JPH04353354A - Control device for heater device - Google Patents

Abstract

PURPOSE:To perform an adequate change from an operation in a forced high combustion mode to another operation in a proportional combustion mode according to the heating load or the wall surface temperature, make a fast rising of a room temperature and make a superior body feeling temperature of a user. CONSTITUTION:A control device composed of a micro-computer and the like stores a room temperature Ti at the beginning of operation (step S1) and makes a maximum combustion amount of a gas burner (step S2). As a specified time elapses from the beginning of operation, the temperature difference T (a temperature gradient) between the room temperature T and an initial room temperature Ti is calculated and stored (steps S3 and S4). In addition, the initial room temperature Ti and the temperature gradient T are referred to a look-up table to calculate a fuzzy inference data To. The transferring temperature Tx is calculated from this inference data To and stored (step S5). After this operation, when the room temperature is higher than Tx, the operation is changed to a combustion control under a proportional combustion mode (steps S6 and S7).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a heater such as a hot air heater or a radiant heater that uses gas or kerosene as fuel.

0002

[Prior Art] Conventionally, for example, hot air heaters were developed in Japanese Patent Application Laid-open No. 63
As disclosed in Publication No. 315857, in the forced strong combustion mode at the beginning of operation, the combustion amount in the burner is controlled to the maximum combustion amount to quickly raise the room temperature, and in the subsequent proportional combustion mode, the combustion amount is controlled to the maximum combustion amount. The combustion chamber is equipped with a control device that proportionally controls the combustion amount between the maximum combustion amount and the minimum combustion amount according to the temperature difference between the set temperature and the room temperature, and maintains the room temperature near the set temperature.

0003

[Problems to be Solved by the Invention] By the way, in the above-mentioned hot air heater control device, when the room temperature reaches a certain temperature (transition temperature) near the set temperature, the forced strong combustion mode is switched to the proportional combustion mode. I was doing it. Since this transition temperature is uniformly determined by the set temperature, depending on the size of the heating load and the wall temperature at the beginning of operation, the transition from forced strong combustion mode to proportional control mode may be too early or too late, causing the user to I was worried that it would cause discomfort.

That is, when the heating load is small, the temperature gradient in the room temperature is large, so the rise in wall temperature is slower than the rise in room temperature. In such a case, if the transition from the forced strong combustion mode to the proportional combustion mode is performed early, the user may feel physically cold immediately after transitioning to the proportional combustion mode.

On the other hand, if the transition from forced strong combustion mode to proportional combustion mode is delayed when the heating load is very small,
The discomfort caused by overshooting the room temperature above the set temperature is greater than the problem of wall temperature. As described above, not only the size of the heating load but also the room temperature (wall temperature) at the beginning of operation has a large influence on the user's perceived temperature.

[0006] This invention was made in view of the above-mentioned facts, and its purpose is to ensure that the transition from the forced strong combustion mode to the proportional combustion mode is carried out appropriately, and to improve the perceived temperature of the user. do.

[0007]

[Means for Solving the Problems] The present invention includes a room temperature detector that detects room temperature, a temperature setting device that adjusts the set temperature, and a temperature sensor that adjusts the set temperature from the start of operation until the room temperature reaches a certain temperature (transition temperature) near the set temperature. During this period, forced strong combustion mode is set, and after that, proportional combustion mode is set. In forced strong combustion mode, the combustion amount in the burner is controlled to the maximum combustion amount, and in proportional combustion mode, the combustion amount in the burner is set. Equipped with a control means such as a microcomputer that performs proportional control between the maximum combustion amount and the minimum combustion amount according to the temperature difference between the temperature and the room temperature,
This control means shifts from the forced strong combustion mode to the proportional control mode based on fuzzy inference data obtained from the room temperature at the beginning of operation, or the temperature difference between the set temperature and the room temperature, and the temperature gradient of the room temperature after the start of operation. Configured to change temperature.

[0008]

[Operation] With this configuration, the wall temperature is estimated from the room temperature at the beginning of operation or the temperature difference between the set temperature and the room temperature, and the size of the heating load is estimated from the temperature gradient of the room temperature after the start of operation. Ru. Then, the transition temperature from forced strong combustion mode to proportional combustion mode is changed based on fuzzy inference data obtained from these data, so forced strong combustion not only quickly brings the room temperature close to the set temperature. Combustion control is performed in accordance with the rise in room temperature and wall temperature, and it is possible to avoid causing discomfort to the user as the combustion control mode shifts.

[0009]

[Embodiment] An embodiment in which the present invention is applied to a gas fan heater will be described below.

