JP2019056518A - Kitchen ventilation system and its method - Google Patents

Abstract

To save energy in kitchen ventilation while securing safety in kitchen internal environment.SOLUTION: Switching means is provided to switch a normal control operation for making a set temperature variable by automatic search to automatically determine a temperature deviation value relating to VAV control air volume so that an air volume of an outdoor unit (32) including an exhaust fan (13) and an air supply fan can be controlled while controlling an air volume of each of variable air volume devices (VAV 80, 81, 82, 83) disposed on a collection duct (21) for collecting air of branch ducts by detecting temperature deviation (74, 50) between the inside of the branch ducts (70) respectively disposed on exhaust hoods (5) and a kitchen room (2), and a safety priority operation operating the VAV with a maximum air volume on the basis of detection (53) of indoor carbon monoxide concentration.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a kitchen ventilation system and a method for exhausting and supplying air suitable for a ventilation facility provided in a kitchen facility such as a hotel or a restaurant.

  In a kitchen that handles fire, a duct is arranged for supplying and exhausting the air, and an exhaust and air supply facility is installed to perform local exhaust for each kitchen by attaching an exhaust hood to the exhaust duct. Furthermore, conventional ventilation equipment in commercial kitchens is equipped with exhaust equipment that discharges cooking exhaust and steam generated from cooking equipment to the outside, and outside air that is necessary for the combustion of cooking equipment is introduced from the outside to adjust the temperature and humidity. Supply air supply equipment, and air conditioning equipment for air conditioning the kitchen and spatially continuous seats.

  FIG. 12 shows a conventional system. For example, the exhaust facilities of the kitchen (2, 3, 4) of the restaurant on the second floor (2F) of the tenant building (1) include a plurality of exhaust hoods (5 , 6, 7, 8), branch ducts (9a, 9b, 9c, 9d) for each exhaust hood, collective ducts (10a, 10b, 10c, 10d), manual dampers that are provided in each collective duct and adjust the exhaust amount or The motor damper (11a, 11b, 11c, 11d), the exhaust duct (12), and the exhaust fan (13) (installed on the rooftop RF in this figure) are configured.

  The exhaust system collects the air collected by the exhaust hood (5, 6, 7, 8) provided for each cooking appliance or for each exhaust section through the branch ducts (9a, 9b, 9c, 9d). 10c, 10d) and hot air (14, 15, 16) by the exhaust fan (13) from the exhaust duct (12) via the motor dampers (11a, 11b, 11c, 11d) in each collecting duct. , 17) is discharged outdoors. Here, the exhaust amount is always a constant amount, and the amount is 20 to 40 times the predetermined exhaust amount obtained from the equipment capacity (total value of the rated combustion amount of each equipment) or the predetermined wind speed in the opening area of the exhaust hood. Multiply

  In the conventional example shown in FIG. 12, the air supply facility includes an external air conditioner (32) for adjusting temperature and humidity having an air supply fan for taking in outside air (30) and a return path (31) with a heat source (not shown). ), A manual damper or each motor damper (34a, 34b, 34c) and an air inlet (36a, 36b, 36c) provided with an air supply duct (33) for each branch of each kitchen (2, 3, 4). .

  This air supply system adjusts the temperature and humidity of the outside air (30) taken in by the air supply fan with an air conditioner, that is, the external air conditioner (32), and then passes through the air supply duct (33) to the air outlet ( Air is supplied to each kitchen from the air supply port (36a, 36b, 36c) via a manual damper or each motor damper (34a, 34b, 34c) for adjusting the blown air volume of 36a, 36b, 36c). The supply amount of outside air (outside air amount) is also always constant, and an amount corresponding to the displacement is introduced by the supply fan.

  Of the above-described exhaust equipment and air supply equipment, the exhaust fan (13) is driven by the exhaust fan inverter (40), and the external air conditioner (32) is driven by the external air conditioner inverter (41). The operation of the exhaust motor dampers (11a, 11b, 11c, 11d) and the supply air motor dampers (34a, 34b, 34c), the exhaust fan inverter (40), and the external air conditioner inverter (41) Is controlled by the control panel (42).

  Kitchen ventilation contributes to securing the necessary amount of outside air for cooking appliances that burn fuel gas, and improving the environment in the kitchen and passenger seats by exhausting odors, steam, and oily smoke in fuel gas and electric cooking appliances. On the other hand, as described above, since a constant amount of exhaust air and outside air are supplied at all times, the fan power and the energy related to adjusting the temperature and humidity of the outside air are consumed enormously, and the power consumption in the tenant building is observed. And the energy consumption per unit area of a store is twice that of an office in a restaurant. In particular, the actual number of restaurants is 15 times as large as the office. For example, when an office in a complex tenant building is 70% and a restaurant is occupying with an occupation area ratio of 30%, the energy consumption ratio is reversed to 30% for the office and 70% for the restaurant. This is because the restaurant kitchen always exhausts a certain amount of air from the kitchen hood regardless of the use of fire.

  In order to promote energy saving in kitchen ventilation, the above-mentioned constant amount of exhaust and outside air introduction can be made variable, and it is possible to ventilate without excess or deficiency by making judgment during use of fire or cooking, without compromising safety and comfort It is possible to operate, and it is necessary to realize a reduction in the introduction cost in building a ventilation system.

Judgment when using fire or cooking shows that various environmental conditions are detected. Although Patent Document 2 describes determination based on carbon dioxide (CO ₂ ) concentration, it is difficult to distinguish between human-derived concentration and combustion-derived concentration, and it cannot be clearly determined in an electric cooking device. . Patent Document 7 and Patent Document 8 describe a judgment that combines temperature and humidity, but the temperature is also high when water vapor is constantly generated, although the installation cost of two sensors is necessary. Humidity detection is unnecessary, and there is a concern about deterioration due to oil or the like in the practical detection principle of the humidity sensor, and the replacement frequency is fast and the maintenance cost is excessive. Further, Patent Document 7 describes that the temperature is detected by infrared radiation, but the pan and the cooking table are likely to be made of shiny metal, have low emissivity, and reflect the surrounding thermal environment. In some cases, the accuracy of the measured value is lost.

  Patent Document 3, Patent Document 5 and Patent Document 6 describe that the use of fire or cooking during temperature is determined by a temperature sensor, but is described as being installed in the vicinity of a cooking device or in an exhaust hood, and a cooking device constituted by a plurality of units Of course, in the hood with a large volume surrounding it, a temperature distribution is generated, and it is necessary to increase the number of sensors installed in order to grasp this, so it is costly, and a representative point is set to avoid it In some cases, it is necessary to compromise as detection information such as a certain response delay.

