JP3292418B2 - Gas appliances - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas appliance such as an oven and a fan heater.

[0002]

2. Description of the Related Art In a conventional gas appliance, for example, an oven, the amount of gas is adjusted only by feeding back the temperature in the refrigerator.

[0003]

However, since the gas amount is controlled only by the internal temperature as in the prior art,
In fact, he did not know the amount of heat used at that time.
Since the amount of heat actually used at this time is not known, there are the following problems. B) Since there are variations in gas components, dimensional accuracy of nozzles, and variations in governor pressure, the gas appliance must be designed with a safety factor of 30% in consideration of these factors. There has been a problem that the design has to be performed with a performance close to 70%.

B) If a gas with a high calorific value flows due to a wrong gas type, there is no other way than to shut off the gas at the maximum temperature, and during that time the gas appliances may be damaged or incomplete combustion may occur. Poison gas generation was possible. C). If a gas having a low calorific value flows due to a wrong gas type, the preheating time may be abnormally long or the gas appliance may be damaged.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is an object of the present invention to make it possible to obtain the maximum heat quantity at the combustion limit and to always provide the shortest preheating time. In addition, variations in overshoot and undershoot during temperature control can be kept constant, stabilizing the baking performance. In addition, gas type errors and nozzle clogging can be detected at a relatively early stage, resulting in damage to gas appliances. Another object of the present invention is to provide a gas appliance that can be small.

[0006]

In order to solve the above-mentioned problems of the prior art and achieve the object of the present invention, a gas appliance of the present invention comprises a measuring means 101 for measuring a rising speed of a temperature in a refrigerator;
A gas flow control valve 102 for controlling a gas flow rate, and a gas flow rate control valve 102 for controlling a gas flow rate based on a used heat quantity estimated from a temperature rise rate measured by the measuring means 101 under a condition where the gas flow rate is constant. Control unit 104 for performing the measurement, and the rate of rise of the internal temperature measured by the measuring means 101
However, the time required for the internal temperature to rise
The control unit 104 controls the storage
When the internal temperature is higher than a predetermined temperature, the measuring means 101
The temperature inside the chamber measured several times required a certain temperature rise
It is characterized in that control is performed using time . Also, measure the rate of rise of the internal temperature.
Measuring means 101 and a flow control valve 1 for controlling a gas flow rate
02 and the measuring means 1 under the condition that the gas flow rate is constant.
Used from the temperature rise rate measured at 01
Gas flow control by the flow control valve 102 based on the amount of heat
And a control unit 104 for performing measurement by the measuring unit 101.
The temperature of the inside of
The temperature is obtained from the temperature, and the control unit 104
When the temperature inside the refrigerator is equal to or higher than a predetermined temperature, the measuring means 10
Use the temperature inside the chamber that has risen for a certain period of time previously measured in step 1.
It is characterized in that it is set to control using
It may be.

[0007]

[0008]

[0009]

[0010]

According to the present invention having the above-described structure, the rate of rise of the internal temperature is measured by the measuring means 101 under the condition that the gas flow rate is kept constant, and the gas rate estimated from the temperature rise rate is measured. The gas flow rate is controlled by the flow rate control valve 102 based on the heat value. Here, measuring means 1
The rise rate of the internal temperature measured at 01 is the internal temperature
It is determined by the time required for a certain temperature rise.
Or the internal temperature measured by the measuring means 101
Is determined by the temperature inside the chamber that has risen for a certain period of time.
It is easy to be configured,
It can measure the rate of temperature rise. And high temperature
When cooking, etc., when the inside of the refrigerator is not sufficiently cold
When ignited again, the temperature inside the chamber immediately after ignition is higher than the specified temperature
In the case of, the temperature in the chamber previously measured by the measuring means 101 is
Time required for a certain temperature rise, or measuring means
Uses the temperature inside the chamber that has risen for a certain period of time measured last time
The amount of heat used automatically
The flow rate can be controlled.

