JPS6230675Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to noise reduction in domestic gas or oil water heaters using a Finch-Eube heat exchanger.

Configuration of conventional example and its problems In a water heater using a conventional Finch-Ube heat exchanger, as shown in FIG. The hot air flow 4 generated by combustion is heat-exchanged in a Finch-Yub heat exchanger 1 to obtain hot water.

Therefore, in such a water heater, in order to effectively pass the hot air flow 4 generated by the burner 2 through the Finch-Uve type heat exchanger, it is necessary to pass the hot air flow 4 from the burner 2 to the heat exchanger, although this is shown in cross-section in FIG. Exhaust passage 5 through 1
The entire combustion and heat exchange circuit system leading to the above is a sealed structure. Therefore, the combustion noise generated by the burner 1 generated in the closed room is repeatedly reflected on the closed wall surface, becomes a saturated sound pressure, and is radiated to the outside from the exhaust pipe 5. At the same time, it is transmitted through the wall surface of the main body of the water heater and is emitted to the outside. The overall noise was extremely loud.

Purpose of the invention The present invention uses a finch-tube heat exchanger to effectively reduce the increase in combustion noise generated in the combustion chamber, heat exchanger, and exhaust circuit system due to the combustion of gas or oil. The purpose is to reduce machine noise.

Structure of the invention In the present invention, the outer wall surface of a Finch-Eube heat exchanger, which was previously a closed type, is constructed from a combination of a heat-resistant perforated plate and a heat-resistant and fire-resistant fibrous heat-insulating material.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.
This will be explained based on the diagram and FIG.

In FIGS. 1, 2, and 3, 1 is a heat exchange fin closely connected to the water supply pipe 2 for heat exchange;
In order to effectively exchange heat with the cold water flowing through the water supply pipe 2, a large number of thin plate-shaped fins are arranged perpendicularly to the water supply pipe 2 at appropriate intervals of several mm. Reference numeral 3 denotes a sound-absorbing heat insulating material disposed on both end faces of the fin 1, which is made of a porous material such as glass fiber, rock wool, or other mineral heat-resistant and fire-resistant fiber material. is arranged parallel to the water supply pipe 2 so as to close the openings on both end faces of the pipe. 4 is a heat-resistant, fire-resistant perforated plate such as an iron plate or ceramic placed on the outer periphery of the sound-absorbing heat-insulating material 3, and the sound-absorbing heat-insulating material 3 is placed between the fin end face and the perforated plate. hold.
5 is a hole drilled in this perforated plate, and the shape and number of these holes are such that the combustion air flow 9 flowing through the Finch-Eube heat exchanger passes through the sound-absorbing heat insulating material and the perforated plate. In order to prevent this leaking airflow, emphasis can be placed on the combustion airflow 9 that is closed by the flow resistance of the wall surface of the fin end plate made of a sound-absorbing heat insulating material and a perforated plate, and that leaks out. Set it as follows.

Reference numeral 6 denotes a side plate constituting the present finch tube heat exchanger. In this configuration example, it is made of a heat-resistant metal material such as an iron plate or a copper plate, and the water supply pipe 2 is passed through and held. Of course, the present side plate 6 is also It is also possible to have a structure similar to that of the fin end plate formed of the sound-absorbing heat insulating material and a perforated plate.

Reference numeral 7 in FIG. 3 denotes an outer wall constituting a combustion chamber, and a burner 8 is included in the combustion chamber 2.

With the above configuration, the combustion noise generated by the burner 8 in the combustion chamber is directly radiated to the outside through the space between the fins 1 of the finch tube heat exchanger, and
In an FF type gas water heater that forcibly supplies combustion air from an external blower (not shown), the combustion air is propagated through an exhaust pipe (not shown) that guides the combustion air to the outside and is emitted to the outside.

On the other hand, the noise generated by the burner 8 inside the combustion chamber reaches the outer wall 7 of the combustion chamber that constitutes the closed combustion chamber, and some of the noise is transmitted through the outer wall 7 of the combustion chamber and becomes ambient noise of the equipment, and some of the noise is outside the combustion chamber. As a result of repeated reflections between the wall surface and the end plates of the finch tube, noise energy is accumulated in the combustion chamber, increasing the noise level, and furthermore, generating standing waves between the combustion chamber and the end surfaces of the finch tube. Noise at a specific frequency is amplified, and these mutually synergize to penetrate the outer wall of the combustion chamber, further increasing the ambient noise level, and at the same time, making the direct propagation sound transmitted from the exhaust section to the outside extremely high. However, the finch tube heat exchanger according to the present invention has porous, heat-resistant and fire-resistant sound-absorbing heat insulating material 3 disposed at the openings on both end faces of the fins 1, and furthermore, a heat-resistant and fire-resistant perforated plate is arranged around the outer periphery of the heat-resistant and fire-resistant sound-absorbing heat insulating material 3. 1. As a result of absorbing the combustion noise generated in the combustion chamber and preventing the accumulation of noise energy due to reflection, not only the noise emitted from the exhaust side but also the noise that propagates through the outer wall. This provides equipment with extremely low noise. Furthermore, the present invention has the effect of preventing the generation of standing waves of a specific frequency due to the reflection of noise generated by both end faces of the finch tube, and as a result, preventing an increase in the specific frequency that is synergistic with combustion noise.