  As a method of making the exhaust amount of the constant amount variable at all times, a motor damper (MD) is installed in the exhaust duct and the opening degree and the rotational speed of the exhaust fan are adjusted. It describes that many are installed in each hood. Although fine air volume control can be performed, the installation cost of the damper becomes large, and a large number of patterns for controlling the damper are set, which increases the cost of creating the control panel. Furthermore, depending on the positional relationship between the position of the air supply outlet and the exhaust hood and the opening position of the spatially continuous passenger seats (counter, serving place, etc.), the exhaust amount of each exhaust hood can vary greatly. In a hood with a large amount and a high exhaust speed, a short circuit with the supply air is generated, and the temperature-controlled supply air is exhausted without being circulated in the kitchen, so that the thermal environment deteriorates and there is a concern about comfort.

  Also, as a method for controlling exhaust without excess or deficiency, Patent Document 5 creates a pattern of exhaust fan air volume and exhaust damper opening that allows the air volume to be changed for an exhaust hood with a maximum air flow or low usage. Patent Document 6 describes that operation is performed by providing several temperature setting values and specifying a setting duration. The operation pattern to be created differs depending on the menu of the meal provided by the store and the customer's order, and when the tenant changes and the cooking appliance changes, it is necessary to set again, which takes time and work cost. Similar concerns arise in temperature setting, and the room and exhaust temperatures and their temperature deviations vary depending on the environmental conditions such as cooling, heating, and air conditioning heat load, so it is necessary to perform periodic resetting. And costly.

In order not to impair the safety, Patent Document 5 takes measures to exhaust at the maximum air volume when detecting an abnormality of a fan or a damper. However, for combustion of fuel gas or charcoal, carbon monoxide (CO) or oxygen (O ₂ ) Concentration detection is required, and if the control concentration range is exceeded, the maximum air volume must be secured.

  In the embodiment of Patent Document 1, a temperature sensor is installed in a branch duct on the upstream side of the exhaust hood, and the exhaust amount is controlled by the difference between the exhaust temperature and the temperature in the kitchen that is hardly affected by each cooking appliance. There is a description that a motor damper (MD) is provided in a branch duct provided in each exhaust hood or a collective exhaust duct downstream of these branch ducts. It is trying to control the exhaust and supply air volume without providing any means to do so.

Japanese Patent Application Laid-Open No. 6-221631 JP 2005-156138 A JP 2006-200818 A JP 2006-284095 A JP 2012-137261 A JP 2012-137262 A Japanese Patent Laid-Open No. 2015-206508 Japanese Patent Application Laid-Open No. 2006-80274

  First, the determination of whether to use fire or cooking is possible by suppressing deterioration of the sensor to be detected, ensuring the reliability of the source, and being able to be detected regardless of the influence of distribution, and at a low cost for promoting the spread of the present invention. It is necessary to consider ease of maintenance and maintenance.

  Secondly, the motor damper installation location for changing the exhaust amount needs to suppress the deterioration of the thermal environment in the kitchen by avoiding a reduction in the damper installation cost and a large difference in the exhaust amount of each exhaust hood.

  Thirdly, in order to control exhaust without excess or deficiency, patterning of exhaust air volume and damper opening, multiple temperature setting values, and fixed values can change meal menus, tenant changes, and seasonal variations in the air conditioning environment. It becomes impossible to follow the influence of the above, and resetting is necessary.

Fourth, in order to consider safety, measures are taken to exhaust at the maximum air volume. In addition to detecting abnormalities in equipment, carbon monoxide (CO) and oxygen (O ₂ ) related to combustion of fuel gas and charcoal fire A risk avoidance system based on the detection of concentrations is required.

  Fifth, a pattern operation based on the exhaust air volume and damper opening assuming the heat generation and combustion amount of each cooking appliance is performed, but the exhaust air volume is not measured and a kitchen having an air volume measuring function is introduced. It is necessary to control the air supply by building a ventilation system.

In general, it is said that the use load factor of kitchen equipment is limited to about 20 to 30%, and excessive and useless ventilation operation is performed even in the unused time zone. In this ventilation operation, the air inside the kitchen must be thrown out and the outside air must be newly introduced after temperature adjustment (temperature adjustment), and not only the exhaust motive energy but also the air conditioning energy is consumed enormously.
Already in general offices, etc., energy-saving air conditioning systems that increase or decrease the amount of outside air are being operated, but if the same control can be performed in consideration of the individual circumstances of many kitchens in the tenant building, significant energy savings can be achieved. The effect can be expected.
In other words, in the normal ventilation operation, the kitchen ventilation system is primarily designed to have an appropriate ventilation capacity so as to save energy, but in a kitchen that handles fire, there is a risk of carbon monoxide generation that has a low probability of occurrence in general offices. Accompanying sex. Therefore, a multifunctional kitchen ventilation system including energy saving and safety improvement is desirable so that the ventilation capacity is maximized and safety is first when an abnormal situation is detected.

The first means of the present invention is:
A plurality of exhaust hoods provided in a plurality of kitchens, a plurality of branch ducts connected to the exhaust hoods, a collective duct connected by joining the plurality of branch ducts, and a downstream duct communicating with the collective duct; In a kitchen ventilation system having an exhaust path configured with an exhaust fan,
An exhaust temperature sensor provided in the ventilation portion of the branch duct;
A variable air volume device provided in a ventilation portion of the collective duct, and including an air volume measuring element and an air volume control element;
Indoor temperature sensors provided in the plurality of kitchens;
An indoor carbon monoxide concentration sensor and / or an indoor oxygen concentration sensor,
The exhaust fan provided in the ventilation portion of the downstream duct and exhausting all the collecting ducts;
With
The variable air volume device that performs air volume control for increasing or decreasing the exhaust air volume based on a temperature deviation between both temperatures detected by the exhaust temperature sensor and the indoor temperature sensor,
The difference between the temperature deviation and the exhaust air volume is set so that the difference between the pre-control exhaust air volume before performing the air volume control and the post-control exhaust air volume after performing the air volume control approaches a target air volume reduction amount. A normal control operation including an air volume control process for automatically searching for a relationship, and performing the automatic search for varying the exhaust air volume after control with the variable air volume device over time;
When detecting an abnormality in carbon monoxide concentration or oxygen concentration, the variable airflow device is switched to the maximum airflow, and the safety priority operation is performed to increase the exhaust airflow requirement toward the exhaust fan;
This is a kitchen ventilation system characterized by a configuration capable of switching between normal control operation and safety priority operation.

