JP3845240B2 - Hot water circulation boiler - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot water circulating boiler, and is intended to detect an abnormality such as sticking of heat exchangers and perform a safe operation.
[0002]
[Prior art]
Conventionally, in this type of hot water circulating boiler, soot has accumulated on the exhaust path and the heat transfer surface of the heat exchanger after long-term use. When soot accumulates on the heat transfer surface of the heat exchanger, the heat insulation effect and the exhaust path blockage cause insufficient air for combustion, reducing the combustion efficiency of the burner and causing incomplete combustion. .
[0003]
In order to solve this problem, in a conventional water heater, as disclosed in, for example, Japanese Patent Laid-Open No. 5-196229, the flow rate sensor built in the hot water outlet via the heat exchanger and the temperature sensor signal The heat efficiency is calculated by calculating the heat transfer amount in the heat exchanger calculated based on the signal from the temperature sensor provided on the inlet side of the heat exchanger and the burner combustion amount, and this heat efficiency is extremely reduced. In some cases, it was judged that soot had accumulated on the heat exchanger.
[0004]
Further, for example, as disclosed in Japanese Patent Laid-Open No. 9-152128, the temperature increase rate of the detected temperature is calculated by the temperature sensor at the outlet of the heat exchanger and the time measuring means, and compared with a reference temperature increase rate set in advance by a test. In some cases, an abnormality of the heat exchanger is detected when the calculated rising speed is slower.
[0005]
[Problems to be solved by the invention]
By the way, in the conventional one disclosed in Japanese Patent Laid-Open No. 5-196229, the configuration and calculation processing are complicated, a lot of sensors are required, and if the accuracy of the sensor is low, it is impossible to calculate an accurate thermal efficiency. The cost for detecting is increased.
[0006]
Further, in the one disclosed in Japanese Patent Laid-Open No. 9-152128, a complicated calculation and an expensive sensor are not necessary, but in a complicated load condition and usage environment such as a hot water circulating boiler, It was very difficult to set a constant reference temperature increase rate under all conditions.
[0007]
[Means for Solving the Problems]
The present invention pays attention to this point, and in order to solve the above-mentioned drawbacks, in particular, the configuration thereof is provided with a burner and a heat exchanger so that hot water can be circulated through a circulation pipe , and a remote controller, an outgoing temperature sensor and a return temperature In a hot water circulating boiler that burns the burner with a combustion amount corresponding to the calculated heat demand in response to an input from the sensor, the duration of the large burner combustion of the burner is counted, An abnormality detection timer is provided that resets the count time when the combustion amount decreases after the count starts. When the abnormality detection timer counts a predetermined time or more, it is determined that soot is accumulated on the heat exchanger and combustion is performed. A control device for stopping is provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, when the soot accumulates on the heat exchanger 14 and the heat exchange rate decreases and the temperature of the circulating hot water does not rise, the abnormality detection timer 29 causes the large thermal power to continue. When the duration of combustion is counted and the abnormality detection timer 29 counts for a predetermined time (here, 6 hours) or more, the control device 28 is safe because soot has accumulated on the heat transfer surface of the heat exchanger 14. Therefore, when the combustion of the burner 15 is stopped, and the load is simply large, the count time of the abnormality detection timer 29 is reset when the combustion amount decreases due to the decrease in the load accompanying the continuation of combustion. Unnecessary combustion stop due to malfunction is not performed.
[0009]
【Example】
An embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a hot water circulation boiler, and hot water heated by the boiler 1 passes through a forward pipe 2 and a forward header 3 to a plurality of snow-melting radiators 4 embedded in the ground. Circulation which is diverted and circulates through each of the snow-melting radiators 4 and melts the snow piled up on the sidewalk, etc., then merges at the return header 5, passes through the return pipe 6 and circulates and circulates again to the boiler 1. A conduit 7 is provided.
[0010]
Reference numeral 8 denotes a remote controller for instructing the start and stop of the operation of the boiler 1, which has an operation switch 9 and is connected to the snowfall sensor control unit 10. The snowfall sensor controller 10 includes a waterfall sensor 11 and an outside air temperature sensor (both not shown), and a snowfall sensor 11 for detecting the presence or absence of snowfall, and an underground temperature embedded in the vicinity of the radiator 4 for melting snow. The snow temperature sensor control unit 10 starts operation of the boiler 1 when the snow begins to fall, and thereafter the ground temperature is raised to a certain temperature or more and the snow falls. Is stopped, the boiler 1 is instructed via the remote controller 8 to stop the operation of the boiler 1.
