JP3316193B2 - Hot air heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a warm air heater, and more particularly to a warm air heater having an antifreezing operation function for preventing freezing of indoor equipment.

[0002]

2. Description of the Related Art Conventionally, as a hot air heater, outside air taken from outside is supplied to a burner (heating means) as combustion air to burn the burner, and the heat exchanger is heated by the burner. 2. Description of the Related Art A so-called FF type hot air heater that discharges exhaust gas to the outside is known.

[0003] During the heating operation by the hot air heater, room air is circulated by a convection fan through a heat exchanger heated by the burner, thereby raising the room air to a desired temperature. That is, this type of warm air heater includes a temperature sensor (room temperature detecting means) for detecting the temperature of indoor air and a room temperature setting means for arbitrarily setting a target indoor temperature, and is detected by the room temperature sensor. So-called temperature control is performed to determine the burner combustion amount (heating amount) based on the difference between the detected room temperature and the target room temperature set by the room temperature setting means. By performing such a temperature control, the burner is burned with an unnecessarily large amount of combustion, so that the room temperature is not unnecessarily raised, so that the fuel consumption can be suppressed well and a comfortable room temperature can be obtained. Obtainable.

[0004] In a cold region where the outside air temperature is extremely low, when the operation of the hot air heater is stopped, the temperature in the room drops, and facilities such as a water pipe installed indoors and an aquarium fish tank are frozen. May be.

Therefore, in order to prevent freezing of indoor equipment and the like, in the above-mentioned warm air heater, when the heating operation is stopped (including during standby by a timer operation), the indoor temperature falls below the freezing temperature of the indoor equipment. In this case, anti-freezing operation control means for forcibly performing a heating operation (anti-freezing operation) for preventing freezing is provided, and the user can arbitrarily set the anti-freezing temperature by the room temperature setting means. It is possible to put.

[0006] In the antifreeze operation, as in the normal heating operation, the fuel control is performed by determining the combustion amount of the burner based on the difference between the antifreeze temperature set by the user and the detected room temperature. , The freezing of indoor equipment can be prevented.

However, the temperature set for the freezing prevention operation may be a temperature for preventing freezing of the indoor equipment with a small amount of heating, and is set to a value lower than the temperature set during the normal heating operation. . Moreover, since the antifreeze operation is started when the detected room temperature falls below the antifreeze temperature set by the user, and then the temperature control is performed, the difference between the antifreeze temperature and the detected room temperature at this time is small. . For this reason, the burner combustion amount during the temperature control is reduced. At this time, when performing the anti-freezing operation, the temperature of the heat exchanger itself is often quite low (cooled to an extremely low temperature by the indoor air), and such a heat exchanger is small as described above. If the state of heating by the burner controlled to the combustion amount is continued, the temperature of the heat exchanger is low, so that dew condensation occurs in the heat exchanger, resulting in deterioration of the useful life of the heat exchanger.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hot-air heater capable of solving the above-mentioned inconveniences and performing temperature control without dew condensation in a heat exchanger in an antifreezing operation. Aim.

[0009]

Means for Solving the Problems To achieve the above object, a hot air heater of the present invention is installed in a main body case,
A heating unit including a heat exchanger, a blower fan that sucks indoor air into the main body case and sends out warm air heated by the heat exchanger to the room, and a room temperature detecting unit that detects room temperature. A heating operation control unit that performs heating control for controlling the operation of the heating unit based on the temperature detected by the room temperature detection unit, wherein the heating operation control unit prevents freezing of indoor equipment. and antifreeze temperature setting means for setting the temperature, the detection when the temperature actuating said heating means when the following set the antifreeze temperature, minimum heating amount set for the heating control of the room temperature detecting means Condensation in the heat exchanger with a large heating amount
It characterized by having a freeze prevention operation control means and a lower limit heating amount setting means for setting a lower limit amount of heat to be prevented.

According to the above construction, the heat efficiency of the heat exchanger can be maintained well without dew condensation in the heat exchanger, and the temperature can be maintained at room temperature for preventing freezing without impairing the life of the heat exchanger. Freezing of indoor equipment can be effectively prevented by the amount of heating.

Further, it is preferable that the heating operation control means includes a temperature control control means for controlling a heating amount of the heating means based on a difference between the detected temperature and the freezing prevention temperature.

