WO2022269685A1

WO2022269685A1 - Ventilation system

Info

Publication number: WO2022269685A1
Application number: PCT/JP2021/023410
Authority: WO
Inventors: 賢治松村; 宏治内藤; 辰旭厳; 隼人森
Original assignee: 日立ジョンソンコントロールズ空調株式会社
Priority date: 2021-06-21
Filing date: 2021-06-21
Publication date: 2022-12-29

Abstract

Provided is a ventilation system for appropriately ventilating a given space. A ventilation system (100) is provided with carbon dioxide concentration sensors (21-23) for detecting the carbon dioxide concentration in a room, an air supply fan (13) for supplying air to the room, an exhaust fan (14) for exhausting air from the room, and a control device (18) for controlling the air supply fan (13) and/or the exhaust fan (14) on the basis of variations in detection values of the carbon dioxide concentration sensors (21-23).

Description

ventilation system

The present invention relates to ventilation systems.

In recent years, due to the spread of infections such as the new coronavirus, it is particularly recommended to ventilate the room. Regarding such ventilation, for example, Patent Document 1 describes that the control means changes the ventilation volume of the ventilation means according to the detection result of the volume detection means.

JP 2020-148374 A

In the technique described in Patent Document 1, the control means changes the ventilation rate according to the volume of the room detected by the volume detection means. there is room for

Therefore, an object of the present invention is to provide a ventilation system that appropriately ventilates the target space.

In order to solve the above-described problems, the present invention provides a carbon dioxide concentration sensor that detects the carbon dioxide concentration in a target space, an air supply fan that supplies air to the target space, an exhaust fan that exhausts air from the target space, and a control unit that controls at least one of the air supply fan and the exhaust fan based on a change in the detected value of the carbon dioxide concentration sensor.

According to the present invention, it is possible to provide a ventilation system that appropriately ventilates the target space.

It is an explanatory view of a ventilation system concerning a 1st embodiment. FIG. 3 is a schematic cross-sectional view of a ventilation unit included in the ventilation system according to the first embodiment; FIG. 4 is an explanatory diagram of a total heat exchanger of a ventilation unit included in the ventilation system according to the first embodiment; 1 is a functional block diagram of a ventilation system according to a first embodiment; FIG. FIG. 4 is an explanatory diagram of time-series data of carbon dioxide concentration when there is no active ventilation and time-series data of carbon dioxide concentration when active ventilation is performed in the ventilation system according to the first embodiment; FIG. 4 is an explanatory diagram relating to experimental results of changes in carbon dioxide concentrations in rooms and corridors in the ventilation system according to the first embodiment. 4 is a flowchart of processing executed by a control device of a ventilation unit included in the ventilation system according to the first embodiment; FIG. 4 is an explanatory diagram showing experimental results of changes in carbon dioxide concentrations in rooms and corridors in the ventilation system according to the first embodiment. FIG. 10 is an explanatory diagram of experimental results showing the estimated number of people based on the carbon dioxide concentration and the actual number of people in the ventilation system according to the first embodiment; 9 is a flowchart of processing executed by a control device of a ventilation unit included in the ventilation system according to the second embodiment; FIG. 11 is a flow chart of processing executed by a control device of a ventilation unit included in a ventilation system according to a third embodiment; FIG.

<<First embodiment>>
FIG. 1 is an explanatory diagram of a ventilation system 100 according to the first embodiment.
A ventilation system 100 shown in FIG. 1 is a system for ventilating a room R1 (target space). As shown in FIG. 1, the ventilation system 100 includes a ventilation unit 10 and a plurality of carbon dioxide concentration sensors 21-24.
The ventilation unit 10 is a device that supplies fresh outdoor air to the room R1 and exhausts the air in the room R1 to the outside. The ventilation unit 10 also has a function of exchanging heat between fresh outdoor air and the air in the room R1. Such a ventilation unit 10 is installed, for example, in the ceiling space of the room R1.

Then, fresh air introduced from the outdoors through an outside air duct (not shown) to the ventilation unit 10 is heat-exchanged in a total heat exchanger 12 (see FIG. 2) described later, and the heat-exchanged air is supplied. Through the duct 31, it is guided to the room R1. In addition, the air introduced from the room R1 to the ventilation unit 10 through the return air duct 32 exchanges heat in the total heat exchanger 12 (see FIG. 2), and the heat-exchanged air passes through the exhaust duct (not shown). It is designed to be led to the outdoors through.

The carbon dioxide concentration sensors 21 to 23 are sensors that detect the carbon dioxide concentration in the room R1 (target space). In the example of FIG. 1, a carbon dioxide concentration sensor 21 is installed on the indoor air suction side of the ventilation unit 10 . In addition to the carbon dioxide concentration sensor 22 installed on the wall 42 of the room R1, another carbon dioxide concentration sensor 23 is also installed on the desk 41 of the room R1. By using a plurality of carbon dioxide concentration sensors 21 to 23 in this way, even if the carbon dioxide concentration distribution in the room R1 is uneven, the average carbon dioxide concentration in the room R1 can be calculated. The detected values of the carbon dioxide concentration sensors 21 to 23 are output to the control device 18 (see FIG. 4) of the ventilation unit 10. FIG.

