JPH0762560B2 - Combustion control device for hot water boiler - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a combustion control device for a hot water boiler.

[0002]

2. Description of the Related Art Conventionally, in a hot water storage type hot water boiler,
The hot water temperature inside the can is detected, and the burner is ON / OFF controlled based on the detected temperature. For example, when the hot water temperature reaches 65 ° C., the burner is stopped, and when the hot water temperature drops to 60 ° C., the burner is operated.

[0003]

In the hot water boiler having such a structure, if the temperature sensor for detecting the hot water temperature in the can fails (disconnection of the electric circuit, etc.), the operation of the hot water boiler becomes uncontrollable, resulting in an emergency. Become dangerous. Incorrect operation control may cause not only damage to the hot water boiler itself but also a serious accident. Therefore, normally, when the temperature sensor fails, the operation of the boiler is forcibly stopped to ensure safety. However, when the operation of the hot water boiler suddenly stops, the hot water used up to that point suddenly disappears, which makes it very inconvenient for practical use. Also, until the failure of the temperature sensor is repaired, the operation of the hot water boiler cannot be restarted, and if it can be repaired in a short time,
When the temperature sensor or the like needs to be replaced, a long repair period is required and hot water cannot be used at all during that period.
This is a fatal situation in the service industry such as hotels.

[0004]

The present invention has been made in view of the above problems, and a hot water boiler is provided with a first temperature sensor for detecting the temperature of hot water in a can to supply hot water to a load. A second temperature sensor for detecting the temperature of hot water in the line is provided in the line, and the detected temperature data of the first temperature sensor corresponding to the predetermined detected temperature of the second temperature sensor (corresponding to the predetermined detected temperature of the first temperature sensor the temperature data storing means for storing the detected temperature data) of the second temperature sensor is provided, the normal operation of the second temperature sensor (first temperature sensor), the detected temperature T ₂ (detection of the first temperature sensor of the second temperature sensor Temperature T ₁ )
A combustion control signal is output to a burner attached to the hot water boiler in accordance with the value of, and when the second temperature sensor (first temperature sensor) fails, the first temperature is stored based on the temperature data stored in the temperature data storage means. It is characterized in that combustion control means for outputting a combustion control signal to the burner in accordance with the value of the temperature T ₁ detected by the sensor (the temperature T ₂ detected by the second temperature sensor) is provided.

[0005]

According to the above configuration, when the second temperature sensor (first temperature sensor) fails, the reference temperature for performing burner combustion control is set to the detected temperature T ₁ of the first temperature sensor (second temperature sensor Detection temperature T ₂ ) and the detection temperature T of the first temperature sensor is detected based on the data stored in the temperature data storage means.
_A combustion control signal can be output to the burner according to the value of ₁ (the temperature T ₂ detected by the second temperature sensor), and the operation of the boiler can be continued without stopping combustion.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a system configuration diagram of a hot water boiler according to an embodiment of the present invention. (3) is a once-through hot water boiler, which connects a number of vertical water pipes between the upper and lower headers and heats the water pipes by a burner (7) to heat the water in the water pipes To A circulation pump (11) and a heat exchanger (12) are connected in series by piping between the hot water outlet (9) and the hot water return port (10) of the hot water boiler (3). (13) is a three-way valve, the hot water outlet on the load side of the heat exchanger (12)
It is inserted in the hot water supply line (5) connected to (14), so that the temperature of the hot water supplied to the load (4) such as curran becomes constant.
The mixing ratio of the amount of hot water from the heat exchanger (12) and the amount of cold water from the cistern tank (15) is automatically controlled.