[0011]
Next, the boiler 1 will be described.
In FIG. 2, 13 is a circulation return port which is connected to the return pipe 6 and is used for melting snow by a heat sink 4 for melting snow and returned to warm water whose temperature has decreased, and 14 is provided with a burner 15 at the bottom. Provided is a once-through heat exchanger for heating hot water returned from the circulation return port 13, 16 is a mixing tank for equalizing the temperature of hot water discharged from the heat exchanger 14, and 17 is the mixing tank. Reference numeral 18 denotes a circulation pump that circulates hot water in the circulation pipe 7 on the downstream side of 16, and 18 is connected to the forward pipe 2, and the hot water heated by the heat exchanger 14 is sent to the radiator 4 for melting snow. A circulation outlet, 19 is an expansion tank that absorbs the expansion of the heated hot water, and 20 is a downstream side of the heat exchanger 14 and detects the temperature of the hot water leaving the heat exchanger 14. 21 is a forward temperature sensor A return temperature sensor for detecting the temperature of hot water flowing into the heat exchanger 14 provided downstream of the radiator 4.
[0012]
The burner 15 is vaporized by spraying kerosene with a fuel pump 24 on a vaporizer 23 heated by a vaporization heater 22, and mixing the vaporized gas with combustion air from a combustion blower 25. Combustion gas is passed through the once-through heat exchanger 14 to heat the hot water and exhausted from an exhaust top 27 provided on the top of the heat exchanger 14. The burner 15 is a fuel pump 24. The combustion amount can be varied by controlling the capacity of the blower 25 and the combustion blower 25. Here, the combustion amount can be varied in three stages of “large”, “medium”, and “small” according to heat demand. Yes.
[0013]
Here, the burner 15 using kerosene as the fuel is used. However, the present invention is not limited to this, and a gas burner having a variable combustion amount using gas fuel may be used, and the heat exchanger 14 is a once-through type. Not only this but a fin tube type heat exchanger may be sufficient.
[0014]
A control device 28 controls the boiler 1 with a microcomputer (not shown) as a main body. The control device 28 receives heat inputs from the remote controller 8, the forward temperature sensor 20, and the return temperature sensor 21, and calculates the heat demand. The vaporization heater 22, the fuel pump 23, the combustion blower 25, and the circulation pump 17 are driven and controlled so that the burner burns at a combustion amount corresponding to the heat demand.
[0015]
Further, the control device 28 has an abnormality detection timer 29 that counts the time when the combustion amount is “large” and resets the count time when the combustion amount falls from “large” to “medium” after starting the counting. However, the hot water temperature does not rise even though it is burning with a large thermal power, and the large thermal power is continued, and the abnormality detection timer 29 counts a predetermined time (here, 6 hours) predetermined by a test or the like. Then, an output indicating an abnormality is generated in the heat exchanger 14 as an abnormality due to deposition of soot and oxide, and the control device 28 stops the combustion of the burner 15 in response to this output, and further an indicator Etc. (not shown) are notified to the effect that the operation has been stopped due to an abnormality of the heat exchanger, and is intended to ensure safety.
[0016]
Next, the operation of this embodiment will be described based on the flowchart of FIG.
First, in step 1 (hereinafter abbreviated as S1), it is checked whether or not the operation switch 9 is turned on. If the operation switch 9 is turned on, the control device 28 calculates the heat demand according to the output of the forward temperature sensor 20 and the return temperature sensor 21 in the next S2. If the heat demand is “large”, “Yes” is obtained in S3, and the process proceeds to the next S4 to burn the burner 15 with a large heating power.
[0017]
When the burner 15 starts large thermal combustion, the abnormality detection timer 29 starts counting in the next S5. After the abnormality detection timer 29 starts counting, a new heat request is calculated in the next S6, and if the heat request is “large”, the burner 15 continues to burn and the abnormality detection timer 29 counts. Then, “Yes” is set in S7, and the process proceeds to the next S8. In S8, the count time of the abnormality detection timer 29 is compared with a predetermined time (here, 6 hours) preset by a test or the like. At this time, since the count time of the abnormality detection timer 29 is less than the predetermined time, the process returns to S6 and the heat request is calculated again.
