JPS58153089A - Heat exchanger - Google Patents

Abstract

PURPOSE:To increase the contact area of a medium to be heated and a heating tube through which a heating medium is passed, by shaping the heater tube disposed in a tank of a heat exchanger in a helical form having turns the diameter of which is changed. CONSTITUTION:A heater tube 16 having one end 16a connected to a manifold 14 is shaped in a helical form, and the other end 16b of the heating tube 16 is connected to a header 20 at a position located lower than the position where said one end 16a is connected to the manifold 14. Between the upper plane where said one end 16a of the heating tube 16 is located and the lower plane where said other end 16b is located, the diameter of turns of the heating tube 16 is decreased gradually downward with respect to the axis of a tank 12. With such an arrangement, heating medium supplied from a supply source into the manifold 14 exchanges heat with water 22 through the wall of the heating tube 16 while passing through the heating tube 16. Here, since the heating tube 16 is shaped in a helical form having diameter-changed turns as described above, it is enabled to increase the contact area of water 22 and the heating tube 16.

Description

[Detailed description of the invention] The present invention relates to a heat exchanger.

Heat exchangers are also used as devices for the purpose of recovering waste heat.

One type of conventional heat exchanger is a so-called coil heat exchanger, in which a coil or thinly wound tube, which is a tube spirally wound on the side surface of a virtual cylindrical body, is placed inside a tank.

Generally, in a heat exchanger, the larger the temperature difference and the heat transfer coefficient between the heat supplying side and the heat receiving side, the higher the efficiency.

In the conventional heat exchanger, the region of the fluid on the low-temperature side that contacts the tubes on the high-temperature side and receives heat transfer is limited to the vicinity of the side surface of the virtual cylindrical body, and there is no opportunity for the fluid to come into contact with the tubes. Less is.

Therefore, the temperature within the region remains high and the temperature difference becomes small. On the other hand, natural convection, which is caused by the temperature difference and whose strength is determined by the magnitude of the temperature difference, also has a weak flow. The value of the heat transfer coefficient varies depending on the strength of the convection, but under the convection, the value is inevitably small, and the efficiency of the heat exchanger itself is low1. The present invention aims to increase the efficiency of the heat exchanger as compared to the conventional heat exchanger, and is characterized by the fact that the heating tube arranged in the tank of the heat exchanger is connected to a vortex with a varying winding diameter. This is because the opportunity for contact between the heating tube through which the heating medium flows and the medium to be heated is increased.

The features of the invention will become clearer from the following description of the illustrated embodiments.

As shown in FIGS. 1 and 2, a heat exchanger 10 according to the present invention includes a tank 12 containing a fluid such as a liquid or gas as a medium to be heated, and a tank 12 disposed within the tank to accommodate the fluid such as a liquid or gas as a medium to be heated. A manifold 14 connected to a supply source (not shown) of a heating medium made of gas or liquid having a higher temperature than the heating medium, and a spiral heating tube 16 whose starting end is connected to the manifold.
and a header 20 located inside the tank 12 and connected to the terminal end of the heating pipe 16 and connected to the piping 18 outside the tank 12.

The manifold 14 and the header 20 are each made of a hollow hollow body, and are heated in water 22, which is a medium to be heated, at a position parallel to the axis of the cylindrical tank 12 and in the lower half of the tank 12. It is arranged with tube 16.

A side wall 12a of the tank 12 is attached to the upper end of the manifold 14.
One end of a supply pipe 24 extending to the outside of the tank 12 is connected to the supply pipe 24, and the other end (not shown) is connected to the supply source of the heating medium. The supply source is, for example, an autoclave used for producing secondary concrete products, and waste steam discharged from the autoclave can be used as a heating material.

The heating tube 16 whose starting end 16a is connected to the manifold 14 is formed in a spiral shape, and its terminal end 16b is connected to the header 2o at a position below the connection position of the starting end 16a. Heating tube 16. The winding diameter of the tank 12 is between the upper plane where the starting end 16a is located and the lower plane where the terminal end 16b is located.
The blade is formed so that it gradually decreases downward from the upper blade with respect to the axis of the blade.