The first temperature sensor (1) is a hot water boiler (3)
The hot water temperature inside the can is detected. The second temperature sensor (2) detects the temperature of hot water in the hot water supply line (5). (6) is temperature data storage means for storing data relating to the correlation between the temperature T ₁ detected by the first temperature sensor (1) and the temperature T ₂ detected by the second temperature sensor (2). There is.
Reference numeral (8) is a combustion control means, which sends a combustion control signal to the burner (7) according to the detected temperature value of one of the first temperature sensor (1) and the second temperature sensor (2). In addition to having a function to output, when the temperature sensor fails (due to disconnection, etc.), the reference temperature for controlling the combustion of the burner (7) is switched to the temperature detected by the other temperature sensor to perform the combustion control. have. That is, while the combustion control signal is being output to the burner (7) according to the value of the temperature T ₂ detected by the second temperature sensor (2), if the second temperature sensor (2) fails, the burner (7) The reference temperature for performing the combustion control of the first temperature sensor (1) is switched to the temperature T ₁ detected by the first temperature sensor (1), and the first temperature based on the data stored in the temperature data storage means (6)
Depending on the value of the temperature T ₁ detected by the temperature sensor (1), the burner (7)
Output a combustion control signal to the first temperature sensor
If the first temperature sensor (1) fails while the combustion control signal is being output to the burner (7) according to the value of the temperature T ₁ detected by (1), the combustion control of the burner (7) will be performed. accordance with the reference temperature detection switch to temperature T _2, the value of the detected temperature T ₂ of the second temperature sensor (2) on the basis of the data stored in the temperature data storing means (6) of the second temperature sensor (2) Output a combustion control signal to the burner (7).

Next, an example of the control circuit will be described with reference to FIG. (7) is a burner, (11) is a circulation pump, (16) is a liquid crystal display, (17) is a driving switch, (1) is a first temperature sensor, and (2) is a second temperature sensor. The liquid crystal display (16) displays a driving state and the like. (6) is a temperature data storage means for storing the above-mentioned data regarding the hot water temperature. (8) is a combustion control means composed of a microcomputer, and the control procedure is stored in advance in its internal memory or external memory. For example, the second temperature sensor
When the detected temperature T ₂ of (2) becomes the set temperature T ₂₀ or higher, the combustion stop signal is output to the burner (7), and when it becomes the set temperature T ₂₁ or lower, the combustion start signal is output to the burner (7). To do. Further, this control procedure includes the backup control operation which is a feature of the present invention.

Below, referring to FIGS. 3 and 4, the case where the combustion stop signal and the combustion start signal are output to the burner (7) according to the value of the temperature T ₂ detected by the second temperature sensor (2), A specific example of the combustion control will be described (at this time, the first temperature sensor is used as a safety means for detecting and displaying the temperature of hot water in the can and for stopping combustion when an abnormally high temperature is detected). ON-OFF to burner (7) in step S1
The detected temperature of the first temperature sensor (1) when the control signal is output is stored in the temperature data storage means (6). A concrete example of the control routine is shown in FIG.
Whether the combustion control means (8) has output an OFF control signal (combustion stop signal) or an ON control signal (combustion start signal) to the burner (7) based on the output signal of the temperature sensor (2) Monitor and judge. As the determination method in step S11, the determination is not made based on the burner control output signal of the combustion control means (8), but the second temperature sensor is directly used.
The determination may be made based on the output signal of (2). When the OFF control signal is confirmed in step S11, the process proceeds to step S12, and the temperature detected by the first temperature sensor (1) at that time is stored in the temperature data storage means (6). Step S
When the ON control signal is confirmed in 11, the process proceeds to step S13, and the detected temperature of the first temperature sensor (1) at that time is stored in the temperature data storage means (6). Thus, the temperature data storage means (6) is turned on from the combustion control means (8) to the burner (7).
Each time the OFF control signal is output, the detected temperature of the first temperature sensor (1) at that time is written (stored).
This detected temperature substantially corresponds to the detected temperature of the second temperature sensor (2) as shown in the graph of FIG.
Only a pair of the ON control signal output temperature and the OFF control signal output temperature is stored in the temperature data storage means (6), and a new ON control signal output temperature and OFF control signal output temperature are input. The data is rewritten for each.

Next, in step S2, the second temperature sensor
Determine whether (2) is normal. This determination is made by a known disconnection detecting means or the like. If YES is determined here, the routine proceeds to step S3, and the combustion control by the second temperature sensor (2) is continued.

