JPS61295417A - Heat exchanger - Google Patents

Abstract

PURPOSE:To attempt to promote the efficiency of heat exchange, utilizing effectively heat exchanging surface relating to convective and radiational heat transfer, and limiting quantity of heat radiation from the bottom of a combustion tube, by providing a combustion tube in a combustion chamber so that the aperture thereof faces a burner and making the bottom of said combustion tube double-bottomed. CONSTITUTION:In a heat exchanger employed for a kerosine boiler etc. high- temperature combustion gas 3 blown out of a burner 2 flows from an aperture end 6 into a combustion tube 5, runs against the bottom thereof, turns reversely, and smoothly flows backward along the inside surface of the combustion tube 5 to the aperture end 6. Therefore, the combustion tube 5 is heated all over the surface to a red heat to heat effectively a water wall 9 by radiation. As the bottom part 7 of the combustion tube 5 is of double-bottomed construction, air layer in a gap 8 therein prevents said bottom part 7 from being heated to redness, limiting heat radiation therefrom. Expanded air in the gap 8 is made to flow out through a plurality of expanded-air vent holes 14 bored on the outer periphery of the bottom part 7. On the other hand, the combustion gas 3 flowing backward to the aperture end 6 is convected forcibly to heat by convective heat transfer the whole surface of the water wall 9 including the surface close to a burner connection port 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a heat exchanger employed in a kerosene boiler or the like.

[Background Art] The present inventor has already attached a burner 2 to a combustion chamber 1 formed inside a vessel body as shown in FIG. A heat exchanger A' has been developed in which the heat exchanger A' is installed so as to face the burner 2. According to the structure of this heat exchanger, the combustion gas 3 of the burner 2 is connected to the open end of the combustion tube 5'. 6 into the combustion tube 5', it makes the combustion tube 5' red hot and heats the heat exchange surface by radiant heat transfer, and as shown by the arrow in the figure, the heat is transferred to the outer peripheral surface of the combustion tube 5'. Although the combustion gas 3 convects between the combustion tube 5' and the heat exchange surface, the heat exchange surface can be heated by convection heat transfer, and the heat exchange surface can be used effectively. The bottom part 7 is the most red-hot, and the amount of heat radiated from here is quite large, but since there is no heat transfer surface opposite the bottom part 7, most of this heat is transferred to non-heat transfer parts such as the silencer 16. It wasn't working effectively.

[Objective of the Invention 1 The present invention has been made in view of the above circumstances, and its purpose is to effectively utilize the heat exchange surface in a heat exchanger by radiant heat transfer and convective heat transfer, and to The objective is to reduce the amount of heat radiated from the bottom and improve the efficiency of upward heat exchange, thereby making the vessel smaller and with higher performance.

[Disclosure of the Invention] The heat exchanger of the present invention is a heat exchanger in which a burner 2 is ignited in a combustion chamber 1 formed inside a vessel body, and a heat medium 4 is heated by combustion gas 3 of the burner 2. A combustion tube 5 with a bottom is installed in a chamber 1 so that its open end 6 faces the burner 2, and the bottom 7 of the combustion tube 5 is a double bottom with a constant gap 8. This configuration has achieved the above objective. In other words, burner 2 burns #J5 opening! Combustion tube 5 from a6
The combustion tube 5 is made red hot and the heat exchange surface is heated by radiation heat transfer, and the combustion gas 3 is convected through the opening between the outer surface of the combustion chamber 15 and the heat exchange surface. The heat is generated by heat transfer, and the heat exchange surface can be used effectively.Moreover, the bottom part 7 of the combustion tube 5, which is most red-hot, is a double bottom with a certain gap 8.
Due to the heat insulating effect of the gap 8, the amount of heat radiated from the bottom 6 of the combustion tube 5 can be reduced and the efficiency of upward heat exchange can be improved.

Hereinafter, the present invention will be explained based on embodiments shown in the accompanying drawings. The embodiment shown in Figure 6'ti is a horizontal type, with water I! serving as a heat exchange surface placed at a predetermined interval on the inner periphery of a cylindrical vessel with a bottom. 19 and the outer circumferential wall form a heat exchange section 10 in which a heat medium 4, which is water, is circulated, and the inside of the vessel is used as a combustion chamber 1. A burner connection port 11 is formed approximately at the center of one end surface of the vessel, and an exhaust port 12 is formed approximately at the center of the other end surface. A burner 2 is attached to a burner connection port 11 and its tip projects into a combustion chamber 1. Combustion chamber 1
Inside, a cylindrical combustion cylinder 5 with a bottom is installed so that its opening nll6 faces the tip of the burner 2.

