JP2018141578A - Hot air heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of appropriately operating an air blowing fan when heating by using an electric heater is started in a hot air heater having a burner and the electric heater.SOLUTION: This invention relates to a hot air heater. The hot air heater includes: a casing having an air supply port and a blowout port; a burner for heating air by burning fuel; an electric heater for heating the air by converting electric power into heat; an overheating prevention temperature sensor for detecting a temperature inside the casing; an air blowing fan for taking in the air from an indoor side via the air supply port, causing the air to pass through the burner and the electric heater and sending out the air to an indoor side via the blowout port; and a control device. When heating by the electric heater is started, in accordance with a detection value obtained by the overheating prevention temperature sensor when heating by using the electric heater is heated, the control device executes forced fan operation different from normal fan operation that is normally performed by the air blowing fan through heating by the electric heater.SELECTED DRAWING: Figure 8

Description

  The present specification relates to a hot air heater.

  Patent Document 1 discloses a housing including an air supply port and an air outlet, a burner that burns fuel to heat air, an electric heater that converts electric power into heat and heats the air, and an air supply port. A hot air heater including a blower fan that takes in air from a room, passes a burner and an electric heater, and sends the air into the room through an air outlet, and a controller is disclosed.

JP-A-7-318166

  In the technique of Patent Document 1, the blower fan is continuously driven even after the burner is extinguished, and heating by the electric heater is started after a predetermined time has elapsed. However, since the electric heater requires a certain amount of time from the start of heating until the temperature rises, it is preferable that heating by the electric heater can be started immediately after extinguishing the burner.

  When heating by the electric heater can be started at a desired timing after the burner is extinguished, the internal state of the hot air heater varies depending on the timing at which the heating by the electric heater is started. For this reason, when starting the heating by the electric heater and performing the normal fan operation normally performed by the blower fan in the heating by the electric heater, there is a risk of causing a problem in the operation of the hot air heater. For example, when the hot air heater includes an overheat prevention temperature sensor that detects the temperature inside the housing, the overheat prevention temperature sensor is heated to high temperature by heating with the burner when the burner is extinguished. When the overheat prevention temperature sensor becomes hot due to heating by the burner, when heating by the electric heater is started and the blower fan performs normal fan operation, the electric heater is operating at a normal temperature. The overheat prevention temperature sensor may detect an abnormally high temperature. Alternatively, when the inside of the hot air heater is sufficiently cooled, when heating by the electric heater is started and the blower fan performs a normal fan operation, the cold air is given to the user until the temperature of the electric heater rises. There is a risk of giving a feeling.

  In this specification, the technique which solves the said subject is provided. In this specification, in the warm air heater provided with a burner and an electric heater, when starting the heating by an electric heater, the technique which can operate a ventilation fan appropriately is provided.

  This specification discloses a warm air heater. The hot air heater includes a casing having an air supply opening and an outlet, a burner that burns fuel to heat the air, an electric heater that converts electric power into heat and heats the air, An overheat prevention temperature sensor that detects temperature, a blower fan that takes in air from the room through an air supply port, passes through a burner and an electric heater, and sends the air into the room through an air outlet, and a control device Yes. The control device is different from the normal fan operation normally performed by the blower fan in the heating by the electric heater when starting the heating by the electric heater according to the detection value of the overheat prevention temperature sensor when starting the heating by the electric heater. Perform forced fan operation.

  According to the warm air heater, when the heating by the electric heater is started, the blower fan performs a forced fan operation according to the detection value of the overheat prevention temperature sensor. Thereby, when the heating by the electric heater is started, the blower fan can be appropriately operated. The detection value of the overheat prevention temperature sensor may be the value before heating by the electric heater, the value at the start of heating by the electric heater, or the heating by the electric heater. You may use the thing after starting. Further, the forced fan operation may be executed before the heating by the electric heater is started, at the same time as the heating by the electric heater, or after the heating by the electric heater is started. There may be.

  The hot air heater described above is configured such that when the detected value of the overheat prevention temperature sensor when the control device starts heating by the electric heater is high, the blower fan in the forced fan operation is set to the blower fan in the normal fan operation. It may be higher than the air blowing amount.

  According to the above hot air heater, when heating by the electric heater is started after extinguishing the burner, if the overheat prevention temperature sensor is at a high temperature due to heating by the burner, the blower fan is operated by forced fan operation. The overheat prevention temperature sensor can be cooled by increasing the air flow rate. This can prevent the overheat prevention temperature sensor from detecting an abnormally high temperature even though the electric heater is operating at a normal temperature.

  In the hot air heater, the control device may shorten the duration of the forced fan operation when the heating capacity of the electric heater is low compared to when the heating capacity of the electric heater is high.

  If the heating capacity of the electric heater is low, there is a risk that the user will feel cold when the forced fan operation is performed for a long time. According to said warm air heater, even if it is a case where the heating capability of an electric heater is low, it can suppress giving a cool air feeling to a user.

  The hot air heater described above is configured such that when the detected value of the overheat prevention temperature sensor is low when the control device starts heating by the electric heater, the blower fan in the forced fan operation is set to the blower fan in the normal fan operation. You may make lower than the ventilation volume of.

  According to the hot air heater described above, when heating by the electric heater is started when the inside of the hot air heater is sufficiently cooled, the forced fan operation is performed until the temperature of the electric heater rises. By reducing the amount of air blown by the blower fan, it is possible to suppress the user from feeling cold air.