If NO is determined in step S2, the process proceeds to step S4. Here, as backup data, it is determined whether or not a pair of temperatures detected by the first temperature sensor (1) corresponding to the ON-OFF control signal output of the second temperature sensor (2) is stored. For example, if the second temperature sensor (2) fails at time t _{0 as} shown in FIG.
The temperature data storage means (6) has ON control signal output value: T ₁₄ and OFF control signal output value: T as backup data.
₁₃ and ₁₃ are remembered. Therefore, the determination in step S4 is YES, the process proceeds to step S5, and the combustion control is switched to the first temperature sensor (1). The burner ON control temperature and the burner OFF control temperature at this time are the above-mentioned T ₁₄ and T ₁₃ , respectively. The first temperature sensor (1)
If only one of the ON control signal output value and the OFF control signal output value exists as the detected temperature of, or if there is a contradiction such as ON control signal output value> OFF control signal output value, Appropriate values are appropriately selected or calculated and used.

If NO is determined in step S4,
In step S6, the combustion control is performed according to the preset ON-OFF default value of the first temperature sensor (1). In this case, since the default value is not based on the actual measurement data for each can, it may not always be suitable as data for backup control. Therefore, the operation of the boiler may be stopped in step S6.

The present invention is not limited to the above embodiment, but can be applied to a system having a structure in which a heat exchanger is not provided as shown in FIG. The temperature data storage means (6) may be provided with a memory area capable of storing a plurality of pairs of temperature control signal output temperature data and OFF control signal output temperature data. In this case, the average value of a plurality of pairs of data is used as backup data during the process of step S5. When the temperature sensor is out of order, the boiler operation manager is notified of that fact, and a message such as "temperature sensor out of order, backup operation in progress" is displayed on the display.

[0014]

EFFECTS OF THE INVENTION Since the present invention has the above-described structure, even if the temperature sensor for combustion control fails, the combustion control of the boiler can be continued by the other normal temperature sensor. It is possible to stably supply hot water having a predetermined temperature without stopping the operation. Then, repairs and component replacements can be carried out at a time frame (such as midnight) that does not hinder the stable supply of hot water. Further, an existing temperature sensor can be used as the backup control temperature sensor, and a low-cost control device can be provided as compared with the case where a backup sensor is separately provided.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing an outline of a control circuit in one embodiment of the present invention.

FIG. 3 is a flowchart showing a main control operation according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a main control operation in the embodiment of the present invention.

FIG. 5 is a graph showing the correlation of changes in hot water temperature.

FIG. 6 is a system configuration diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1 First Temperature Sensor 2 Second Temperature Sensor 3 Hot Water Boiler 4 Load 5 Hot Water Supply Line 6 Temperature Data Storage Means 7 Burner 8 Combustion Control Means

Claims (2)

[Claims] 1. A hot water boiler (3) is provided with a first temperature sensor (1) for detecting the temperature of hot water in a can, and the hot water temperature in the line is supplied to a hot water supply line (5) for supplying hot water to a load (4). A second temperature sensor (2) for detecting is provided, and a temperature data storage means (6) for storing temperature data detected by the first temperature sensor (1) corresponding to a predetermined detection temperature of the second temperature sensor (2) is provided. During normal operation of the second temperature sensor (2), a burner attached to the hot water boiler (3) according to the value of the temperature T ₂ detected by the second temperature sensor (2).
A combustion control signal is output to (7), and when the second temperature sensor (2) fails, the temperature T ₁ detected by the first temperature sensor (1) is detected based on the temperature data stored in the temperature data storage means (6). A combustion control device for a hot water boiler, comprising combustion control means (8) for outputting a combustion control signal to a burner (7) according to the value of. 2. A hot water boiler (3) is provided with a first temperature sensor (1) for detecting the temperature of hot water in a can, and the hot water temperature in the line is supplied to a hot water supply line (5) for supplying hot water to a load (4). A second temperature sensor (2) for detecting is provided, and temperature data storage means (6) for storing the temperature data detected by the second temperature sensor (2) corresponding to the predetermined temperature detected by the first temperature sensor (1) is provided. During normal operation of the first temperature sensor (1), a burner attached to the hot water boiler (3) according to the value of the temperature T ₁ detected by the first temperature sensor (1).
A combustion control signal is output to (7), and when the first temperature sensor (1) fails, the temperature T ₂ detected by the second temperature sensor (2) is detected based on the temperature data stored in the temperature data storage means (6). A combustion control device for a hot water boiler, comprising combustion control means (8) for outputting a combustion control signal to a burner (7) according to the value of.