  The second means of the present invention includes an air outlet for supplying outside air to the kitchen, a collective duct connected to a branch duct provided with the air outlet, and an air flow measuring element and an air flow control element in the ventilation portion of the collective duct. A variable air volume device having a built-in structure, an upstream duct communicating with the collective duct, and an air supply fan provided in the upstream duct or an external air conditioner including the air supply fan, so as to maintain a pressure balance inside and outside the kitchen And means for controlling the rotation of the variable air volume device and the air supply fan or the exhaust fan in addition to the kitchen ventilation system.

The third means of the present invention is:
A plurality of exhaust hoods provided in a plurality of kitchens, a plurality of branch ducts connected to the exhaust hoods, a collective duct connected by joining the plurality of branch ducts, and a downstream duct communicating with the collective duct; In a kitchen ventilation method having an exhaust path configured with an exhaust fan,
An exhaust temperature sensor provided in the ventilation portion of the branch duct;
A variable air volume device provided in a ventilation portion of the collective duct, and including an air volume measuring element and an air volume control element;
Indoor temperature sensors provided in the plurality of kitchens;
An indoor carbon monoxide concentration sensor and / or an indoor oxygen concentration sensor,
The exhaust fan provided in the ventilation portion of the downstream duct and exhausting all the collecting ducts;
With
Providing the variable air volume device for performing air volume control for increasing or decreasing the exhaust air volume based on a temperature deviation between both temperatures detected by the exhaust temperature sensor and the indoor temperature sensor;
The difference between the temperature deviation and the exhaust air volume is set so that the difference between the pre-control exhaust air volume before performing the air volume control and the post-control exhaust air volume after performing the air volume control approaches a target air volume reduction amount. Including an air volume control process for automatically searching for a relationship, and performing a normal control operation for performing the automatic search to vary the exhaust air volume after control with the variable air volume device over time,
Or
When an abnormality in carbon monoxide concentration or oxygen concentration is detected, the variable air volume device is switched to the maximum air volume, and a safety priority operation is performed to increase the required exhaust air volume toward the exhaust fan, and the abnormality is not detected. It is a kitchen ventilation method characterized by switching to the normal control operation again.

The fourth means of the present invention is:
An air outlet for supplying outside air to the kitchen; a collective duct connected to a branch duct provided with the air outlet; and a variable air volume device incorporating an air volume measuring element and an air volume control element in a ventilation portion of the collective duct; An upstream duct communicating with the collective duct, an air supply fan provided in the upstream duct or an external air conditioner including the air supply fan,
Controlling the rotation of the variable air volume device and the air supply fan or the exhaust fan so as to maintain the pressure balance inside and outside the kitchen is a means added to the above-described kitchen ventilation method.

  In the present invention, by controlling the air volume based on the relationship between the temperature deviation signal and the exhaust air volume, which is an invention specific matter, the supply air volume of the kitchen has been conventionally constant from the relationship of maintaining the pressure balance inside and outside the kitchen. Can be changed by the present invention, and as a result, the energy consumption of the heat source and the fan can also be reduced. However, there is also a need for a system that can cope with the danger of carbon monoxide poisoning due to the handling of fire peculiar to the kitchen, and the present invention provides a kitchen ventilation system characterized by an exhaust system technology that is compatible and compatible with both. Can provide. In addition, since the target energy saving can be maintained in another kitchen different from the kitchen where the ventilation is changed to avoid danger, the kitchen ventilation means of the present invention can contribute to the achievement of the energy saving plan for each store.

  Further, in the present invention, the duct internal temperature sensor (duct thermo) is attached to the exhaust duct of each hood, and the use state of the fire is judged from the respective temperature measurement values, and the exhaust duct of the grouped hood group is present. To provide a control system capable of minimizing the number of VAVs to be installed and controlling the introduction cost because a variable air volume device (VAV) incorporating an air volume measuring element and an air volume control element is operated to control the air volume. Is possible. In this way, appropriate air volume management can be performed under different cooking conditions in each kitchen of each store, so kitchen ventilation means that consider energy saving in response to seasonal, breakfast to dinner cooking changes, and heat content changes depending on cooking contents As well as an unprecedented superior effect that can cope with abnormalities such as carbon monoxide concentration.

It is a whole system block diagram of this invention. 1 is a detailed system diagram illustrating an example of a system configuration of the present invention in one kitchen. It is explanatory drawing of the switching conditions which increase the wind force which defines the inverter output for exhaust_gas | exhaustion of this invention. It is a flowchart of the initial setting of this invention. It is a flowchart of the setting process of the air volume control of this invention. It is a flowchart of the determination process of the air volume control of this invention. It is an example of actual data in which the temperature deviation between the room temperature and the duct temperature and the exhaust air volume change every time. This is an example of actual data in which the exhaust air volume changes every time, including when the carbon monoxide concentration increases. It is data which shows the change for every time of the total air supply amount and load electric energy of a kitchen at the time of performing 100% driving | operation with constant supply air. It is the data which shows the change for every time of the total supply air volume and load electric energy of the kitchen at the time of performing the variable supply air operation of this invention in units of time. It is the data which compared the amount of primary energy use in the case of the ventilation 100% operation, and the case of the ventilation variable control operation. It is the data which compared the annual running cost in the case of 100% ventilation operation and the case of variable ventilation control operation. It is the schematic which shows a conventional system.

  Hereinafter, a kitchen ventilation system according to an embodiment of the present invention will be described with reference to the drawings. In the detailed description of the invention, the same reference numerals are given to the same devices in the prior art. Their names and functions are also the same. In the following embodiments, an example of the configuration and operation of the exhaust system from each kitchen and the entire air supply system to each kitchen will be described.

(First embodiment)
FIG. 1 shows a system configuration (100) of the present invention, and as an example, shows three kitchens (2, 3, 4) divided into the second floor (2F) of a tenant building. Each kitchen has a room temperature sensor (50, 51, 52), a carbon monoxide (CO) concentration sensor (53, 54, 55), an I / O board (60, 61, 62) and an exhaust hood (5, 6, 7, 8). In addition to or in place of the carbon monoxide (CO) concentration sensor (53, 54, 55), an abnormality detection sensor such as an oxygen concentration sensor or a smoke detection sensor may be provided.

  The exhaust path shown in FIG. 1 includes duct internal temperature sensors (74, 75, 76, 77) attached to branch ducts (70, 71, 72, 73) of each exhaust hood (5, 6, 7, 8), and , Variable air volume devices (Variable Air Volume: VAV, 80, 81, 82, 83) for each collecting duct (21, 22, 23, 24) each collecting branch ducts (70, 71, 72, 73), each set An exhaust fan (13) that performs concentrated exhaust with an exhaust duct (12) further collecting ducts (21, 22, 23, 24).