  The present specification also discloses another hot air heater. The hot air heater includes a casing having an air supply opening and an outlet, a burner that burns fuel to heat the air, an electric heater that converts electric power into heat and heats the air, An overheat prevention temperature sensor that detects temperature, a blower fan that takes in air from the room through an air supply port, passes through a burner and an electric heater, and sends the air into the room through an air outlet, and a control device Yes. When the heating by the electric heater is started according to the heating mode by the burner before the heating by the electric heater is started and the timing at which the heating by the electric heater is started, the control device normally uses the blower fan in the heating by the electric heater. The blower fan is caused to execute a forced fan operation different from the normal fan operation to be performed.

  According to the hot air heater, when the heating by the electric heater is started, depending on the heating mode by the burner before starting the heating by the electric heater and the timing at which the heating by the electric heater is started, Perform forced fan operation. Thereby, when the heating by the electric heater is started, the blower fan can be appropriately operated. Note that the forced fan operation may be performed before the heating by the electric heater is started, at the same time as the heating by the electric heater, or after the heating by the electric heater is started. There may be.

  In the case of the above hot air heater, when the control device has a short elapsed time from the time when the heating capability of the burner is high at the end before the heating by the electric heater is started to the time when the heating by the electric heater is started In addition, the air blowing amount of the blower fan in the forced fan operation may be higher than the air blowing amount of the blower fan in the normal fan operation.

  If the elapsed time from the time when the heating capacity of the burner was high at the end before the heating by the electric heater was started to the time when the heating by the electric heater was started is short, the overheat prevention temperature sensor is heated by the burner. It is considered that the temperature is high. According to the warm air heater described above, in such a case, the overheat prevention temperature sensor can be cooled by increasing the air blowing amount of the blower fan by the forced fan operation. This can prevent the overheat prevention temperature sensor from detecting an abnormally high temperature even though the electric heater is operating at a normal temperature.

  In the hot air heater, the control device may shorten the duration of the forced fan operation when the heating capacity of the electric heater is low compared to when the heating capacity of the electric heater is high.

  If the heating capacity of the electric heater is low, there is a risk that the user will feel cold when the forced fan operation is performed for a long time. According to said warm air heater, even if it is a case where the heating capability of an electric heater is low, it can suppress giving a cool air feeling to a user.

  In the case of the above hot air heater, when the control device has a long elapsed time from the time when the heating capacity of the burner is high at the end before the heating by the electric heater is started to the time when the heating by the electric heater is started In addition, the air flow rate of the blower fan in the forced fan operation may be lower than the air flow rate of the blower fan in the normal fan operation.

  If the elapsed time from the time when the heating capacity of the burner was high before the start of heating by the electric heater to the time of starting heating by the electric heater is long, the inside of the hot air heater It is considered cooled. According to the hot air heater described above, in such a case, until the temperature of the electric heater rises, the amount of air blown by the blower fan is lowered by the forced fan operation, thereby giving the user a feeling of cold air. This can be suppressed.

The figure which shows typically the structure of the gas fan heater 2 which concerns on an Example. The figure which shows typically the electric system of the gas fan heater 2 which concerns on an Example. The flowchart explaining operation | movement of the gas fan heater 2 which concerns on an Example. The flowchart explaining operation | movement of the gas fan heater 2 which concerns on an Example. The flowchart explaining operation | movement of the gas fan heater 2 which concerns on an Example. The flowchart explaining operation | movement of the gas fan heater 2 which concerns on an Example. The flowchart explaining operation | movement of the gas fan heater 2 which concerns on an Example. The figure which shows the example of a time-dependent change of the heating aspect by the burner 10, the heating aspect by the electric heater 24, and the ventilation aspect by the ventilation fan 12 in the gas fan heater 2 which concerns on an Example. The figure which shows the example of a time-dependent change of the heating aspect by the burner 10, the heating aspect by the electric heater 24, and the ventilation aspect by the ventilation fan 12 in the gas fan heater 2 which concerns on an Example. The figure which shows the example of a time-dependent change of the heating aspect by the burner 10, the heating aspect by the electric heater 24, and the ventilation aspect by the ventilation fan 12 in the gas fan heater 2 which concerns on an Example. The figure which shows the example of a time-dependent change of the heating aspect by the burner 10, the heating aspect by the electric heater 24, and the ventilation aspect by the ventilation fan 12 in the gas fan heater 2 which concerns on an Example. The figure which shows the example of a time-dependent change of the heating aspect by the burner 10, the heating aspect by the electric heater 24, and the ventilation aspect by the ventilation fan 12 in the gas fan heater 2 which concerns on an Example. The figure which shows the example of a time-dependent change of the heating aspect by the burner 10, the heating aspect by the electric heater 24, and the ventilation aspect by the ventilation fan 12 in the gas fan heater 2 which concerns on an Example. The figure which shows the example of a time-dependent change of the heating aspect by the burner 10, the heating aspect by the electric heater 24, and the ventilation aspect by the ventilation fan 12 in the gas fan heater 2 which concerns on an Example.

(Example)
A gas fan heater 2 according to an embodiment of a hot air heater will be described with reference to FIG. The gas fan heater 2 takes in air from the room through the air supply port 4 on the back surface, burns the fuel gas using the sucked air as combustion air, and converts the air heated by the combustion of the fuel gas into the air outlet 6 on the front surface. The room is heated by sending it into the room. The gas fan heater 2 is a so-called open type gas fan heater.

  The gas fan heater 2 takes in indoor air from a gas supply pipe 8 that supplies fuel gas, a burner 10 that burns fuel gas from the gas supply pipe 8, and an air supply port 4, and blows out the heated air 6, a blower fan 12 that is sent into the room, a control unit 14 that controls the operation of the gas fan heater 2, an operation unit 16 that allows the user to operate the gas fan heater 2, and a housing 18 that houses these. Yes.