As shown in FIG. 1, another carbon dioxide concentration sensor 24 is provided in a corridor R2 (adjacent space) adjacent to a room R1 (target space) with a wall 42 or a door 43 interposed therebetween. This carbon dioxide concentration sensor 24 is a sensor that detects the carbon dioxide concentration in the corridor R2. A detected value of the carbon dioxide concentration sensor 24 is output to the control device 18 (see FIG. 4) of the ventilation unit 10 .

FIG. 2 is a schematic cross-sectional view of a ventilation unit 10 provided in the ventilation system.
In addition, the outline arrow shown in FIG. 2 has shown the direction through which air flows. 2, illustration of the carbon dioxide concentration sensor 21 (see FIG. 1) provided in the ventilation unit 10 is omitted.
As shown in FIG. 2, the ventilation unit 10 includes a housing 11, a total heat exchanger 12, an air supply fan 13, and an exhaust fan . The housing 11 is a housing that accommodates the total heat exchanger 12, the air supply fan 13, the exhaust fan 14, and the like. The housing 11 has an outdoor intake port 11a to which an outdoor air duct (not shown) is connected as an opening for introducing fresh air from the outdoors, and an indoor air inlet 11a to which an air supply duct 31 (see FIG. 1) is connected. A blowout port 11b is provided. The housing 11 also includes an indoor air intake port 11c connected to a return air duct 32 (see FIG. 1) as an opening for guiding air from the room R1 (see FIG. 1), and an exhaust duct (not shown). is provided with an outdoor outlet 11d to which is connected.

The total heat exchanger 12 is a heat exchanger that performs heat exchange (sensible heat/latent heat exchange) between fresh air from the outdoors and air from the room R1 (see FIG. 1). The total heat exchanger 12 has a square prism shape and is installed so as to divide the internal space of the housing 11 into four regions. These four areas include an area 15a that guides fresh air from the outdoors to the total heat exchanger 12 via the outdoor intake port 11a, and an indoor outlet 11b that directs air heat-exchanged by the total heat exchanger 12. and a region 15b that leads to room R1 (see FIG. 1) through. The remaining two regions include a region 15c that guides the air from the room R1 (see FIG. 1) to the total heat exchanger 12 through the indoor-side intake port 11c, and and a region 15d leading to the outside through the outlet 11d.

The air supply fan 13 shown in FIG. 2 is a fan that supplies air to the room R1 (target space), and is provided in the area 15b of the ventilation unit 10. By driving the air supply fan 13, fresh outdoor air is sucked and led to the total heat exchanger 12, and the air heat-exchanged in the total heat exchanger 12 is blown out to the room R1 (see FIG. 1). be done. The air supply fan 13 is controlled by a controller 18 (see FIG. 4), which will be described later.

The exhaust fan 14 shown in FIG. 2 is a fan that exhausts air from the room R1 (target space), and is provided in the area 15d of the ventilation unit 10. As shown in FIG. By driving the exhaust fan 14, the air in the room R1 (see FIG. 1) is drawn in and led to the total heat exchanger 12, and the air heat-exchanged in the total heat exchanger 12 is blown out to the outdoors. The exhaust fan 14 is controlled by a control device 18 (see FIG. 4), which will be described later.
Further, while the ventilation unit 10 is being driven, the rotational speeds of the air supply fan 13 and the exhaust fan 14 are generally equal, but depending on the operation mode, the air supply fan 13 and the exhaust fan 14 may be driven at different rotational speeds. There is also

FIG. 3 is an explanatory diagram of the total heat exchanger 12 of the ventilation unit.
3 shows part of the heat exchange element 12m included in the total heat exchanger 12. As shown in FIG. The heat exchange element 12m is formed with a flow path 121m that guides air flowing from the outdoors into the region 15a (see FIG. 2) of the ventilation unit 10 (see FIG. 2) to another region 15b (see FIG. 2). Further, the heat exchange element 12m is formed with a flow path 122m for guiding the air flowing from the room into the region 15c (see FIG. 2) of the ventilation unit 10 (see FIG. 2) to another region 15d (see FIG. 2). there is These

flow paths

121m and 122m are alternately provided in the stacking direction of the heat exchange elements 12m. Further, the

flow paths

121m and 122m are formed such that the air flow directions are substantially perpendicular to each other. Note that FIG. 3 is an example, and the configuration of the total heat exchanger 12 is not limited to this.

FIG. 4 is a functional block diagram of the ventilation system 100. As shown in FIG.
The ventilation system 100 shown in FIG. 4 includes, in addition to the carbon dioxide concentration sensors 21 to 24 (see also FIG. 1), the air supply fan 13 (see also FIG. 2), and the exhaust fan 14 (see also FIG. 2), a remote controller 16, a remote control transmitting/receiving section 17, and a control device 18 (control section).
A remote controller 16 is a device operated by a user. By operating the remote control 16, selection of the operation mode of the ventilation unit 10 (see FIG. 2), setting change, and the like are performed. The remote control transmitter/receiver 17 is a communication interface between the remote control 16 and the control device 18 .

The controller 18 controls the air supply fan 13 and the exhaust fan 14 based on changes in the detection values of the carbon dioxide concentration sensors 21-24. The control device 18 includes electronic circuits such as a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and various interfaces (not shown) as a hardware configuration. Then, the program stored in the ROM is read out and developed in the RAM, and the CPU executes various processes. As shown in FIG. 4, the control device 18 includes a storage section 18a and a control section 18b.

