JPH09178267A - Fan forced heater of gas combustion type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect an indoor temperature even during operation, in which combustion is temporarily stopped, by mounting an indoor temperature sensor in a suction port of a casing in a fan forced heater of gas combustion type, in which control of operation involves operation to stop combustion to revolve a blower. SOLUTION: A temperature sensor 7 is mounted in a heating air suction port 10 of a casing 2 to be connected to a control unit 6 through a lead line 71. Thus the sensor is disposed away from a burner 4 to be hardly exposed to radiant heat, and indoor air contacts well with the sensor even when a blower 5 revolves at low speed. The control unit 6 receives a detected indoor temperature from the temperature sensor 7 and a set temperature of an indoor temperature setting switch 15 to appropriately control operations of a gas burner 4 and a blower 5. When an indoor temperature is higher than a predetermined temperature higher than the set temperature, such control is effected to stop combustion of the gas burner 4 and to have the blower 5 performing stand-by operation at low rotational frequency until combustion is resumed. When an indoor temperature is lower than the predetermined temperature, the gas burner 4 and the blower 5 are proportionally controlled depending upon a temperature difference between the indoor temperature and the predetermined temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of room temperature detection accuracy in a gas combustion type hot air heater of a system in which the temperature is automatically adjusted to a room temperature set by a user.

[0002]

2. Description of the Related Art A hot air heater using a gas burner as a heat source,
For example, an inlet for heating air and an inlet for combustion air separated from the inlet for heating air are provided on the back surface,
The casing is provided with a hot air outlet on the front surface.
A blower that sucks heating air from the suction port and blows warm air from the outlet is provided in the casing. A cross-flow type centrifugal fan, for example, is used for this blower from the viewpoint of making the warm air heater compact.

In this warm air heater, a room temperature sensor for detecting the room temperature in the casing, a heating temperature setting means for setting a room temperature desired by the user, and the room temperature sensor and the heating temperature setting are provided. By the input signal from the means,
A control device for controlling the combustion load of the gas burner and the rotation speed of the blower is additionally provided.

In the control device, the amount of heat generated by the heating source and the amount of air blown by the blower are appropriately controlled while detecting the room temperature by the room temperature sensor so that the room temperature set by the user can be obtained. And when the room temperature is higher than the set temperature,
When the room temperature cannot be lowered even if the gas burner is burned with the minimum heat generation limit, it is necessary to temporarily stop the combustion of the gas burner. When the fuel gas is supplied to the gas burner, combustion air is sucked through the inlet by the ejector action of the fuel gas jet.

[0005]

However, in the conventional hot air heater, since the room temperature sensor is attached to the inlet for the heating air and the inlet for the combustion air separated from the heating air, the combustion of the gas burner is stopped. However, the room air cannot be sucked, and the room temperature sensor cannot accurately detect the room temperature.

An object of the present invention is to provide a gas combustion type hot air heater capable of accurately detecting the room temperature even in an operating state in which the combustion of the gas burner is temporarily stopped.

[0007]

According to the present invention, there is provided an inlet for heating air and an inlet for combustion air separated from the inlet for heating air, and a hot air outlet is provided on the front surface. And a gas burner for sucking and burning combustion air through the inlet by the ejector action of a fuel gas jet, and a suction port for sucking the air from the suction port. A blower for blowing warm air from the room, a room temperature sensor for detecting an indoor temperature, a heating temperature setting means, the room temperature sensor and the heating temperature setting means, and the room temperature detected by the room temperature sensor and the The set temperature set by the heating temperature setting means is input, and the gas burner and the blower are rotated while the combustion of the gas burner is stopped. In the gas combustion type hot air heater to a control device mounted to perform laden operation control rolling condition, the room temperature sensor, characterized in that attached to the suction port of the casing.

[0008]

According to the present invention, the room temperature sensor is attached to the intake port even when the blower is operated with the combustion of the gas burner stopped and the blower is rotated (for example, post-purge). Since it is located in the intake airflow, the room temperature can be accurately detected. Therefore, when the room temperature gradually drops with the stop of the combustion of the gas burner and becomes equal to or lower than the predetermined temperature, the timing of reigniting the gas burner can be accurately detected. The blower may be continuously operated at a low speed even after the post-purge has been completed.

According to the third aspect of the present invention, in the gas-fired hot air heater, heated air that passes around the gas burner and is heated by the gas burner, and suction air that is directly sucked by the blower without passing around the gas burner. A mixing type hot air heater that mixes with the mixed air and blows out from the hot air outlet, and the room temperature sensor is directly sucked by the blower in the suction port without passing around the gas burner. Attached to the suction port of the mixing air. Accordingly, the room temperature sensor can be reliably placed in the indoor airflow even when the blower is rotating at a low speed.

In the structure according to the fourth aspect, the room temperature sensor is attached to the inside of the filter detachably provided on the outer surface of the suction port. As a result, the sensor is protected from dust and the like, and maintenance-free for a long period of time can be achieved.