  FIG. 1 also shows an air supply path. When the air supply fan or the air supply fan is included, the outside air (30) taken in by the air conditioner (32) that adjusts the temperature and humidity is supplied from the air supply duct (33) to the air supply ports of the respective kitchens (2, 3, 4). (36a, 36b, 36c) is supplied via variable air volume devices (85, 86, 87) provided. The air supply fan of other air supply paths and the return path (31) with the heat source (not shown) are the same as in the conventional system, but the exhaust hood (5, 6, 7, 8) and the air supply port (36a, 36b, 36c) is arranged so that the supply airflow circulates in the kitchen and communicates with the exhaust hood (5, 6, 7, 8) so that there is a correlation between the exhaust amount and the supply amount. It is set to maintain the pressure balance. That is, the positional relationship is such that the supply air flow and the exhaust flow do not circulate in the kitchen and the short circuit configuration is not obtained.

  Although the signal wiring of the control system is omitted in FIG. 1, the central monitoring server (not shown) manages the recording data and set values of the kitchen ventilation system, and the kitchen ventilation control panel according to the required specification (purpose) (90) cooperates with the existing control panel (42), and each variable air volume device (80, 81, 82, 83, 85, 86) via the I / O panel (60, 61, 62) installed in each kitchen. 87) and control to the inverters (40, 41). The exhaust fan (13) is driven by the exhaust fan inverter (40) and the external air conditioner (32) is driven by the external air conditioner inverter (41). The kitchen ventilation control panel (90) supervises all commands, and the operation of the exhaust system variable air volume devices (80, 81, 82, 83) and the air supply system variable air volume devices (85, 86, 87), and the exhaust. The fan inverter (40) and the external air conditioner inverter (41) are linked. In this kitchen ventilation control panel (90), the exhaust volume of all the ducts is calculated based on the exhaust air volume received from the I / O boards (60, 61, 62) of each kitchen, and the variable air volume devices (80, 81, 82, 83) and the exhaust fan inverter (40), and at the same time, according to the exhaust amount, calculate the supply air amount to maintain the pressure balance inside and outside the kitchen room, and for the variable air volume devices (85, 86, 87) and the external air conditioner Instruct the inverter (41).

  FIG. 2 is a diagram showing a detailed configuration by taking one kitchen (2) of FIG. 1 as an example. In this kitchen system (2S), the reference numerals attached to the respective components are the same as those in FIG. Explaining the main components anew, the exhaust system includes an exhaust hood (5a, 5b) provided near the cooker (2a, 2b) and an in-duct temperature sensor (74a) for measuring the temperature of the exhaust air (14a, 14b). , 74b) are provided in each branch duct (70a, 70b), and are a collective duct (21), an exhaust variable air volume device (80), an exhaust fan (13), and an inverter (40) thereof. The air supply system includes an air supply duct (33), an air supply variable air volume device (85), an external air conditioner (32), and an air supply port (36a). 30) is placed in the kitchen (2). The kitchen room (2) is provided with a room temperature sensor (50) and a carbon monoxide concentration sensor (53), and the control system is an I / O board (60), sensor signal lines such as room temperature and carbon monoxide concentration (92 ), Variable air volume damper drive and air volume sensor and control line (94), inverter control line (97), kitchen ventilation control panel (90) equipped with touch panel (90a) signal line (96) and server line ( 98), its server (101), and central monitoring board bus (42a).

  The exhaust air volume of the exhaust variable air volume device (80) provided for each kitchen (2) is determined by the following (1) initial setting process and (2) control setting value calculation process by automatic calculation. A switching method for increasing the air volume from the air volume will be described with reference to FIG. The horizontal axis of FIG. 3 is the temperature deviation between the temperature of the exhaust duct and the room temperature, and the vertical axis is the exhaust air volume of the variable air volume device (80), but the exhaust fan inverter (40) based on the required exhaust air volume from each kitchen. ) May be understood as a similar operation. For example, in the case where only one kitchen is targeted in the tenant building as in the example of FIG. 2, the exhaust fan (13) is only the variable exhaust air volume device (80) described above, so the exhaust required air volume is the exhaust fan. Proportional to inverter (40) output. By the way, when the kitchen user sets the temperature deviation to 10 ° C. in consideration of the type of cooking appliance, the frequency of use, and the cooling / heating conditions, measurement with the temperature sensors (74a, 74b) and the room temperature sensor (50) in the duct. The air volume is increased from the time when the value reaches 10 ° C., and when the set value is 20 ° C., the air volume is increased from the time when the measured value reaches 20 ° C. In other words, the damper ventilation of the variable airflow device and the airflow sensor are relayed from the kitchen ventilation control panel (90) to the I / O board (60) so that the airflow increases in proportion to the temperature deviation based on the temperature information from the duct. And to the control line (94) and the inverter control line (97). At this time, since the type of cooking equipment and the usage time zone change with time, the maximum temperature deviation is always detected among the temperature deviations of the plurality of ducts, and the required exhaust air volume is determined as the priority hood, or the total temperature deviation, Alternatively, any of the average temperature deviation can be set.

  FIG. 4 is a flowchart for initial setting of the kitchen ventilation system of the present invention. First, the kitchen user determines a measurement period day for a certain period as an air volume data calculation period based on initial calculation or commercial time (S101), and the temperature in the duct, the temperature in the kitchen, the average air volume, etc. at each time are stored in the server. (S102), together with an initial calculation start instruction (S103), a core time for operating the air conditioner in one day, for example, 9 am to 11 pm is set (S104). Therefore, the temperature deviation maximum value (A) is selected using the data accumulated in step S102 (S105), and then the arbitrarily set temperature set value (S106) and the actual temperature deviation maximum correction calculation. Either one is selected in comparison with the value (S107) (S108), and an initial temperature setting value (A ') for each duct is obtained (S109). On the other hand, after the commercial core time average exhaust amount, that is, the designed maximum air volume is averaged for a certain period (S111, S112), the commercial core time average exhaust air volume (B) is determined (S113), and this value is reduced. This is the standard value.

  FIG. 5 shows a flowchart of the air volume control process. 5A shows a process for determining the air volume reduction rate, and FIG. 5B is a flowchart for calculating a control set value by automatic calculation including a determination process. First, the kitchen user determines the target reduction rate (S121) of the exhaust air volume and gives the value two widths. One is a reduction rate width setting 1 (S122) in which the target allowable range is strict and narrow, and the other is a reduction rate width setting 2 (S123) in which the target allowable range is loose and wide. Further, the kitchen user determines two temperature change coefficients 1 and 2 so that the reduction rate is automatically changed every moment and the reduction rate is automatically searched. Here, one temperature change coefficient 1 is defined as a small reduction rate change (x), and the other temperature change coefficient 2 is defined as a large reduction rate change value (X). Therefore, the reduction rate is automatically changed every moment as described later with values (S124, S125) obtained by multiplying the initial temperature setting value (A ') described in FIG. 4 by the temperature change coefficients 1 and 2.