In addition to a predetermined program, the storage unit 18a stores in advance data such as a formula (formula (1) described below) used for estimating the number of people in the room R1 (see FIG. 1). In addition, the storage unit 18a stores the momentary detection values of the carbon dioxide concentration sensors 21-24. The control unit 18b executes predetermined processing based on the data stored in the storage unit 18a. As a specific example, the control unit 18b estimates the number of people n in the room R1 (see FIG. 1) based on the following formula (1).

Note that _Vr included in the formula (1) is the volume of the space (that is, the volume) of the room R1 (see FIG. 1). A method of calculating this volume _Vr will be described later. C included in the formula (1) is the carbon dioxide concentration in the room R1, which is detected by the carbon dioxide concentration sensors 21-23 (see FIG. 1). As such a carbon dioxide concentration C, for example, a value obtained by averaging detection values of the three carbon dioxide concentration sensors 21 to 23 is used.

The n included in the formula (1) is the number of people in the room R1. Also, _vh with a dot is the amount of carbon dioxide generated per person in the room. This dotted v _h is, for example, 6.185×10 ⁻⁶ [m ³ /s], which is a known value. C ₀ included in equation (1) is the outdoor carbon dioxide concentration. This outdoor carbon dioxide concentration C ₀ is, for example, 400 [ppm] (=0.0004 [m ³ /m ³ ]), which is a known value.

The dotted _Vv included in equation (1) is the amount of ventilation by the ventilation unit 10 (see FIG. 2), and is calculated based on the rotational speeds of the air supply fan 13 and the exhaust fan 14 . In addition to the cross-sectional area of each duct connected to the ventilation unit 10, the wind velocity when the air supply fan 13 and the exhaust fan 14 are driven at a predetermined rotational speed is measured in advance, and the measurement result is used as the ventilation volume. You may make it use for calculation. C _C included in equation (1) is the carbon dioxide concentration in the corridor R2 (see FIG. 1) and is detected by the carbon dioxide concentration sensor 24 provided in the corridor R2.

The dotted V _C included in equation (1) is the flow rate of air leaking from room R1 (see FIG. 1) to corridor R2 (see FIG. 1). In addition to the volume _Vr of the space of the room R1, the flow rate of the air leaking from the room R1 to the corridor R2 (dotted Vc) is specified as follows with respect to the _formula (1). That is, the volume V _r and the dotted V _C described above fill the room R1 with high-concentration carbon dioxide at the construction stage (or the preliminary test stage) of the ventilation unit 10, and further, the carbon dioxide concentration in the room R1 The numerical value is specified by measuring the change over time.

For example, the ventilation unit 10 (see FIG. 1) is installed, carbon dioxide concentration sensors 21 to 23 (see FIG. 1) are installed in the room R1, and another carbon dioxide concentration sensor 24 (see FIG. 1) is installed. The following work is performed in a state of being installed in the corridor R2. That is, a worker uses a carbon dioxide cylinder (not shown) or dry ice (not shown) to fill the room R1 with high-concentration carbon dioxide. Then, the operator closes the door 43 (see FIG. 1) with the room R1 left unmanned, stops the ventilation unit 10 (that is, does not perform forced ventilation), and displays the time series of the carbon dioxide concentration in the room R1. Get data.

FIG. 5 is an explanatory diagram of time-series data of carbon dioxide concentration when there is no active ventilation and time-series data of carbon dioxide concentration when active ventilation is performed.
Note that the horizontal axis of FIG. 5 is the elapsed time from the point at which the room R1 was filled with the high-concentration carbon dioxide concentration, and the vertical axis is the carbon dioxide concentration of the room R1. Even without forced ventilation, carbon dioxide leaks from the room R1 to the corridor R2 through the gap of the door 43 (see FIG. 1). Concentration gradually decreases. Such ventilation through the gap of the door 43 or the like is called natural ventilation.

After acquiring the time-series data in natural ventilation (data of the thick line graph in FIG. 5), the worker uses a carbon dioxide cylinder (not shown) or dry ice (not shown) to move the room R1 (Fig. 1 ) is refilled with high-concentration carbon dioxide. Then, the worker closes the door 43 (see FIG. 1) while the room R1 is unmanned, and drives the air supply fan 13 and the exhaust fan 14 of the ventilation unit 10 (see FIG. 2) at a predetermined rotational speed. Time-series data of the carbon dioxide concentration in the room R1 is obtained while such forced ventilation is being performed.

In this case, forced ventilation is performed by the ventilation unit 10 (see FIG. 1) in addition to natural ventilation through the gap of the door 43 (see FIG. 1). Therefore, as shown in the thin line graph in FIG. 5, the carbon dioxide concentration in room R1 (see FIG. 1) drops more steeply than in the case of no forced ventilation (that is, only natural ventilation). Based on these two pieces of time _- series data, in addition to the volume _Vr of the space of the room R1 in the equation (1), the dotted Vc, which is the flow rate of the air leaking from the room R1 to the corridor R2, is calculated, and the storage unit 18a (see FIG. 4). In this way, by considering natural ventilation through the gap of the door 43, etc., the number of people in the room R1 can be estimated with high accuracy based on the detected value of the carbon dioxide concentration.

