigerant circulating in the vapor compression refrigeration cycle, water, chlorofluorocarbon, hydrocarbon, ammonia, carbon dioxide, or a mixture of any two or more of these refrigerants can be used.

  In addition, the heat transfer device 10 can be used in an evaporator for Rankine cycle. In this case, the evaporator having the heat transfer device 10 has a condenser that condenses the working fluid (the “liquid” of the present invention), a pump that boosts the working fluid condensed by the condenser, and a pressure that is boosted by the pump. It functions as an evaporator which comprises a part of Rankine cycle provided with the evaporator which evaporates the working fluid and the expander which expands the working fluid evaporated with the evaporator. In addition, if this Rankine cycle is used for binary power generation in which power generation is performed using relatively low-temperature heat, the working fluid circulating in the Rankine cycle may be a relatively low boiling point fluorocarbon or the like, A mixture of working fluids similar to those described for the vapor compression refrigeration cycle (for example, a mixture of chlorofluorocarbons or a mixture of hydrocarbons) may be used. If this Rankine cycle is used for thermal power generation, etc. As the working fluid circulating in the Rankine cycle, water or the like is used.

  Although several examples of application of the evaporator having the heat transfer device have been illustrated, the evaporator can be used for a boiler that simply heats and evaporates a liquid such as water.

<2>
The configuration disclosed in the above embodiment (including another embodiment, the same applies hereinafter) can be applied in combination with the configuration disclosed in the other embodiment as long as no contradiction arises. The embodiment disclosed in the document is an exemplification, and the embodiment of the present invention is not limited to this, and can be appropriately modified without departing from the object of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for a heat transfer device, a full liquid regenerator and an evaporator that can easily cause liquid boiling.

DESCRIPTION OF SYMBOLS 1 Full liquid type regenerator 2 Container 10 Heat transfer apparatus 11 Heat transfer member 12 Heat transfer surface 13 Punching metal material 13a Through hole

Claims (7)

A heat transfer surface in contact with the liquid and transferring heat from the heat transfer surface to the liquid; and
A punching metal material having a plurality of through holes,
A heat transfer device in which the punching metal material is arranged to face the heat transfer surface at an interval. The heat transfer member is a heat transfer tube in which a heat medium flows,
The heat transfer device according to claim 1, wherein the heat transfer tube is a smooth tube, a low fin tube having a fin structure on the heat transfer surface, or a reentrant tube having a reentrant structure on the heat transfer surface.   The heat transfer device according to claim 1 or 2 is disposed in the liquid stored in the container and mixed with an absorbing liquid and a refrigerant liquid, and the refrigerant liquid is used as the heat transfer of the heat transfer device. A full liquid regenerator that evaporates by heat transferred from the surface.   The full liquid regenerator according to claim 3, wherein the refrigerant liquid is water and the absorbing liquid is an aqueous lithium bromide solution.   The full liquid regenerator according to claim 3, wherein the refrigerant liquid is ammonia and the absorbing liquid is water.   An evaporator in which the heat transfer device according to claim 1 or 2 is disposed in the liquid stored in a container and evaporates the liquid by heat transmitted from the heat transfer surface of the heat transfer device.   The evaporator according to claim 6, wherein the liquid is water, chlorofluorocarbon, hydrocarbon, ammonia, carbon dioxide, or a mixture of any two or more of these liquids.

Images