  The daily report data (S126, S127) for a predetermined day stored in the server (S120) excludes the forced release date (S128, S129) and obtains the control-time core time average exhaust air volume (C) (S130). Next, using the control-time core time average exhaust air volume (C) and the value (B) (S113) obtained from the commercial core time average exhaust air volume shown in FIG. Calculate (S131).

    D = (1- (C / B)) × 100 (%) (1)

  Next, the target reduction rate (D ′) (S121) is compared with the calculated value of Expression (1) (S132) (Expression 2).

    E = D−D ′ (2)

  The value E is compared with the reduction rate width setting 1 (S133), and is within the absolute value of the reduction rate width setting 1, that is, (positive value of the reduction rate width setting 1)> E> (reduction rate width setting 1) Negative ventilation), the kitchen ventilation control panel (90) causes the I / O board (60) to maintain the minimum value of the temperature deviation that is the minimum displacement of the exhaust fan (13) (S142). To the variable air volume device (80) and to the exhaust fan inverter (40) via the existing control panel (42).

  If the E value exceeds the positive value of the reduction rate width setting 1 in the determination of setting 1 (S133), the process proceeds to the first determination of setting 2 (S134) and is compared with the reduction rate width setting 2 (reduction) If the positive value of the rate range setting 2)> E> (the positive value of the reduction rate range setting 1), the set value −x is set so that the minimum value of the temperature deviation that becomes the minimum air volume of the exhaust system variable air volume device is slightly lowered. Automatically set to ° C. (S141). If E> (a positive value of the reduction rate width setting 2), it is automatically set to the set value −X ° C. so as to slightly lower the minimum value of the temperature deviation that is the minimum air volume of the exhaust system variable air volume device (S140). ).

  If the E value is less than the negative value of the reduction rate width setting 1 in the determination of setting 1 (S133), the process proceeds to the second determination (S135) of setting 2, and is compared with the reduction rate width setting 2 (reduction rate width) If the negative value of setting 1)> E> (negative value of reduction rate width setting 2), the minimum value of the temperature deviation, which is the minimum air volume of the exhaust system variable air volume device, is automatically increased to the set value + x ° C. It sets (S143). Further, if (negative value of reduction rate width setting 2)> E, the minimum value of the temperature deviation, which is the minimum air volume of the exhaust system variable air volume device, is automatically set to the set value + X ° C. so as to be slightly lowered (S144). .

  As explained in FIGS. 5A and 5B, the minimum air volume adjustment in the exhaust system variable air volume device is automatically performed by tracking the temperature deviation value by the programmable logic controller (PLC) installed in the kitchen ventilation control panel (90). Can follow. More specifically, after the initial setting described with reference to FIG. 4, initial data is calculated from the duct internal temperature and room temperature measurement for a certain period and the rated operation of the exhaust fan, and then the automatic control operation is started. The air volume reduction rate is calculated in a certain period after the automatic operation, and the setting condition of the minimum air volume is increased / decreased according to the flow of FIGS. 5A and 5B in a certain period so as to narrow the deviation from the target reduction rate. When it is determined on the program that the target reduction rate has been achieved, the minimum air volume setting condition is maintained, and when it greatly exceeds, the system has a function of automatically reducing according to the program. That is, providing a plurality of steps S122, S123, S124, and S125 described with reference to FIG. 5A can constitute a flowchart that gradually approaches an air volume reduction amount for energy saving. For example, a two-stage automatic search process is performed in which coarse adjustment is performed when the difference between the reduction target value and the actual value is large, and fine adjustment is performed when the difference is small.

  FIG. 6 shows data obtained by conducting an experiment using an actual kitchen. The data in FIG. 6 is an example showing the relationship between the temperature deviation in the duct temperature and the room temperature and the exhaust air volume when the control operation is performed according to the flow in FIGS. 5A and 5B. The upper diagram in FIG. 6 shows exhaust air volume data, and shows changes in exhaust air volume per time in an exhaust system variable air volume device having a maximum air volume of 7000 cubic meters per hour. The lower figure of FIG. 6 is data of temperature deviation between the temperature in the duct and the room temperature, the solid line shows the temperature change of the duct 1 mounted immediately above the high heat cooker, and the dotted line shows the temperature change of the duct 2 of the low heat cooker. Is receiving. In this kitchen, the temperature deviation changes greatly during the busy cooking hours in the morning and around 1 pm, around 4 pm, around 6 pm, and around 9 pm. With respect to this temperature change, the exhaust air volume maintains forced maximum exhaust as a system operation around 9 am to 10 am, but after that time zone, the exhaust air volume also changes following the temperature deviation change. That is, it can be seen that the exhaust air volume at about 15:00 and 17:00 to 18:00 in a time zone with a relatively small temperature deviation is reduced by about 4000 cubic meters per hour.

  The increase / decrease of the exhaust air volume is linked to the increase / decrease of the supply air volume. Since this has a relationship of (exhaust air volume) ≒ (supply air volume) so as to maintain the pressure balance inside and outside the kitchen in order to let the air flow into the kitchen, this interlocking occurs. Therefore, when the exhaust air volume is reduced, the kitchen ventilation control panel (90) reduces the supply air volume of the air supply variable air volume device (85) and the external air conditioner (32) to reduce the consumption of the heat source for air conditioning. That is, since the power of the external air conditioner is reduced in conjunction with the control operation according to the flow of FIGS. 5A and 5B, a great energy saving effect is obtained.

  1 and 2, a carbon monoxide concentration sensor (53) is provided in addition to the room temperature sensor (50). This is installed to replace the system operation of the safety priority operation in which the exhaust system is forcibly operated at the maximum capacity when carbon monoxide gas is generated from the cooker during the exhaust air flow control operation. A detection signal that informs the abnormality by the carbon monoxide concentration sensor (53) is output via the I / O board (60), and the PLC installed in the kitchen ventilation control board (90) issues an interrupt request, and the corresponding variable air volume. The device (80) is forcibly fully opened and the exhaust fan (13) is increased in displacement so that it is transmitted to the I / O board (60) and the existing control board (42), respectively, and the central monitoring board bus (42a). Alarm display is performed with. This forced full opening continues with an alarm as long as abnormality detection continues. As described above, the normal control operation according to FIGS. 5A and 5B described above can be switched to the safety priority operation. Then, when the alarm is released, the interrupt process is canceled and the control operation is resumed, but the control operation is performed again according to the set value defined in FIG. 5B. Although the carbon monoxide concentration sensor (53) has been described here, the same operation is performed even when an oxygen concentration sensor or smoke detector is used to detect an abnormality in oxygen concentration or smoke.