FIG. 6 is an explanatory diagram relating to experimental results of changes in carbon dioxide concentrations in rooms and corridors.
The horizontal axis of FIG. 6 is the elapsed time from the time when the room R1 (see FIG. 1) was filled with high-concentration carbon dioxide, and the vertical axis is the concentration of carbon dioxide in the room R1. The data in FIG. 6 are obtained when the room R1 (see FIG. 1) is filled with high-concentration carbon dioxide, the room R1 is unmanned, and forced ventilation is performed by the ventilation unit 10 (see FIG. 1). It is the time series data of the acquired carbon dioxide concentration.

The thick solid line graph in FIG. 6 is the carbon dioxide concentration actually measured in room R1 (see FIG. 1), and the thin solid line graph is the carbon dioxide concentration actually measured in corridor R2 (see FIG. 1). . Also, the dashed line graph in FIG. 6 shows the momentary change in room R1 when natural ventilation (dotted V _C included in equation (1)) through a gap in door 43 (see FIG. 1) is taken into consideration. is the calculated value of the carbon dioxide concentration of On the other hand, the dashed-dotted line graph in FIG. 6 is the hourly calculated value of the carbon dioxide concentration in the room R1 when natural ventilation through the gap of the door 43 (see FIG. 1) is not considered.

As shown in FIG. 6, the calculated value of carbon dioxide concentration in room R1 (see FIG. 1) when natural ventilation is not taken into account (one-dot chain line) has a certain degree of accuracy, but the actual carbon dioxide concentration in room R1 ( thick solid line). On the other hand, the calculated carbon dioxide concentration in room R1 (dashed line) when natural ventilation is taken into account has a relatively small error from the actual carbon dioxide concentration (thick solid line) in room R1 (see FIG. 1). Therefore, even when using the _formula (1) described above, the room can be The number of people in room R1 can be estimated with high accuracy. The amount of ventilation (air volume) by the ventilation unit 10 (see FIG. 1) hardly changes the flow rate of natural ventilation from the room R1.

FIG. 7 is a flow chart of processing executed by the control device of the ventilation unit (see FIGS. 1 and 4 as appropriate).
Note that at the time of "START" in FIG. 7, the volume of the space in the room R1 (V _r in formula (1)) and the flow rate of air leaking from the room R1 to the corridor R2 (dotted V _C in formula (1)) is already calculated and stored in the storage unit 18a of the control device 18 (see FIG. 4).
In step S101 of FIG. 7, the control device 18 detects the carbon dioxide concentration of the room R1 and the like. Specifically, the control device 18 reads the detected values of the three carbon dioxide concentration sensors 21 to 23 in the room R1 and reads the detected value of the carbon dioxide concentration sensor 24 in the corridor R2. As the carbon dioxide concentration in the room R1, the controller 18 uses, for example, a value obtained by averaging the detection values of the three carbon dioxide concentration sensors 21-23.

FIG. 8 is an explanatory diagram showing experimental results of changes in carbon dioxide concentrations in rooms and corridors.
Note that the horizontal axis of FIG. 8 is the time (from 7:00 in the morning to 21:00 at night), and the vertical axis is the concentration of carbon dioxide. Also, the thick solid line graph in FIG. 8 is the measured value of the carbon dioxide concentration in the room R1 (see FIG. 1). On the other hand, the thin solid line graph in FIG. 8 is the measured value of the carbon dioxide concentration in the corridor R2 (see FIG. 1). Each data in FIG. 8 was obtained in a state where the ventilation unit 10 was in operation after construction.

In the example of FIG. 8, as shown in the thick solid line graph, the concentration of carbon dioxide in the room R1 (see FIG. 1) rises sharply from around 8:30 due to people coming to work, etc., and then the door 43 (see FIG. 1) opens. The concentration of carbon dioxide fluctuates due to the comings and goings of people through the road, and the concentration of carbon dioxide gradually decreases from around 17:00 as people leave work. On the other hand, as for the carbon dioxide concentration in the corridor R2 (see FIG. 1), as shown in the thin solid line graph, after the carbon dioxide concentration rises from around 8:30, people pass through the door 43 (see FIG. 1). The concentration of carbon dioxide fluctuates with entry and exit. Since the corridor R2 is not particularly ventilated, after 19:00, the concentration of carbon dioxide in the corridor R2 is higher than in the room R1 where forced ventilation is performed with few people in the room. .

Again, return to FIG. 7 and continue the description.
After detecting the carbon dioxide concentration in the room R1 and the like in step S101, the control device 18 estimates the number of people in the room in step S102. That is, the control device 18 substitutes the detection result of the carbon dioxide concentration in step S101 into the equation (1) to calculate the number of people in the room R1 (target space). As described above, since the formula (1) also takes into consideration natural ventilation through the gap of the door 43 (see FIG. 1), etc., the number of people in the room can be increased based on the carbon dioxide concentration in the room R1. It can be estimated with accuracy.

FIG. 9 is an explanatory diagram of experimental results showing the estimated number of people based on the carbon dioxide concentration and the actual number of people.
Note that the horizontal axis of FIG. 9 is the time (from 7:00 in the morning to 21:00 at night), and the vertical axis is the number of people in the room R1. Further, the solid line graph indicates that the control device 18 calculates the number of people in the room R1 during ventilation based on the change in the carbon dioxide concentration in the room R1 and the change in the carbon dioxide concentration in the corridor R2 in FIG. This is the estimated result. On the other hand, the white circles in FIG. 9 indicate the actual number of people in the room R1. As shown in FIG. 9, even when the number of people in the room R1 changes (people come in and out through the door 43), the The number of people in the room is estimated with high accuracy.