  The air supply port 4 is formed on the upper side of the back surface of the housing 18, and the air outlet 6 is formed on the lower side of the front surface of the housing 18. Inside the casing 18, a part of the air flowing in from the air supply port 4 is supplied to the burner 10 as combustion air, and the remaining air is mixed with the combustion exhaust gas of the burner 10 and led to the outlet 6. A passage 20 is formed. The blower fan 12 is disposed downstream of the burner 10 in the internal air passage 20 (between the burner 10 and the outlet 6). The air supply port 4 is provided with an air filter 22 that suppresses entry of dust and the like.

  An electric heater 24 is provided between the blower fan 12 and the outlet 6 in the internal air passage 20. The electric heater 24 generates heat when energized and heats the air passing through the internal air passage 20. The electric heater 24 includes a plurality of heat generating portions, and the energization can be switched on / off for each heat generating portion. The electric heater 24 can switch the heating capacity by switching the number of heat generating parts to be energized.

  The gas supply pipe 8 is provided with an electromagnetic on-off valve 26 that opens and closes the gas supply pipe 8 and a motor-driven flow rate adjustment valve 27 that adjusts the opening degree of the gas supply pipe 8. The gas supply pipe 8 is supplied with a fuel gas such as a city gas (for example, a gas mainly composed of methane gas (CH 4) such as 13A) from the outside of the gas fan heater 2. The burner 10 is provided with an igniter 28 above the flame opening. The burner 10 can adjust the heating capacity by adjusting the flow rate of the fuel gas to be burned.

  An indoor temperature sensor 30 is provided on the rear surface of the housing 18. The indoor temperature sensor 30 detects the temperature of indoor air sucked into the housing 18 from the air supply port 4. As the indoor temperature sensor 30, various types such as a thermocouple and a thermistor can be used.

  An overheat prevention temperature sensor 32 is provided in the internal air passage 20. The overheat prevention temperature sensor 32 detects the temperature inside the housing 18. As the overheat prevention temperature sensor 32, various types such as a thermocouple and a thermistor can be used.

  As shown in FIG. 2, the operation unit 16 includes an operation switch 34 that instructs the user to start and stop the operation of the gas fan heater 2, a mode selection unit 36 that selects an operation mode of the gas fan heater 2, and a heating target temperature. A temperature setting unit 38 to be set, a display unit 40 that displays various information such as an operation mode, a heating target temperature, and a room temperature, an abnormality notification buzzer 41 that notifies the user of the occurrence of an abnormality, and the like are provided. The operation mode of the gas fan heater 2 is selected from a burner single mode, an electric heater single mode, and a burner electric heater combined mode. In the burner single mode, the gas fan heater 2 heats the air by the burner 10 and does not heat the air by the electric heater 24. In the electric heater single mode, the gas fan heater 2 heats the air by the electric heater 24 and does not heat the air by the burner 10. In the burner electric heater combined mode, the gas fan heater 2 first heats the air by the burner 10 for a predetermined time (for example, 1 hour), then ends the air heating by the burner 10, and then air by the electric heater 24. The heating is performed.

  The control unit 14 controls operations of the blower fan 12, the electric heater 24, the on-off valve 26, the flow rate adjusting valve 27, the igniter 28, and the like. The control unit 14 includes a memory 42 for storing various programs and data, and a timer 44 for timing.

  The controller 14 can adjust the heating capability of the burner 10 in multiple stages when heating the air by the burner 10. In the present embodiment, a case where the heating ability of the burner 10 can be adjusted in two steps of strong and weak will be described as an example. The control unit 14 adjusts the amount of fuel gas supplied to the burner 10 by adjusting the opening degree of the flow rate adjustment valve 27 according to the heating capacity of the burner 10 and adjusts the rotation speed of the blower fan 12 to adjust the air flow. Adjust the air flow.

  The controller 14 can adjust the heating capacity of the electric heater 24 in multiple stages when heating the air by the electric heater 24. In the present embodiment, a case where the heating capacity of the electric heater 24 can be adjusted in two steps of strong and weak will be described as an example. The control unit 14 adjusts the electric power supplied to the electric heater 24 according to the heating capacity of the electric heater 24 and adjusts the rotational speed of the blower fan 12 to adjust the air blowing amount.

  When the air is heated by the electric heater 24, the control unit 14 performs an abnormal stop process when the temperature detected by the overheat prevention temperature sensor 32 exceeds a predetermined upper limit temperature (for example, 60 ° C.). In the abnormal stop process, the control unit 14 stops heating by the electric heater 24, notifies the user of the occurrence of the abnormality with the abnormality notification buzzer 41, and detects an abnormally high temperature on the display unit 40 with the overheat prevention temperature sensor 32. Is displayed. Thereby, it is possible to prevent the members in the vicinity of the electric heater 24 inside the casing 18 from being exposed to an abnormally high temperature and being damaged during the heating by the electric heater 24.

  Below, operation | movement of the gas fan heater 2 is demonstrated, referring the flowchart of FIGS. 3-7. When the start of operation of the gas fan heater 2 is instructed, the control unit 14 executes the processing of FIGS.

  In step S2 of FIG. 3, the control unit 14 determines whether or not the operation mode of the gas fan heater 2 is the electric heater single mode. When the operation mode of the gas fan heater 2 is the burner single mode or the burner electric heater combined mode (NO in step S2), the process proceeds to step S4.

  In step S4, the control unit 14 determines whether or not the temperature detected by the overheat prevention temperature sensor 32 exceeds a first predetermined temperature (for example, 40 ° C.). When the detected temperature of the overheat prevention temperature sensor 32 exceeds the first predetermined temperature (in the case of YES), it is determined that the overheat prevention operation of the burner 10 is necessary, and the process proceeds to step S6. If the detected temperature of the overheat prevention temperature sensor 32 does not exceed the first predetermined temperature (in the case of NO), the process proceeds to step S10.