Further, in the present invention, the heating operation control
The heating means controls the heating by the temperature control means.
An operation having operation control means for operating the room temperature setting means
Means for controlling the anti-freezing temperature setting means,
When the operation of the heating operation control means is stopped,
Operation means for activating the antifreeze operation control means is provided.
Is desirable .

[0013] According to this, the warm air heater of the present invention provides a normal heating operation for the user to obtain a comfortable room temperature and a freezing operation for preventing freezing of indoor equipment while the heating operation is stopped. Preventive operation can be performed.

Further, the freezing prevention temperature setting means can be operated by the operating means for operating the room temperature setting means, and the heating control controlled by the temperature control means based on the difference between the freezing prevention temperature and the detected temperature. By performing the anti-freezing operation based on the amount, the operating means for setting the room temperature and the temperature control means of the conventional warm air heater can be shared for the anti-freezing operation control.

In order to achieve the above object, a hot air heater of the present invention is provided in a main body case and has a heat exchanger provided with a heating means, sucks indoor air into the main body case, and heats the indoor air. A blower fan for sending the warm air heated by the exchanger into the room, and a room temperature detecting means for detecting the indoor temperature,
Room temperature setting means for setting a target temperature in the room; determining a heating amount of the heating means based on a difference between a detected temperature of the room temperature detecting means and a target temperature of the room temperature setting means;
Temperature control means having a heating amount set therein, heating operation control means for controlling the heating means based on the heating amount determined by the temperature control means, and freezing of indoor equipment having a temperature lower than the target temperature. and antifreeze temperature setting means for setting the antifreeze temperature is the temperature to prevent, when the detected temperature is equal to or less than antifreeze temperature of the freeze prevention temperature setting means, before
The anti-freezing control means for operating the heating means to operate the temperature control control means with the anti-freezing temperature as a target temperature and for performing the anti-freezing operation by the heating means based on the heating amount determined by the temperature control control means. And the lower limit of the heating amount determined by the temperature control control means during the anti-freezing operation,
The greater amount of heat than the minimum amount of heating the set with a lower limit
And a lower limit heating amount setting means for setting a lower limit heating amount for preventing dew condensation in the heat exchanger .

According to this, the user can perform the heating operation for obtaining a comfortable room temperature and the antifreezing operation for preventing the freezing of the indoor equipment while the heating operation is stopped. That is, when performing the normal heating operation, the temperature control control unit sets the temperature control unit according to a difference between the target room temperature (for example, 16 ° C. or more) set by the room temperature setting unit and the detected room temperature detected by the room temperature detection unit. The heating amount of the heating means is determined, and the heating operation control means operates the heating means based on the heating amount.

Further, when the heating operation is stopped and the room temperature drops, and when the detected room temperature falls below the freezing prevention temperature (for example, 5 ° C.), the above-mentioned freezing prevention operation is performed. When performing the anti-freezing operation, the temperature control unit determines the heating amount of the heating unit according to the difference between the anti-freezing temperature and the detected room temperature, and the anti-freezing operation control unit determines the heating amount based on the heating amount. The operation of the heating means is performed.

Further, in the antifreezing operation, if the temperature of the heat exchanger itself is low and the heating is continued with the heating amount of the heating means being small, dew condensation may occur in the heat exchanger. Therefore, in the present invention, by providing the lower limit heating amount setting means in the anti-freezing operation control means, the lower limit of the heating amount determined by the temperature control control means is set to a value lower than the heating amount at which condensation occurs in the heat exchanger. Use a large heating amount. Thereby, even if the temperature of the heat exchanger itself is low, it is possible to raise the temperature of the heat exchanger itself to a temperature at which dew condensation does not occur, and it is possible to reliably prevent the dew condensation from occurring in the heat exchanger. it can.

[0019]

An embodiment of the present invention will be described with reference to the drawings. 1 is a system configuration diagram of the hot air heater of the present embodiment, FIG. 2 is a control block diagram of a main part of the hot air heater of FIG. 1, and FIG. 3 is a flowchart for explaining the antifreeze operation in FIG. is there.

