JP5210234B2 - Latent heat recovery type water heater - Google Patents

Description

  The present invention relates to a latent heat recovery type water heater having a drain neutralization tank for neutralizing and draining strongly acidic drain water.

  Conventionally, in this type, drain water generated when the temperature of the exhaust gas drops below the dew point due to heat exchange between the exhaust gas after combustion and the latent heat exchanger is replaced by a neutralizer filled with a neutralizing agent. The product was neutralized and drained by circulating it.

JP 2001-272110 A

  By the way, in this conventional system, when the neutralization tank is clogged, the neutralization tank is filled with drain water and is filled with the drain water up to the exhaust path of the instrument, and the neutralization tank of the neutralization tank is the first place where abnormal combustion occurs. Clogging is detected, and this is also the case with water leakage from the heat exchanger, and there is a problem that clogging of the neutralization tank and water leakage from the heat exchanger cannot be accurately detected. Met.

  In order to solve the above-mentioned problems, the present invention particularly has a configuration in which a main heat exchanger that recovers sensible heat from exhaust gas generated by combustion of a combustion burner and heats running water, and a heat exchanger that exchanges heat with the main heat exchanger. An auxiliary heat exchanger that supplies the main heat exchanger with flowing water heated and recovered from latent heat from exhaust gas, and the auxiliary heat exchanger that houses the exhaust gas inlet above the bottom and the outlet at the top. A heat exchange case and a neutralization tank filled with a neutralizing agent to neutralize and drain the strongly acidic drain water generated in the auxiliary heat exchanger that communicates with the bottom of the heat exchange case. In the heat exchange case, an exhaust thermistor that detects an abnormality of the main heat exchanger by detecting the exhaust gas temperature is provided, and the exhaust thermistor is connected to the neutralization tank at the lower part of the heat exchange case. Provided in the vicinity, the neutralization tank is clogged or the auxiliary heat exchanger water Re is also that so as to notification detecting.

  As described above, according to the present invention, the communication port in front of the neutralization tank is clogged or the neutralization tank itself is clogged, or water leakage occurs from the auxiliary heat exchanger. Because the temperature of the exhaust thermistor that detects clogging of the main heat exchanger from the abnormality of the exhaust gas temperature at 200 ° C. or higher is drastically reduced to 20 to 70 ° C. Clogging of the neutralization tank and water leakage of the auxiliary heat exchanger can be accurately detected and reported, so detection of clogging of the communication port in front of the neutralization tank, clogging of the neutralization tank itself, and water leakage of the auxiliary heat exchanger There is no need for special sensors, and one exhaust thermistor can detect and report four abnormalities. It is extremely economical and efficient, and can be used safely for a long time. is there.

The schematic block diagram of one Embodiment of this invention. Explanatory drawing of the heat exchange case. The block diagram of the principal part electric circuit.

Next, an embodiment of the present invention will be described with reference to the drawings.
1 is a main body of a water heater, and a combustion chamber 4 having a gun-type combustion burner 2 and a combustion fan 3 mounted downward at the upper end is provided inside, and the combustion chamber 4 further includes a combustion chamber 4. A main heat exchanger 5 for recovering sensible heat of exhaust gas is provided.

  6 is a communication path that communicates the bottom of the combustion chamber 4 with one end, and a heat exchange case 8 that has an outlet 7 at the top communicates with the other end. The exhaust gas from the combustion chamber 4 is U-turned through the communication path 6. The air is discharged from the outlet 7 by the blowing force of the combustion fan 3 through the heat exchange case 8.

  The heat exchange case 8 communicates with the communication path 6 via a communication pipe 9, the communication pipe 9 penetrates the bottom of the heat exchange case 8 and protrudes slightly upward, and an inlet 10 is formed at the tip thereof. Further, in this heat exchange case 8, an auxiliary heat exchanger 14 configured by arranging a plurality of heat receiving tubes 13 made of a meandering stainless tube between the forward header 11 and the return header 12 is housed. The exchanger 14 heats the feed water by recovering latent heat in the exhaust gas, and supplies the heated water to the main heat exchanger 5.