In FIG. 2, reference numeral 1 denotes an exterior case having an air intake port 2 on the back and a warm air outlet 3 at the lower front. A blower guide case 4 is provided to guide the warm air to the hot air outlet 3. A gas burner 5, a combustion chamber 6 facing the gas burner 5, a ventilation fan 7, and a heat shield plate 8 are provided in the ventilation guide case 4. Further, an igniter 10 is attached to the combustion chamber wall 9. 11 is a room temperature detector such as a thermistor installed near the air intake port 2; 12
is a fuel supply device that supplies gas fuel to the gas burner 5, which includes a gas pipe 13, a proportional control valve 14, and two solenoid valves 1.
It consists of 5 and 16. Further, 17 is a control device that controls combustion in the gas burner 5.

FIG. 3 shows the basic configuration of the control device 17. In FIG. 3, numeral 18 is a microcomputer (hereinafter referred to as microcomputer) as a control means having a built-in A/D converter, and the input side of the microcomputer 19 includes an operation switch 19, a temperature setting device 20, and a room temperature detector. 11 are provided. Further, on the output side of the microcomputer 18, a proportional control valve 14, solenoid valves 15 and 16, an igniter 10, and a blower fan 7 are provided. Reference numeral 24 denotes a rotation speed detector of the blower fan 7, and a rotation speed signal of this rotation speed detector 24 is input to the microcomputer 19.

A combustion control program shown in the flowchart of FIG. 1 is stored in the microcomputer 18, and when the operation switch 19 is turned on, the microcomputer 18 performs the following combustion control (steps S1 to S1 in FIG. 1). (See S7).

When the operation switch 19 is turned on, the microcomputer 18 converts the room temperature T detected by the room temperature detector 11 into the initial room temperature T.
Store as i. In addition, the upper limit control temperature T is obtained by increasing or decreasing the set temperature Ts adjusted by the temperature setting device 20 by a constant temperature α.
h(Ts+α) and lower limit control temperature Tl(Ts−α) are respectively determined and stored. Also, at this time, microcomputer 1
8 performs combustion control in a forced strong combustion mode so that the gas burner 5 performs combustion.

That is, the microcomputer 18 first operates the blower fan 7 to pre-purge the gas burner 5, and then operates the igniter 10, opens the proportional control valve 14 and the solenoid valves 15 and 16, and turns on the gas burner. Start combustion at 5. Further, the valve opening degree of the proportional control valve 14 is maximized, and the amount of air blown by the ventilation fan 7 is controlled to the maximum amount commensurate with the amount of fuel supplied to the gas burner 5.
combustion at maximum combustion rate. Of course, the amount of hot air blown out from the hot air outlet 3 is also maximized,
Room temperature rises rapidly.

When a certain period of time has elapsed since the start of operation, the microcomputer 18 determines and stores the temperature difference ΔT (temperature gradient) between the temperature T detected by the room temperature detector 11 at that time and the initial room temperature Ti. Then, by comparing the initial room temperature Ti and the temperature gradient ΔT with a look-up table as shown in Table 1, a corrected temperature To is obtained, and by adding this corrected temperature To to the lower limit control temperature Tl, the forced strong combustion mode is set. The transition temperature Tx to the proportional combustion mode is determined and stored.

[0016]

[Table 1]

The above-mentioned lookup table is determined as follows and is stored in the microcomputer 18 in advance.

First, the following conditions are determined based on past experience and experimental data. b) Estimate the heating load based on the temperature gradient ΔT. b) When the temperature gradient ΔT is large (heating load is small),
Since the rise in wall temperature is slower than the rise in room temperature, the wall temperature should be improved. c) When the temperature gradient ΔT is very large, the discomfort due to overshoot is greater than the improvement in wall temperature, so the improvement in wall temperature should be limited. d) When the room temperature (wall temperature) is high, the wall temperature will not be improved. e) When the temperature gradient is small (heating load is large), there is little delay in the rise in wall temperature relative to the rise in room temperature, so no improvement is made to the wall temperature.

The fuzzy rules determined by these conditions are as shown in Table 2. Based on this fuzzy rule, fuzzy inference is performed from the initial room temperature Ti and the temperature gradient ΔT, and the obtained data is organized into the lookup table shown in Table 1. Of course, instead of storing the lookup table in microcontroller 18, microcontroller 1
The transition temperature Tx may be determined based on the data obtained as a result of fuzzy inference.