[0011]

[0012]

[0013]

[0014]

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. Examples of the gas appliance of the present invention include an oven and a gas fan heater, and an oven will be described below as an example. FIG. 1 shows a schematic overall configuration diagram of the present invention. In FIG. 1, 1
Numeral denotes a cooking cabinet of the oven, 11 denotes a burner for heating the inside of the cooking cabinet 1, and 112 denotes a gas nozzle provided at the tip of the gas passage portion 106. Reference numeral 102 denotes a flow rate control valve disposed on the upstream side of the gas nozzle 112 of the gas passage portion 106 for controlling a gas flow rate. In the embodiment, the flow rate control valve 102 is a proportional type flow rate valve generally abbreviated as a proportional valve. A control valve 102a is used. This proportional type flow control valve 102a is, for example, as shown in FIG. 6, and is constituted by attaching a plunger 108 of an electromagnetic solenoid unit 107 to a diaphragm valve 109, and controlling the flow through a coil unit 110 of the electromagnetic solenoid unit 107. The open state of the diaphragm valve 109 is adjusted by changing the current value. The control of the proportional flow control valve 102a is performed by a control signal from the control unit 104. In FIG. 1, reference numeral 111 denotes a temperature sensor for detecting the temperature in the cooking cabinet 1, and a detection signal from the temperature sensor 111 is input to the control unit 104. Gas passage 10
An electromagnetic valve 113 is provided upstream of the flow control valve 102 of No. 6.

Next, the oven will be described. 2 to 4 show an example of an oven used in the present invention.
The front side of the cooking cabinet 1 is an opening, and this opening can be hermetically closed by an openable and closable door 25. A burner 11 and a combustion fan 15 that constitute the heating unit 2 are disposed in a substantially central portion behind the cooking cabinet 1 so as to be shifted in front and rear. The burner 11 is disposed in the combustion chamber 4 provided behind the cooking cabinet 1, and the combustion fan 15 is disposed in the combustion fan storage chamber 5 provided behind the combustion chamber 4. Here, a passage chamber 7 partitioned by a partition plate 6 is provided between the combustion chamber 4 and the combustion fan storage chamber 5, and a portion above the partition plate 6 is a passage through which hot air passes.
A plurality of hot air inlets 9 are provided in the upper and lower portions of the left and right side surfaces of the cooking cabinet 1 in the front-rear direction. Ducts 8 are provided on the left and right for communicating from both sides of the combustion fan storage chamber 5 to hot air inlets 9 on both sides of the cooking cabinet 1. In the embodiment, the temperature in the duct 8 and the temperature in the cooking cabinet 1 are almost the same, so that the temperature sensor 111 is arranged in the duct 8 and the temperature in the duct 8 is detected to detect the temperature in the cooking cabinet 1. It is considered that the temperature in the inside is detected. A hot air outlet 10 communicating with the combustion chamber 4 is provided at an upper portion of a rear surface portion of the cooking cabinet 1, and hot air entering the combustion chamber 4 from the hot air outlet 10 further flows from the passage above the partition plate 6 to the passage chamber 7. It has become. The combustion chamber 4 is provided with a combustion air supply port 19 to which combustion air is supplied. An exhaust port 13 is provided in the rear wall 12 of the combustion fan storage chamber 5.
Is connected to an exhaust passage 21 whose tip is open to the outside. Behind the combustion fan storage room 5, a cooling fan storage room 14 is provided.
The combustion fan storage chamber 5 and the cooling fan storage chamber 14 are separated by a heat insulating plate 22, and the heat of the exhaust chamber 20 is reduced by the heat insulating plate 22.
It does not affect the motor 18 disposed rearward. A part of the cooling fan storage chamber 14 communicates with the exhaust path 21, and the cooling fan storage chamber 14 is provided with a cooling air suction port 28. A cooling fan 17 is further fixed to the output shaft 16 of the combustion fan 15.
The cooling fan 17 is disposed in the cooling fan storage chamber 14, and the output shaft 16 is rotated by a motor 18 disposed behind the cooling fan storage chamber 14.

