JPH1137687A - Heat transfer tubes for heat exchangers for air conditioning - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise both of evaporation performance and condensation performance by making them cope with the flow in reverse directions different in flow velocity by varying the tilt angles of the rising faces on both sides of many spiral ribs having angles in reverse directions to the axis of a pipe. SOLUTION: Many spiral ribs 2 which have angles reverse to each other to the axis of a pipe are made at a band-shaped copper plate or the like, in the shape of dividing its circumference, and the ribs 2 cross each other at the first crossing 5 and the second crossing 6, and the tilt angle of an upstream rising face 3 at the time of the flow direction of a refrigerant when functioning as an eaporator being a is made gentler than the tilt angle of the downstream rising face 4. Then, a heat conductive pipe 1 is manufactured by welding the edges liquidtightly by electric welding after formation of the ribs 2, thereby molding itself in tubular form. Hereby, when the direction of the flow of the refrigerant is reversed and the function is switched into an evaporator or vice versa into a condenser, this pipe can raise both the evaporation performance and condensation performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat transfer tube of an air conditioner heat exchanger.

[0002]

2. Description of the Related Art A conventional heat transfer tube of an air conditioner heat exchanger is shown in FIG.
As shown in FIG. 5 and FIG. 5, a number of spiral projections having trapezoidal cross sections having angles opposite to each other with respect to the tube axis are formed on the inner surface of the heat transfer tube 1 by dividing the circumference of the tube into four. By forming the ridge 2, the liquid refrigerant moves along the ridge 2, the liquid film thickness of the liquid refrigerant is leveled, and the performance as a heat exchanger is improved. Although the heat transfer coefficient is improved by the ridges 2, the pressure loss in the pipe is also increased. Therefore, it is necessary to determine the dimensions of the ridges 2 so as to appropriately balance the heat transfer rate and the pressure loss in the pipe.

[0003]

However, in the above configuration, in the heat pump in which the refrigerant circuit is reversed by the four-way valve, when the flow direction of the refrigerant is reversed and the functions of the evaporator and the condenser are switched, the flow velocity of the refrigerant in the pipe is reduced. In addition, the ratio between the gas refrigerant and the liquid refrigerant, the distribution state in the pipe, and the like change greatly, so that the appropriate shape of the ridge changes, and there is a problem that it is not possible to appropriately cope with both the evaporator and the condenser. In the present invention, in view of the above problems, in a heat exchanger in which the flow of the refrigerant is reversed and the function is switched between an evaporator and a condenser, the heat for air conditioning that can improve both the evaporation performance and the condensation performance is provided. It is an object to provide a heat exchanger tube of an exchanger.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a multi-piece having an inner surface formed by dividing the circumference of a pipe by an even number of four or more and having angles opposite to each other with respect to the pipe axis. In the heat transfer tube of the air conditioner heat exchanger formed with the helical ridges, the rising surfaces on both sides of the ridges have different inclination angles to cope with flows in different directions at different flow velocities. It has a configuration.

[0005] Further, among the intersections where the ridges having opposite angles intersect, the second height of the ridges at the second intersection where the surface having the steep inclination angle is on the inside is adjacent. It is configured such that the surface where the inclination angle is steep is lower than the first height of the ridge at the first intersection where the surface is outside, and gradually increases from the second height to the first height. .