In the illustrated example, the plurality of heating tubes 16 having the above configuration are each supported by a plurality of brackets 28 attached to a support member 26 fixed to the inner wall of the tank 12. Further, although the intervals between the tube parts from the starting end 16a to the terminal end 16b of the heating tube 16 are formed closely, it is possible to create a state where the intervals are sparse or there is no such spacing, that is, the starting end 16a and the terminal end 16b. The entire heating tube 16 including the heating tube 16 can be arranged on one plane. Furthermore, instead of the heating tube 16 having a winding diameter that gradually decreases, the winding diameter may gradually increase.

It is preferable that a plurality of heating tubes 16 be arranged in the tank 12. In this case, the distance between the heating tubes 16 depends on the type and temperature of the heating medium and medium to be heated, and the capacity of the tank 12. It is selected as appropriate, taking into account the following.

The header 2 (l) to which the terminal end 16b of the heating pipe 16 is connected is fixed to the bottom of the tank 12, the pipe 18 is connected to the lower end of the header 20, and the side wall 12a at the lower end of the tank 12 is fixed to the bottom of the tank 12.
It extends outward through the .

A supply port 30 for supplying water 22, which is a medium to be heated, into the tank 12 and a drain port 32 for removing water 22 are provided at the upper and lower ends of the side wall 12a of the tank 12, respectively. .

A water intake port 34 for the heated water 22 is arranged on the tank side wall 12a near the top of the uppermost heating pipe 16, and a vent port 36 communicating with the atmosphere is provided at the top of the tank.

The heating medium introduced into the manifold 14 from the source passes through the heating tubes 16 while passing through the walls of the heating tubes into water 2.
As described above, since the heating tube 16 is formed in a spiral shape with a varying winding diameter, the area of the water 22 that comes into contact with the heating tube 16 is expanded. This is a factor that increases the temperature difference between human blood and water 22 in the heating tube 16 when the surface area of the heating tube 16 is set to be the same as the surface area of the coil or spiral tube in conventional heat exchange. appear. Therefore, strong convection is induced, and this
In addition, the heating medium that has completed the 3° heat exchange, which increases the heat transfer coefficient, is collected in the header 20 and discharged to the outside of the system via the piping 18. Convection often reaches turbulent regions with high velocity1
In this case, it becomes difficult to take out hot water from the water intake port 34, so a float (not shown) is floated on the water surface in advance, and the other end of a hose (not shown) attached to one end is connected to the float. It is desirable to take out the relatively high temperature hot water below the water surface by connecting to the water intake port 34 inside the tank 12.According to the present invention, the heating pipe The chances of the heated medium coming into contact with the heated medium can be increased. As a result, the temperature difference and heat transfer coefficient between the heating tube and the heated medium can be increased, and the efficiency of the heat exchanger can be significantly improved1.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a heat exchanger according to the present invention, and FIG. 2 is a -F side view of a heating tube whose winding diameter gradually decreases. lO: heat exchanger, 12: tank, 14: manifold, 16: heating tube, 18: piping,
2o: Header, 22: Heated medium, 24: Supply pipe. Agent: Patent Attorney Nobuyuki Matsunaga Figure 1 Figure 2 26

Claims (5)

[Claims] (1) A tank containing a medium to be heated inside, a manifold disposed within the tank and connected to a supply source of the heating medium, and a tank through which the heating medium flows, one end of which is connected to the manifold. A heat exchanger comprising a heating tube and a header connected to the other end of the heating tube and connected to piping outside the tank, wherein the heating tube is formed in a spiral shape and whose winding diameter changes. (2) The heat exchanger according to claim (1), wherein the heating tubes are arranged on the same plane. (3) The heat exchanger according to claim (1), wherein both ends of the heating tube are on different planes. (4) The heat exchanger according to claim (3), wherein the heating tube has a winding diameter that gradually decreases between the hemispherical surfaces. (5) The heat exchanger according to claim (3), wherein the heating tube has a winding diameter that gradually increases between the hemispherical surfaces.