  In this safety priority operation, the variable air volume device (80) is forced to fully open and the exhaust fan (13) increases the exhaust amount. Therefore, the abnormal state at the time of the alarm becomes a bottleneck caused by a cooker failure when calculating the achievement degree of energy saving. However, in the system of the present invention, as described in FIG. 5A of the normal control operation, the influence of the step S128 is included in the calculation of the air volume at the time of forced full opening, and the influence is excluded. Can be eliminated. Therefore, the air volume reduction amount can be accurately grasped by the means of the present invention.

  FIG. 7 is data in which a change in the exhaust amount that changes even when the carbon monoxide concentration becomes an abnormal value appears. The upper diagram in FIG. 7 is the data on the exhaust air volume as in FIG. 6, and shows the change in the exhaust air volume. The lower diagram of FIG. 7 shows temperature deviation data (solid line) and carbon monoxide gas concentration (dotted line) between the duct internal temperature and room temperature. In this example, since an increase in carbon monoxide concentration (14 ppm) was detected around 9 am in the morning, the forced air opening of the variable air volume device and the exhaust air demand to the exhaust fan inverter (40) are increased. FIG. 7 shows that the carbon monoxide concentration immediately decreased below the detection limit due to the forced full opening of the variable air volume device during the abnormality detection.

  The kitchen ventilation system according to the present invention (FIG. 1) is provided with a temperature sensor (thermo in the duct) in the branch duct of each exhaust hood of each store, and an air volume measurement function in place of a motor damper introduced in the design or existing system A variable air volume device (VAV) with a temperature sensor and carbon monoxide (CO) concentration sensor is installed in the kitchen, and the signal information of each sensor and VAV is newly installed via the I / O board. It exchanges with the ventilation control panel to control the damper opening of the VAV and the rotational speed of the exhaust fan to increase or decrease the exhaust amount. At the same time, the outside air volume is adjusted. As with the exhaust, a variable air volume device (VAV) with an air volume measurement function is introduced instead of the motor damper introduced in the design or existing system, and the balance between exhaust and air supply is taken into account in the aforementioned kitchen ventilation control panel. The amount of outside air supply is increased or decreased by controlling the damper opening of the VAV and the rotation speed of the air supply fan installed in the external air conditioner.

  When judging whether to use fire or cooking, an exhaust temperature rise due to heat generated by the cooking appliance is detected, and a temperature sensor is provided in the branch duct connected to each exhaust hood to determine the average exhaust temperature from a plurality of cooking appliances. Use the difference between the temperature in the kitchen that is not affected by the heat from the cooking equipment. The exhaust temperature in the duct can be substituted by the duct surface temperature, in which case the outer surface of the surface temperature sensor or the sensor and the outer surface of the duct are covered together with heat insulation to reduce the thermal effect of the disturbance. The temperature sensor shall have specifications with good responsiveness and accuracy. Since the exhaust air speed in the duct is as fast as several meters per second, even if the exhaust gas whose temperature has risen due to the heat generated by the cooking equipment leaks from the hood, it can be detected in a few seconds by the temperature sensor in the branch duct. The installation method in the duct is a structure in which the sensor part can be inserted and removed, facilitating cleaning of oil stains and sensor replacement.

  As a method of constantly changing the amount of exhaust, a variable air volume device (VAV) with an air volume measurement function is installed in the duct where multiple exhaust hood branch ducts gather to increase or decrease the exhaust air volume of the entire exhaust hood or the entire kitchen. To do. As a result, the short circuit between the exhaust and supply air in the kitchen is suppressed, and the temperature-controlled supply air is exhausted without being circulated in the kitchen to prevent the thermal environment from deteriorating and impairing comfort. . In addition, the number of variable air volume devices can be greatly reduced, and the introduction cost can be reduced. For the air flow measurement function, a mechanism based on differential pressure detection is recommended, and the specifications are such that oil stains on the detection unit can be easily cleaned and replaced.

  In order to control exhaust without excess or deficiency, the use of cooking or cooking conditions for each exhaust hood is ascertained based on the temperature deviation between the exhaust and the kitchen detected by a temperature sensor (thermo in the duct) provided in the branch duct of each exhaust hood. The temperature deviation when operating at the maximum (rated) airflow previously grasped by the airflow measuring function of the variable airflow device is clarified. Subsequently, the relationship between the temperature deviation of each exhaust hood and the exhaust air volume is automatically searched and optimized so as to reach the target air volume reduction amount, and set as a set value. The temperature deviation changes due to store meal menus, tenant changes, seasonal changes in the air-conditioning environment, etc., so it is not fixed, and it is reset and reset automatically after a predetermined period of time. Promote energy saving of kitchen ventilation while reducing the cost of setting work.

  The major risks due to variable exhaust are carbon monoxide poisoning and oxygen concentration deficiencies. These concentrations are detected in the kitchen, and a system is established to ensure the maximum air volume when out of the control concentration range.

  As a method of changing the air supply amount of the outside air, a variable air volume device (VAV) having an air volume measuring function is installed in the duct, and the air supply volume is increased or decreased based on the measured exhaust air volume. The system configuration maintains the internal and external pressure balance.

  The kitchen ventilation control panel configures a communication protocol with a mod bus, forms a communication network with the central monitoring room, transmits the operation status such as alarms to the central monitoring room, and relays each I / O panel to start the variable air volume device Sends and receives instructions and failure information of control signal variable air volume devices to the inverter.

Kitchen ventilation control panel performs PLC (programmable logic controller) operation, relays each I / O board to command to variable air volume device, room temperature sensor, duct temperature sensor, carbon monoxide concentration sensor, smoke detector Signal reception, failure of variable air volume device and wind speed / air volume detection input. The kitchen ventilation control panel can set individual targets for each kitchen, and can set an appropriate energy saving target according to the store environment.

  Summarizing the control of the variable air volume device, the initial activation starts with the activation instruction of the kitchen ventilation control panel, and enters into the operation of objective control determined by automatically calculating the variable air volume device with the server after the maximum air volume operation for a certain time. Adjustment between the exhaust air system and the variable air volume system of the air supply system maintains the pressure balance inside and outside the room, and each variable air volume device is fully open according to the indoor temperature and duct temperature, smoke detection, carbon monoxide concentration, and oxygen concentration. Adjust by the sequence determined by air blow or PLC. When a system failure, abnormal smoke, or carbon monoxide concentration is detected, an alarm output is notified to the central monitoring room, and a damper fully open command is sent to the variable air volume device.

