JPH02161267A - Heat pump air conditioner - Google Patents

Abstract

PURPOSE:To remarkably improve a heat transfer coefficient of evaporation and condensation of a refrigerant by forming spiral channels having mutually reverse directional angles to a pipe axis in the form of halving the inner circumference of the pipe on the inner face of a using heat transfer pipe to specify the direction of a refrigerant flow. CONSTITUTION:Spiral channels 11a, 11a and 11b, 11b having mutually reverse directional angles to a pipe axis in the form of halving the inner circumference of the pipe on the inner face of a heat transfer pipe 10 are formed, and refrigerant steam is made turbulent to improve a heat transfer effect in either flow direction in the case where a refrigerant is allowed to flow. In the case where the refrigerant is allowed to flow from B to A direction, when the heat transfer pipes 10 are assembled in an indoor heat exchanger 6, in the case of cooling operation the refrigerant is allowed to flow from B to A direction and in the case of heating operation the reverse flow of A to B direction is performed, since the refrigerant is effectively agitated by the channels 11a, 11b.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention is configured such that one device can perform both cooling and heating by switching the flow direction of the refrigerant flowing within the heat exchange system. This paper concerns improvements to heat pump air conditioners.

[Prior art 1] The inner surface of the heat transfer tube, which allows the refrigerant to flow through the tube and perform the necessary heat exchange, was initially smooth, but as thermodynamic research progressed, the inner surface of the tube did not remain smooth but had a certain shape. It has been found that the heat transfer coefficient is better when the unevenness is formed, and recently, as shown in Fig. 4, the mainstream is to form a spiral continuous groove 11' on the inner surface of the heat exchanger tube 10'. It became so.

One of the effects of forming the spiral groove 11' in this way is that it increases the surface area of the inner surface of the tube and increases the heat transfer area.

However, not only that, the presence of spiral irregularities inside the pipes causes the circulating refrigerant to become agitated and turbulent, which improves the heat transfer coefficient. In some cases, the refrigerant liquid flowing inside the pipe is scraped up along the spiral ends tt', tt', and the entire inner surface of the pipe is wetted with the refrigerant liquid, which can be expected to improve the heat transfer coefficient. .

Although the above-mentioned heat exchanger tube with an inner spiral extinguisher exhibits the excellent heat transfer characteristics described above, it is not advantageous in all cases, and there are problems such as the following, especially when the refrigerant is condensed inside the tube. It has been pointed out that there is.

In other words, the refrigerant liquid condensed in the pipe accumulates at the bottom of the pipe due to gravity and flows down the pipe.
Because of the presence of ', 11', the liquefied refrigerant does not flow smoothly, causing a spiral? 1111'11' occurs, resulting in the entire inner surface of the tube being wetted.

When the inner surface of the tube is wetted with liquid in this manner, the inner wall surface of the tube does not come into direct contact with the gaseous refrigerant vapor, which may reduce the heat transfer coefficient to a large IJ. Therefore, in the case of a condensing heat transfer tube, it is more important to enable direct contact between the inner wall surface of the tube and the refrigerant vapor over a larger surface area.

[Problem to be Solved by the Invention 1] In recent years, heat pump air conditioners that allow one air conditioner to be used for both cooling and heating have shown remarkable contradictions.

This heat pump air conditioner uses one heat exchange system,
By switching the refrigerant circuit, the refrigerant is boiled or condensed within the heat transfer tube, and when the refrigerant flows to one side, it produces a cooling effect, and when it flows to the opposite side, it produces a heating effect. It has become.

Therefore, during cooling in which heat exchange is performed by boiling the refrigerant, the spiral grooves it' and tt' function extremely effectively and can greatly improve heat exchange efficiency, but the same heat transfer tube is used for condensing. During heating, the spiral grooves 11'', 11'
It is conceivable that the scraping up of the refrigerant liquid caused by the above-mentioned reduction in the heat transfer coefficient may occur.

The purpose of the present invention is to solve the problems of the prior art described above,
It effectively prevents the scraping up of the refrigerant liquid within the heat transfer tube during condensation, and promotes the scraping up phenomenon during evaporation.
It is an object of the present invention to provide a bomb air conditioner that is constructed so as to exhibit maximum efficiency in heat transfer.

``Means for Solving the Problems J'' The present invention performs cooling and heating by switching the direction of the refrigerant flowing inside the heat transfer tube. In this way, spiral grooves having opposite angles to the tube axis are formed, and when condensing the refrigerant, the groove angle is such that the condensed refrigerant liquid flows in the cross direction of the grooves along the angle of the groove. The heat exchanger tubes are arranged like this.

[Action J: The spiral groove formed on the inner surface of the heat transfer tube is
If the configuration is such that the tubes are divided and have opposite angles to the tube axis, the presence of the springs will make the refrigerant vapor turbulent both when the refrigerant boils and when it condenses, improving the heat transfer effect. When the refrigerant flows into the heat tube from the - direction, the refrigerant is scraped up by the grooves, and when it flows from the opposite direction, the refrigerant is collected in the cross direction of the grooves, and the scraping does not occur. If heat transfer tubes are installed by selecting the direction in which the refrigerant is collected in the direction in which the condensed refrigerant flows, the heat transfer effect of the heat pump will be maximized.

[Example] Below, nine examples of the present invention will be explained.