[0018]
When the large thermal power combustion continues and the count time of the abnormality detection timer 29 counts over a predetermined time, “Yes” is obtained in S8, the process proceeds to the next S9, the burner 15 is stopped, and the heat exchange is performed on the display unit in the next S10. The device 14 is informed that there is an abnormality. This notification can display, for example, the fact that there is an abnormality in the heat exchanger 14 with an error code on the segment display, or can notify that an abnormality has occurred with a buzzer sound along with the error code display. It is further preferable that the control device 28 is locked out together with the operation stop so that the user does not start the operation simply by pressing the operation switch 9, and the operation can be started after maintenance by a repairer or the like.
[0019]
Next, the combustion amount is calculated in S2, and if the heat demand is other than “large”, “No” is determined in S3, and the process proceeds to S11. If the heat demand calculated in S2 is “medium”, the answer is “Yes” in S11, and the process proceeds to S12 to burn the burner 15 with medium heating power, and the count time of the abnormality detection timer 29 is reset in the next S13. To do.
[0020]
If the heat demand calculated in S2 is “Small”, “No” in S3 and S11, the process proceeds to S14, “Yes” in S14, the process proceeds to S15, and the burner 15 is burned with small thermal power, and in the next S16. The abnormality detection timer 29 is reset. If there is no heat request calculated in S2, the process proceeds to S17 with "No" in S3, S11, and S14, the burner 15 is extinguished, and the abnormality detection timer 29 is reset in the next S18.
[0021]
In addition, when the heat demand calculated in S2 or S6 is “Large” and the burner 15 is burned with great thermal power, the heat demand newly calculated in S6 becomes “Medium” or less. In S7, “No” is set, and the burner 15 is combusted in response to a new heat request, and the abnormality detection timer 29 is reset.
[0022]
When the heat demand becomes “large” or less in this way, combustion is performed at a combustion amount corresponding to each heat demand or the fire is extinguished and the abnormality detection timer 29 is reset, and the process returns to S2 again to monitor the continuation of the large thermal power combustion. It will continue.
[0023]
Although the present embodiment has been described as a hot water circulation boiler for melting snow, the present invention is not limited to this, and can also be used for heating, for example, hot water that is meanderingly disposed in a house floor as the radiator 4. The present invention is also useful for a floor heating system using a pipe, and a hot air heating apparatus that performs heating by a fan convector, a panel radiator, or the like installed indoors as the radiator 4.
[0024]
【The invention's effect】
As described above, according to the present invention, it is not necessary to set difficult calculations and conditions as in the prior art, and combustion is stopped when the count of the abnormality detection timer that counts the duration of large thermal combustion exceeds a predetermined time. Therefore, it is possible to reliably detect abnormalities such as soot sticking to the heat exchanger with simple control and condition settings, and to perform safe operation. Since the count time of the abnormality detection timer is reset when the combustion amount is reduced due to the decrease in the amount of combustion, unnecessary combustion stop due to malfunction is not performed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a boiler according to the embodiment.
FIG. 3 is a block diagram of a control apparatus according to the embodiment.
FIG. 4 is a flowchart showing the operation of the embodiment.
[Explanation of symbols]
1 Boiler 4 Radiator 7 Circulation Line 14 Heat Exchanger 15 Burner 20 Outward Temperature Sensor 21 Return Temperature Sensor 28 Controller 29 Abnormality Detection Timer

Claims (1)

It is equipped with a burner and a heat exchanger so that hot water can be circulated through a circulation line , receives heat input from the remote control, the forward temperature sensor, and the return temperature sensor, calculates the heat demand, and responds to the calculated heat demand. In the hot water circulation boiler that burns the burner with the combustion amount, the duration time of the large-burning combustion of the burner is counted, and an abnormality detection timer is provided that resets the counting time when the combustion amount decreases after starting the counting, A hot water circulating boiler comprising a control device for determining that soot and the like are accumulated in the heat exchanger and stopping combustion when the abnormality detection timer counts a predetermined time or more.

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