This principle will now be explained with reference to FIG.

Combustion noise generated within the combustion chamber generally does not have a specific direction. Therefore, the noise transmitted into the finch-tube heat exchanger is repeatedly reflected between the parallel fins or in the water supply pipe, and is transmitted along the exhaust flow, and at the same time, it is also transmitted in the direction of both end faces parallel to the fins. The noise is transmitted and reaches the opening in the fin end face or the outer wall surface of the combustion chamber that holds the heat exchanger and seals the fin end face opening. In this case, the incident sound wave indicated by the dotted line _S1 in Figure 2 is attenuated by the sound-absorbing heat insulating material 3, reaches the surface of the perforated plate 4, and part of it is attenuated by the perforated plate. It is transmitted to the outside, but most of it is reflected by this surface, becomes _S2 , and returns to the inside of the finches tube heat exchanger, where it is attenuated by the sound absorption effect of the sound-absorbing heat insulating material 3. Therefore, the sound waves that return to the Finch-Hube heat exchanger by reflection are attenuated twice by sound absorption in the incident and reflection paths, and the reflected energy is much larger than that of the incident waves. As a result, the sound pressure of the standing waves generated by this repetition is greatly reduced compared to the case without the sound absorbing heat insulating material 3. Note that this ratio varies depending on the thickness and sound absorption coefficient of the sound-absorbing heat insulating material, and cannot be revised unconditionally. On the other hand, the sound wave S ₁₀ transmitted to the perforated portion of the perforated plate 4 is similarly transmitted to the sound absorbing heat insulating material 3
There is almost no _S20 component, which is attenuated through the hole 5 and transmitted to the outside through the hole 5 and reflected from the wall surface, and is generated by repeated and superimposed sound wave reflections. Standing waves cannot exist. On the other hand, the sound waves that are sound-absorbed and attenuated by the sound-absorbing heat insulating material 3 and have passed through the perforated plate 4 and its hole portion 5 are generally transmitted to the exterior material (not shown) that constitutes the exterior of this type of product. The noise that is transmitted to the outside of the product is extremely low.

Effects of the invention As explained above in detail, the fin pipe heat exchanger with this configuration effectively reduces the reflected energy of sound waves at the end faces of the fins by using the sound-absorbing heat insulating material. It is possible to prevent the level from increasing, and also to suppress the generation of standing waves caused by repeated reflections.
As a result, an extremely low-noise device can be provided by preventing the specific frequency from increasing, which would cause unpleasant noise due to the superposition of standing waves. Furthermore, the insulation effect of the sound-absorbing insulation material prevents the external transfer of thermal energy generated by combustion and effectively increases the temperature of the fins, resulting in extremely efficient heat exchange characteristics. As a result, a low-noise, high-efficiency gas water heater can be provided, contributing to energy conservation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of an embodiment of the Finch-Ube heat exchanger of the present invention, FIG. 2 is a detailed view showing the wall structure of the heat exchanger, and FIG. 3 is a Finch-Ube heat exchanger of the present invention. FIG. 4 is a partial cross-sectional view showing the configuration of an embodiment of a combustion section using an exchanger, and FIG. 4 is a cross-sectional view of the configuration of a conventional gas combustion water heater. 1... Heat exchange fin, 2... Water supply pipe, 3... Sound absorbing heat insulating material, 4... Perforated plate, 5... Hole, 6...
Side plate, 9... Combustion air flow.

Claims (1)

[Claims for Utility Model Registration] (1) A water supply pipe is passed through the surface of a large number of heat exchange fins at right angles to the surface of the heat exchange fins stacked at small intervals. A heat exchanger made by bonding sound-absorbing insulation materials and holding them with fire-resistant and heat-resistant perforated plates. (2) The heat exchanger according to claim 1, wherein the four end faces parallel to the hot air flow are made of a heat-resistant, fire-resistant sound-absorbing heat-insulating material and a heat-resistant, fire-resistant perforated plate.