  In step S6, the control unit 14 drives the blower fan 12 at a first rotational speed (for example, 600 rpm). The first number of rotations is the number of rotations of the blower fan 12 for realizing the amount of blown air required for the overheat prevention operation of the burner 10.

  In step S8, the control unit 14 waits until a first predetermined time (for example, 20 seconds) elapses after the blower fan 12 is driven at the first rotational speed in step S6. The first predetermined time is a time required for the overheat prevention operation of the burner 10. If the first predetermined time has elapsed (YES), the process proceeds to step S10.

  In step S10, the control unit 14 drives the blower fan 12 at the second rotational speed (for example, 200 rpm). The second number of rotations is the number of rotations of the blower fan 12 for realizing the amount of blown air required when the burner 10 is ignited.

  In step S <b> 12, the control unit 14 opens the on-off valve 26, adjusts the opening degree of the flow rate adjustment valve 27, and ignites the burner 10 by igniting with the igniter 28. After step S12, the process proceeds to step S14 in FIG.

  In step S14 of FIG. 4, the control unit 14 determines whether or not a driving end operation has been performed. If the operation end operation has not been performed (NO), the process proceeds to step S16.

  In step S16, the control unit 14 determines whether or not the elapsed time since the ignition of the burner 10 in step S12 has reached a second predetermined time (for example, 1 hour). The second predetermined time is a time during which heating by the burner 10 can be continuously performed. If the elapsed time since ignition of the burner 10 has not reached the second predetermined time (in the case of NO), the process proceeds to step S18.

  In step S18, the control unit 14 determines whether or not the temperature detected by the room temperature sensor 30 exceeds the heating set temperature. When the temperature detected by the room temperature sensor 30 does not exceed the heating set temperature (in the case of NO), the process proceeds to step S20.

  In step S <b> 20, the control unit 14 adjusts the opening degree of the flow rate adjustment valve 27 to increase the heating capability of the burner 10.

  In step S22, the control unit 14 sets the rotational speed of the blower fan 12 to a third rotational speed (for example, 900 rpm). The third number of rotations is a number of rotations that realizes the amount of air blown by the blower fan 12 when heating the air by the burner 10 with the heating capability of the burner 10 being strong.

  In step S24, the control unit 14 sets the time for forced fan operation (forced fan time) to be performed after the burner 10 is extinguished to a third predetermined time (for example, 155 seconds). The third predetermined time is a time required for the forced fan operation when the heating capability of the burner 10 is strong and the electric heater 24 is not heated after the burner 10 is extinguished. After step S24, the process returns to step S14.

  In step S18, when the temperature detected by the room temperature sensor 30 exceeds the heating set temperature (in the case of YES), the process proceeds to step S26.

  In step S <b> 26, the control unit 14 adjusts the opening degree of the flow rate adjustment valve 27 to weaken the heating capability of the burner 10.

  In step S28, the control unit 14 sets the rotational speed of the blower fan 12 to a fourth rotational speed (for example, 500 rpm). The fourth number of rotations is a number of rotations that realizes the amount of air blown by the blower fan 12 when the air is heated by the burner 10 with the heating capability of the burner 10 weakened. The fourth rotational speed is a rotational speed smaller than the third rotational speed.

  In step S30, the control unit 14 determines whether or not the currently set forced fan time exceeds a fourth predetermined time (for example, 95 seconds). The fourth predetermined time is a time required for the forced fan operation when the heating capability of the burner 10 is weak for a certain period of time before the burner 10 is extinguished and the electric heater 24 is not heated after the burner 10 is extinguished. It is. If the forced fan time does not exceed the fourth predetermined time (in the case of NO), the process proceeds to step S32. In step S32, the control unit 14 sets the forced fan time to a fourth predetermined time. After step S32, the process returns to step S14.

  If the forced fan time exceeds the fourth predetermined time in step S30 (in the case of YES), the process proceeds to step S34. In step S34, the controller 14 subtracts the forced fan time by unit time every time a unit time (for example, 1 second) elapses after the heating ability of the burner 10 is weakened. After step S34, the process returns to step S14.

  If the operation end operation has been performed in step S14 (in the case of YES), or if the elapsed time since the burner 10 was lit in step S16 has reached the second predetermined time (in the case of YES), the process proceeds to step S36. move on.

  In step S <b> 36, the control unit 14 closes the on-off valve 26 and the flow rate adjustment valve 27 and extinguishes the burner 10.

  In step S38, the control unit 14 determines whether or not the operation mode of the gas fan heater 2 is the burner electric heater combined mode and the operation stop operation is not performed. If the operation mode of the gas fan heater 2 is the burner single mode, or if the operation is stopped (NO), the process proceeds to step S40.

  In step S40, the control unit 14 drives the blower fan 12 at the fifth rotational speed (for example, 600 rpm). The fifth rotational speed is a rotational speed that realizes the air blowing amount of the blower fan 12 required in the forced fan operation immediately after the burner 10 is extinguished.

  In step S42, the control unit 14 determines whether or not a driving start operation has been performed. If the operation start operation has not been performed (NO), the process proceeds to step S44.

  In step S44, the control unit 14 determines whether or not the elapsed time since the burner 10 was extinguished in step S36 has reached the forced fan time. If the elapsed time since extinguishing the burner 10 has not reached the forced fan time, the process returns to step S42. When the elapsed time after extinguishing the burner 10 reaches the forced fan time (in the case of YES), the process proceeds to step S46.

  In step S46, the control unit 14 stops the blower fan 12. After step S46, the control unit 14 ends the operation of the gas fan heater 2.

  If the operation start operation is performed in step S42 (in the case of YES), the process proceeds to step S48.