Referring to FIG. 1, this hot air heater is, for example, an FF type gas hot air heater, and has a ventilation path 2 and a ventilation path 2 in a main body case 1 disposed in the room. The apparatus includes a blower fan 3 for convection of room air through the air passage, and a combustion device main body 4 for heating room air flowing through the blower passage 2.

The combustion apparatus main body 4 includes a burner 5 serving as a heating means, a combustion chamber 6 containing the burner, and a heat exchanger 7 connected to the combustion chamber 6. The supply cylinder 8 is connected, and the exhaust pipe 9 of the combustion exhaust gas is connected via the heat exchanger 7. The air supply cylinder 8 and the exhaust cylinder 9 extend outside the main body case 1 and are led out. Further, a combustion fan 10 for supplying combustion air to the burner 5 in the combustion chamber 6 is provided in the air supply cylinder 8, and the combustion fan 10 is rotatably provided in the air supply cylinder 8. And a combustion fan motor 12 for rotating the combustion fan. Note that the air supply cylinder 5 and the exhaust cylinder 6 may have a coaxial double structure.

The burner 5 in the combustion chamber 6 is connected to a gas supply pipe 13 that is piped and introduced from outside the main body case 1.
The fuel gas supplied from the gas supply pipe 13 is mixed with the combustion air introduced into the combustion chamber 6 from the supply cylinder 8, and the mixture is burned. An ignition electrode 14 for igniting the burner 5 and a flame detector 15 such as a frame rod or a thermocouple for detecting the flame of the burner 5 are provided in the combustion chamber 6 so as to face the burner 5. Have been.

The gas supply pipe 13 is provided with two open / close solenoid valves 16 and 17 and a gas proportional valve 18.

The air passage 2 has an air inlet 19 and an air outlet 20 on the back and front of the main body case 1, respectively, and is formed through the heat exchanger 7 therebetween. And
An air filter 21 is attached to the intake port 19, and a louver 22 for adjusting the blowing direction of the warm air is
Has been assembled.

The blower fan 3 includes rotating wings 24 provided in the blower passage 2 facing the intake port 19 of the blower passage 2, and a blower fan motor 25 for rotating the blades 24. The blower fan 3 draws room air into the blower passage 2 through the air inlet 19 by the rotation of the rotary wings 24, and blows the sucked air through the heat exchanger 7 in the blower passage 2. The air flows toward the outlet 20 and is blown into the room through the outlet 20.

A room temperature sensor 26 (room temperature detecting means) for detecting the temperature of room air taken into the air passage 2 by the blower fan 3 as room temperature is provided at a position facing the air inlet 19 in the air passage 2. Have been.

Referring to FIGS. 1 and 2, the gas hot air heater of the present embodiment further controls its operation by the electromagnetic valve 1.
6, 17 and the gas proportional valve 18, the combustion fan motor 12, the blower fan motor 25, the controller 27 for performing the operation via the ignition electrode 14, the operation switch 28 for the user to instruct the start and stop of the operation, the freeze described later. An operation device 3 including an anti-freezing operation setting switch 29 for setting execution of the anti-freezing operation, a room temperature setting switch 30 for setting a target room temperature for the heating operation and an anti-freezing temperature for the anti-freezing operation, and the like.
1 is provided. In the present embodiment, the room temperature setting switch 30 is used for setting a desired room temperature for a heating operation as room temperature setting means and for setting an antifreeze temperature for an antifreeze operation as a freezing temperature setting means. Switching can be performed according to the operation setting operation of the operation or the anti-freezing operation. Also, specifically, the set room temperature for the heating operation set by the room temperature setting switch 30 is 16 ° C. or more, and the set room temperature for the antifreeze operation is 5 ° C. to 15 ° C., which is higher than the set room temperature for the heating operation. Is also low. The room temperature set for the antifreeze operation is different from the temperature for obtaining a comfortable room temperature, and is different from the temperature for obtaining a comfortable room temperature because the equipment in the temperature chamber (for example, a water pipe installed in the room or an aquarium fish tank) does not freeze. What is necessary is just the minimum required temperature.

As shown in FIG. 2, the controller 27
The main functional components according to the present invention include a heating operation control means 32, an antifreezing operation control means 33, and a temperature control control means.