[0011]

1 to 3 show a gas combustion type hot air heater 1. The warm air heater 1 includes a box-shaped casing 2 that is flat in the vertical direction, has a round upper portion, and has a flat lower end. Inside the casing 2, a left side portion is a main body accommodation chamber 21 that accommodates the main body case 3, and a right side portion is a control device room 22.

On the body accommodating chamber 21 side of the casing 2, a horizontally long hot air outlet 24 is opened at the lower part of the front plate 23 which is the front surface, and a large area of heating air is sucked at the upper part of the back plate 25 which is the rear surface. A mouth 10 is provided. In addition, the control equipment room 2
On the back surface of 2, a back plate 25 has an opening 26 for introducing combustion air having a small area. The heating air inlet 10 and the combustion air inlet 26 are both rectangular plate-shaped common filters F (FIG. 2, FIG. 2) detachably attached to the back plate 25.
(See FIG. 3).

The main body case 3 has a vertically flat box shape, and an upper part constitutes an upper case 31 accommodating the gas burner 4, and a lower part constitutes a lower case 51 accommodating a blower 5, and the upper case 31 and An air passage is formed by the lower case 51. The upper case 31 has a heating air inlet 32 on almost the entire back surface thereof, and a cooling air inlet 34 is opened at a lower portion of the front plate 33.

The lower end of the heating air inlet 32 is joined to the lower end of the heating air inlet 10, and the heating air inlet 32 is connected.
The upper end of is set lower than the upper end of the heating air inlet 10, and a cooling air inlet 35 facing the upper end 11 of the inlet 10 is formed.

A gas burner 4 is installed in the upper case 31, and the upper case 31 above the gas burner 4 is installed.
The top plate 36 has a mountain-shaped cross section. The top plate 36
An air flow deflecting plate 37 having a chevron-shaped cross section is installed in parallel below the.

The gas burner 4 is disposed in a box-shaped heat-resistant sheet metal burner accommodating portion 41 which is vertically flat. The burner accommodating portion 41 is provided with a horizontally long secondary air inlet 43 for combustion at the lower part of the back plate 42, and an exhaust port 44 opening below the air flow deflecting plate 37 at the ceiling.

As shown in FIG. 2, between the upper end of the back plate 42 and the top plate 36 of the upper case 31, a mixing air inlet through which a part of the heating air sucked from the heating air inlet 32 is sucked. 38 is formed. Secondary air inlet 4 for combustion
3 and a lower end of the heating air inlet 32 (lower end of the heating air intake port 10) are formed with a mixing air suction port 39 facing the lower end portion 12 of the suction port 10.

As shown in FIG. 3, a burner body 45 is installed in the burner housing 41, and the burner body 45 is installed.
Is a fuel gas blowing nozzle 46 and an introduction passage 47 for sucking primary air by an ejector action of a jet flow of the fuel gas.
Extends through the right side wall of the main body case 3 and the burner accommodating portion 41 to the inlet 26 at the rear of the control equipment chamber 22.

In the burner body 45, the combustion air sucked from the inlet 26 is used as primary air, and the heating air sucked from the inlet 10 flows into the body case 3 from the heating air inlet 32. It is heating air, and further, a part of the heating air sucked from the combustion secondary air inlet 43 into the burner housing 41 is burned as combustion secondary air.

The blower 5 is a cross-flow type cylindrical centrifugal fan 52 disposed inside the hot air outlet 24.
And has a motor 54 for driving the fan 52, and as shown by an arrow, sucks indoor air from the suction port 10 and blows warm air from the hot air outlet 24. The lower case 51 is formed in a structure in which a fan 52 acts as a crossflow fan that causes upper air to flow downward. Below the lower case 51 is a blower nozzle 53 that reaches the warm air outlet 24.

When the gas burner 4 burns, as described above, the combustion air is sucked as the primary air from the inlet 26, and is burned together with the secondary air sucked from the combustion secondary air inlet 43. The combustion exhaust gas passes through the upper end portion 11 of the suction port 10 and the rest of the air sucked from the heating air inlet 32 to the upper portion of the main body case 3 and the front plate 33 of the main body case 3.
And the space A between the burner housing 41 and the front plate of the burner housing 41.

The air-fuel mixture mixed in the space A is sent to the fan 52.
The heating air that has been sucked by and flows downward, and is the heating air that has flowed into the main body case 3 from the heating air inlet 32 of the heating air that has been sucked in from the lower end of the suction port 10.
Cold air and cooling air inlet 3 sucked from the mixed air suction port 39 facing the lower end portion 12 of 0 and passed directly below the bottom plate of the burner accommodating portion 41 by the fan 52.
It is mixed with the cold air sucked from No. 4 and blown out from the warm air outlet 24 through the blower nozzle 53.