To summarize the characteristics of the present invention,
(1) A point where the set value is determined and the air volume is adjusted in relation to it.
(2) The set value is determined based on the duct temperature and room temperature deviation data.
(3) According to the paragraph number 0036 described above, the air volume reduction rate is preset.
(4) Use of the difference between the temperature in the duct and room temperature as a means of capturing changes in the amount of heat generated by the appliance in the kitchen,
(5) As described in paragraph 0044 above, the minimum air volume is managed,
(6) In actual air volume adjustment, priority is given to the hood with the largest temperature difference from the set value.
(7) The point which constituted the system corresponding to abnormalities, such as carbon monoxide concentration.

(Second embodiment)
In the first embodiment, the system operation in the case of detecting the abnormality of the carbon monoxide concentration has been described. However, the system operation of the present invention also copes with various abnormalities including such abnormality detection. This is given as a second example.

Summarizing the forced full open of the variable airflow device (a damper fully open state capable of blowing the maximum airflow), the following command is issued from the kitchen ventilation control panel even when it is based on the following detection.
(I) When the detection temperature of the room temperature sensor exceeds the set value, a forced fully open signal is sent to the corresponding variable air volume device to reach the maximum opening of the damper, and normal operation after the detected temperature falls below the set value Return to. In this case, the differential of the operating temperature and the return temperature of the thermostat is determined by the setting of the kitchen user.
(II) When smoke is detected, a forced fully open signal is transmitted to the corresponding variable air volume device, and after a warning is released, normal control control is resumed after a certain period of time.
(III) When the concentration of carbon monoxide is detected, a forced fully open signal is issued from the nearest variable airflow device, and a warning is issued when the concentration is judged as a dangerous level. The normal control operation is restored when the initial detection value is reached.
(IV) The oxygen concentration is also operated in the same manner as the above (III).
(V) An alarm is issued when the damper opening is stuck as a failure judgment of the variable airflow device.

  When the above-mentioned abnormality such as carbon monoxide concentration occurs, the required exhaust air volume is increased as described above to increase the VAV (80) damper opening and the exhaust fan (13) air volume. As a result, the suction pressure is also increased for the other ducts connected to the exhaust duct, which affects other kitchens that do not increase the exhaust demand. Maintains the air flow control process described above in the kitchen ventilation control panel without affecting the target reduction set by.

<Demonstration experiment>
The verification experiment of the said Example was conducted. Kitchen area 94 square meters, heat source DHC, outside air treatment air conditioner cooling capacity 94.3 kW, heating capacity 199.6 kW, outside air treatment air conditioner fan air volume 32900 cubic meters per hour, air conditioner motor capacity 18.5 kW (INV), exhaust fan air volume 32500 cubic meters Every hour, exhaust fan motor capacity was 15 kW (INV). As the above equipment conditions, the kitchen operation time was from 9:00 am to midnight, and the following results were obtained.

  FIG. 8 is a graph showing the relationship between the average value for each hour and the outside air load and the time change of the air volume by summing up the air supply / exhaust air volume every month. FIG. 8 shows the change in power consumption from 9:00 am to midnight before operating the ventilation system of the present invention, that is, when the air supply amount and the outside air load are 100%. The bar graph on the lower side of FIG. 8 shows the state of the kitchen air supply volume at each time (one hour unit). In FIG. 8, since the air supply is 100% commercial operation, there is no change from time to time, and it is constant from 9 am to night (dashed line: 140), and the lunch time zone (10:00 to 12:00) and dinner at night Although the time zone (17:00 to 20:00) is constant, the power consumption shown on the upper side of FIG. 8 is different in summer and winter, and the peak time (122 in summer (dotted line: 120)) from 12:00 to 14:00. ) At a maximum of 120 to 130 kilowatts of outdoor air load, and 130 kilowatts at the peak of the night (132) in winter (two-dot chain line: 130) is a state when the supply air is 100%.

  FIG. 9 shows the change from 9 am in the morning to midnight in the kitchen air supply volume and the external air load in the variable air supply accompanying the exhaust control when the kitchen ventilation system of the present invention is applied. . The lower bar graphs (150a to 150r) in FIG. 9 show the state of the kitchen air supply airflow for each time (one hour unit). Reduced to 18000 cubic meters / hour during the lunch time zone (152), reduced to a maximum of 12000 cubic meters / hour during the following time zone (154) (156), and again 18000 cubic meters / hour during the evening dinner time zone (158) The band (160) is reduced to 1500 cubic meters / hour (162). The power consumption shown on the upper side of FIG. 9 is different from that in FIG. 8 in summer and winter, and fluctuates to 120 to 130 kilowatts at the maximum from 12 to 14:00 in summer and 110 kilowatts at midnight in winter. Therefore, as shown in FIG. 9, in the kitchen ventilation system of the present invention, the exhaust air volume is reduced by the above-described automatic search process in the time zone where the kitchen operation rate is low, and accordingly, the load on the air supply system is also reduced. In particular, the energy saving effect is synergistically excellent, including the heat source energy of the outdoor air treatment, such as air volume reduction (162) at the peak of outdoor air load in winter (162) or air volume reduction (156) at the peak of outdoor air load in summer (122). Will give.

FIG. 10 shows such a synergistic energy saving effect, and based on the relationship between the hourly intake air volume and the external unit load described in FIGS. It is data of.
The vertical axis represents the amount of energy used by the heat source and the fan, comparing the ventilation at 100% (140) with the ventilation control operation of the present invention. The left side of FIG. 10 is when the ventilation is 100%, assuming that the heat source is 1182 gigajoules and the fan is 833 gigajoules, for a total of about 2000 gigajoules, the heat source is 838 gigajoules in the ventilation control operation of the present invention. The fan portion is reduced to 514 gigajoules, or a total of about 1300 gigajoules, that is, 33% of annual primary energy consumption reduction.

FIG. 11 shows an estimated value of the annual running cost obtained by the reduction of the annual energy consumption explained in FIG. The vertical axis shows the cost of the heat source and the fan comparing the ventilation at 100% and the ventilation control operation of the present invention. On the left side of FIG. 11, when the ventilation is 100%, the heat source component is 87%, the fan component is 13%, and the total is 100%. In the ventilation control operation of the present invention, the heat source component is 62% and the fan component is 8%. %, The total running cost can be reduced to 70%.
Therefore, by introducing the kitchen ventilation optimum control system, not only can the power consumption of the air supply / exhaust fan be reduced, but also the air conditioning energy for cooling and heating the outside air can be greatly reduced.
As a result of experiments conducted in the kitchen for one year, we were able to reduce primary energy and running costs by about 30% annually. In addition, according to the prototype experiment, no problem has been found that is a practical defect in the thermal environment and air quality in the kitchen room. In addition, it has been demonstrated that even if the present invention is implemented, the simple investment recovery period can be 5 years or less.