[0020]

[Table 2]

[0021] Once the transition temperature Tx is determined in this way,
The microcomputer 18 compares the room temperature T and the transition temperature Tx. When the room temperature T becomes equal to or higher than the transition temperature Tx, the combustion control in the forced strong combustion mode shifts to the combustion control in the proportional combustion mode. In this proportional combustion mode, as shown in FIG. 4, when the room temperature T is below the lower limit control temperature Tl, the gas burner 5
When the combustion amount Q at the gas burner 5 becomes the maximum (Qmax) and the room temperature T is higher than the upper limit control temperature Th, the combustion amount Q at the gas burner 5 becomes the minimum (Qmin), and when the room temperature T is between Th and Tl, the combustion The quantity Q is controlled between Qmax and Qmin continuously or in multiple stages. Therefore, the room temperature T can be accurately maintained near the set temperature Ts.

FIG. 5 shows the control characteristics of the gas fan heater control device described above. ■ in Figure 5 is the temperature gradient Δ
This figure shows a case where T is relatively large and the initial room temperature Ti is relatively high. In this case, for example, α is set to 2deg.
Then, the transition temperature Tx becomes 1 degree higher than Tl, and the overshoot is slightly increased to improve the wall temperature. On the other hand, when the temperature gradient ΔT is larger than ■, To is 0.6 deg, and the wall temperature is improved to the extent that discomfort due to overshoot does not increase. Also, when the temperature gradient is smaller than ■, as in ■, there is less delay in the rise in wall temperature with respect to the rise in room temperature, so To is 0.
．． At 6deg, the improvement in wall temperature will be modest.

[0023] ■The temperature gradient ΔT is relatively large, and
This shows a case where the initial room temperature Ti is low. In this case, To is 2.6 degrees, and the wall temperature is sufficiently improved by utilizing overshoot. On the other hand, in the case of ■ where the temperature gradient ΔT is larger than ■, overshoot is taken into consideration, and in the case of ■ where the temperature gradient ΔT is smaller than ■, the rise in wall temperature follows the rise in room temperature. Considering that, the improvement in wall temperature will be smaller than ■.

In the embodiment described above, the transition temperature T is determined based on the fuzzy inference data obtained from the room temperature Ti at the beginning of operation and the temperature gradient ΔT of the room temperature T after the start of operation.
Although x is changed, the transition temperature Tx may be changed by performing a fuzzy calculation based on the temperature difference between the room temperature Ti and the set temperature Ts at the beginning of the operation and the temperature gradient ΔT.

[0025]

[Effects of the Invention] Since the present invention is configured as described above, the amount of combustion in the burner is maximized at the beginning of heating operation, and the room temperature can be quickly raised to near the set temperature, and thereafter, the burner The amount of combustion is controlled proportionally according to the heating load, making it possible to maintain the room temperature close to the set temperature with high precision.Not only is the room temperature controlled well, but the transition from forced strong combustion mode to proportional combustion mode is also possible. This is done appropriately according to not only the heating load but also the wall temperature, and it is possible to prevent discomfort to the user due to room temperature overshoot or radiation from the wall immediately after the transition from forced strong combustion mode to proportional combustion mode. It is possible to improve the sensible temperature of the user.

[Brief explanation of drawings]

FIG. 1 is a flowchart for explaining the operation of an embodiment of the present invention.

FIG. 2 is a schematic configuration explanatory diagram of a gas fan heater showing an example of a hot air heater.

FIG. 3 is a block diagram of a control device showing an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing the relationship between room temperature (set temperature) and combustion amount in proportional combustion mode.

FIG. 5 is an explanatory diagram of control characteristics of a control device according to an embodiment of the present invention.

[Explanation of symbols]

5 Gas burner 11 Room temperature detector 17 Control device 18 Microcomputer 19 Operation switch 20 Temperature setting device

Claims (1)

[Claims] Claim 1: A room temperature detector that detects the room temperature, a temperature setting device that adjusts the set temperature, and a forced strong combustion mode from the start of operation until the room temperature reaches a certain temperature (transition temperature) near the set temperature. , and after that, the proportional combustion mode is set. In the forced strong combustion mode, the combustion amount in the burner is controlled to the maximum combustion amount, and in the proportional combustion mode, the combustion amount in the burner is controlled to the temperature difference between the set temperature and the room temperature. The controller is equipped with a control means such as a microcomputer that performs proportional control between the maximum combustion amount and the minimum combustion amount, and this control means controls the room temperature at the beginning of operation, or the temperature difference between the set temperature and the room temperature, and the temperature difference between the set temperature and the room temperature after the start of operation. A control device for a heater, characterized in that the control device is configured to change a transition temperature from a forced strong combustion mode to a proportional control mode based on fuzzy inference data obtained from a temperature gradient of a room temperature.