FIG. 1 is an explanatory diagram showing the piping circuit of the HEATBON 1 air conditioner, and the case of cooling operation using this device will first be described.

During cooling operation, valves 2.2' and 2'' are closed, and refrigerant vapor is sent out from the compressor 1 as shown by the arrow in the figure.
The refrigerant vapor passes through the valve 3', is condensed in the outdoor heat exchanger 7, and flows into the order receiver 5 through the valve 3''.Furthermore, the refrigerant liquid that has been adiabatically expanded and cooled by the expansion valve 4' is transferred to the indoor heat exchanger. 6, where the refrigerant evaporates to cool the room, passes through the valve 3, and returns to the compressor 1 as indicated by the arrow in the figure.

In the case of heating operation, the direction in which the refrigerant flows is opposite to that in the case of cooling.

That is, with the valves 3.3' and 3'' closed, refrigerant vapor is sent out from the compressor 1 as shown by the arrow, passes through the valve 2', and is condensed while dissipating heat in the indoor heat exchanger 6. With this behavior, the refrigerant passes through the valve 2 and returns to the compressor 1 as shown by the arrow.

Conventionally, the heat transfer tubes installed in the heat exchanger have spiral grooves 11' having the same angle with respect to the tube axis, as shown in FIG.
11' was formed, and as explained above, the phenomenon of stirring up by the liquid during condensation was unavoidable.

In the present invention, a heat exchanger tube 10 as shown in a half-cut cross-sectional view in FIG. 2 is installed.

The inner surface of the heat exchanger tube 10 according to the present invention has spiral grooves 11a, lla, and 11b that divide the inner circumference of the tube into two and have opposite angles to the tube axis.

ttb is formed and both arms 11a and 11b
are formed in such a relationship that they intersect with each other at an intersection 12.

In order to manufacture the heat exchanger tube 10 having such arms 11a and 11b, the method shown in FIG. All that is required is to process the inclined erasers 11a and 11b for forming grooves, then roll them into a pipe shape as shown in the figure, and seam weld 13 the edges together by, for example, high-frequency induction heating. Of course, in the illustrated example, the erasers 11a and ttb intersect exactly at the intersection 12, but the erasers 11a and llb may not intersect exactly, but may be staggered, or there may be some separation at the tips. There is no problem in configuring the width of the eraser to be different for lla and llb.However, by making it symmetrical as shown in the figure, meandering during rolling is prevented, and the quality is improved. There are also benefits that can be achieved if it is good.

If the spiral grooves 11a and llb are configured as described above, when the refrigerant flows into the heat exchanger tube 10, these gushes 11a and llb will flow regardless of the direction in which the refrigerant flows.
The presence of b makes the refrigerant vapor turbulent and improves the heat transfer effect.

Therefore, depending on whether the refrigerant flows in the direction from A to B in FIG. . That is, when the refrigerant flows from B to A direction, the refrigerant is effectively scooped up by the fountains 11a and llb, whereas when A flows from A to B direction, the refrigerant is drawn up along the fountains 11a and llb. The refrigerant is collected in the direction of the intersection, and no scraping of the refrigerant occurs.

Therefore, when installing the heat transfer tubes 1O in the indoor heat exchanger 6 shown in FIG. 1, in the case of cooling operation, the refrigerant is
The flow should be in the direction A from A, and in the case of heating operation, the flow should be the opposite from A to B. More preferably, the intersection 12 of the grooves should be located on the lower side. Thus, in the case of cooling operation, the boiling refrigerant is stirred up into the heat transfer tube, improving the heat exchange efficiency for cooling as described above, while in the case of heating operation, the boiling refrigerant is pumped up into the heat transfer tube. The pumping up of the refrigerant liquid caused by
, llb, it is possible to maintain a large direct contact area of the refrigerant with the inner surface of the tube, and to establish heat exchange under optimal efficiency, which can improve the heat exchange efficiency for heating.

Note that it is desirable that the above-mentioned angle of rotation be set in the same manner in the outdoor heat exchanger.

[Effects of the Invention] As described above, the heat exchanger tubes according to the present invention are arranged according to the present invention. The condensation heat transfer coefficient of the refrigerant can be significantly improved, making it possible to downsize the heat exchanger and ultimately the refrigerant equipment, and reduce equipment costs and running costs. There is great value.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the piping circuit of a heat pump air conditioner, Fig. 2 is a half cross-sectional view of the heat exchanger tube according to the present invention used in the device of Fig. 1, and Fig. 3 is the heat exchanger tube shown in Fig. 2. FIG. 4 is a half-cut sectional view of a conventional heat exchanger tube. 10゜la. :Compressor, :Valve, :Valve, :! lj Zhang valve, : Order receiver, Royal indoor heat exchanger, : Outdoor heat exchanger, : Heat exchanger tube, : Reverse angle spiral groove, Two-way spiral groove, : Information cross section.

Claims (1)

[Claims] (1) The flow direction of the refrigerant in the heat transfer tubes of the heat exchanger is reversed during cooling and heating, and by switching the refrigerant circuit using one device, both cooling and heating can be performed. In air conditioners that can be used for air conditioning, a spiral groove is formed on the inner surface of the heat transfer tube to divide the inner periphery of the tube into two and have opposite angles to the tube axis to condense the refrigerant and exchange heat. is a heat pump air conditioner in which heat transfer tubes are arranged such that the groove angles allow condensed refrigerant liquid to flow in the cross direction of the grooves.