  In step S48, the control unit 14 sets the remaining time obtained by subtracting the elapsed time from extinguishing the burner 10 in step S36 from the set forced fan time, as the forced fan time. After step S48, the process returns to step S2 in FIG.

  In step S2 of FIG. 3, when the operation mode of the gas fan heater 2 is the electric heater single mode (in the case of YES), the process proceeds to step S50.

  In step S50, the control unit 14 determines whether the forced fan time has already been set. If the forced fan time is set in step S50 (YES), the process proceeds to step S54 in FIG. If the forced fan time is not set in step S50 (NO), the process proceeds to step S52. In step S52, the control unit 14 sets the forced fan time to the third predetermined time. After step S52, the process proceeds to step S54 in FIG.

  If the operation mode of the gas fan heater 2 is the burner electric heater combined mode in step S38 in FIG. 4 and the operation stop operation is not performed (in the case of YES), the process proceeds to step S54 in FIG.

  In step S <b> 54 of FIG. 5, the control unit 14 starts heating with the electric heater 24. At this time, the control unit 14 adjusts the heating capability of the electric heater 24 to a preset heating capability.

  In step S56, the control unit 14 determines whether or not the temperature detected by the overheat prevention temperature sensor 32 exceeds a second predetermined temperature (for example, 50 ° C.). If the detected temperature of the overheat prevention temperature sensor 32 exceeds the second predetermined temperature (in the case of YES), the process proceeds to step S58.

  In step S58, the control unit 14 drives the blower fan 12 at the fifth rotational speed.

  In step S60, the control unit 14 determines whether or not the heating capacity of the electric heater 24 is strong. If the heating capacity of the electric heater 24 is strong (in the case of YES), the process proceeds to step S62.

  In step S62, the control unit 14 subtracts a fifth predetermined time (for example, 40 seconds) from the set forced fan time. The fifth predetermined time is a time when the forced fan time should be shortened when the heating capability of the electric heater 24 is strong. After step S62, the process proceeds to step S72.

  If the heating capability of the electric heater 24 is weak (NO) in step S60, the process proceeds to step S64.

  In step S64, the control unit 14 subtracts a sixth predetermined time (for example, 50 seconds) from the set forced fan time. The sixth predetermined time is a time when the forced fan time should be shortened when the heating capability of the electric heater 24 is weak. The sixth predetermined time is longer than the fifth predetermined time. Therefore, when the heating capability of the electric heater 24 is weak, the shortening range of the forced fan time is larger than when the heating capability of the electric heater 24 is strong. . After step S64, the process proceeds to step S72.

  If the temperature detected by the overheat prevention temperature sensor 32 does not exceed the second predetermined temperature (NO) in step S56, the process proceeds to step S66.

  In step S66, the control unit 14 determines whether or not the detected temperature of the overheat prevention temperature sensor 32 exceeds a third predetermined temperature (for example, 40 ° C.). The third predetermined temperature is a temperature lower than the second predetermined temperature. When the detected temperature of the overheat prevention temperature sensor 32 exceeds the third predetermined temperature (in the case of YES), the process proceeds to step S68.

  In step S68, the control unit 14 drives the blower fan 12 at a sixth rotational speed (for example, 400 rpm). The sixth rotation number is a lower rotation number than the fifth rotation number.

  In step S70, the control unit 14 sets the forced fan time to a seventh predetermined time (for example, 60 seconds). The seventh predetermined time is a time shorter than the third predetermined time or the fourth predetermined time. After step S70, the process proceeds to step S72.

  In step S72, the control unit 14 waits until the elapsed time after starting heating with the electric heater 24 in step S54 reaches the forced fan time. When the elapsed time from the start of heating with the electric heater 24 reaches the forced fan time (when YES), the process proceeds to step S74 in FIG.

  In step S74 of FIG. 6, the control unit 14 determines whether or not the heating capacity of the electric heater 24 is strong. When the heating capability of the electric heater 24 is strong (in the case of YES), the process proceeds to step S76.

  In step S76, the control unit 14 drives the blower fan 12 at a seventh rotational speed (for example, 500 rpm). The seventh number of rotations is a number of rotations that realizes the amount of air blown by the blower fan 12 when heating the air by the electric heater 24 with the heating capability of the electric heater 24 being strong. The seventh rotation speed can be said to be the rotation speed in the normal fan operation normally performed by the blower fan 12 when the heating capability of the electric heater 24 is strong. The seventh rotation number is a lower rotation number than the fifth rotation number. After step S76, the process proceeds to step S80.

  If the heating capacity of the electric heater 24 is weak (NO) in step S74, the process proceeds to step S78.

  In step S78, the control unit 14 drives the blower fan 12 at an eighth rotational speed (for example, 400 rpm). The eighth rotation number is a rotation number that realizes the amount of air blown by the blower fan 12 when heating the air by the electric heater 24 with the heating capacity of the electric heater 24 weak. The eighth rotation speed can be said to be the rotation speed in the normal fan operation normally performed by the blower fan 12 when the heating capability of the electric heater 24 is weak. The eighth rotation number is a lower rotation number than the fifth rotation number, and is a lower rotation number than the seventh rotation number. After step S78, the process proceeds to step S80.

  In step S80, the control unit 14 waits until the operation stop condition is satisfied. If the operation stop condition is satisfied (YES), the process proceeds to step S82.

  In step S <b> 82, the control unit 14 stops energization of the electric heater 24 and ends the heating by the electric heater 24.

  In step S84, the control unit 14 stops the blower fan 12. After step S86, the control unit 14 ends the operation of the gas fan heater 2.

  If the temperature detected by the overheat prevention temperature sensor 32 does not exceed the third predetermined temperature (in the case of NO) in step S66 of FIG. 5, the process proceeds to step S86 of FIG.