The temperature control means 34 sets the temperature set by the room temperature setting switch 30 as a target room temperature, and based on the difference between the target room temperature and the detected room temperature detected by the room temperature sensor 26, Combustion amount (heating amount)
Is provided.

The heating operation control means 32 controls the heating operation based on the combustion amount determined by the combustion amount determination section 35 of the temperature control control means 34 when the operation start is instructed by the operation switch 28. I do. That is, the combustion amount determination unit 35 determines the required combustion amount of the burner 5 according to the difference between the room temperature detected by the room temperature sensor 26 and the set room temperature for heating operation (the target room temperature during heating operation) by the room temperature setting switch 30. The heating operation control means 32 obtains the burner 5 from time to time so as to burn the burner 5 at the required combustion amount.
The supply amount of fuel gas and the supply amount of combustion air are controlled via the gas proportional valve 18 and the combustion fan motor 12, respectively, and the air flow of the blower fan 3 corresponding to the required combustion amount is obtained. The blower fan motor 25 is controlled, and thereby the temperature control operation of the hot air heater is performed.

The antifreeze operation control means 33 burns the burner 5 at the required combustion amount determined by the combustion amount determination section 35 of the temperature control control means 34 in the same manner as the heating operation control means 32 described above. , The amount of fuel gas supplied to the burner 5 and the amount of combustion air supplied are controlled via the gas proportional valve 18 and the combustion fan motor 12, respectively, and the air volume of the blower fan 3 corresponding to the required combustion amount is obtained. The blower fan motor 25 is controlled so as to be controlled. At this time, the anti-freezing operation control means 33 determines the difference between the room temperature detected by the room temperature sensor 26 and the set room temperature for anti-freezing operation (freezing prevention temperature) by the room temperature setting switch 29 in the temperature control control means 34. The combustion amount determining unit 3
5, the required combustion amount of the burner 5 is obtained every moment.

Further, the anti-freezing operation control means 33 includes a lower limit combustion amount setting section 36 (lower limit heating amount setting means). The lower limit combustion amount setting unit 36 is provided with the temperature control control unit 34.
Is to set the lower limit of the combustion amount determined by the combustion amount determination section 35 of FIG. To explain the lower limit combustion amount set at this time, for example, when the outside air temperature is excessively decreased, the room temperature is also excessively decreased, so that the heat exchanger 7 itself is also cooled to low indoor air. ing. on the other hand,
During the anti-freezing operation, the difference between the detected room temperature by the room temperature sensor 26 and the anti-freezing temperature by the room temperature setting switch 29 is often very small, and the required combustion amount of the burner 5 determined by the combustion amount determination unit 35 is large. May be small. In this state, if the combustion of the burner 5 is continued, dew condensation occurs in the heat exchanger 7 that has been cooled to room air. Therefore, in the lower limit combustion amount setting unit 36, the lower limit is set to a heating amount larger than the heating amount at which dew condensation occurs in the heat exchanger.

Next, the operation of the warm air heater of this embodiment will be described. First, a basic operation during the heating operation will be briefly described with reference to FIGS. It is assumed that a desired target room temperature is set in advance by the room temperature setting switch 30 during the heating operation. O of the operation switch 28 by the user
When an operation start command is given to the controller 27 by the N operation, the controller 27 activates the combustion fan 10, then causes the ignition electrode 14 to generate spark discharge for a certain period of time, and at the same time, the electromagnetic valve 16 of the gas supply pipe 13. 17 and the gas proportional valve 18 are opened to start supplying a predetermined amount of fuel gas to the burner 5, thereby performing the ignition process for the burner 5. Then, the ignition of the burner 5 is confirmed by the flame detector 15.

After the burner 5 is ignited in this way, the controller 27 controls the blower fan motor 25 to start the operation of the blower fan 3. Thereby, the indoor air is sucked into the air passage 2 through the air inlet 21,
The sucked air is heated through the heat exchanger 7 which is heated by the combustion heat of the burner 5 in the process of flowing toward the air outlet 20 through the air passage 2, and is blown out as hot air from the air outlet 20. You.