[0006] Furthermore, the second height of the second intersection is reduced to the pipe reference inner surface.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS With the above configuration, in a heat exchanger in which the flow direction of the refrigerant is reversed and the function is switched between an evaporator and a condenser, both the evaporation performance and the condensation performance can be improved. It becomes the heat transfer tube of the heat exchanger for air conditioning.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention shown in FIGS. 1 to 3 will be described. The heat transfer tube 1 of the heat exchanger in which the direction of flow of the refrigerant of the heat pump, which reverses the refrigerant circuit by the four-way valve, switches between the evaporator and the condenser by reversing the flow direction, is, as shown in a developed view of FIG. In the form of dividing the circumference into four parts, a number of spiral ridges 2 having angles opposite to each other with respect to the tube axis are formed. The ridge 2 intersects at the first intersection 5 and the second intersection 6, and the inclination angle of the upstream rising surface 3 in the flow direction a is larger than the inclination angle of the downstream rising surface 4, It is gentle. After forming the ridge 2,
The heat transfer tube 1 is formed by forming into a tubular shape and joining in a liquid-tight manner by electric welding. The first intersection 5 is a portion that intersects such that the steeply inclined surface is on the outside, and the second intersection 6 is a portion that intersects such that the steeply inclined surface is on the inside, The second height of the ridge at the second intersection 6 is reduced to the pipe reference inner surface 7 so as to gradually increase to the first height h of the ridge 2 at the adjacent first intersection 5. As a result, as shown in FIG. 3, in the circumferential direction, the second intersection 6 having no protrusion of the ridge 2 and the ridge 2
And the first intersecting portions 5 having the highest are alternately arranged. The above configuration operates as follows. The flow direction a is the direction of the flow of the refrigerant when functioning as an evaporator, and the flow direction b is the direction of the flow of the refrigerant when functioning as a condenser. When functioning as an evaporator, the flow rate of the refrigerant is faster than when functioning as a condenser,
By making the rising surface 3 gentle, pressure loss in the pipe can be reduced.

Among the intersections where the ridges 2 having mutually opposite angles intersect, the surface having the steep inclination angle is on the inside, and the ridges at the second intersection 6 where the flow in the flow direction b collides. Is reduced to the pipe reference inner surface, and in the flow direction b, impurities in the refrigerating machine oil and the refrigerant travel along the rising surface 4 having the steep inclination angle and the second intersection 6. Since the second intersection 6 has no protrusion at all, it flows without being accumulated, and a decrease in performance can be prevented.

[0010]

As described above, according to the present invention,
In a heat exchanger in which the flow direction of the refrigerant is reversed and the function is switched between an evaporator and a condenser, the heat exchanger tube of the air-conditioning heat exchanger can improve both the evaporation performance and the condensation performance.

[Brief description of the drawings]

FIG. 1 is a developed view showing the configuration of the inner surface of one embodiment of a heat transfer tube of a heat exchanger for air conditioning according to the present invention.

FIG. 2 is a longitudinal sectional view of a heat transfer tube of an air conditioner heat exchanger according to an embodiment of the present invention, taken along a tube axis.

FIG. 3 is a view A in FIG. 1 of one embodiment of the heat transfer tube of the heat exchanger for air conditioning according to the present invention.

FIG. 4 is a developed view showing a configuration of an inner surface of a heat transfer tube of a heat exchanger for air conditioning according to a conventional example.

5 is a view B of FIG. 4 of the heat transfer tube of the heat exchanger for air conditioning according to the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat transfer tube 2 Convex stripe 3 and 4 Rise surface 5 First intersection 6 Second intersection 7 Pipe standard inner surface

Claims (3)

[Claims] 1. An air-conditioning heat exchange system in which a plurality of spiral ridges having angles opposite to each other with respect to a pipe axis are formed on an inner surface of the pipe by dividing the circumference of the pipe by four or more even numbers. The heat transfer tube of an air-conditioning heat exchanger characterized in that the heat transfer tube of an air conditioner is adapted to cope with flows in opposite directions having different flow velocities by making the rising angles on both sides of the ridge different. . 2. Among the intersections where the ridges having angles opposite to each other intersect, the second height of the ridges at the second intersection where the steeply inclined surface is on the inside is adjacent. It is characterized in that the inclination angle is lower than the first height of the ridge at the first intersection where the surface with the steep angle is on the outside, and gradually increases from the second height to the first height. The heat transfer tube of the heat exchanger for air conditioning according to claim 1. 3. The heat exchanger tube for an air-conditioning heat exchanger according to claim 1, wherein the second height of the second intersection is reduced to a pipe reference inner surface.