In this way, the control device 18 can detect changes in the detected values of the carbon dioxide concentration sensors 21 to 23 (see FIG. 1) provided in the room R1 (target space) and another carbon dioxide concentration provided in the corridor R2 (adjacent space). At least one of the air supply fan 13 and the exhaust fan 14 is controlled based on the change in the detected value of the carbon concentration sensor 24 (see FIG. 1).

Again, return to FIG. 7 and continue the description.
After estimating the number of people in the room R1 in step S102, the control device 18 calculates the amount of ventilation by the ventilation unit 10 in step S103. For example, the control device 18 multiplies the number of people in the room R1 (target space) estimated in step S102 by the required ventilation volume per person (for example, 30 [m ³ /h]). Based on this, the ventilation amount of the room R1 by the ventilation unit 10 is calculated. In this way, the controller 18 adjusts the amount of ventilation in response to changes in the number of people in the room R1.

When the control device 18 calculates the ventilation volume, a predetermined margin may be added to the value obtained by multiplying the number of people in the room by the required ventilation volume. As a result, even if the estimated number of people based on the carbon dioxide concentration is slightly smaller than the actual number of people in the room, insufficient ventilation in the room R1 can be suppressed.

Next, the controller 18 controls the air supply fan 13 and the exhaust fan 14 in step S104. That is, the control device 18 controls the motors of the air supply fan 13 and the exhaust fan 14 so that the amount of air calculated in step S103 is supplied/exhausted. The control device 18 increases the rate of increase in the rotational speed of the air supply fan 13 and the rate of increase in the rotational speed of the exhaust fan 14 as the rate of change in carbon dioxide concentration in the room R1 (target space) increases. is preferred. As a result, it is possible to appropriately increase or decrease the ventilation rate of the room R1 based on the rate of change in the carbon dioxide concentration.
Note that the control device 18 may control only one of the air supply fan 13 and the exhaust fan 14 in step S104. That is, the controller 18 (control section) may control at least one of the air supply fan 13 and the exhaust fan 14 based on changes in the detected values of the carbon dioxide concentration sensors 21-24.

Further, when the rate of increase in carbon dioxide concentration in room R1 (target space) is equal to or greater than a predetermined value, control device 18 increases at least one of the rotation speed of air supply fan 13 and the rotation speed of exhaust fan 14. preferably. As a result, the amount of ventilation in the room R1 is increased, so that an increase in the carbon dioxide concentration can be suppressed, and the transmission of pathogens from person to person can be suppressed.
In addition, it is preferable that the control device 18 increases the rotation speed of the air supply fan 13 and the exhaust fan 14 as the number of people in the room R1 (target space) increases based on the change in the detected value of the carbon dioxide concentration. . As a result, as the number of people (estimated value) in the room R1 increases, the flow rate of fresh air supplied to the room R1 also increases, so that the room R1 can be properly ventilated.

As described above, the control device 18 controls the air supply fan 13 and the exhaust fan 14 based on the value obtained by multiplying the number of people in the room R1 (target space) by the required ventilation amount per person. do. Therefore, an appropriate amount of air is supplied to the room R1 according to the number of people in the room. As a result, the air volume of the ventilation unit 10 is prevented from becoming excessively large, so the power consumption of the ventilation unit 10 can be reduced. Also, whether the number of persons in the room is relatively large or small, an appropriate amount of air is supplied to the room R1.
After performing the process of step S104 in FIG. 7, the process of the control device 18 returns to "START"("RETURN"). Thus, the control device 18 repeats the series of processes shown in FIG.

It should be noted that when the controller 18 changes the rotational speeds of the air supply fan 13 and the exhaust fan 14, these rotational speeds may be increased or decreased stepwise. For example, the control device 18 may drive each of the air supply fan 13 and the exhaust fan 14 at any one of three stages of high speed, medium speed, and low speed. This eliminates the need to continuously change the rotational speeds of the air supply fan 13 and the exhaust fan 14, thereby eliminating the need for an inverter (not shown). Therefore, the manufacturing cost of the ventilation unit 10 can be reduced.

In addition, the control device 18 causes the remote control 16 (see FIG. 4) to display the value obtained by multiplying the number of people in the room R1 (see FIG. 1) by the required ventilation amount per person, and displays the actual ventilation. The amount may be displayed on the remote controller 16 . As a result, the ventilation volume when the necessary ventilation volume of fresh air is supplied to each person in the room (calculated ventilation volume) and the actual ventilation volume (for example, the ventilation volume when it is increased or decreased in 3 stages) The user can grasp the magnitude of . Therefore, it is possible for the user to feel that the ventilation is properly performed, and it can be used as a reference when the administrator considers a system change or the like. Note that the above display may be performed not only on the remote controller 16 (see FIG. 4) but also on a mobile terminal (not shown) such as a mobile phone, a smart phone, or a tablet.

