JPS59191893A - Structure for improving heat-transfer coefficient of viscousliquid flow in pipe of heat exchanger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Description: TECHNICAL FIELD The present invention relates to a structure for improving the heat transfer coefficient of viscous liquids with low thermal conductivity flowing in pipes of heat exchangers, such as transformer and bearing lubricating oils.

Prior Art Oil for lubricating and cooling the bearings of a steam turbine or gas turbine is cooled in an oil cooler to absorb the mechanical heat generated in the bearings, but it is a poor conductor of heat. It is a well-known fact that heat flows in a laminar flow through the pipes of a heat exchanger.

As a result of this property, oil has a low heat transfer coefficient, which has the disadvantage of requiring large and expensive heat exchangers for cooling.

The reason why the heat transfer coefficient of oil, which has poor thermal conductivity and is applied in a laminar flow, is low is that the boundary layer that flows at a low velocity g along the pipe surface acts as a heat insulating layer, and the boundary layer flows from the hot oil to the pipe. This can be explained by the fact that it blocks the path of the heat flux towards the wall. The cooled oil forms a slightly thick layer on the pipe wall soil and flows through the wall soil at a low speed, while the hot oil flows through the center of the pipe and is hardly cooled. Heat can only flow by conduction.

According to current technology, longitudinally disposed internal ribs are used. The essence of this solution is that the heat passes through a short path in the cross section, which results in a much lower resistance. The disadvantage of this method is that it increases the resistance, weight, and therefore manufacturing cost of the heat exchanger.

OBJECT AND CONSTRUCTION OF THE INVENTION An object of the present invention is to eliminate the drawbacks of slope by using a structure that removes the low-temperature boundary layer formed during the laminar flow of oil from the center of the pipe.

The difference between the structure according to the present invention and the internal ribs of the prior art is that the conventional internal ribs divide the tubular space into channels parallel or nearly parallel to the length of the pipe. The structure according to the present invention divides the space into sections perpendicular to the pipe axis, and forces the boundary layer formed on the pipe wall soil in the divided sections into position with the hot oil flowing in the middle of the pipe. It consists in being exchanged. As a result, oil layers are also formed that flow parallel to the longitudinal axis of the pipe, but there are no separating surfaces between them and they often exchange positions with each other as they progress through the pipe.

A characteristic of conventional internal ribs is that the size of their surface approximates the inner surface of the pipe. The surface of the structure of the invention is much smaller and presents no problems from a heat transfer point of view. Conventional internal ribs are made of thermally conductive metal. Thermal conductivity is not a factor in the structure of the invention, so it can be made of any plastic material.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in more detail by way of example embodiments with reference to the accompanying drawings.

FIG. 1 shows one cooling pipe of a heat exchanger according to an embodiment of the present invention. In said cooling pipe 1, a partition wall 2 is fixed on a fixed wire 3 in a plane perpendicular to the longitudinal direction 1 of the cooling pipe and arranged in a sequentially repeating manner. Fixed wire 3 is held at both ends of the pipe by fixtures 4.

The low-temperature oil flowing through the pipe wall soil forming a thin layered boundary N and the sacrilege 1 oil flowing in the center of the pipe are able to change direction as shown by the arrow by the partition wall 2, and this causes the low-temperature oil to change direction. Flows towards the inside of the pipe 11,
Meanwhile, hot oil flows towards the pipe wall. In Fig. 1, a longitudinal section of a partition wall 2 having two channels is shown.

It is also possible to make the partition wall 2 slightly thicker than the inner diameter of the pipe 1 before assembly, so that after the partition wall 2 is assembled, it is pressed against the wall of the pipe 1 by its own elasticity. . In this case, the fixing wire 3 and fixture 4 can be omitted.

FIG. 2 shows another embodiment of the partition wall 2. In FIG. A deflection channel 6 pressed from the septum ring 5 deflects the boundary layer flowing between the wall of the pipe I (not shown) and the septum ring 5 towards the center of the pipe 1. This deflection action is facilitated by the locking ring 7, which
serves at the same time to attach the bulkhead to the wall of the pipe 1. The support portion 8 is integrally formed from the material of the partition ring 5, which allows each component to be arranged concentrically.

