JPH02223762A - Heating control device for hot water supply equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heating control device for a water heater that starts heating by detecting the inflow of water into a heat exchanger.

[Prior Art] For example, in a gas water heater, when a user turns on the hot water tap to start hot water supply and water flows into the heat exchanger, this is detected by the water flow switch or flow sensor, and the burner is ignited. and heating begins.

On the other hand, the water heater is equipped with a hot water temperature controller (temperature setting device) for setting the hot water temperature so that hot water at a temperature desired by the user can be obtained.

[Problem to be Solved by the Invention 1] In such water heaters, when the hot water tap is closed and the water supply stops, the hot water in the heat exchanger is further heated by residual heat, so the temperature becomes higher than the set temperature. . Therefore,
When the hot water supply is restarted after stopping the hot water supply, the temperature of the hot water flowing out from the heat exchanger becomes higher than the set temperature.

At this time, if there is a large amount of residual heat from the heat exchanger, etc., if the burner heats the water as soon as hot water starts, the temperature of the hot water flowing out of the heat exchanger will be higher than the set temperature, which may be dangerous in some cases. Sometimes.

In addition, if hot water is supplied at a relatively high temperature and then the set temperature is lowered to a lower temperature, even if the residual heat is not very large, the heat exchanger and the hot water inside the heat exchanger may temperature is higher than the newly set set temperature, and by the time the hot water temperature during reheating reaches the new set temperature,
it takes time.

Therefore, when heating starts (by starting hot water supply), even if heating 1 is the heating amount to obtain the new set temperature, the hot water in the heat exchanger will be further heated, so the new set temperature will be changed. It becomes higher than the temperature.

The present invention is a heating control device for a water heater that allows hot water to be safely used when hot water is reheated without being heated more than necessary for the set temperature! ? - The purpose is to provide.

[Means for Solving the Problems] The present invention includes a water flow detection means for detecting water flowing into a heat exchanger, a temperature setting means for setting a target temperature, and a water flow detection means for detecting water flowing into a heat exchanger, and a temperature setting means for setting a target temperature. Temperature detection that detects temperature
In the heating control device for a water heater equipped with 14 stages 2-, the water flow detection means detects the inflow of water into the heat exchanger LQ.
In this case, the technical means is to start heating the heat exchanger according to the temperature difference between the set temperature of the temperature setting means and the temperature detected by the temperature detection means.

[Effect] In the present invention, the inflow of water into the heat exchanger is detected.

Then, the detected temperature of hot water flowing out of the heat exchanger is compared with the set temperature, and heating is started according to the temperature difference.

[Effects of the Invention] In the present invention, since heating is started according to the temperature difference between the outlet temperature and the set temperature at the start of hot water supply, the hot water in the heat exchanger is not heated by residual heat as in the case of reheating hot water. and
If the temperature is -1·min higher than the set temperature, heating will not start immediately.

Therefore, since unnecessary heating is not performed, the water heater can be used safely42 and 5.Also, even if the set temperature is changed after use, Since heating is started, the start of heating can be delayed.

Therefore, overheating relative to the set temperature can be prevented, and the water heater can be used safely.

[Example] Next, a heating control device for a water heater according to the present invention will be described based on an example shown in the drawings.

The gas combustion type water heater 1 shown in FIG. 2 includes a burner group 11 including a plurality of burners arranged in a combustor case 10 that forms a combustion chamber. A blower 12 is provided below the combustor case 10 for supplying combustion air to the burner group 11. Burner group in combustor case 10 ] A water tube type heat exchanger 13 is provided on the F side of the combustor case 10 , and water passing through the inside is heated by combustion heat from the burner group 11 . Near the burner group 11 in the combustor case 10,
a sparker 14 that ignites the burner group 11; and a sparker 14 that ignites the burner group 11;
The frame rod 15 detects ignition of the flame rod 15. Furthermore, an exhaust port 2 is provided above the combustor case 10 for discharging combustion exhaust gas to the outside.

A slanted nozzle pipe 16 for supplying fuel gas is provided below the burner group 11.
A plurality of fuel jets 16a are provided to jet fuel gas corresponding to each burner.

The fuel pipe 20 that guides the fuel gas to the nozzle pipe 6 has two solenoid valves 21 and 22 that allow the fuel gas to pass through when energized.
! Governor proportional valves 23 that adjust the amount of fuel gas supplied by controlling the supply pressure according to the current are provided in order from the upstream side.

A water supply pipe 17 that leads water from a water supply source (not shown) to the heat exchanger 13 is equipped with an electric water flow control device 18 for adjusting the amount of hot water supply, and a water flow switch 19 for detecting water passing through the heat exchanger 13. The heat exchanger 1 is provided in order from the upstream side.
A hot water outlet temperature thermistor 25 for detecting the outlet temperature of hot water flowing out from the heat exchanger 13 is provided in the hot water supply pipe 7a downstream of the hot water supply pipe 3.

The control device 30 is made up of a control circuit centered on a microcomputer, and as shown in FIG. 1, controls the water heater through each functional section of a sequence control section 31, a temperature control section 32, and a drive section 33.

The sequence control unit 31 controls the blower 12, each electromagnetic valve 21, 22, and the sparker 14 in a predetermined sequence in response to the water flow signal from the water flow switch 19, starts the ignition operation, and starts the water flow. When the water signal stops, each solenoid valve 21. ．． 22 to stop combustion.