According to the first embodiment, the control device 18 controls the carbon dioxide concentration of the room R1 (see FIG. 1), which is the target space, as well as the carbon dioxide concentration of the corridor R2 (see FIG. 1) adjacent to the room R1. Based on, the number of persons in the room R1 is estimated. As a result, the control device 18 can accurately estimate the number of people in the room R1, taking into account natural ventilation through the gap of the door 43 (see FIG. 1) and the like. Also, even if the number of people in the room changes due to the entrance and exit of people through the door 43, the control device 18 can estimate the number of people in the room at every moment with high accuracy. Moreover, since there is no particular need to install a camera (not shown) for detecting people in the room in the ventilation unit 10, the manufacturing cost of the ventilation unit 10 can be reduced.

Further, the control device 18 controls at least one of the air supply fan 13 and the exhaust fan 14 based on changes in the detection values of the carbon dioxide concentration sensors 21-24. Incidentally, conventionally, when the value of the carbon dioxide concentration in the room R1 reaches a predetermined threshold value, the control is performed such that the ventilation rate is increased. With such control, the amount of ventilation does not increase until the concentration of carbon dioxide in room R1 reaches a predetermined threshold, so there is a problem in that the ventilation of room R1 is difficult to progress. In contrast, in the first embodiment, as described above, the ventilation rate is controlled based on changes in the carbon dioxide concentration in the room R1. Device 18 is enabled to increase ventilation. Therefore, the room R1 can be properly ventilated.
Further, the control device 18 calculates the ventilation volume of the ventilation unit 10 by multiplying the number of people in the room based on the carbon dioxide concentration by the required ventilation volume per person. As a result, fresh air can be supplied to the room R1 (see FIG. 1) in just the right amount, so that insufficient ventilation of the room R1 can be suppressed, and an increase in power consumption associated with excessive ventilation can be suppressed. In addition, since the room R1 is properly ventilated, even if a person's exhalation contains a pathogen such as a virus, it is possible to suppress the infection of other persons.

<<Second embodiment>>
In the second embodiment, when the air supply fan 13 (see FIG. 2) and the exhaust fan 14 (see FIG. 2) are driven at the minimum air volume, the total required ventilation volume is smaller than the actual ventilation volume. The difference from the first embodiment is that the control device 18 notifies the user of the time. Others (such as the configuration of the ventilation system 100: see FIGS. 1 to 4) are the same as in the first embodiment. Therefore, the portions different from the first embodiment will be described, and the description of the overlapping portions will be omitted.

FIG. 10 is a flowchart of processing executed by the control device of the ventilation unit provided in the ventilation system according to the second embodiment (see FIGS. 1 and 4 as appropriate).
Note that steps S101 to S104 in FIG. 10 are the same as those in the first embodiment (see FIG. 7), so description thereof will be omitted. After controlling the air supply fan 13 and the exhaust fan 14 in step S104, the control device 18 determines whether the air supply fan 13 and the exhaust fan 14 are driven at the minimum air volume in step S205. The "minimum air volume" is an air volume corresponding to the lower limit of rotation speed (value greater than zero) of the motor (not shown) of the air supply fan 13 and the motor (not shown) of the exhaust fan 14. Yes, it is preset.

In step S205, if the air supply fan 13 and the exhaust fan 14 are driven at the minimum air volume (S205: Yes), the process of the control device 18 proceeds to step S206. On the other hand, in step S205, when the air supply fan 13 and the exhaust fan 14 are driven at an air volume larger than the minimum air volume (S205: No), the process of the control device 18 returns to "START" ("RETURN").

In step S206, the control device 18 determines whether or not the total required ventilation volume is smaller than the actual ventilation volume. That is, the control device 18 determines whether or not the value obtained by multiplying the required ventilation volume per person by the estimated number of people in the room R1 (total required ventilation volume) is smaller than the current actual ventilation volume. determine whether In step S206, if the total required ventilation volume is smaller than the actual ventilation volume (S206: Yes), the process of the control device 18 proceeds to step S207. On the other hand, in step S206, if the total required ventilation volume is greater than or equal to the actual ventilation volume (S206: No), the process of the control device 18 returns to "START" ("RETURN").

In step S207, the control device 18 notifies the user that there is room for energy saving. That is, when each of the air supply fan 13 and the exhaust fan 14 is driven at the minimum air volume (S205: Yes), the control device 18 determines the number of people in the room R1 (target space) and the number of people per person. When the value obtained by multiplying the required ventilation volume by is less than the minimum air volume (S206: Yes), the remote controller 16 (see FIG. 4) or portable terminal (not shown) displays that there is room for energy saving.

For example, when the air supply fan 13 and the exhaust fan 14 are driven at one of three stages of high speed, medium speed, and low speed, suppose that the air supply fan 13 and the exhaust fan 14 are driven at low speed (minimum air volume). (S205: Yes). In such a case, when the total required ventilation volume is smaller than the actual ventilation volume (S206: Yes), the number of stages of air volume adjustment of the ventilation system 100 is increased, or the air volume is continuously changed. may be considered by the administrator to save energy. After performing the process of step S207, the process of the control device 18 returns to "START" ("RETURN").

According to the second embodiment, when the air supply fan 13 and the exhaust fan 14 are driven at the minimum air volume (S205 in FIG. 10: Yes), when the total required ventilation volume is smaller than the actual ventilation volume ( S206: Yes), the control device 18 notifies the user that there is room for energy saving (S207). As a result, even when the method of adjusting the air volume of the ventilation unit 10 is changed, it is possible to achieve further energy saving.