In this embodiment, the suction port 10 is formed in a grill shape in which a plurality of lateral slit-like ventilation holes 16 are provided in two rows in the vertical direction. In addition, the inlet 26 for the combustion air
Is also formed in a grill having a large number of lateral slit-shaped ventilation holes arranged in two rows in the vertical direction.

The room temperature sensor 7 is connected to the control unit 6 via a lead wire 71. The mounting position of the room temperature sensor 7 is such that the temperature sensing portion 72 corresponds to the center of the fan 52 in the left-right direction and the lower end portion 12 of the suction port 10 facing the suction port 39 of the mixed air.

This is because the lower end 12 of the suction port 10 facing the suction port 39 is separated from the burner 4 and is less likely to receive radiant heat, and the suction port has little ventilation resistance even when the blower 5 is rotating at a low speed. The reason for this is that the indoor air flow is highest at 39. In this embodiment, the room temperature sensor 7
Is attached by fixing a resin bracket 14 to the casing wall 13 between the slit-shaped ventilation holes 16 of the suction port 10 and holding the lead wire 71.

Fuel gas is supplied to the gas burner 4 from a gas pipe L in which a main valve M, a safety valve V, and a flow control valve G are provided, and combustion air is supplied from the inlet 26.
The gas burner 4 is equipped with an ignition device P and a combustion detection device Q such as acid deficiency fire. A control unit 6 which is an electronic control device is installed in the control equipment room 22.

The control unit 6 includes a room temperature (suctioned air temperature) detected by the room temperature sensor 7 and a temperature setting switch 15.
By inputting the set temperature (shown in FIG. 3), the operations of the gas burner 4 and the blower 5 are appropriately controlled. In this control, if the room temperature becomes higher than the predetermined temperature higher than the set temperature,
The combustion of the gas burner 4 is stopped, and a standby operation of rotating the blower 5 at a low speed is performed until the combustion is restarted. When the room temperature is lower than the predetermined temperature, the gas burner 4 and the blower 5 are proportionally controlled according to the difference between the room temperature and the set temperature.

During this standby operation, the room temperature is accurately detected, and when the room temperature falls below a predetermined temperature, the gas burner 4 is burned by reigniting. As in the present invention, if the room temperature sensor 7 is installed at a position corresponding to the center of the fan 52 in the left-right direction, the room temperature sensor during standby operation even if the suction force is strong and the rotation speed of the fan 52 is low at that position. Since 7 is located in the indoor intake air flow, the room temperature can be accurately detected. As a result, the timing of reignition can be properly controlled.

[Brief description of the drawings]

FIG. 1 is a perspective view from the back of a gas combustion type hot air heater.

FIG. 2 is a side cross-sectional view of a main body accommodation chamber of a gas combustion type hot air heater.

FIG. 3 is a schematic configuration diagram of a gas combustion type warm air heater.

[Explanation of symbols]

 1 Gas Combustion Type Hot Air Heater 10 Air Intake Port 2 for Heating 2 Casing 21 Main Body Chamber 22 Control Equipment Room 24 Hot Air Outlet 26 Combustion Air Inlet 3 Main Body Case 4 Gas Burner 5 Blower 6 Control Unit (Control Unit) 7 Room temperature sensor

Claims (4)

[Claims] 1. A casing having a heating air inlet and a combustion air inlet separated from the heating air inlet and having a hot air outlet on the front surface thereof. In the casing, a gas burner that sucks and burns combustion air through the inlet by the ejector action of a fuel gas jet, and a blower that sucks air from the inlet and blows warm air from the outlet. A room temperature sensor for detecting an indoor temperature, a heating temperature setting means, the room temperature sensor and the heating temperature setting means, and the room temperature detected by the room temperature sensor and the heating temperature setting means. By inputting a set temperature, operation control including an operation state in which the gas burner and the blower are rotated while the combustion of the gas burner is stopped, In Cormorant controller and the attached gas-fired warm-air heating machines, gas combustion type hot air heater, characterized in that the temperature sensor was attached to the suction port of the casing. 2. The gas burner according to claim 1,
Combustion air sucked from the inlet is used as primary air,
A part of the air sucked from the suction port is burned as secondary air for combustion, and the combustion exhaust and the rest of the air sucked from the suction port are mixed and blown out from the warm air outlet. A gas combustion type hot air heater. 3. The gas combustion type hot air heater according to claim 1 or 2, wherein the heating air passing around the gas burner and the mixing air directly sucked by the blower without passing around the gas burner. Is a mixing-type warm air heater that mixes and blows out from the warm air outlet, the room temperature sensor, of the mixing air directly sucked by the blower does not pass around the gas burner in the inlet. A gas-fired hot air heater characterized by being attached to the suction port. 4. The gas combustion type hot air heater according to claim 1, wherein the room temperature sensor is mounted inside a filter that is detachably provided on an outer surface of the suction port.