JPH07190561A - Evaporator for absorption type refrigerator - Google Patents

Abstract

PURPOSE:To provide an evaporator in which the surface of an evaporating coil has excellent dispersibility and adherability of refrigerant liquid and which has easy manufacture and a low manufacturing cost. CONSTITUTION:An evaporator for an absorption type refrigerator comprises an evaporating coil 7 in which a copper tube 71 for circulating chilled water therein is wound in a longitudinally cylindrical state, and a refrigerant scattering unit 8 for dropping refrigerant liquid to the coil 7, wherein the surface of the coil 7 is covered with a fibrous layer (nonwoven fabric layer) 72.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant evaporator for an absorption refrigeration system.

[0002]

2. Description of the Related Art In an absorption refrigeration system, a low-concentration absorbing solution such as an aqueous lithium bromide solution is heated and boiled in a regenerator to form a solution (refrigerant) and a highly-concentrating absorbing solution (high-concentration aqueous lithium bromide solution) Separated. The refrigerant is liquefied by the condenser and supplied to the evaporator, and takes heat of evaporation from the evaporation coil. The high-concentration absorption liquid is supplied to the absorption coil arranged in the same closed space and absorbs the evaporated refrigerant to become a low-concentration absorption liquid.
The evaporator includes an evaporation coil in which water as a heat-carrying fluid circulates, and a refrigerant liquid spraying device for dropping the refrigerant liquid to the evaporation coil.

[0003]

In this evaporator, it is desirable that the refrigerant liquid, the supply amount of which varies depending on the operating conditions, be attached to the entire surface of the evaporation coil as uniformly as possible. An object of the present invention is to provide an evaporator in which the surface of the evaporation coil is excellent in the dispersion / adhesion of the refrigerant liquid, and the manufacturing is easy and the manufacturing cost can be reduced.

[0004]

The present invention is directed to an evaporation coil formed by vertically winding a metal pipe in which a heat carrier liquid circulates, and an evaporation coil installed above the evaporation coil. In a vaporizer of an absorption type refrigerating apparatus, which comprises a refrigerant liquid sprinkler for dripping a liquid, a fibrous layer is attached to the surface of the vaporizing coil.

[0005]

According to the present invention, since the surface of the evaporation coil is a fibrous layer, the refrigerant liquid permeates and moves quickly and can be smoothly distributed on the entire surface of the evaporation coil.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an absorption refrigeration system. This absorption refrigerating apparatus includes a gas-liquid separation section 2 having a medium-concentration absorbent partition 22 with an airtight spherical shell ceiling 2A above an absorbent boiling section 1 for heating and boiling a low-concentration absorbent with a gas burner B. It has a high temperature regenerator 100 arranged. A vertical cylindrical low-temperature regenerator 3 having a ceiling 3B having a gap 3A is provided on the outer periphery of the gas-liquid separator 2. An absorber 4 is installed on the outer periphery of the low temperature regenerator 3, and an evaporator 5 is installed on the outer periphery of the absorber 4.

The absorption liquid boiling section 1 has an absorption liquid heating tank 11 heated by the gas burner B.
A pumping pipe 12 is vertically projected from the top of 1. An upper pumping pipe 13 projecting into the gas-liquid separating section 2 is continuously provided at the upper end of the pumping pipe 12, and the upper end of the upper pumping pipe 13 prevents the sudden boiling up of the boiling absorption liquid and also separates the gas-liquid. A baffle 14 is attached to accelerate the movement.

The gas-liquid separating section 2 is a medium-concentration absorption liquid having a refrigerant partition cylinder 21 arranged on the outer periphery of the upper pumping pipe 13 and an airtight spherical shell ceiling 2A arranged on the outer periphery of the refrigerant partition cylinder 21. It is composed of a partition tube 22. The low temperature regenerator 3 is arranged on the outer periphery of the medium concentration absorbent partition 22.

The upper part of the absorbing liquid boiling section 1 communicates with the inside of the gas-liquid separating section 2 through an ascending flow path L1 for the boiling absorbing solution (the pumping pipe 12 and the upper pumping pipe 13). The upper part of the low temperature regenerator 3 is a gas-liquid separation section 31, and the gas-liquid separation section 31 is in communication with the condenser 6 via the gaps 3A and 3C. The lower part of the condenser 6 and the refrigerant liquid sprinkler 8 installed above the evaporation coil 7 of the evaporator 5 are connected by a refrigerant liquid supply path L6 in which a proportional control valve V3 is interposed.

In the absorber 4, a cooling coil 41 wound in a vertical cylindrical shape is arranged inside an inner portion of an annular airtight container 40 provided on the outer periphery of the low temperature regenerator 3, and the cooling coil 41 is provided above the cooling coil 41. The coil 41 is equipped with an absorbent sprayer 42 for spraying a high-concentration absorbent. Bottom part of absorber 4 and absorption liquid boiling part 1
Is connected by an absorbing liquid supply path L4 with a liquid pump P interposed. A condenser 6 is installed above the absorber 4. The condenser 6 is connected to the low temperature regenerator 3 via the gap 3C.
A cooling coil 61 is provided inside an annular airtight container 60 which communicates with the top of the.

