JPH0961015A - Evaporation coil of absorption refrigeration system - Google Patents

Abstract

(57) [PROBLEMS] To provide an evaporation coil of an absorption type refrigeration system which can prevent deterioration of mechanical strength, is easy to process, and hardly causes increase in cost. SOLUTION: An absorption type in which a copper pipe 10 is wound in a cylindrical surface shape, both ends 11, 12 are bent outward, cooling water is flown inside, and a refrigerant is dropped from above to perform heat exchange. In the evaporation coil 1 of the refrigeration system, the copper pipe 10
The multi-angled slant grooves 13 and 14 inclined at the same angle are provided by cold forging in both directions on all outer peripheral surfaces except both end portions 11 and 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporator of an absorption refrigeration system using an aqueous solution of lithium bromide as an absorption liquid.

[0002]

2. Description of the Related Art In an absorption refrigeration system, a low-concentration aqueous solution (absorption liquid) of lithium bromide or the like is heated and boiled in a regenerator to produce a solution (refrigerant) such as water and a high-concentration absorption liquid (high-concentration liquid). Lithium bromide solution of concentration). The refrigerant is liquefied by a condenser provided with a cooling coil, supplied to the evaporator, and removes heat of evaporation from the evaporation coil arranged in the evaporator.

The evaporation coil of this absorption refrigerating apparatus uses a copper pipe having excellent heat conductivity and workability, and has a structure in which it is wound in a cylindrical surface in accordance with a container of a vertical cylindrical evaporator. . In addition, as a heat transfer tube for an absorption refrigerating apparatus, Japanese Utility Model Publication No. 5-8424 proposes an oblique groove that intersects the surface of a cooling coil of an absorber.

[0004]

The heat transfer tube of the conventional absorption type refrigerating apparatus is subjected to oblique groove processing by cutting or the like, which requires time and labor for manufacturing, resulting in high cost and low strength of the entire tube. Therefore, there is a problem that it is necessary to increase the wall thickness. An object of the present invention is to provide an evaporation coil for an absorption refrigerating apparatus which can prevent deterioration of mechanical strength, is easy to process, and causes little increase in cost.

[0005]

According to the present invention, a copper pipe is wound in a vertical cylindrical shape, a heat transfer fluid is flown inside, and a refrigerant is dropped from above onto the outer peripheral surface of the copper pipe to exchange heat. In the evaporation coil of the absorption refrigeration apparatus for performing the above, the multi-periphery slant groove inclined at the same angle is provided on the entire outer peripheral surface of the copper pipe by cold forging so that the inclined grooves intersect each other. Is characterized by.

According to a second aspect of the present invention, the oblique groove is formed by rolling the oblique groove in one direction and then rolling the oblique groove in the other direction.

[0007]

In the evaporation coil of this absorption refrigeration system, the oblique grooves in the two intersecting directions are formed by cold forging, so the oblique groove parts are work hardened and the parts other than the oblique grooves are raised. The wall thickness increases. Therefore, it is possible to prevent the strength from decreasing. Further, since the inclined groove is provided on the entire cylindrical surface, it is possible to secure the expansion of the refrigerant that is partially dropped from the upper side in the cylindrical surface direction. Further, since the unevenness increases the surface area, the heat exchange efficiency is improved.

According to the second aspect of the present invention, the copper pipe is passed through the oblique groove rolling device twice in the reverse direction, so that the oblique groove in the reverse direction which intersects easily can be cold forged, and the increase in cost is small. .

[0009]

1 shows an evaporation coil 1 of an absorption refrigerating apparatus according to the present invention, which is formed by winding a copper pipe 10 in a vertical cylindrical shape. The copper pipe 10 has a plurality of oblique grooves 13 and 14 inclined at the same angle on the entire outer peripheral surface except both ends 11 and 12 which are extended outward in the radial direction.
Are provided in opposite directions so as to intersect with each other. In the copper pipe 10, the slant groove forming portions except for the both end portions 11 and 12 are wound in a cylindrical surface shape according to the shape of the evaporation container, and the both end portions 11 and 12 in which the slant groove is not formed on the outer peripheral surface are The connection part is bent outward in the radial direction.

The oblique grooves 13 and 14 are formed by cold forging by passing the copper pipe 10 which is a straight pipe between the rollers having rolling teeth. In order to form the oblique grooves 13 and 14 in the opposite direction, the copper pipe 10 is first passed between the rollers to provide one oblique groove 13, and then is passed in the opposite direction to form the oblique groove 14. In addition, the slanted groove 1 is entirely formed including both end portions 11 and 12.
3, 14 may be formed.

The slanted grooves 13 and 14 have an inclination angle of 15 to 60 degrees, a depth of 0.1 to 0.5, and a width of 0.5 to 2, and have an arc or U-shaped cross section. It has, and is provided at intervals of 0.5 to 2. As a result, the refrigerant dripped onto the upper end of the wound evaporation coil 1 from the funnel-shaped refrigerant dropping port 46 of the refrigerant liquid spraying tool 41 installed above the evaporation coil 1 shown in FIG. 14 spreads smoothly,
Evaporation is done efficiently. In addition, the rolling groove 1
The areas other than 3 and 14 rise up to increase the surface area of the evaporation coil 1 due to the unevenness, so that the evaporation is more efficiently performed and the heat exchange efficiency is improved.