<<Third Embodiment>>
In the third embodiment, when the carbon dioxide concentration in the room R1 (see FIG. 1) is equal to or higher than a predetermined value, the rotational speeds of the air supply fan 13 (see FIG. 2) and the exhaust fan 14 (see FIG. 2) are increased. is different from the first embodiment. Others (such as the configuration of the ventilation system 100: see FIGS. 1 to 4) are the same as in the first embodiment. Therefore, the portions different from the first embodiment will be described, and the description of the overlapping portions will be omitted.

FIG. 11 is a flowchart of processing executed by the control device of the ventilation unit provided in the ventilation system according to the third embodiment (see FIGS. 1 and 4 as appropriate).
Note that steps S101 to S104 in FIG. 11 are the same as those in the first embodiment (see FIG. 7), so description thereof will be omitted. After controlling the air supply fan 13 and the exhaust fan 14 in step S104, the control device 18 determines whether or not the concentration of carbon dioxide in the room R1 is equal to or higher than a predetermined value in step S305. For example, the control device 18 determines whether or not the average value of the detection values of the three carbon dioxide concentration sensors 21 to 23 provided in the room R1 is equal to or greater than a predetermined value.

The above-mentioned "predetermined value" is a threshold value that serves as a criterion for determining whether or not to increase the rotation speed of the air supply fan 13 and the exhaust fan 14 regardless of the estimated number of people in the room R1, and is set in advance. ing. As a specific example, when the carbon dioxide concentration in room R1 reaches 1000 [ppm] (=0.001 [m ³ /m ³ ]) based on the air environment measurement regulations based on the Building Satellite Management Act, The control device 18 may determine that the condition of step S305 is satisfied.

In step S305, if the carbon dioxide concentration in room R1 is greater than or equal to the predetermined value (S305: Yes), the process of control device 18 proceeds to step S306. On the other hand, in step S305, if the carbon dioxide concentration in the room R1 is less than the predetermined value (S305: No), the process of the control device 18 returns to "START" ("RETURN").

In step S306, the control device 18 increases the rotational speeds of the air supply fan 13 and the exhaust fan 14. In this way, even if the current ventilation volume is greater than the total required ventilation volume (value obtained by multiplying the number of people in the room R1 by the required ventilation volume per person), the control device 18 When the concentration of carbon dioxide in (the target space) is equal to or higher than the predetermined value (S305: Yes), the rotational speeds of the air supply fan 13 and the exhaust fan 14 are increased (S306). As a result, the amount of fresh air supplied to the room R1 increases, so the carbon dioxide concentration in the room R1 can be lowered to an appropriate range.

After performing the process of step S306, the process of the control device 18 returns to "START" ("RETURN"). Then, the control device 18 increases the rotation speeds of the air supply fan 13 and the exhaust fan 14 until the carbon dioxide concentration in the room R1 becomes less than the predetermined value (S306).

According to the third embodiment, when the carbon dioxide concentration in the room R1 is equal to or higher than the predetermined value (S305: Yes), the control device 18 increases the rotational speeds of the air supply fan 13 and the exhaust fan 14 (S306). As a result, the amount of fresh air supplied to the room R1 increases, so the carbon dioxide concentration in the room R1 can be lowered to an appropriate range.

<<Modification>>
Although the ventilation system 100 according to the present invention has been described above in each embodiment, the present invention is not limited to these descriptions, and various modifications can be made.
For example, in each embodiment, three carbon dioxide concentration sensors 21 to 23 are provided in room R1 (see FIG. 1), and another carbon dioxide concentration sensor 24 is provided in corridor R2 (see FIG. 1). Illustrated, but not limited to. That is, if there is almost no air leakage from the room R1 to the corridor R2, there is no particular need to provide the carbon dioxide concentration sensor 24 in the corridor R2. In such a case, the control device 18 controls the air supply fan 13 and the exhaust fan 14 based on changes in the detection values of the carbon dioxide concentration sensors 21 to 23 in the room R1.
Further, even if the natural ventilation destination from the room R1 is not the corridor R2 but the outdoors, there is no particular need to provide a carbon dioxide concentration sensor (not shown) outside the room R1. This is because the outdoor carbon dioxide concentration is known.

Further, in the second embodiment, when the air supply fan 13 and the exhaust fan 14 are driven at the minimum air volume (S205 in FIG. 10: Yes), when the total required ventilation volume is smaller than the actual ventilation volume ( Although S206: Yes) and the process of informing the user that there is room for energy saving (S207), the present invention is not limited to this. For example, if the determination process in step S206 of FIG. 10 is omitted and the control device 18 drives each of the supply fan 13 and the exhaust fan 14 at the minimum air volume, the remote controller 16 can confirm that the air supply fan 13 and the exhaust fan 14 are driven at the minimum air volume. (See FIG. 4) or may be displayed on a portable terminal (not shown). This can be used as a reference when the user stops ventilation by operating the remote control 16 or the like.

