JPS60202283A - Evaporator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an evaporator for a heat pump air conditioner or refrigerator.

Conventional Structure and Problems It is known that a fluidized bed heat exchanger in which solid particles are suspended and fluidized in an air stream can achieve a high heat transfer coefficient. In such a fluidized bed heat exchanger, in order to continuously float and flow solid fluids without using special means, the airflow direction must necessarily be vertically upward. In addition, in heat exchangers that absorb heat from the air by flowing low-temperature fluid through the tubes, such as evaporators in heat pump air conditioners, if the surface temperature of the heat transfer surface becomes lower than the dew point temperature of the air, moisture in the air will be removed. Condensation occurs on the surface of the heat transfer surface, a so-called condensation phenomenon.

In this way, the condensed water created becomes air resistance, so
It is necessary to eliminate it immediately. However, in a fluidized bed heat exchanger that allows solid fluid to float and flow, a solid particle fall prevention member made of a perforated body such as a metal mesh is installed below the heat exchanger to prevent the solid fluid from falling. The condensed water that falls from the heat transfer surface falls onto the solid particle fall prevention member and becomes droplets due to its surface tension, and is pushed up by the vertical upward airflow, causing minute openings such as meshes. When solid particles pass through the holes, they accumulate on or block the fall prevention member, causing a significant increase in air resistance, as well as worsening the airflow distribution and reducing the fluidity of solid particles. It has been considered difficult to apply a fluidized bed heat exchanger to an evaporator due to disadvantages such as deterioration of the heat exchanger.

OBJECTS OF THE INVENTION It is an object of the present invention to apply a fluidized bed heat exchanger to an evaporator, which has been considered difficult in the past, and to make the evaporator more compact and high-performance.

Structure of the Invention In order to achieve the above object, the present invention provides a group of heat transfer tubes through which a low-temperature fluid flows, solid particles suspended and fluidized by air passing around the group of heat transfer tubes, and a drop of the solid particles. The evaporator is constructed of a solid particle fall prevention member made of a hydrophilically treated open pore body that prevents the solid particles from falling.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows an embodiment of the evaporator of the present invention. Inside the casing 2, where air flows in the direction of arrow 1, low temperature fluid flows in the direction of arrow 3.
A group of heat transfer tubes 4 is disposed below the group of heat transfer tubes 4, that is, on the air inlet side, to prevent solid particles 5 floating and flowing by the air passing around the group of heat transfer tubes 4 from falling. A solid particle fall prevention member 6 is provided, and further,
A solid particle scattering prevention member 7 for preventing the solid particles from scattering is disposed above the heat transfer tube group 4, that is, on the air outlet side, thereby forming an evaporator.

FIG. 2 is a detailed view of the solid particle fall prevention member 6,
The upper member 6 of the solid particle falling part has a perforated body 8 made of metal.
Hydrophilic treatment is performed by coating with a hydrophilic material 9 such as a resin containing an inorganic silicon compound or the like. Note that a metal mesh may be used as the open hole body.

In the above configuration, the low temperature fluid flowing within the heat exchanger tube group 4;
The air flowing vertically upward within the casing 2 and the solid particles 6 suspended and fluidized by this air flow exchange heat through the partition walls of the heat transfer tube group 4. At this time, when the surface temperature of the heat transfer surface of the heat transfer tube group 4 becomes lower than the dew point temperature of the air, moisture in the air condenses on the surface of the heat transfer surface, causing a dew condensation phenomenon. When the water droplets 10 condensed like kernels coalesce and become larger, they fall downward due to the action of gravity. The falling water droplets first collide with the solid particle fall prevention member 6, but since the surface of the solid particle fall prevention member 60 has been treated to be hydrophilic as described above, they do not form into droplets but form a thin water film. , the solid particles quickly pass through the solid particle fall prevention member 6, fall downward, and are removed.

Therefore, water droplets do not accumulate on the second part of the solid particle fall prevention member 6 or block the openings to increase air resistance, and a good airflow distribution can be maintained.
Because it floats and flows well, a high heat transfer coefficient can be obtained.

Effects of the Invention As is clear from the above description, the evaporator of the present invention includes a group of heat transfer tubes through which a low-temperature fluid flows, solid particles suspended and fluidized by air passing around the group of heat transfer tubes, and Since it is composed of a solid particle fall prevention member made of a hydrophilic-treated open pore body that prevents solid particles from falling, water droplets that have fallen onto the solid particle fall prevention member are
It can be processed quickly, prevents increase in air resistance, keeps solid particles in a good floating and fluid state, makes effective use of the high heat transfer properties of fluidized bed heat exchangers, and has a small evaporator. High performance can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an evaporator according to an embodiment of the present invention, and FIG. 2 is a partially sectional perspective view of a solid particle fall prevention member. 4... Heat exchanger tube group, 5... Solid particles, 6...
...Solid particle fall prevention member, 8...Open-pore body, 9...Hydrophilic material. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure 2

Claims (1)

[Claims] Solid particles consisting of a group of heat transfer tubes through which a low-temperature fluid flows, solid particles suspended and fluidized by air passing around the group of heat transfer tubes, and a hydrophilically treated open-pore body that prevents the solid particles from falling. An evaporator constructed from fall prevention members.