A water dish is placed on the bottom of the cooking cabinet 1, and an oven dish and a grill are arranged in the middle of the cooking cabinet 1. . The gas cooking apparatus is capable of performing both cooking at a normal cooking temperature of 250 ° C. or less and high-temperature cooking at 300 ° C. or more. In the above configuration, the burner 1
When the gas is burned by the combustion fan 1 and the combustion fan 15 is rotated, the hot air generated by the combustion of the burner 11 is passed through the duct 8 by the combustion fan 15 through the hot air inlets 9 provided on both sides of the cooking cabinet 1 through the cooking cabinet 1. Forcibly flows into the cooking chamber 1, heats the inside of the cooking chamber 1, returns to the combustion chamber 4 again from the hot air outlet 10 provided at the upper part of the rear surface of the cooking chamber 1,
The inside of the cooking chamber 1 is heated while the hot air is reheated and circulated so as to be heated again by the flame of the burner 11 in the combustion chamber 4 and flow again into the cooking chamber 1 through the duct 8 by the combustion fan 15. is there. Therefore, the heating unit 2 including the burner 11 and the combustion fan 15,
A duct 8, a hot air inlet 9, a cooking cabinet 1, a hot air outlet 10 and the like constitute a hot air circulation path 29. Some of the circulating hot air is exhausted from the exhaust port 13 to the exhaust chamber 20,
The air is exhausted to the outside via the exhaust path 21. In this case, the external air is sucked in by the cooling fan 17 and flows into the exhaust path 21 to lower the temperature of the exhaust gas exhausted from the exhaust path 21, and the motor 18 is cooled by the cooling operation of the cooling fan 17 by the outside air. To prevent heating.

The oven used in this embodiment is
The capability of the burner 11, the capability of the combustion fan 15, and the like are set so that the heating unit 2 can cook by heating the internal temperature to 300 ° C. or higher. For this reason, it is possible not only to perform conventional cooking at an internal temperature of 250 ° C. or less, but also to perform high-temperature cooking at an internal temperature of 300 ° C. or more as necessary. FIG. 5 shows a block circuit diagram of the oven of the present invention. 1
01 is a measuring means for measuring a rising speed of the temperature in the refrigerator,
In this embodiment, the measuring means 101 determines the time t required for the internal temperature to rise by a certain temperature, and inputs the value to the control unit 104. Then, the amount of heat used is estimated based on the time t and the measurement value of the gas flow rate, and the flow control valve 10 is adjusted by correcting the correlation between the used heat amount and the gas flow rate based on the estimated value. Control unit 1
The gas flow rate is controlled by controlling the amount of heat to be used to control the amount of heat to be used. In FIG. 5, reference numeral 105 denotes an abnormality output unit 105 that determines that an abnormality has occurred when the time required for the internal temperature to rise to a certain temperature is outside the set time, shuts off the gas and issues an alarm, and 115 denotes a control unit. Alarm means such as lighting or a buzzer for generating an alarm based on an output from the abnormality output unit 105 provided in the unit 104.

Here, the flow control valve 102 is a proportional flow control valve 102a as in the embodiment, and the measuring means 101 measures the control current value of the proportional flow control valve 102a. The case where the control unit 104 adjusts the gas flow rate by correcting the correlation between the control current value and the control current value will be specifically described. As described above, in the embodiment, the temperature sensor 111 for detecting the inside temperature is attached to the duct portion 8 beside the cooking cabinet 1, and the temperature of this portion is regarded as the inside temperature. Then, only in the case of high-temperature cooking requiring preheating in the oven, the time t until the internal temperature reaches 100 ° C. to 175 ° C. is determined by the measuring means 101 by the temperature sensor 111 and the control unit 1
Enter in 04. At this time, the control current value Is flowing to the proportional flow control valve 102a flowing at this time is maintained at a constant value. Here, the time t is the amount of heat used (kca).
It has been experimentally confirmed that only l) is affected and the others are hardly affected. Therefore, the time t
Is obtained, a change in the amount of heat due to a variation in the gas component or the like can be found, so that correction to a correct amount of heat can be performed. As described above, in the embodiment, the control unit 104 is controlled based on the inside temperature information.
By controlling the control current flowing through the proportional flow rate control 102a, the gas flow rate is adjusted so as to obtain a correct heat quantity (kcal / h), that is, a correct input quantity.

In the following, the rate of rise of the internal temperature measured by the measuring means 101 is determined by the time required for the internal temperature to rise by a certain temperature, the amount of heat used is estimated, and based on the estimated amount of heat, A method for controlling the gas flow rate so as to obtain a correct amount of heat (input) after correction by controlling the control current flowing through the proportional flow rate control valve 102a will be described in detail.