As described above, when the combustion of the burner 5 and the operation of the blower fan 3 are started, as described above, the temperature control controller 34 sets the burner 5 according to the difference between the detected room temperature of the room temperature sensor 26 and the target room temperature. Is determined, and the heating operation control means 32 performs a temperature adjustment control for controlling the combustion operation of the burner 5 and the air volume of the blower fan 3. In this case, basically, as the detected room temperature of the room temperature sensor 26 approaches the target room temperature, the burn amount of the burner 5 is reduced, and the rotation speed of the blower fan 3 is reduced to reduce the blow amount of the warm air. . Further, when the detected room temperature of the room temperature sensor 26 becomes lower than the target room temperature due to a change in the target room temperature or the like, the combustion amount of the burner 5 is increased, and the rotation speed of the blower fan 3 is increased to reduce the amount of hot air blown. increase. Then, during such a heating operation,
When the operation switch 28 is turned off, the heating operation is stopped.

The above operation is a basic operation in the heating operation of the warm air heater of the present embodiment. Furthermore, the warm air heater of the present embodiment operates indoors when the heating operation is stopped. An antifreeze operation can be performed so that the temperature does not excessively decrease and indoor equipment (for example, a water pipe installed in the room or an aquarium for aquarium fish) does not freeze.

Next, the operation during the anti-freezing operation will be described.
Before the operation for preventing freezing, the room temperature setting switch 30
It is assumed that the anti-freezing temperature is set as the target room temperature. As shown in FIG. 3, when the heating operation is stopped, the anti-freezing operation setting switch 29 is turned on by the user (YES in STEP 1), and the detected room temperature of the room temperature sensor 26 is set to the target. When the temperature falls below the room temperature (YES in STEP 2), the anti-freezing operation control means 33 operates to give an operation start command to the controller 27. The controller 27 activates the combustion fan 10 in STEP 3, then generates a spark discharge on the ignition electrode 14, and controls the solenoid valve 1 of the gas supply pipe 13.
By opening the gas proportional valve 18 and the gas proportional valve 18, the supply of a predetermined amount of fuel gas to the burner 5 is started, and thereby the ignition process for the burner 5 is performed. Thereafter, as described above, the controller 27 controls the blower fan motor 25 to start the operation of the blower fan 3 and blows out hot air.

Next, in STEP 4, the temperature control control means 34 determines the combustion amount Q of the burner 5 according to the difference between the detected room temperature of the room temperature sensor 26 and the target room temperature, and proceeds to STEP 5. In the present embodiment, at this time, the combustion amount Q determined by the combustion amount determination unit 35 of the temperature control controller 34
Is a specific calorie value calculated based on the difference between the detected room temperature and the target room temperature, from 40 kcal / min (weak combustion) to 112 kcal / min.
It is any value within the range of kcal / min (strong combustion). The present inventor has found through various tests that if the heat value is lower than 70 kcal / min, condensation occurs when the temperature of the heat exchanger 7 itself is low. Therefore, in the lower limit combustion amount setting section 36 of the antifreezing operation control means 33, the lower limit combustion amount value is set as 70 kcal / min.

Steps 5 and 6 are operations of the lower limit combustion amount setting section 36. In STEP5, when the value of the combustion amount Q determined by the combustion amount determination unit 35 of the temperature control controller 34 falls below 70 kcal / min, (STE
(YES in P5), the value of the combustion amount Q is forcibly set to 70 kcal / min in STEP6, the process proceeds to STEP7, and the combustion amount Q
Is burned at a value of 70 kcal / min. On the other hand, ST
In EP5, if the value of the combustion amount Q determined by the temperature adjustment control means 34 combustion amount determination unit 35 is not less than 70 kcal / min (NO in STEP5), the process proceeds to STEP7 without going through STEP6, and proceeds to STEP4. The burner 5 burns at the determined combustion amount Q.

Then, the temperature control operation in STEP 4 to STEP 7 is performed until the detected room temperature exceeds the temperature obtained by adding 1 ° C. to the target room temperature in STEP 8 (NO in STEP 8),
When the detected room temperature exceeds the temperature obtained by adding 1 ° C. to the target room temperature (YES in STEP 8), the process proceeds to STEP 9 and proceeds to burner 5
The antifreeze operation is terminated by stopping the combustion of the fuel cell.