The effects of the present invention are summarized again.
(1) The kitchen ventilation system (FIG. 1) according to the present invention can be constructed by replacing or easily adding to the components of the conventional system (FIG. 12), and can be applied to both newly built and refurbished properties.
(2) By changing the exhaust amount and the supply amount of the outside air according to the present invention, the energy related to the adjustment of the temperature and humidity of the outside air can be significantly reduced together with the fan power. As a result of actual measurement, the outdoor air processing load can be further reduced after lunch in summer and after dinner in winter. (Fig. 8, Fig. 9)
(3) After confirming the introduction effect for one year in a plurality of kitchens in a multi-use tenant building, the operation of the kitchen ventilation system according to the present invention for the operation of a constant amount of exhaust (100% exhaust) at all times, It was demonstrated that both primary energy and running cost can be reduced by about 30% (FIGS. 10 and 11).

2, 3, 4 ... Kitchen 5, 6, 7, 8 ... Exhaust hoods 9a, 9b, 9c, 9d, 70, 71, 72, 73 ... Branch ducts 10a, 10b, 10c, 10d, 21 , 22, 23, 24 ... collective ducts 11a, 11b, 11c, 11d, 34a, 34b, 34c ... motor damper 12 ... exhaust duct 13 ... exhaust fans 14, 15, 16, 17 ... -Hot air, exhaust air 30 ... outside air 31 ... return path 32 ... external air conditioner 33 ... air supply ducts 36a, 36b, 36c ... air supply port, outlet 40 ... Exhaust fan inverter 41 ... External air conditioner inverter 42 ... Control panels 50, 51, 52 ... Room temperature sensors 53, 54, 55 ... Carbon monoxide (CO) concentration sensors 60, 61, 62 ... I / O boards 74, 75, 76, 77 ... Duct temperature sensors 80, 81, 82, 83, 85, 86, 87 ... Variable air volume device 90 ... Kitchen ventilation control panel 92 ... Sensor signal line 94 ... Damper drive and air volume of variable air volume device Sensor and control line 96 ... signal line 97 ... inverter control line 98 ... server line 101 ... server 120 ... external load 122 of summer power consumption ... summer consumption peak band 130 ... External load of winter power consumption 132 ... Winter consumption peak zone 140 ... Kitchen air supply volume 150a-150r during 100% commercial operation ... Applying the kitchen ventilation system of the present invention Air supply air volume 152 at the time of each day ··· Lunch time zone 154 · · · Time zone after lunch 156 · · · Air volume reduction at summer outdoor air load peak 158 · Dinner at night Wind reduce the amount of time outside air load peak time zone 162 ... winter time zone 160 ... after dinner

Claims (4)

A plurality of exhaust hoods provided in a plurality of kitchens, a plurality of branch ducts connected to the exhaust hoods, a collective duct connected by joining the plurality of branch ducts, and a downstream duct communicating with the collective duct; In a kitchen ventilation system having an exhaust path configured with an exhaust fan,
An exhaust temperature sensor provided in the ventilation portion of the branch duct;
A variable air volume device provided in a ventilation portion of the collective duct, and including an air volume measuring element and an air volume control element;
Indoor temperature sensors provided in the plurality of kitchens;
An indoor carbon monoxide concentration sensor and / or an indoor oxygen concentration sensor,
The exhaust fan provided in the ventilation portion of the downstream duct and exhausting all the collecting ducts;
With
The variable air volume device that performs air volume control for increasing or decreasing the exhaust air volume based on a temperature deviation between both temperatures detected by the exhaust temperature sensor and the indoor temperature sensor,
The difference between the temperature deviation and the exhaust air volume is set so that the difference between the pre-control exhaust air volume before performing the air volume control and the post-control exhaust air volume after performing the air volume control approaches a target air volume reduction amount. A normal control operation including an air volume control process for automatically searching for a relationship, and performing the automatic search for varying the exhaust air volume after control with the variable air volume device over time;
When detecting an abnormality in carbon monoxide concentration or oxygen concentration, the variable airflow device is switched to the maximum airflow, and the safety priority operation is performed to increase the exhaust airflow requirement toward the exhaust fan;
A kitchen ventilation system characterized by a configuration capable of switching between these normal control operation and safety priority operation.
An air outlet for supplying outside air to the kitchen; a collective duct connected to a branch duct provided with the air outlet; An upstream duct communicating with the collective duct, and an air supply fan provided in the upstream duct or an external air conditioner including the air supply fan,
The kitchen ventilation system according to claim 1, wherein rotation of the variable air volume device and the supply fan or the exhaust fan is controlled so as to maintain a pressure balance inside and outside the kitchen.
A plurality of exhaust hoods provided in a plurality of kitchens, a plurality of branch ducts connected to the exhaust hoods, a collective duct connected by joining the plurality of branch ducts, and a downstream duct communicating with the collective duct; In a kitchen ventilation method having an exhaust path configured with an exhaust fan,
An exhaust temperature sensor provided in the ventilation portion of the branch duct;
A variable air volume device provided in a ventilation portion of the collective duct, and including an air volume measuring element and an air volume control element;
Indoor temperature sensors provided in the plurality of kitchens;
An indoor carbon monoxide concentration sensor and / or an indoor oxygen concentration sensor,
The exhaust fan provided in the ventilation portion of the downstream duct and exhausting all the collecting ducts;
With
Providing the variable air volume device for performing air volume control for increasing or decreasing the exhaust air volume based on a temperature deviation between both temperatures detected by the exhaust temperature sensor and the indoor temperature sensor;
The difference between the temperature deviation and the exhaust air volume is set so that the difference between the pre-control exhaust air volume before performing the air volume control and the post-control exhaust air volume after performing the air volume control approaches a target air volume reduction amount. Including an air volume control process for automatically searching for a relationship, and performing a normal control operation for performing the automatic search to vary the exhaust air volume after control with the variable air volume device over time,
Or
When an abnormality in carbon monoxide concentration or oxygen concentration is detected, the variable airflow device is switched to the maximum airflow, and safety priority operation is performed to increase the exhaust airflow requirement toward the exhaust fan,
A kitchen ventilation method characterized by switching to the normal control operation again in accordance with non-detection of the abnormality.
An air outlet for supplying outside air to the kitchen; a collective duct connected to a branch duct provided with the air outlet; and a variable air volume device incorporating an air volume measuring element and an air volume control element in a ventilation portion of the collective duct; An upstream duct communicating with the collective duct, an air supply fan provided in the upstream duct or an external air conditioner including the air supply fan,
The kitchen ventilation method according to claim 3, wherein the rotation of the variable air volume device and the air supply fan or the exhaust fan is controlled so as to maintain a pressure balance inside and outside the kitchen.

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