The bottom of the refrigerant partition cylinder 21 communicates with the top of the low temperature regenerator 3 through the medium-concentration absorbent supply path L2. A high temperature heat exchanger H2 and a solenoid valve V1 with an orifice are attached to the medium-concentration absorbent supply path L2. Refrigerant divider 21
A refrigerant liquid receiving portion 26 is provided between the medium-concentration absorbent liquid partition tube 22 and the medium-concentration absorbent liquid partition tube 22, and communicates with the condenser 6 through a refrigerant flow path L5.

The inner periphery of the annular bottom plate 30 of the low temperature regenerator 3 is welded to the outer peripheral wall of the lower portion of the medium concentration absorbent partition 22. The lower part of the low temperature regenerator 3 has a high-concentration absorbent supply path L3.
Is connected to the absorbent dispersion device 42. The cooling coil 41 in the absorber 4 is connected to the cooling coil 61 in the condenser 6, and is further connected to the cooling tower 43 by the circulation path L7.
The absorbing liquid circulates in the order of absorbing liquid boiling section 1-gas-liquid separating section 2 -low temperature regenerator 3 -absorber 4 -liquid pump P -absorbing liquid boiling section 1.

In the evaporator 5, an evaporation coil 7 wound in a vertical cylindrical shape is arranged outside a cooling coil 41 in an annular airtight container 40, and a refrigerant liquid is placed in the evaporation coil 7 above the evaporation coil 7. A coolant / liquid sprayer 8 for spraying is attached. The evaporation coil 7 is, for example, a copper pipe 71 as shown in FIGS.
(Stainless steel pipe or iron pipe may be wound) in a vertical cylindrical shape, and fibers are sprayed on the surface together with an adhesive to form a non-woven fabric layer (fibrous layer) 72. The fibers may be sprayed after the adhesive is applied to the surface of the copper tube. Further, the non-woven fabric layer 72 can also be formed by so-called dipping, in which the evaporation coil 7 is dipped in the liquid in which the fibers are dispersed and then pulled up to attach the fibrous layer to the surface of the evaporation coil 7.

As the fibers, natural fibers, glass fibers, and fine metal wires can be used in addition to synthetic fibers having excellent corrosion resistance. A filament with a diameter of 0.05 mm to 0.2 mm is desirable, a twisted yarn can also be used, and a length is 0.5 cm to 2.0 c.
Those of m are preferred. As described above, since the non-woven fabric layer 72 can be formed by spraying the surface of the evaporation coil 7 or the like, the fibrous layer can be easily provided and the manufacturing cost can be reduced.

The refrigerant liquid sprinkler 8 comprises an annular receiving pan 81 having a diameter similar to that of the evaporating coil 7, and a siphon pipe 83 arranged in a row on, for example, an outer peripheral wall 82 of the peripheral wall of the receiving pan 81. The siphon pipe 83 is formed by bending a metal plate having a groove in the center and attaching it to the outer peripheral wall 82 so as to form a flow path 84 along the inner surface and the outer surface beyond the upper edge of the outer peripheral wall 82. The flow path 84 is set so that the lower end 85 on the outer surface side is lower than the pan 81, and the refrigerant liquid in the pan 81 is sucked up by the capillary phenomenon and drops from the lower end 85 on the outer surface. The dropped refrigerant liquid is dropped onto the evaporation coil 7, adheres to and is absorbed by the upper end of the nonwoven fabric layer 72, and quickly permeates the entire surface of the nonwoven fabric layer 72 by the action of capillarity and gravity. At the same time, the refrigerant is evaporated from the surface of the non-woven fabric layer 72 using the low pressure in the airtight container 40 to cool the cold water in the evaporation coil 7. Further, the evaporation coil 7 is wound in close contact in the vertical (up and down) direction. However, even if the contact is insufficient due to processing variations and a gap is created, the non-woven fabric layer 72 can fill the gap and evaporate. The refrigerant liquid can be uniformly attached to the entire surface of the coil 7.

Next, the operation of this absorption refrigeration system will be described. The low-concentration absorption liquid (lithium bromide aqueous solution) containing a large amount of the refrigerant (water) is heated in the absorption liquid boiling section 1 so that the refrigerant contained in the absorption liquid boils and enters the gas-liquid separation section 2. Here, the refrigerant is partly separated and the absorption liquid having a medium concentration is transferred to the ascending flow path L.
The gas-liquid separation section 2 is provided by the baffle 14 provided at the outlet of 1.
Collected in the medium-concentration absorbent receiving part 20. The refrigerant is condensed in the medium-concentration absorbent partition 22 and flows downward.

