JPH0249505Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) This invention relates to a heat exchanger for a gas water heater.

(Prior Art) The closer the endothermic tubes of a heat exchanger are to the burner, the higher the temperature of the water supply and the heating flame of the burner, so condensation tends to occur, corroding the endothermic tubes, and the so-called after-boiling phenomenon also has a significant drawback. Therefore, as a measure to eliminate this drawback, only the part of the conventional heat absorption tube near the burner is made into a double pipe structure, and cold water is poured into the central cold water inner pipe, and high temperature water is poured into the hot water outer pipe surrounding the cold water inner pipe. Some proposals and implementations have been made to prevent dew condensation and the after-boiling phenomenon by flushing water.

(Problem to be solved by the invention) In the conventional double heat absorption pipe, a series of inner cold water pipes are inserted through the center of the outer hot water pipe, and the inner cold water pipes are fixed at both ends of the outer hot water pipe. Thermal distortion caused by the temperature difference between the outer hot water pipe and the hot water outer pipe had the disadvantage that cracks formed at the fixed parts at both ends, causing water leakage. In order to solve this problem, this invention provides a joint in which the cold water inner pipes are inserted into each other, and uses the joint to release these thermal distortions, thereby preventing the function of the double heat absorption pipe from being impaired due to water leakage. To provide a heat exchanger for a gas water heater that eliminates the risk and has excellent durability.

(Means for solving the problem) This invention is a heat exchanger partially equipped with a double heat absorption pipe A consisting of a cold water inner pipe 1 and a hot water outer pipe 2.
The above-mentioned problem has been solved by adopting a technical measure characterized in that the cold water inner pipe 1 of the double heat absorption pipe A is provided with a joint part B that is inserted into each other.

(Function) Since this device has the above structure, the double heat absorption tube A
Thermal distortion due to the temperature difference between the cold water inner pipe 1 and the hot water outer pipe 2 is absorbed and released as quickly as possible by the mutually inserted joint B provided in the cold water inner pipe 1. No cracks will occur at the fixed ends of the tube 2. Therefore, the function as a double heat absorption tube can be effectively exhibited at all times.

(Example) An example of a heat exchanger for a gas water heater according to this invention will be described below with reference to the drawings.

In the drawing, A is a double heat absorption pipe consisting of a cold water inner pipe 1 and a hot water outer pipe 2. The cold water inner pipe 1 is inserted into the center of the hot water outer pipe 2 keeping the same axis, and the cold water inner pipe 1 is connected to the hot water pipe. It has a double structure in which both ends a and b of the outer tube 2 are fixed and integrally connected. This double heat absorbing tube A is provided only in a portion of the heat absorbing tube A' of the heat exchanger C near the burner 6. Reference numeral B denotes a joint part provided in the middle of the cold water inner pipe 1 of the double heat absorption pipe A, and this joint part B is connected in a plug-in relationship. That is, as shown in detail in FIG. 2, one large-diameter joint end 3 is provided with the other small-diameter joint end 4 so that it can be freely inserted into and removed from the other, and these are connected in a mutually insertion relationship. There is a slight play gap in the axial direction to allow the joint portion B to freely expand and contract in the axial direction, thereby allowing thermal strain to be absorbed and escaped properly without any hindrance. Furthermore, the joining relationship between the large-diameter joint end 3 and the small-diameter joint end 4 in this joint B does not require complete watertightness.

In addition, in FIG. 1, 5 is an endothermic fin of heat exchanger C, 6 is a gas burner that heats heat exchanger C,
D is a hydraulically responsive flasher that automatically controls the amount of gas supplied to the gas burner 6 in comparison with the amount of water supplied to the heat exchanger C, and also has a reset valve that also supplies or cuts off the gas by supplying or cutting off the water supply. vessel, 7 is a gas pipe, 8
9 is a water supply pipe, and 9 is a hot water outlet pipe.

(Effect of the invention) As explained above, this invention
It has a simple structure in which the cold water inner pipe 1 is provided with a joint part B that is inserted into each other, and the thermal strain caused by the temperature difference between the cold water inner pipe 1 and the hot water outer pipe 2 in the double heat absorption pipe A is transferred to the joint part B. Therefore, since the water is absorbed and released as quickly as possible, it is possible to prevent the problem of cracking caused by the load in the fixed portions a and b at both ends of the cold water inner pipe 1 and hot water outer pipe 2. Therefore, there is no risk of water leakage, which prevents the initial high-temperature water from being discharged during continuous re-ignition and discharge, eliminates the risk of burns from high-temperature water due to the after-boiling phenomenon, and prevents condensation and water leakage. Since there is no corrosion of the heat absorption tubes caused by heat absorption, the original function of the double heat absorption tubes is fully demonstrated, and its durability is significantly improved. moreover,
Since the joint B does not require complete watertightness, it is easy to manufacture.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a heat exchanger for a gas water heater according to this invention, with only the main parts cut away, and FIG. 2 is a sectional view of the cold water inner pipe. 1...Cold water inner pipe, 2...Hot water outer pipe, A...Double heat absorption pipe, B...Joint part.

Claims (1)

[Scope of utility model registration request] Double heat absorption pipe A consisting of cold water inner pipe 1 and hot water outer pipe 2
A heat exchanger for a gas water heater, characterized in that a joint part B is provided in the cold water inner pipe 1 of the double heat absorption pipe A in a mutually inserted relationship.