  In step S86 in FIG. 7, the control unit 14 drives the blower fan 12 at the ninth rotation speed (for example, 300 rpm). The 9th rotation speed is a rotation speed smaller than the 7th rotation speed or the 8th rotation speed.

  In step S88, the control unit 14 waits until the elapsed time from the start of heating with the electric heater 24 in step S54 of FIG. 5 reaches an eighth predetermined time (for example, 60 seconds). When the elapsed time from the start of heating by the electric heater 24 reaches the eighth predetermined time (when it becomes YES), the process proceeds to step S90.

  In step S90, the control unit 14 determines whether or not the heating capacity of the electric heater 24 is strong. If the heating capacity of the electric heater 24 is strong (in the case of YES), the process proceeds to step S92.

  In step S92, the control unit 14 drives the blower fan 12 at the seventh rotational speed. After step S92, the process proceeds to step S96.

  In step S90, when the heating capability of the electric heater 24 is weak (in the case of NO), the process proceeds to step S94.

  In step S94, the control unit 14 drives the blower fan 12 at the eighth rotational speed. After step S94, the process proceeds to step S96.

  In step S96, the control unit 14 waits until the operation stop condition is satisfied. If the operation stop condition is satisfied (YES), the process proceeds to step S98.

  In step S98, the control unit 14 stops energization of the electric heater 24 and ends the heating by the electric heater 24.

  In step S100, the control unit 14 stops the blower fan 12. After step S100, the control unit 14 ends the operation of the gas fan heater 2.

  FIG. 8 to FIG. 10 show the rotation of the blower fan 12 when the operation mode of the gas fan heater 2 is the burner electric heater combined mode and heating with the electric heater 24 is started immediately after the burner 10 is extinguished. The change in number over time is shown.

  FIG. 8 shows the change over time in the rotational speed of the blower fan 12 when the burner 10 has a high heating capability and the electric heater 24 has a high heating capability when the burner 10 is extinguished. When the heating capability of the burner 10 at the time of extinguishing the burner 10 is strong, the overheat prevention temperature sensor 32 is heated to a high temperature by the heating by the burner 10 when the heating by the electric heater 24 is started. In this case, in order to operate the overheat prevention temperature sensor 32 normally, it is necessary to perform the forced fan operation of the blower fan 12 with a high air flow rate and cool the overheat prevention temperature sensor 32. In this case, in the gas fan heater 2 of the present embodiment, from the start of heating of the electric heater 24 by the processes of steps S56, S58, S60, S62, and S72 in FIG. 5 until the forced fan time elapses. The blower fan 12 is operated at a higher rotational speed (fifth rotational speed) than the rotational speed (seventh rotational speed) of the blower fan 12 in the normal fan operation when the heating capacity of the electric heater 24 is increased. Thereby, the overheat prevention temperature sensor 32 can be operated normally. In this case, the forced fan time (the time obtained by subtracting the fifth predetermined time from the third predetermined time) is the forced fan time (third predetermined time when the electric heater 24 is not heated after the burner 10 is extinguished). ) Is set shorter. As a result, it is possible to prevent the user from feeling cold.

  FIG. 9 shows changes over time in the rotational speed of the blower fan 12 when the burner 10 has a high heating capability and the electric heater 24 has a low heating capability when the burner 10 is extinguished. Also in this case, as in the case of FIG. 8, the overheat prevention temperature sensor 32 is at a high temperature due to the heating by the burner 10 when the heating by the electric heater 24 is started. In this case, in the gas fan heater 2 of the present embodiment, from the start of heating of the electric heater 24 by the processing of steps S56, S58, S60, S64, and S72 in FIG. 5 until the forced fan time elapses. The blower fan 12 is operated at a higher rotational speed (fifth rotational speed) than the rotational speed (eighth rotational speed) of the blower fan 12 in the normal fan operation when the heating capacity of the electric heater 24 is weakened. Thereby, the overheat prevention temperature sensor 32 can be operated normally. In this case, the forced fan time (the time obtained by subtracting the sixth predetermined time from the third predetermined time) is the forced fan time (third predetermined time when the electric heater 24 is not heated after the burner 10 is extinguished). ) Is set shorter. As a result, it is possible to prevent the user from feeling cold. Further, when the heating capacity of the electric heater 24 is weak, there is a greater possibility that the user feels cold air during the forced fan operation than when the heating capacity of the electric heater 24 is strong. For this reason, the forced fan time in FIG. 9 (the time obtained by subtracting the sixth predetermined time from the third predetermined time) is the forced fan time in FIG. 8 (the time obtained by subtracting the fifth predetermined time from the third predetermined time). ) Is set even shorter. As a result, it is possible to prevent the user from feeling cold.

  FIG. 10 shows that when the burner 10 is extinguished, a sufficient time has passed since the heating capability of the burner 10 was switched from strong to weak, and the heating fan 12 has a high heating capability. The change of the rotation speed with time is shown. In this case, since the overheat prevention temperature sensor 32 is not so high when heating by the electric heater 24 is started, it is necessary to cool the overheat prevention temperature sensor 32 by driving the blower fan 12 with a high air flow rate. There is no. Rather, if the blower fan 12 is driven at a high rotational speed until the temperature of the electric heater 24 rises, there is a risk of giving the user a feeling of cold air. In this case, in the gas fan heater 2 of the present embodiment, from the start of heating of the electric heater 24 by the processes of steps S56, S66, S68, S70, and S72 of FIG. 5, until the forced fan time elapses. The blower fan 12 is operated at a rotational speed (sixth rotational speed) lower than the rotational speed (seventh rotational speed) of the blower fan 12 in the normal fan operation when the heating capacity of the electric heater 24 is increased. As a result, it is possible to prevent the user from feeling cold.