Now, assuming that the weight of the oven is W ₀ , the specific heat of the oven is Cp ₀ , the temperature of the oven heated during the time t ₀ is ΔT ₀ , and the amount of heat applied to the oven is Q ′ ₀ , Q ′ ₀ = Wo · Cp ₀ · ΔT ₀ [kcal] (1), and the amount of heat Qo required at that time is Q ₀ = Q ′ ₀ / η (= constant) [kcal] (2) η; oven The reference gas consumption q _{0 at} this time is: q ₀ = Q ₀ / H ₀ [m ³ ] (3) H ₀ ; heat value of the reference gas [kcal / m ³ ] The gas amount q emitted from the nozzle is q = A · S · (p / d) ^1/2 [m ³ / h] (4) A: orifice coefficient, S: nozzle cross-sectional area p: gas pressure, d; specific gravity of the gas also, the relationship between the proportional valve current and gas flow rate I = B · (p / d ) 1/2 + C [mA] ......... (5) B; constant, ; Constant (3), (4), (5) from _{Q 0 = H 0 · q 0} = H 0 · A · S · (p / d) 1/2 · t 0/3600 sec = (A / 3600 / B) · H ₀ · S · t ₀ · (I−C) [kcal] (6) Therefore, in general, Q ₀ = H · S · t · (I−C) = constant (7) H: Gas calorific value [kcal / m ³ ] S: Nozzle area [m ² ] t: Required time [sec] I: Control current of proportional flow control valve [mA] Here, equation (7) is used. Since H and S are always the same, I = K / t + C (8) If it takes t ₀ seconds when the reference current is I ₀ , K = t ₀ · (I ₀ −C) Become. Therefore, the reference equation is I = t ₀ · (I ₀ −C)
/ T + C (9) Next, when H (gas calorific value) or S (nozzle area) changes, K in equation (8) changes. The control current of the proportional type flow control valve at that time I ₀ flowing K = t ₁ · When required t ₁ seconds (I ₀ -C) Therefore _{I = t 1 · (I 0} -C) / t + C ......... (10) (Note) FIG. 10 shows graphs of the above equations (9) and (10). Also, if the heat quantity is Q _0, it always takes t ₀ seconds, so (1
The value obtained by inserting t ₀ into the equation (0) is I ₁ . Therefore, I ₁ = t ₁ · (I ₀ −C) / t ₀ + C Next, in the formula (5), when the same gas is used in the same device, I = B ′ · Ip + C (5) ′ (5) Related Accordingly corrected equation (10) below;) · Ip ₀ + C 'control current value of the proportional type flow control valve when put the reference input Ip ₀ in formula I ₁ = B because becomes I _1' request control current value Ii of the proportional type flow control valve to obtain the input Ip ₁ to the _{Ii = (I 1 -C) /} Ip 0 · Ip 1 + C ......... (11) in addition, proportional flow control valve in FIG. 7 A graph showing the relationship between the control current of 102a and the amount of heat (input) is shown. FIG. 8 is a graph showing the relationship between the control current I of the proportional flow control valve 102a and the time t required for temperature rise.

However, from the above description, even if H (heat generation amount of gas), S (nozzle area), p (gas pressure) change, etc., an accurate heat amount (input) [kcal /
h]. Also, limits on combustion chamber capacity can be used. That is, FIG. 9 shows a combustion limit (a heat generation amount indicating a limit of the combustion chamber capacity, that is, Ip = −4.63T + 63) between the heat amount (input) and the internal temperature.
A graph showing the relationship in 15) is shown.
When the temperature in the cooking cabinet is 300 ° C., the input Ip is the amount of heat of the limit of the combustion chamber capacity as indicated by a in FIG. 9, and when the temperature in the cooking cabinet is 350 ° C., the input Ip is
As for p, the amount indicated by b in FIG. 9 is the heat quantity at the limit of the combustion chamber capacity, and can be adjusted to the input quantity at the limit of the combustion chamber capacity based on the temperature in the refrigerator. That is, the limit start dash mode becomes possible. Further, in the case of a defect such as a wrong gas type, a wrong nozzle, or clogging of chips, the time required for the internal temperature to rise to a certain temperature is outside the set time. The electromagnetic valve 113 is closed by the output from the abnormality output unit 105 to shut off the gas and an alarm is issued from the alarm means 115.