FIG. 3 shows an absorption type refrigerating apparatus 100, which has a cooling tower (cooling tower) 15 and an indoor unit 200 attached thereto to form a cooling / heating apparatus. The absorption refrigeration system 100 includes a regenerator 2 including a high temperature regenerator 21 and a low temperature regenerator 22. A gas burner B as a heating source is arranged below the high temperature regenerator 21.

An absorber 3 is provided on the outer periphery of the low temperature regenerator 22, an evaporator 4 is provided on the outer periphery of the absorber 3, and a condenser 5 is mounted above the evaporator 4. High temperature regenerator 2
1, the low temperature regenerator 22, the absorber 3, the evaporator 4 and the condenser 5 are concentrically arranged and welded together to form the refrigerator main body 300.

The absorber 3 has a cooling coil 31 wound in a vertical cylindrical shape inside an inner portion of an annular airtight container 30 provided on the outer periphery of the low temperature regenerator 22, and above the cooling coil 31. A high-concentration absorbent sprayer 32 for spraying the high-concentration absorbent is mounted on 31. The bottom part of the absorber 3 and the bottom part of the high temperature regenerator 21 are connected by an absorption liquid supply passage in which a heat exchanger H and an absorption liquid pump P1 are interposed.

The evaporator 4 comprises the evaporation coil 1 arranged outside the cooling coil 31 in the airtight container 30 and the refrigerant liquid sprinkler 41 mounted above the evaporation coil 1. Both ends 1 of the evaporation coil 1
The rubber hoses 43 and 44 are connected to the indoor unit 200, and pumps P2 circulate cold / hot water as a heat medium fluid in the indoor unit 200 to form a cold heat source cycle for air conditioning.

The refrigerant liquid sprinkler 41 is provided with a liquid receiving trough 45 in the form of an annular dish, and a funnel-shaped refrigerant dropping port 46 which is provided at the outer edge of the liquid receiving trough 45 at regular intervals. Drop it on top. As shown in FIG. 2, the dripped refrigerant wets the surface of the copper pipe 10 by surface tension to form a film and drops downward due to the action of gravity, while the evaporation coil 1 in the airtight container 30 is at a low pressure. The heat of vaporization is taken from and evaporated to cool the hot and cold water flowing in the evaporation coil 1.

From the viewpoint of heat exchange efficiency, it is desirable that the refrigerant film formed on the surface of the evaporation coil 1 be distributed as uniformly as possible over the entire surface. The oblique grooves 13 and 14 have a function of laterally diffusing the refrigerant dropped on the evaporation coil 1 from the dropping point, and improve the heat exchange efficiency.

The condenser 5 is an annular airtight container 50 provided on the outer periphery of the low temperature regenerator 22 and above the airtight container 30.
The cooling coil 51 is arranged inside the. Above the low temperature regenerator 2, there is a gas-liquid separating section 23, which communicates with the upper portion of the condenser 5 via a gap 5A.

The lower part of the condenser 5 and the evaporation coil 1 of the evaporator 4
The refrigerant spraying tool 41 installed above is communicated with a refrigerant liquid supply path in which an electromagnetic valve V3 with an orifice is provided. The high-concentration absorbent receiving part 24 of the low-temperature regenerator 22 is connected to the high-concentration absorbent spreading device 32 in the absorber 3 by the high-concentration absorbent supply path via the heat exchanger H, and , Is dropped onto the cooling coil 31 from the high-concentration absorbent sprayer 32.

Absorption heat is generated when the vaporized refrigerant generated in the evaporation coil 1 of the evaporator 4 is absorbed by the high-concentration absorption liquid.
The cooling coil 31 is connected to the cooling coil 51, and is further connected to the cooling tower 15 through the circulation path L, and the absorbed heat is the cooling tower 15.
Is exhausted to the atmosphere. Cooling water is supplied from the cooling water pump P3 to the cooling tower 15 → cooling coil 31 → evaporation coil 51 →
It circulates in the order of the cooling tower 15. The absorption liquid is the high temperature regenerator 21 → the low temperature regenerator 22 → the absorber 3 → the absorption liquid pump P1 →
It circulates in the order of the high temperature regenerator 21.

[Brief description of drawings]

FIG. 1 is a perspective view of an evaporation coil of an absorption refrigeration system.

FIG. 2 is an enlarged front view of a main part of FIG.

FIG. 3 is a conceptual diagram of an air conditioner using an absorption refrigeration system.

[Explanation of symbols]

 1 Evaporation Coil 10 Copper Pipes 11, 12 Both Ends 13, 14 Oblique Groove 2 Regenerator 3 Absorber 4 Evaporator 41 Refrigerant / Liquid Disperser 5 Condenser 100 Absorption Refrigeration System 200 Indoor Unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuto Ikeda 2-26 Fukuzumicho, Nakagawa-ku, Nagoya City Rinnai Corporation

Claims (2)

[Claims] 1. An evaporation of an absorption refrigeration system in which a copper pipe is wound in a vertical cylindrical shape, a heat transfer fluid is flown inside, and a refrigerant is dropped from above onto the outer peripheral surface of the copper pipe for heat exchange. In the coil, an absorption refrigerating device, characterized in that, on the entire outer peripheral surface of the copper pipe, a plurality of oblique grooves inclined at the same angle are provided by cold forging in both directions so that the inclined grooves intersect. Evaporation coil. 2. The absorption refrigerating apparatus according to claim 1, wherein the oblique groove is formed by rolling an oblique groove in one direction and then rolling an oblique groove in the other direction. Evaporation coil.