Since the inside of the gas-liquid separation unit 2 is at about atmospheric pressure and the inside of the low temperature regenerator 3 is maintained at a low pressure of 70 mmHg, the medium concentration of the absorbing liquid is a solenoid valve with an orifice through the supply line L2. It is supplied to the top of the low temperature regenerator 3 via V1. At this time, the medium-concentration absorption liquid is the high temperature heat exchanger H2.
The liquid-liquid heat exchange is performed by the low-temperature low-concentration absorption liquid, and the liquid is cooled. The medium-concentration absorption liquid may be supplied into the low temperature regenerator 3 from the bottom of the low temperature regenerator 3. The medium-concentration absorbent partition 22 that separates the gas-liquid separator 2 and the low-temperature regenerator 3 is a heat transfer wall for heating the absorbent in the low-temperature regenerator 3 with the refrigerant vapor in the gas-liquid separator 2. The refrigerant liquid generated by the condensation on the inner surface of the medium-concentration absorbent partition 22 is made to flow down to the refrigerant liquid receiving portion 26 between the refrigerant partition 21 and the medium-concentration absorbent partition 22.

The medium-concentration absorption liquid in the low-temperature regenerator 3 is reheated by the heat of the gas-liquid separation unit 2 through the medium-concentration absorption liquid partition tube 22, and the gas-liquid separation unit 31 above the low-temperature regenerator 3 is heated. The vaporized refrigerant is completely separated and flows down into the high-concentration absorbent receiving section 36 between the medium-concentration absorbent partition 22 and the outer wall 35. As a result, the high-concentration absorption liquid is supplied to the absorption liquid spraying tool 42 above the absorber 4 via the supply path L3. At this time, the high-concentration absorbent is supplied to the low-temperature heat exchanger H provided in the supply path L3.
While being cooled in 1, the low-concentration absorption liquid in the supply path L4 is heated. Further, the refrigerant vapor separated by the gas-liquid separating section 31 enters the condenser 6 through the gaps 3A, 3C, is cooled by the cooling coil 61 and is liquefied.

The liquefied refrigerant in the condenser 6 is supplied to the evaporator 5 via the supply path L6 while the flow rate is controlled by the proportional control valve V3 in accordance with the required refrigerating capacity. The inside of the airtight container 40 is in a substantially vacuum state of about 5 mmHg, and the refrigerant sprayed from the refrigerant liquid spraying tool 8 to the evaporation coil 7 is evaporated and the evaporation heat is taken from the evaporation coil 7. Thereby, the water in the evaporation coil 7 is cooled and supplied to the indoor unit 52 of the air conditioner for cooling. The evaporated refrigerant is absorbed by the high-concentration absorbent dropped from the absorbent sprayer 42 in the absorber 4, so that the inside of the airtight container 40 is maintained at a low pressure.

Since absorption heat is generated at the time of absorption, a cooling coil 41 is arranged in the absorber 4, the absorption heat is absorbed by the cooling water in the cooling coil 41, and then the cooling heat is discarded outside by the cooling tower 43. The absorption capacity is maintained. As a result, the heat input from the air conditioner indoor unit (object to be cooled) 52 is sent from the evaporator 5 to the absorber 4, and then applied to the cooling water by the action of the cooling coil 41 and discharged from the cooling tower 43 to the outside. . Note that the dropping of the refrigerant liquid from the receiving tray 81 of the refrigerant liquid spraying device 8 may be performed by a siphon method other than the above, and in a pipe such as a spring pin penetrating the bottom wall of the receiving tray 81 and planted substantially vertically. May be done through. Furthermore, although the non-woven fabric layer is used as the fibrous layer in the above-described embodiments, a woven fabric such as metal fiber, synthetic fiber or natural fiber may be attached to form the fibrous layer.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an absorption refrigeration system of the present invention.

FIG. 2 is a perspective view of an evaporation coil and a refrigerant liquid spraying device.

FIG. 3 is a cross-sectional view of essential parts of an evaporation coil and a refrigerant liquid spraying device.

[Explanation of symbols]

 1 Absorbing Liquid Boiling Part 2 Gas-Liquid Separating Part 3 Low Temperature Regenerator 4 Absorber 5 Evaporator 6 Condenser 7 Evaporating Coil 8 Refrigerant Liquid Disperser 71 Copper Tube (Metal Tube) 72 Nonwoven Layer 100 High Temperature Regenerator

Front Page Continuation (72) Inventor Kazumi Yamamoto 4-1-2 Hiranocho Chuo-ku, Osaka City Osaka Gas Co., Ltd.

Claims (1)

[Claims] 1. An evaporation coil, which is formed by winding a metal tube in which a heat-transporting liquid is circulated inside in a vertical tube shape, and a refrigerant liquid spraying device which is installed above the evaporation coil and drops the refrigerant liquid on the evaporation coil. An evaporator for an absorption refrigeration apparatus, comprising a fibrous layer deposited on the surface of the evaporation coil.