In particular, here, the detected temperature 1' of the outlet hot water temperature thermistor 25 and the set temperature 'r's set by the controller 40 are
10. By heating, the hot water temperature can be increased.
When i'out exceeds the set temperature 'x''Set, that is, when the detected temperature T is higher than the predetermined temperature Ta (here, Ta is determined based on the condition of Ta<TSet according to the minimum heating amount). When the temperature is set to a certain value (the fixed temperature), heating is not started until the detected temperature () becomes equal to or lower than the predetermined temperature 'T'a.

Therefore, for example, if there is after-boiling during re-supply of hot water, excessive heating is not performed, and therefore overshoot can be reduced.

In addition, in the case where the preset temperature 'rset is reset to a lower value when reheating hot water, excessive heating can be prevented. When it is no longer detected, the fuel supply is stopped using each electromagnetic valve 21 and 22, and the temperature control unit 32 controls the set temperature 'rset of the controller 40 and the hot water temperature thermistor. The combustion amount is determined based on the detected temperature T of No. 25.

The drive section 33 drives the blower 12 according to the combustion amount determined by the temperature control section 32, detects the number of rotations of the blower tl:l, 2, and controls the governor according to the operation G of the blower 12. Controls the proportional valve 23.

Next, the gas combustion water heater 1 of this embodiment having the above configuration
The ignition operation will be explained based on FIG. 3.

Before use, when a hot water tap (not shown) is opened, water flows into the heat exchanger 13 from the water supply pipe 17.

If water flow is detected by the water flow switch 19 (YES in step 1), the detected temperature 1'' is the set temperature 1's
If the temperature is lower than the predetermined temperature Ta (YES in step 2), the blower 12 is controlled to a predetermined rotational speed to supply combustion air and perform blip-purging. is performed, a spark discharge is performed in the sparker 14, each electromagnetic valve 21, 22 is opened, and an ignition operation is performed in which the governor proportional valve 23 is controlled to a predetermined opening degree (step 3), and the burner group 11 Fuel adjusted for ignition is ejected from the fuel injection port 16a of the nozzle 16, mixes with combustion air, and ignites.

If the detected temperature] is equal to or higher than the predetermined temperature Ta, the ignition operation is not performed until the detected temperature becomes lower than the predetermined temperature Ta.

When the ignition of the burner group 11 is detected by the flame rod 15, the temperature of the blower 12 and the governor proportional valve 23 is controlled based on the combustion amount determined by the temperature control section 32, and combustion is performed (step 4〉.

This combustion is performed while water flow is detected (NO in step 5).

When the hot water tap is closed and the water supply stop is detected (YES in step 5), each electromagnetic valve 21, 22 is opened and combustion is stopped (step 6).

As described above, in this embodiment, while the detected temperature 1' of the outlet hot water temperature thermistor 25 is higher than the set temperature "l'set" and the temperature difference is more than a predetermined value, hot water is supplied and the water is not supplied. Even if the hot water flows into the heat exchanger, combustion will not start. Therefore, when hot water is reheated, the hot water outlet temperature 'rout will be set to the set temperature "l".
If the temperature is higher and heating is not required immediately, overshoot will not occur because excessive heating will not occur. Therefore, it can be used safely.

Also, after using it at a high temperature setting of -1'Set,
As in the case where the set temperature Tset is changed to a lower value after a while, there is little heating due to after-boiling, but there is still hot water at a temperature sufficiently higher than the new set temperature 'rset in the heat exchanger. Even in such a case, since heating does not start immediately, unnecessary heating is not performed.

In the above example, the temperature difference between the set temperature and the hot water temperature is
If the predetermined conditions are not met, combustion will not start, but in the case of a water heater that detects the temperature of water entering the heat exchanger, the time until combustion starts will depend on the temperature difference between the outlet temperature and the set temperature. The time t may be determined and measured by a timer, and combustion may be started when the time t has elapsed.

In the above embodiments, the water flow signal was obtained by the water flow switch, but the water flow signal may be obtained by a flow rate sensor.

In the above embodiments, a water heater using a burner fueled by gas is shown, but a water heater using other fuel such as petroleum may be used, or a water heater using electric heating may be used.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing the functional configuration of the control device for the gas combustion water heater of this embodiment, FIG. 2 is a schematic configuration diagram showing the configuration of the gas combustion water heater of this embodiment, and FIG. It is a flowchart for explaining the operation of this embodiment. In the figure, 19... water flow sensor (water flow detection means), 25...
... hot water temperature thermistor (temperature detection means), 30 ... control device (heating control bag fi of water heater), 40 ... controller (temperature setting means).

Claims (1)

[Claims] 1) Water flow detection means for detecting water flowing into the heat exchanger;
In a heating control device for a water heater, comprising a temperature setting means for setting a target temperature, and a temperature detection means for detecting the temperature of hot water flowing out from the heat exchanger, the water flow detection means is configured to flow toward the heat exchanger. Heating control for a water heater, characterized in that when an inflow of water is detected, heating of the heat exchanger is started according to a temperature difference between a set temperature of the temperature setting means and a temperature detected by the temperature detecting means. Device.