A flame shielding plate 13 is provided on the bottom 7 of the combustion tube 5 to form a double bottom that forms a constant gap 8 with the bottom surface. A muffler 16 is installed near the exhaust port 12 of the combustion chamber 1. Therefore, the high-temperature combustion soot 3 ejected from the burner 2 flows into the combustion #i5 from the open end 6, collides with the bottom, and reverses the combustion #i5.
It flows smoothly on the inner surface of 5 and flows back to the open end 6. For this reason, the entire combustion tube 5 becomes red hot and effectively heats the water wall 9 by radiant heat transfer, as shown by the arrow a'' in the figure. In this case, the combustion tube 5 becomes red hot and the flow of combustion gas is violently turbulent near the bottom, which promotes vaporization and mixing of the liquid fuel, resulting in good combustion. In addition, since the bottom 7 of the combustion tube 5 has a double bottom, the air layer in the gap 8 directly causes the bottom 7 to
The amount of heat radiated from the bottom part 7 is reduced by preventing it from becoming red hot. The expanded air within the gap 8 is made to flow out through a plurality of expansion air vent holes 14 bored in the outer periphery of the bottom portion 7. On the other hand, the combustion gas 3 flowing back toward the open end 6 is forced to convect as shown by the arrow, and heats the entire surface of the water wall 8 including the vicinity of the burner connection port 9 due to convection heat transfer. This heat exchanger A has a water supply port 14 at one end of the heat exchange section 10.
is connected to city water, and the hot water supply inlet 15 is connected to the hot water tap.The thermostat operates according to the amount of heat medium 4 used, which is hot water, and the burner 2 is automatically ignited or extinguished. The heat medium 4, which is hot water, is kept at a predetermined temperature at all times. In the embodiment shown in FIG. 3, a heat insulating material 15 is filled in the gap 8 of the bottom 7 of the combustion stop cylinder 5 to reduce the conduction of heat from the flame shield plate 13 to the bottom surface, and to reduce the radiation from the bottom 7. It uses less heat. In the embodiment shown in Figure @4, the outer surface 7a of the bottom 7 of the combustion tube 5 on the exhaust port 12 side is made to have a mirror surface or a state close to it to prevent radiation of heat from the bottom 7 of the combustion tube 5. .

[Effect of the invention 1] In the present invention, the bottomed combustion front is installed in the combustion chamber so as to face the burner so that its open end faces the burner. The combustion gas can be fed into the combustion tube from the open end of the cylinder, causing the combustion tube to become red hot, causing radiant heat transfer, heating the heat exchange surface, and causing combustion gas to convect between the outer surface of the combustion tube and the heat exchange surface. The heat exchange surface can be heated by convection heat transfer, and the heat exchange surface can be used effectively, and the bottom of the combustion tube, which is most red-hot, is a double bottom with a certain gap. Therefore, the heat insulating effect of this gap can reduce the amount of heat radiated from the bottom of the combustion tube and improve the efficiency of upward heat exchange, resulting in a smaller body and higher performance. can.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention, FIG. 2 is a sectional view showing a combustion tube in the same as above, FIG. The figure is a cross-sectional view showing a combustion tube in still another embodiment of the present invention, and FIG. In the burner, 3 is a combustion chamber, 4 is a heat medium, 5 is a combustion cylinder, 6 is an open end, 7 is a bottom, and 8 is a gap. Agent Patent Attorney Ishi 1) Ai 7 Figure 1 Figure 2 Figure 1 - Figure 5

Claims (1)

[Claims] (1) In a heat exchanger in which a burner is ignited in a combustion chamber formed inside the vessel and a heat medium is heated by the combustion gas of the burner, a bottomed combustion tube is placed in the combustion chamber and facing the burner at its open end. A heat exchanger characterized in that the combustion cylinder is installed so as to face the burner, and the bottom of the combustion cylinder is formed as a double bottom with a certain gap.