  15 is a neutralization that collects drain water generated from the auxiliary heat exchanger 14 in communication with the heat exchange case 8 through an inflow pipe 17 that communicates with a communication port 16 formed at the bottom of the heat exchange case 8. In the tank, the inside is divided into two chambers by a partition plate 18, and a neutralizing agent 19 made of calcium oxide granules that neutralizes the strongly acidic drain water is filled in both chambers. The water is neutralized by the neutralizing agent 19 and drained from a drain pipe 20 provided at a substantially middle portion in the height direction.

  Reference numeral 21 denotes a hot water supply control circuit constituted by a microcomputer, which is connected to a remote controller 22 provided in the kitchen or the like, and communicates with the main heat exchanger 5 so that the hot water supply temperature becomes the hot water supply set temperature set by the remote controller 22. The amount of combustion of the combustion burner 2 is controlled in accordance with the detected temperature of the hot water supply thermistor 24 provided in the hot water supply pipe 23, and the hot water supply control circuit 21 detects flowing water by the flow sensor 25 also provided in the hot water supply pipe 23. By doing so, the combustion burner 2 starts combustion as the combustion fan 3 starts to be driven.

An exhaust thermistor 26 is provided in the lower part of the heat exchange case 8 and below the exhaust gas inlet 10 and detects the exhaust gas temperature after passing through the main heat exchanger 5. When the main heat exchanger 5 is clogged with soot, the front and rear are detected at 260 ° C. or higher and the clogging of the main heat exchanger 5 is displayed on the display unit 27 of the remote controller 22 via the hot water supply control circuit 21. The exhaust thermistor 26 is connected to the communication port 16 and the inflow pipe 17, the neutralization tank 15, and the drain pipe 20 at a place away from the neutralization tank 15. When the drain water level rises to the position of the exhaust thermistor 26 in the heat exchange case 8, the exhaust thermistor 26 detects the drain water temperature of 20 ° C. to 70 ° C., and the communication port 16 and the inflow pipe 17. And neutralization tank 15 and drain pipe 0 through the hot water supply control circuit 21 that is clogged state dust, and displays on the display unit 27 of the remote controller 22 is for informing to or generates an error tone.
A water supply pipe 28 is connected to the auxiliary heat exchanger 14.

Next, the operation of this embodiment will be described.
When a hot water tap (not shown) at an appropriate location is opened and hot water supply is started, the flow sensor 25 detects the flow of the hot water and the combustion fan 3 is driven via the hot water control circuit 21 so that the combustion burner 2 Starts combustion, and exhaust gas generated by this combustion makes a U-turn from the combustion chamber 4 through the communication path 6 and flows into the heat exchange case 8, and flows through the heat exchange case 8 from above to below. Thus, heat is exchanged with the feed water flowing into the auxiliary heat exchanger 14 and exhausted from the outlet 7.

  The hot water whose temperature has risen in the auxiliary heat exchanger 14 flows into the main heat exchanger 5 where it is further heated by heat exchange with the exhaust gas generated by the combustion of the combustion burner 2 and discharged from the hot water tap as hot water. The combustion amount (thermal power) of the combustion burner 2 at this time is detected by the hot water supply thermistor 24 provided in the hot water supply pipe 23 exiting the main heat exchanger 5, and this temperature is determined by the user himself / herself. It is adjusted so as to reach a hot water supply set temperature set by the remote controller 22.

  Next, in the heat exchange case 8, the drain water generated by the latent heat recovery of the feed water and exhaust gas flowing through the auxiliary heat exchanger 14 is naturally transferred from the outer peripheral wall of the auxiliary heat exchanger 14 to the bottom of the heat exchange case 8. It is collected by dropping, flows into the neutralization tank 15 from the communication port 16 through the inflow pipe 17, and the drain water is neutralized by the neutralizing agent 19 filled in the neutralization tank 15 to reduce the PH. The water is drained from the drain pipe 20, and the drain water generated in the auxiliary heat exchanger 14 is sequentially processed to improve the heat exchange efficiency.

