JP2000320927A - Refrigerant coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate a complete evaporation and a complete condensation of a refrigerant by constituting a refrigerant circuit to allow a gas-like refrigerant to flow in a heat transfer tube from windward when the air is heated and to allow a liquid-like refrigerant to flow in a heat transfer tube from leeward when the air is cooled and constituting the tube to be spirally formed. SOLUTION: The refrigerant coil is constituted to insert a straight portion of a heat transfer tube 2 to a fin group 1, which is constituted so that the many plate fins 4 are aligned in parallel at a predetermined pitch. A plurality of stags of the tubes 2 are provided so that the group 1 fall from a windward side to a leeward side toward a ventilating direction A while passing through its normal direction (a direction perpendicular to a plane of the fins 4), and a refrigerant circuit B is constituted so that a gas-like refrigerant flows in the tube 2 from the windward side when the air is heated and a liquid-like refrigerant flow in the tube 2 from the leeward side when the air is cooled. The tube 2 is partly or entirely spirally formed, and a straight portion of the tube 2 is formed in an elliptical tube so that its radial cut section becomes an elliptical shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant coil.

[0002]

2. Description of the Related Art As shown in FIG. 4, in a conventional refrigerant coil, a straight tube portion of a heat transfer tube inserted into a fin group is a circular tube.
A plurality of rows of heat transfer tubes were provided so as to have a cross flow in the ventilation direction.

[0003]

However, in the refrigerant coil having such a structure, there is a problem that heat transfer is poor and it is difficult to completely evaporate and condense the refrigerant, so that a load of a pump for sending the refrigerant increases. Then, this invention aims at providing the refrigerant coil which solves the said subject.

[0004]

In order to solve the above-mentioned problems, the present invention provides a plurality of heat transfer tubes inserted in a fin group so as to face in the ventilation direction and descend from the windward side to the leeward side, The refrigerant circuit is configured such that the gaseous refrigerant flows into the heat transfer tube from the windward side during air heating, and the liquid refrigerant flows into the heat transfer tube from the leeward side during air cooling. further,
The heat transfer tube is formed into an elliptical tube.

[0005]

1 and 2 illustrate a refrigerant coil according to the present invention. The refrigerant coil includes a fin group 1 and a heat transfer tube 2, and FIG.
The straight tube portions 3, 3,... Of the heat transfer tubes 2 are inserted and attached to the fin group 1. The fin group 1 includes a large number of plate fins 4, 4,.
Are arranged in parallel at a predetermined pitch. The arrow indicated by the symbol A indicates the direction of ventilation by a fan (not shown).

The heat transfer tubes 2 are provided in a plurality of stages so as to penetrate the fin group 1 in the normal direction thereof (the direction perpendicular to the plane of the plate fins 4) and to descend in the ventilation direction A from the windward side to the leeward side. The refrigerant circuit B is configured so that the gaseous refrigerant flows into the heat transfer tube 2 from the windward side during air heating, and the liquid refrigerant flows into the heat transfer tube 2 from the leeward side during air cooling.

The leeward ends (indicated by black circles in FIG. 1) of the plurality of stages of heat transfer tubes 2, 2,... Are connected to the header 5 and the leeward ends (indicated by white circles in FIG. Connect and connect. The refrigerant circuit B has a pipe 7 through which the refrigerant flows, a pump P through which the refrigerant in the pipe 7 can be freely circulated, and a heat exchange function such as a refrigerator.・ Heat exchange section C that can freely convert gaseous refrigerant to liquid refrigerant
And If the heat transfer tube 2 is formed so that a part or the whole draws a spiral as shown in the drawing, the effective length of the heat transfer tube can be increased, and the amount of heat exchanged with air can be increased with a small refrigerant flow rate, and the power of the pump P ( Load).

During the heating operation of the refrigerant coil (at the time of coil ventilation air heating), a high-temperature gaseous refrigerant flows from the header 5 into the heat transfer tubes 2, 2,. Through the fin group 1, the low-temperature coil ventilation air exchanges heat with the refrigerant, the air becomes warm air, and the gaseous refrigerant is condensed and liquefied and flows out of the flow divider 6. At this time, the refrigerant is liquefied while flowing from top to bottom, and the specific gravity is increased (heavy), so that the flow speed is increased, and the power (load) of the pump P for sending the refrigerant can be reduced.