FIG. 10 shows a graph obtained from the above equation (9) (an equation serving as a reference) and the above equation (10). The control current value of the valve is determined. In FIG. 10, t ₀ is a reference time and I ₀ is a reference current value. When the measurement time is t ₁ , the current value is corrected to I ₁ . This correction is performed by the control unit 104 and the control current value of the proportional flow control valve is controlled so as to be the corrected control current, whereby a correct input, that is, a correct calorie [kcal / h] is obtained. The amount of gas can be adjusted in this way.

In the present invention, when the internal temperature immediately after ignition is equal to or higher than a predetermined temperature, the control unit 104 uses the time required for the internal temperature previously measured by the measuring means 101 to rise by a certain temperature. And set it to control
You. Thus, in high-temperature cooking or the like, the amount of gas is adjusted and controlled so that a desired amount of heat can be obtained even when the interior is not sufficiently cooled and the ignition is performed.
Then, in the above control, the control unit 104
There is no previous data when the internal temperature is higher than the specified temperature
The time required for the internal temperature to rise by a certain temperature
It is set to control using time.

In the above embodiment, the rate of rise of the internal temperature measured by the measuring means 101 is determined by the time required for the internal temperature to rise by a certain temperature. Alternatively, the rate of increase in the internal temperature measured by the means 101 may be determined based on the internal temperature that has increased during a certain period of time. FIG. 11 is a graph showing the relationship between the temperature ΔT (° C.) at which the temperature has risen between 120 seconds and 220 seconds after ignition and the control current of the proportional flow control valve 102a.

In this embodiment, the control unit 104
An abnormality output unit 105 is provided to determine an abnormality when the temperature inside the refrigerator has risen during a certain period of time is out of the set temperature and shut off the gas to give an alarm. In this case, the gas is stopped, and an alarm is issued by the alarm means 115. In this case, the control unit 104 is set to perform control using the internal temperature that has been measured for a certain period of time previously measured by the measuring unit when the internal temperature immediately after ignition is equal to or higher than a predetermined temperature , In high-temperature cooking or the like, the amount of gas is adjusted and controlled so that a desired amount of heat can be obtained even when ignition is performed when the inside of the refrigerator is not sufficiently cooled. And the control unit 10
4 indicates that the internal temperature immediately after ignition in the above control is a predetermined temperature.
Over time, if there is no previous data, at a certain time
Set to control using a rising standard chamber temperature
I have.

[0027]

According to the first aspect of the present invention, as described above, the measuring means for measuring the rise rate of the internal temperature, the flow rate adjusting valve for adjusting the gas flow rate, and the gas flow rate Since the control unit performs gas flow adjustment by the flow control valve based on the used heat quantity estimated from the temperature rise rate measured by the measuring means under the constant conditions, the variation due to the gas component and the nozzle It is possible to obtain the correct amount of heat even if there is a variation in the gas pressure or the gas pressure, etc. In addition, the maximum input of the combustion limit can be input, and the shortest preheating time is always possible. . In addition, since the variation in overshoot and undershoot during temperature control is constant, the baking performance is also stable. Moreover, the rise in the internal temperature measured by the measuring means
When the speed required for the internal temperature to rise by a certain temperature
The rate of rise in the internal temperature
Can be easily obtained. Furthermore, the control unit
However, when the internal temperature immediately after ignition is higher than a predetermined
The temperature inside the chamber measured last time by a constant means rises by a certain temperature
Is set to control using the time required for
So the previous cooking is over in case of high temperature cooking
The time has not passed so much and the inside of the refrigerator has cooled down enough
It can be controlled to get accurate heat even when it is not
is there.