By applying the embodiment shown in FIG. 3, even better results with respect to heat transfer are obtained. According to this embodiment, the partition wall 2, which is attached to a fixed wire 3 and fixed within the pipe l, repeats reciprocating movements. The partition wall can be moved upwardly by periodically moving the fixed wire 3 by an externally provided drive mechanism.

The embodiment shown in FIG. 3 is such that the flux of the medium to be cooled tensions a spring 9 attached to a fixed wire 3;
It can be embodied so that the partition wall 2 can be moved. By periodically stopping the flux of the medium to be cooled for short periods of time, the spring 9 connects the fixed wire 3 and the partition wall 2? In this way, the bulkhead 2 removes the boundary layer, which is continuously increasing in thickness, from the wall surface of the pipe 1 and pushes it towards the center of the cross-section of the pipe. , resulting in it being free to the aqueous medium. 6. Electrically actuated and electronically controlled closure devices or mechanical devices to obtain a periodic flow of the medium to be cooled.6. may be placed in the flow of the heat exchanger. It is also possible to obtain this motion by harnessing the energy of the flowing medium.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is a perspective view and a front view of an embodiment of the partition wall, and Fig. 3 is another embodiment improved to resemble the non-explosion [Sj]. FIG. 1... Pipe, 2... Partition wall, 3... Fixed wire,
5... Bulkhead ring, 6... Deflection channel, 7...
・Lock ring, 8...Support part, 9...Spring. Patent Applicant Transelect Portfolio Magyar Villamosagi Kurukulsk Delmino\Lalat Patent Application Agent Akira Aoki Patent Attorney Kazuyuki Nishidate Patent Attorney Kyosuke Tsuchinakayama Patent Attorney Akira Yamaguchi Patent Attorney Masaya Nishiyama Hungarian H.C. 1055 Budapest Nefadseleg Uratsa 14 Procedural Amendment (Method) % Formula % 1. Indication of the Case 1980 Patent Application No. 14554 2. Name of the Invention for Improving the Heat Transfer Coefficient of a Viscous Liquid Flow in Pipe No. 1 of a Heat Exchanger Structure 3, Relationship with the case of the person making the amendment Patent applicant name Transelect Portion Magyar Viramosagi Kurkelskedermi Balarad 4, Agent (4 others) 6. Subject of amendment (11th order ￥t "Application ``Representative person'' column (2) Power of attorney (3) 1 Drawing Z Contents of amendment (1) (2) Attached circular (3) Engraving of drawing (no change in content) 8, List of attached documents ( 1) Request for correction (1 copy) (2) Power of attorney and translation (1 copy each) (3) Engraved drawings (1 copy)

Claims (1)

[Scope of Claims] 1. A structure for improving the heat transfer coefficient of a viscous liquid flowing inside a pipe of a heat exchanger, wherein the partition wall (2) is connected to the pipe (1).
The deflection channel f6)fX is formed to deflect the boundary layer flowing on the wall surface of the pipe (1), and the partition wall is perpendicular to the axis of the pipe (1) and divides the internal space of the pipe (1) into 11 sections. A structure whose life is %. 2. The partition wall (2) is attached to a fixed wire (3), and the wire is fixed to the pipe by a 1 t·l foot odor (4). structure. 3. A structure mounted on the first part of the claim, characterized in that the partition wall (2) has a periodic motion and is connected to a mechanism connected to a 181 constant wire (3). . 4 Fixed wire (3) is connected to spring (9),
Claim 1, characterized in that a heat exchanger stream is provided with a device for producing a periodic flux of the medium in the wafer.
Structures listed in section. A structure according to claim 4, characterized in that: 6. A structure according to claim 4, characterized in that the periodic flux of the medium is obtained by the energy of the flowing medium.