In the present embodiment, the lower limit of the amount of combustion in the lower limit combustion amount setting section 36 of the anti-freezing operation control means 33 is set to 70 kcal / min. It is preferable that the combustion amount is a minimum amount that does not cause dew condensation in the exchanger 7, and it is needless to say that the amount is increased or decreased according to the shape and size of the heat exchanger 7 or the capacity of the burner 5.

Further, in the present embodiment, the FF type heater in which the combustion fan 10 takes combustion air from the outside and forcibly exhausts the air to the outside has been described. Hot air heaters, such as FE type heaters that forcibly exhaust air to the outside using a blower and CF type heaters that take combustion air from the room and exhaust them to the outside by natural ventilation using an exhaust pipe However, the present invention can be applied to a hot air heater using a liquid fuel as well as a gas fuel. A similar effect can be obtained by applying the antifreeze operation control of the present invention without being limited to the above.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a hot air heater according to an embodiment of the present invention.

FIG. 2 is a control block diagram of a main part of the warm air heater of FIG. 1;

FIG. 3 is a flowchart for explaining an antifreezing operation in FIG. 2;

[Explanation of symbols]

1─ body case, 7─ heat exchanger, 5─ burner (heating means), 3─ blower fan, 26─ room temperature sensor (room temperature detection means), 30─ room temperature setting switch (room temperature setting means / freezing prevention temperature setting means) , 34 ° temperature control control means, 32 ° heating operation control means, 33 ° anti-freezing operation control means, 36 ° lower limit combustion amount setting section (lower limit heating amount setting means).

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F24H 3/06 304

Claims (6)

(57) [Claims] 1. A heating means provided in a main body case and provided with a heat exchanger, and a blower fan for sucking room air into the main body case and sending warm air heated by the heat exchanger into the room. Room temperature detecting means for detecting the temperature of the room; and the heating means based on the detected temperature of the room temperature detecting means.
A heating operation control unit that performs heating control to control the amount of heating , wherein the heating operation control unit is a freezing prevention temperature setting unit that sets a temperature that prevents freezing of indoor equipment; and the room temperature. when operating the heating means when the detected temperature is the freeze prevention temperature below set of detection means, preventing condensation of the heat exchanger minimum heating amount greater than the heating amount set for the heating control lower limit Lower heating amount
Warm air heater characterized by having a freeze prevention operation control means and a lower limit heating amount setting means for setting. 2. The apparatus according to claim 1, wherein said heating operation control means includes a temperature adjustment control means for controlling a heating amount of said heating means based on a difference between said detected temperature and said freezing prevention temperature. Hot air heater as described. 3. The hot air heater according to claim 1, wherein the room temperature detecting means is disposed in a suction path for sucking room air into the main body case. 4. The heating operation control means includes means for controlling the temperature control.
The stage has heating operation control means for performing the heating control,
The above-mentioned freezing prevention is performed by operating means for operating the room temperature setting means.
The temperature setting means is operable.
3. The hot air heater according to 2 . 5. The heating operation control means according to claim 4, wherein said heating operation control means includes an operation means for activating said anti-freezing operation control means when the operation of said heating operation control means is stopped. Hot air heater as described. 6. A heat exchanger provided in a main body case and provided with a heating means, a blower fan for sucking room air into the main body case and sending out warm air heated by the heat exchanger to the room. Room temperature detecting means for detecting an indoor temperature; a room temperature setting means for setting a target indoor temperature; and a heating means based on a difference between a detected temperature of the room temperature detecting means and a target temperature of the room temperature setting means. Determine the heating amount
A temperature control control unit with a minimum heating amount set, and a heating operation control unit that controls the heating unit based on the heating amount determined by the temperature control control unit. Anti-freezing temperature setting means for setting an anti-freezing temperature which is a temperature for preventing freezing; and when the detected temperature is equal to or lower than the anti-freezing temperature of the anti-freezing temperature setting means, the heating means is operated to activate the anti-freezing temperature. a freeze prevention control means for performing the freeze prevention operation by the heating means based on heating amount determined by the previous SL temperature control means to the target temperature, heating is determined by the temperature control means when the antifreezing operation the amount, the lower limit amount of heating to prevent condensation of the heat exchanger larger heat quantity than the minimum amount of heating said set as a lower limit
A warm air heater comprising: a lower limit heating amount setting means for setting.