In addition, the control device 18 causes the remote controller 16 (see FIG. 4) or a portable terminal (not shown) to display a value obtained by multiplying the estimated number of people in the room by the required ventilation volume per person, and displays the value in the room R1. The natural ventilation amount (leakage amount per unit time) may be displayed on the remote control 16 or the portable terminal. If the above value is equal to or less than the natural ventilation amount, there is no problem even if the ventilation by the ventilation unit 10 is stopped.
Also, the control device 18 may cause the remote controller 16 or a portable terminal (not shown) to display information including the total required ventilation volume, the natural ventilation volume, and the actual ventilation volume. Such a display can also be used as a reference when the user stops ventilation by operating the remote controller 16 or the like.

Further, when the value obtained by multiplying the estimated number of people in the room by the required ventilation amount per person is equal to or less than the natural ventilation amount of the room R1, the control device 18 stops the ventilation by the ventilation unit 10. good too. Thereby, the power consumption of the ventilation unit 10 can be further reduced.

Further, in each embodiment, a case where a carbon dioxide cylinder (not shown) or dry ice (not shown) is used when filling the room R1 (see FIG. 1) with high-concentration carbon dioxide in the construction stage will be described. However, it is not limited to this. For example, by accommodating a plurality of people in the room R1, the carbon dioxide concentration in the room R1 is increased, and then the room R1 is unmanned and unventilated to acquire time-series data of the carbon dioxide concentration. good too. The same applies to the case where the room R1 is unmanned and forcedly ventilated.

Also, in each embodiment, the case where the three carbon dioxide concentration sensors 21 to 23 (see FIG. 1) are provided in the room R1 has been described, but the present invention is not limited to this. For example, the number of carbon dioxide concentration sensors provided in room R1 may be one, two, or four or more. Also, a plurality of carbon dioxide concentration sensors may be provided in the corridor R2 (see FIG. 1).

Moreover, although each embodiment demonstrated the structure provided with the ventilation unit 10 (refer FIG. 2) with the total heat exchanger 12 (refer FIG. 2), it does not restrict to this. For example, each embodiment can be applied to various types of ventilation units such as a configuration in which the total heat exchanger 12 is omitted and air is simply supplied and exhausted.
Also, in addition to the ventilation unit 10 (see FIG. 2), an air conditioning unit (not shown) for cooling operation and heating operation may be provided. In such a configuration, the ventilation unit 10 and the air conditioning unit may be independent of each other, or may be connected to each other via a communication line.

Moreover, each embodiment is described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the described configurations. Moreover, it is possible to add, delete, or replace part of the configuration of each embodiment with another configuration.
Further, the mechanisms and configurations described above show those considered necessary for explanation, and do not necessarily show all the mechanisms and configurations on the product.

100 ventilation system 10

ventilation unit

21, 22, 23 carbon dioxide concentration sensor 24 carbon dioxide concentration sensor (another carbon dioxide concentration sensor)
12 total heat exchanger 13 air supply fan 14 exhaust fan 16 remote control 18 control device (control unit)
42 Wall 43 Door R1 Room (target space)
R2 corridor (adjacent space)

Claims

a carbon dioxide concentration sensor that detects the carbon dioxide concentration in the target space;
an air supply fan for supplying air to the target space;
an exhaust fan for exhausting air from the target space;
and a control unit that controls at least one of the air supply fan and the exhaust fan based on a change in the detected value of the carbon dioxide concentration sensor.
The control unit increases at least one of the rotation speed of the air supply fan and the rotation speed of the exhaust fan when the rate of increase in carbon dioxide concentration in the target space is equal to or greater than a predetermined value. 2. The ventilation system of claim 1.
The control unit increases the range of increase in the rotation speed of the air supply fan and the range of increase in the rotation speed of the exhaust fan as the rate of change of the carbon dioxide concentration in the target space increases. A ventilation system according to claim 1 .
2. The control unit according to claim 1, wherein the greater the number of people in the target space based on the detected value of carbon dioxide concentration, the higher the rotation speed of the air supply fan and the exhaust fan. ventilation system.
The control unit controls the air supply fan and the exhaust fan based on a value obtained by multiplying the number of people in the target space by the required ventilation amount per person. 5. Ventilation system according to 4.
6. The ventilation system according to claim 5, wherein the control unit causes a remote controller or a mobile terminal to display the value and the actual ventilation volume.
2. When each of the air supply fan and the exhaust fan is driven at a minimum air volume, the control unit causes a remote controller or a portable terminal to display that the air supply fan and the exhaust fan are driven at the minimum air volume. The ventilation system described in .
When the air supply fan and the exhaust fan are each driven at the minimum air volume and the value is less than the minimum air volume, the control unit notifies the remote controller or the mobile terminal that there is room for energy saving. 6. Ventilation system according to claim 5, characterized in that it displays.
The control unit increases the rotational speeds of the air supply fan and the exhaust fan when the carbon dioxide concentration in the target space is equal to or higher than a predetermined value even when the current ventilation volume is greater than the value. 6. The ventilation system according to claim 5, wherein
Further comprising another carbon dioxide concentration sensor provided in an adjacent space adjacent to the target space via a wall or door,
The control unit controls the air supply fan based on a change in the detected value of the carbon dioxide concentration sensor provided in the target space and a change in the detected value of the another carbon dioxide concentration sensor provided in the adjacent space. and controlling at least one of the exhaust fan.
The ventilation system according to claim 1, wherein the controller increases or decreases the rotational speeds of the air supply fan and the exhaust fan in stages when changing the rotational speeds of the air supply fan and the exhaust fan.