According to the second aspect of the present invention, the storage
Measuring means for measuring the rate of rise in internal temperature and adjusting the gas flow rate
Flow control valve, and
Use estimated from the temperature rise rate measured by the measuring means
Gas flow control by the flow control valve based on the heat quantity
Control unit, so that the variation due to gas components
Due to variations in nozzles, gas pressure, etc.
Can also obtain the correct amount of heat,
The maximum input of the combustion limit can be input and always the shortest
Preheating time is possible. Also, when adjusting the temperature,
Variations in bar shoot and undershoot are also constant
Therefore, the baking performance is also stable. Moreover, measurement
The rise rate of the internal temperature measured by the means
Being required at the elevated internal temperature,
The rate of temperature rise can be easily obtained.
You. Further, the control unit determines that the internal temperature immediately after the ignition is a predetermined temperature.
In the above case, the measurement is performed for a certain period of time
Set to control using the raised internal temperature.
Therefore, in the case of high-temperature cooking,
The time has not passed so much and the inside of the refrigerator is cold enough
A device that can be controlled to provide accurate heat even when it is not
It is.

[0029]

[0030]

[0031]

[0032]

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of the present invention.

FIG. 2 is a schematic side sectional view showing an example of an oven used in the present invention.

FIG. 3 is a schematic front sectional view of the same.

FIG. 4 is a schematic plan sectional view of the same.

FIG. 5 is a block circuit diagram of the present invention.

FIG. 6 is a cross-sectional view showing a proportional-type flow control valve used in the first embodiment.

FIG. 7 is a graph showing a relationship between a control current and a calorific value (input) of the proportional flow control valve according to the first embodiment.

FIG. 8 is a graph showing a relationship between a control current of the proportional flow control valve and a time required for temperature rise.

FIG. 9 is a graph showing a relationship between a calorific value (input) and a temperature in a refrigerator at a combustion limit.

FIG. 10 is a graph for obtaining a control current value of a proportional-type flow control valve based on a measurement time based on the above reference formula.

FIG. 11 is a graph showing a relationship between a control current of the proportional flow control valve and a temperature rise for a predetermined time.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Measuring means 102 Flow control valve 102a Proportional flow control valve 104 Control unit 105 Output unit for abnormality

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Joe Uchida, 1-15-1 Oka, Minami-shi, Minato-ku, Osaka-shi Inside Herman Co., Ltd. (72) Takashi Matsumoto 1-1-52, Oka, Minami-shi, Minato-ku, Osaka-shi (72) Inventor Hideki Matsubara 4-1-2, Hiranocho, Chuo-ku, Osaka-shi Osaka Gas Co., Ltd. (72) Inventor Tomohiro Kitamoto 4-1-2, Hiranocho, Chuo-ku, Osaka-shi Osaka Gas Co., Ltd. Examiner Takeshi Shinkai (56) References JP-A-6-26642 (JP, A) JP-A-62-141417 (JP, A) JP-A-62-202944 (JP, A) JP-A 52-18869 ( JP, A) JP-A-59-103044 (JP, U) JP-A-5-23213 (JP, U) JP-A 57-196902 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) F23N 1/00 F23N 5/00-5/24

Claims (2)

(57) [Claims] 1. A measuring means for measuring a rise rate of a temperature in a refrigerator, a flow control valve for adjusting a gas flow rate, and an estimation based on a temperature rise rate measured by the measurement means under a condition of a constant gas flow rate. A control unit for adjusting the gas flow rate by the flow rate control valve based on the amount of heat used is provided .
The rate of rise of the temperature inside the oven is a certain temperature
It is determined by the time it takes to ascend,
When the internal temperature immediately after ignition is equal to or higher than a predetermined temperature,
The temperature inside the chamber previously measured by the measuring means rises by a certain temperature
Is set to control using the time required for
Gas appliance, characterized in that that. 2. Measuring means for measuring a rate of rise of the temperature in a refrigerator.
And a flow control valve to adjust the gas flow, and a constant gas flow
Temperature rise rate measured by the above measuring means under the condition
Flow control valve based on the amount of heat used
Control unit for adjusting the gas flow rate.
The rate of rise in the internal temperature rises for a certain period of time
It is determined by the temperature inside the chamber, and the control
When the temperature inside the chamber is higher than the predetermined temperature,
Control using the temperature inside the chamber that has risen for a certain period of time
A gas appliance characterized by being set to be controlled .