  11-14, the initial operation mode of the gas fan heater 2 is the burner single mode, and after the burner 10 is extinguished, the operation mode of the gas fan heater 2 is switched to the heater single mode and the operation is started again. The change with time of the rotational speed of the blower fan 12 is shown.

  In FIG. 11, the heating capability of the burner 10 at the time of extinguishing the burner 10 is strong, and so much time has not passed from the extinction of the burner 10 to the start of heating by the electric heater 24, and the heating of the electric heater 24 is performed. The time-dependent change of the rotation speed of the ventilation fan 12 in case capability is strong is shown. In this case, the overheat prevention temperature sensor 32 is heated to a high temperature by the burner 10 and has not been sufficiently cooled before the heating by the electric heater 24 is started. In this case, in the gas fan heater 2 of the present embodiment, the process from steps S56, S58, S60, S62, and S72 in FIG. 5 until the forced fan time elapses after the heating by the electric heater 24 is started. Meanwhile, the blower fan 12 is operated at a higher rotation speed (fifth rotation speed) than the rotation speed (seventh rotation speed) of the blower fan 12 in the normal fan operation when the heating capacity of the electric heater 24 is increased. Thereby, the overheat prevention temperature sensor 32 can be operated normally. In this case, the total of the forced fan time after the burner 10 is extinguished, that is, the forced fan time before starting the heating of the electric heater 24 and the forced fan time after starting the heating of the electric heater 24 (third The time obtained by subtracting the fifth predetermined time from the predetermined time is set to be shorter than the forced fan time (third predetermined time) when the electric heater 24 is not heated after the burner 10 is extinguished. As a result, it is possible to prevent the user from feeling cold.

  In FIG. 12, the heating capability of the burner 10 at the time of extinguishing the burner 10 is strong, and so much time has not passed between the extinction of the burner 10 and the start of heating by the electric heater 24, and the heating of the electric heater 24 is performed. The time-dependent change of the rotation speed of the ventilation fan 12 in case capability is weak is shown. Also in this case, as in the case of FIG. 11, the overheat prevention temperature sensor 32 is heated by heating with the burner 10, and has not been sufficiently cooled before the heating with the electric heater 24 is started. . In this case, in the gas fan heater 2 of the present embodiment, from the start of heating of the electric heater 24 by the processing of steps S56, S58, S60, S64, and S72 in FIG. 5 until the forced fan time elapses. The blower fan 12 is operated at a higher rotational speed (fifth rotational speed) than the rotational speed (eighth rotational speed) of the blower fan 12 in the normal fan operation when the heating capacity of the electric heater 24 is weakened. Thereby, the overheat prevention temperature sensor 32 can be operated normally. In this case, the forced fan time after extinguishing the burner 10 (the time obtained by subtracting the sixth predetermined time from the third predetermined time) is the forced fan time when the electric heater 24 is not heated after the burner 10 is extinguished. It is set shorter than the fan time (third predetermined time). As a result, it is possible to prevent the user from feeling cold. Further, when the heating capacity of the electric heater 24 is weak, there is a greater possibility that the user feels cold air during the forced fan operation than when the heating capacity of the electric heater 24 is strong. For this reason, the forced fan time after extinguishing the burner 10 in FIG. 12 (the time obtained by subtracting the sixth predetermined time from the third predetermined time) is the forced fan time after extinguishing the burner 10 in FIG. It is set shorter than (a time obtained by subtracting the fifth predetermined time from the third predetermined time). As a result, it is possible to prevent the user from feeling cold.

  In FIG. 13, the heating capability of the burner 10 at the time of extinguishing the burner 10 is strong, and a certain amount of time has passed from the extinction of the burner 10 to the start of heating by the electric heater 24. The time-dependent change of the rotation speed of the ventilation fan 12 in case capability is strong is shown. In this case, since the overheat prevention temperature sensor 32 is not so high when heating by the electric heater 24 is started, it is necessary to cool the overheat prevention temperature sensor 32 by driving the blower fan 12 with a high air flow rate. There is no. Rather, if the blower fan 12 is driven at a high rotational speed until the temperature of the electric heater 24 rises, there is a risk of giving the user a feeling of cold air. In this case, in the gas fan heater 2 of the present embodiment, from the start of heating of the electric heater 24 by the processes of steps S56, S66, S68, S70, and S72 of FIG. 5, until the forced fan time elapses. The blower fan 12 is operated at a rotational speed (sixth rotational speed) lower than the rotational speed (seventh rotational speed) of the blower fan 12 in the normal fan operation when the heating capacity of the electric heater 24 is increased. As a result, it is possible to prevent the user from feeling cold.

  FIG. 14 shows that the heating capability of the burner 10 at the time of extinguishing the burner 10 is strong, and it takes a long time from the extinction of the burner 10 to the start of heating by the electric heater 24. The change with time of the rotational speed of the blower fan 12 in the case where is strong is shown. In this case, when the heating by the electric heater 24 is started, the overheat prevention temperature sensor 32 is sufficiently cooled, and it is necessary to drive the blower fan 12 with a high air flow to cool the overheat prevention temperature sensor 32. Absent. Rather, if the blower fan 12 is driven at a high rotational speed until the temperature of the electric heater 24 rises, there is a risk of giving the user a feeling of cold air. In this case, in the gas fan heater 2 of the present embodiment, until the forced fan time elapses after the heating of the electric heater 24 is started by the processes of steps S56 and S66 in FIG. 5 and steps S86 and S88 in FIG. During this time, the blower fan 12 is operated at a lower rotation speed (9th rotation speed) than the rotation speed (seventh rotation speed) of the blower fan 12 in the normal fan operation when the heating capacity of the electric heater 24 is increased. . As a result, it is possible to prevent the user from feeling cold. Further, the rotational speed (the ninth rotational speed) of the blower fan 12 in the forced fan operation in FIG. 14 is further lower than the rotational speed (sixth rotational speed) of the blower fan 12 in the forced fan operation in FIG. Is set. As a result, it is possible to prevent the user from feeling cold.