  Further, when the clogging of the main heat exchanger 5 is detected by the exhaust thermistor 26, the detected temperature of the exhaust thermistor 26 is read by the hot water supply control circuit 21 at all times, and the exhaust gas temperature flowing into the heat exchange case 8 becomes the exhaust thermistor 26. When the temperature is 260 ° C. or higher, the fact that the main heat exchanger 5 is clogged is indicated on the display unit 27 of the remote controller 22 connected to the output side via the hot water supply control circuit 21. May be displayed to notify the user, and at the same time, an error sound may be emitted from the remote controller 22.

  On the other hand, if the communication port 16 or the inflow pipe 17 located away from the neutralization tank 15 or the neutralization tank 15 itself or the drain pipe 20 near the neutralization tank 15 is clogged with dust or the like, When drain water accumulates below and passes through the inlet 10, drain water flows out from the communication pipe 9 to the communication path 6. Therefore, the exhaust thermistor 26 provided below the inlet 10 contacts the drain water or drain water. If the detected temperature of the exhaust thermistor 26 reaches 20 ° C. to 70 ° C., the hot water supply control circuit 21 will clog the communication port 16, the inflow pipe 17, the neutralization tank 15 and the drain pipe 20 with dust, etc. It is determined that the overflow has occurred, and this is displayed on the display unit 27 of the remote controller 22 connected to the output side to notify the user, and at the same time, the remote controller 22 emits an error sound. It ’s good.

  As a result, only the exhaust thermistor 26 detects clogging of the main heat exchanger 5 due to soot, as well as overflow detection and neutralization of drain water due to clogging of the communication port 16 and the inflow pipe 17 located away from the neutralization tank 15. The neutralization tank 15 close to the tank 15 itself and the drain water leakage due to clogging of the exhaust pipe 20 can also be detected, and a single sensor can easily detect many abnormalities, reducing the number of parts and simplifying the configuration and assembling man-hours. It is possible to reduce costs, and there is no risk of cost reduction or malfunction, and one sensor can be used efficiently. Moreover, detection of clogging of the main heat exchanger 5 prevents abnormal combustion, and it is separated from the neutralization tank 15. In addition, it can accurately detect clogging in a place that is near or conversely, and reliably prevent parts from being oxidized or damaged by overflowing drain water, so that it can be used safely for a long time.

2 Combustion Burner 3 Combustion Fan 5 Main Heat Exchanger 7 Outlet 8 Heat Exchange Case 10 Inlet 14 Auxiliary Heat Exchanger 15 Neutralization Tank 16 Communication Port 19 Neutralizing Agent 26 Exhaust Thermistor

Claims (1)

  A main heat exchanger that recovers sensible heat from the exhaust gas generated by combustion of the combustion burner and heats the flowing water, and the main heat exchanger and the flowing water heated by recovering latent heat from the exhaust gas after heat exchange with the main heat exchanger Auxiliary heat exchanger to be supplied, a heat exchange case that houses the auxiliary heat exchanger and has an exhaust gas inlet above the bottom and an outlet at the top, and an auxiliary heat exchange that communicates with the bottom of the heat exchange case A neutralization tank filled with a neutralizing agent for neutralizing and draining the strongly acidic drain water generated in the vessel, and detecting the exhaust gas temperature in the heat exchange case. The exhaust thermistor for detecting an abnormality of the main heat exchanger is provided, and the exhaust thermistor is provided in the vicinity of the communication port with the neutralization tank at the lower part of the heat exchange case, and the neutralization tank is clogged or the auxiliary heat exchanger Latent heat characterized by detecting and notifying water leaks Osamugata water heater.

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