During the cooling operation of the refrigerant coil (at the time of coil ventilation air cooling), a low-temperature liquid refrigerant flows from the flow divider 6 into the heat transfer tubes 2, 2,. Through the fin group 1, the high-temperature coil ventilation air exchanges heat with the refrigerant, the air becomes cold air, and the liquid refrigerant evaporates and vaporizes and flows out of the header 5. At this time, the refrigerant evaporates while flowing from bottom to top and the specific gravity becomes small (light), so that the ascending speed increases, and the power (load) of the pump P that sends the refrigerant
Need less. In addition, since the flow direction of the refrigerant and the flow direction of the refrigerant are counterflow (countercurrent), the most efficient heat exchange without waste can be performed, and the amount of heat transfer and exchange heat increases.
In order to effectively exert these effects, the heat transfer tubes 2 are preferably provided in three stages and three rows or more. However, the number of stages of the heat transfer tubes 2 may be increased or decreased according to the size of the refrigerant coil and the heat exchange capacity. It is.

As shown in FIG. 3, the straight tube portion 3 of the heat transfer tube 2
Is formed into an elliptical tube having a radially cut surface having an elliptical shape,
When viewed from the central axis direction (longitudinal direction of the straight pipe portion 3), the elliptical long axis of the straight pipe portion 3 is made substantially parallel to the ventilation direction A. In the present invention, the major axis of the ellipse is the both ends (vertex) of the major axis of the ellipse.
Means a straight line passing through. As described above, since the cross section of the straight pipe portion 3 is an elliptical shape having a small shape drag, the ventilation resistance is smaller and the pressure loss is reduced, and the dead water area becomes narrower than in the case of a circular heat transfer tube. The contact area (heat transfer area) with the air flow in the part 3 is increased, and the heat exchange efficiency is further improved, which is optimal for a low flow rate refrigerant coil.

Note that the heat transfer tube 2 may be a circular tube or any shape. In the refrigerant circuit B, the pump P is omitted,
The refrigerant may be naturally circulated by freely changing the circulation direction.

[0012]

According to the first aspect of the present invention, the heat transfer is good, the refrigerant can be completely evaporated and completely condensed, the flow rate of the refrigerant is small, the amount of heat transfer and exchange heat is large, and the heat exchange efficiency in cooling is particularly high. The size of the pump for sending the refrigerant coil and the refrigerant can be reduced. According to the second aspect, the heat exchange efficiency is further improved.

[Brief description of the drawings]

FIG. 1 is a simplified side view showing one embodiment of a refrigerant coil of the present invention.

FIG. 2 is a simplified perspective view.

FIG. 3 is a side sectional view of a main part.

FIG. 4 is a perspective view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fin group 2 Heat transfer tube A Ventilation direction B Refrigerant circuit

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[Procedure amendment]

[Submission Date] January 26, 2000 (2000.1.2
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

[0012]

According to the first aspect of the present invention, the heat transfer is good, the refrigerant can be completely evaporated and completely condensed, the flow rate of the refrigerant is small, the amount of heat transfer and exchange heat is large, and the heat exchange efficiency in cooling is particularly high. The size of the pump for sending the refrigerant coil and the refrigerant can be reduced. Moreover, the effective length of the heat transfer tube can be increased,
Pump that can exchange a large amount of heat with air with a small refrigerant flow rate
Power (load) is small. According to the second aspect, the heat exchange efficiency is further improved.

Claims (2)

[Claims] A plurality of heat transfer tubes inserted into a fin group are provided so as to face a ventilation direction and descend from a windward side to a leeward side. A refrigerant coil having a refrigerant circuit B configured to flow into the heat pipe 2 and to flow the liquid refrigerant from the leeward side into the heat transfer pipe 2 during air cooling. 2. The refrigerant coil according to claim 1, wherein the heat transfer tube 2 is formed as an elliptic tube.