  In the above embodiment, the case where the control unit 14 causes the blower fan 12 to execute the forced fan operation according to the temperature detected by the overheat prevention temperature sensor 32 as shown in steps S56 and S66 of FIG. Instead of the above, the control unit 14 causes the blower fan 12 to execute the forced fan operation according to the heating mode by the burner 10 before the heating by the electric heater 24 is started and the timing at which the heating by the electric heater 24 is started. It is good also as a structure. For example, step S56 in FIG. 5 is performed from the time when the burner 10 extinguishes with the heating capability increased, or from the time when the heating capability of the burner 10 switches from strong to weak until the heating of the electric heater 24 is started. If the elapsed time is within a predetermined time (for example, 100 seconds), the process may proceed to step S56, and otherwise, the process may proceed to step S66. Similarly, the process from step S66 when the burner 10 extinguishes with the heating capability increased or when the heating capability of the burner 10 switches from strong to weak until the heating of the electric heater 24 starts. When the time exceeds the third predetermined time and the elapsed time from the time when the burner 10 is extinguished to the time when heating of the electric heater 24 is started exceeds the fourth predetermined time, the process proceeds to step S86 in FIG. It is good also as a process which progresses and progresses to step S68 in other than that.

  In the above-described example, the gas fan heater 2 is illustrated and described as an embodiment of the hot air heater. However, the hot air heater disclosed in the present specification is not limited to this, for example, an oil fan. A heater, a gas heater, an oil heater, etc. may be used.

  In the above embodiment, the hot air heater uses the air taken in from the room via the air supply port as combustion air for the burner, and sends the combustion exhaust gas from the burner into the room through the outlet. Although the case where it is what is called an open type warm air heater was demonstrated, the warm air heater which this specification discloses is not restricted to this. The warm air heater disclosed in this specification uses, for example, so-called half-air that uses air taken in from a room via an air supply port as combustion air for the burner and discharges combustion exhaust gas from the burner to the outside. It may be a closed type hot air heater, or the so-called closed type hot air heater that uses the air taken from the outside as combustion air for the burner and discharges the combustion exhaust gas from the burner to the outside. It may be.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Gas fan heater 4: Air supply port 6: Air outlet 8: Gas supply pipe 10: Burner 12: Blower fan 14: Control unit 16: Operation unit 18: Housing 20: Internal air passage 22: Air filter 24: Electricity Heater 26: Open / close valve 27: Flow rate adjustment valve 28: Igniter 30: Indoor temperature sensor 32: Overheat prevention temperature sensor 34: Operation switch 36: Mode selection unit 38: Temperature setting unit 40: Display unit 41: Abnormality alarm buzzer 42: Memory 44: Timer

Claims (8)

A housing having an air supply opening and an air outlet;
A burner that burns fuel and heats the air;
An electric heater that converts electric power into heat and heats the air;
An overheat prevention temperature sensor that detects the temperature inside the housing;
A blower fan that takes in air from the room through the air supply port, passes the burner and the electric heater, and sends the air into the room through the air outlet;
Equipped with a control device,
When the control device starts heating by the electric heater according to the detection value of the overheat prevention temperature sensor when starting heating by the electric heater, it differs from the normal fan operation normally performed by the blower fan in heating by the electric heater. A hot air heater that causes the fan to perform forced fan operation.   When the detection value of the overheat prevention temperature sensor when the control device starts heating by the electric heater is high, the air blowing amount of the blower fan in the forced fan operation is higher than the air blowing amount of the blower fan in the normal fan operation. The hot air heater according to claim 1.   The hot air heater according to claim 2, wherein the control device shortens the duration of the forced fan operation when the heating capacity of the electric heater is low compared to when the heating capacity of the electric heater is high.   When the detection value of the overheat prevention temperature sensor when the control device starts heating by the electric heater is low, the air blowing amount of the blower fan in the forced fan operation is made lower than the air blowing amount of the blower fan in the normal fan operation. The hot air heater according to any one of claims 1 to 3. A housing having an air supply opening and an air outlet;
A burner that burns fuel and heats the air;
An electric heater that converts electric power into heat and heats the air;
An overheat prevention temperature sensor that detects the temperature inside the housing;
A blower fan that takes in air from the room through the air supply port, passes the burner and the electric heater, and sends the air into the room through the air outlet;
Equipped with a control device,
When the control device starts heating by the electric heater according to the heating mode by the burner before starting heating by the electric heater and the timing to start heating by the electric heater, the blower fan is usually used for heating by the electric heater. A warm air heater that causes a blower fan to execute a forced fan operation different from the normal fan operation.   The blower fan in forced fan operation when the elapsed time from the time when the control device starts heating with the electric heater from the time when the heating capacity of the burner is high at the end before the heating with the electric heater is started is short The warm air heater according to claim 5, wherein the air blowing amount is higher than the air blowing amount of the blower fan in the normal fan operation.   The hot air heater according to claim 6, wherein the control device shortens the duration of the forced fan operation when the heating capacity of the electric heater is low compared to when the heating capacity of the electric heater is high.   The blower fan in forced fan operation when the controller has a long elapsed time from the time when the heating capability of the burner is high until the time when heating by the electric heater is started before the heating by the electric heater is started. The warm air heater according to any one of claims 5 to 7, wherein the air blowing amount is lower than the air blowing amount of the air blowing fan in the normal fan operation.