JP7340742B2 - Heat exchange ventilation system - Google Patents

Description

The present invention relates to mixed air operation control in a heat exchange type ventilation system.

Conventionally, as shown in the schematic diagram of FIG. 6, this type of heat exchange type ventilation device has a main body 101 with a heat exchange air supply path 104 that ventilates from an outdoor suction port 102 to an indoor air supply port 103, and an indoor air intake path that sucks inside air. A heat exchange exhaust heat air path 107 that ventilates from the port 105 to the outdoor exhaust port 106; a heat exchange circulation air path 109 that ventilates the inside air taken in from the indoor suction port 105 to the indoor air supply port 103 through the circulation port 108; A heat exchange type ventilation device is known that includes a heat exchange element 110 that exchanges heat between a supply air flow and an air supply fan 111 that generates a supply air flow, and an exhaust fan 112 that generates an exhaust flow.

In a conventional heat exchange type ventilation system, when the outdoor suction port 102 is opened, the outdoor exhaust port 106 is closed, and the circulation port 108 is opened, the heat exchange air supply air path 104 and the heat exchange circulation air path 109 are closed. It is possible to perform mixed wind operation by utilizing
(For example, see Patent Document 1).

JP2017-229828A

When such a conventional heat exchange type ventilation device is operated with mixed air, for example, when the outside air temperature is low in winter, there is a problem in that dew condensation occurs on the heat exchange element. Condensation on the heat exchange element eventually causes clogging of the heat exchange element, reducing the ventilation function. In order to prevent the occurrence of dew condensation on the heat exchange element, intermittent operation is sometimes performed, but there is also the problem that mixed air operation cannot be continued at all times.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a heat exchange type ventilation device that can continue mixed air operation while suppressing dew condensation on a heat exchange element.

In order to achieve this object, the heat exchange type ventilation device of the present invention includes a heat exchange element that exchanges heat between the outside air taken in from the outdoor suction port and the inside air taken in from the indoor suction port, and A heat exchange air supply air passage in which outside air is supplied into the room from the indoor air supply port via the heat exchange element, and inside air taken in from the indoor suction port is exhausted outdoors from the outdoor exhaust port via the heat exchange element. an air supply fan provided in the heat exchange air supply air path to supply outside air; an exhaust fan provided in the heat exchange exhaust air path to exhaust internal air; An exhaust circulation damper provided at the outdoor exhaust port, and the exhaust circulation damper closes the outdoor exhaust port, and the exhaust fan circulates the indoor air sucked from the indoor suction port through the heat exchange element to the indoor air supply port. a heat exchanger circulation air passageway, a temperature/humidity detection means for detecting the temperature and humidity of the indoor air passing through the indoor air intake port, a temperature detection means for detecting the temperature of the airflow passing through the indoor air supply opening, and the air supply fan. and a control unit that controls the rotation speed of the exhaust fan, when the heat exchange circulation air passage and the heat exchange air supply air passage are configured, the control unit controls the rotation speed of the exhaust fan. An indoor dew point temperature is calculated based on the temperature and humidity detected by the temperature/humidity detection means, and when the temperature detected by the temperature detection means is lower than the indoor dew point temperature, the control section controls the rotation speed of the exhaust fan. and when the temperature detected by the temperature detection means is higher than the indoor dew point temperature, the rotation speed of the exhaust fan is reduced, thereby achieving the intended purpose. It is something.

By the mixed air operation of the heat exchange type ventilation device of the present invention, the mixed air operation can be continued while preventing dew condensation occurring within the heat exchange type ventilation device.

1 is a diagram showing the configuration of Embodiment 1 of the present invention. FIG. 1 is a diagram showing the configuration of Embodiment 1 of the present invention. FIG. It is a figure which shows the flowchart which determines the operating state of Embodiment 1 of this invention. It is a figure which shows the flowchart which controls the mixed air operation of Embodiment 1 of this invention. It is a graph showing the relationship between supply air temperature and circulating air volume in mixed air operation control in Embodiment 1 of the present invention. FIG. 1 is a schematic configuration diagram of a conventional technique.

Embodiments of the present invention will be described based on the drawings. However, the embodiments described below are exemplified to embody the technical idea of the present invention, and the present invention is not limited to the following embodiments. In particular, unless there is a specific description, the numerical values, materials, shapes, relative positions thereof, etc. described in the embodiments are not intended to limit the scope of the present invention, but are merely examples. do not have.

A heat exchange type ventilation device according to claim 1 of the present invention includes a heat exchange element for exchanging heat between outside air taken in from an outdoor suction port and inside air taken in from an indoor suction port; A heat exchange air supply air passage in which air is supplied indoors from an indoor air supply port via a heat exchange element, and heat from inside air sucked in from the indoor suction port and exhausted outdoors from an outdoor exhaust port via the heat exchange element. an exchange exhaust air path, an air supply fan provided in the heat exchange air supply air path to supply outside air, an exhaust fan provided in the heat exchange exhaust air path to exhaust internal air, and the outdoor exhaust port. and a heat exchanger that closes an outdoor exhaust port with the exhaust circulation damper, and circulates internal air sucked from the indoor air intake port through the heat exchange element to the indoor air supply port by the exhaust fan. a circulating air path, and temperature and humidity detection means for detecting the temperature and humidity of the indoor air passing through the indoor suction port;
In the heat exchange type ventilation apparatus, the heat exchange type ventilation apparatus includes a temperature detection means for detecting the temperature of the airflow passing through the indoor air supply port, and a control section for controlling the rotation speed of the air supply fan and the exhaust fan. When an air passage and the heat exchange air supply air passage are configured, the control unit calculates the indoor dew point temperature based on the temperature and humidity detected by the temperature and humidity detection means, and the control unit calculates the indoor dew point temperature based on the temperature and humidity detected by the temperature and humidity detection means. When the temperature detected by the temperature detection means is lower than the indoor dew point temperature, the rotation speed of the exhaust fan is increased, and when the temperature detected by the temperature detection means is higher than the indoor dew point temperature, the rotation speed of the exhaust fan is increased. It is characterized by decreasing the number of

Thereby, the heat exchange type ventilation device can reduce the concentration of particulates in the indoor air through mixed air operation while suppressing the occurrence of dew condensation inside the air passage of the heat exchange type ventilation device.

The heat exchange type ventilation device according to claim 2 of the present invention is characterized in that the control unit can change the time period during which the exhaust fan is changed to a predetermined rotation speed.

Thus, for example, when increasing the rotation speed of the exhaust fan, by shortening the time it takes to reach a predetermined rotation speed, the circulating air volume immediately increases, while the external air volume decreases relatively quickly. Therefore, it is possible to improve the condition where condensation occurs more quickly.

In the heat exchange type ventilation apparatus according to claim 3 of the present invention, when the temperature detected by the temperature detection means continues to be lower than the indoor dew point temperature for a predetermined period of time, the control unit controls the outdoor suction port to It is characterized by closing the provided outdoor air supply shutter.

As a result, the outdoor air supply shutter can be closed, completely shutting off outside air, and the heat exchanger circulation air path allows the warm indoor air to suppress condensation more quickly. be.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

(Embodiment 1)
A heat exchange type ventilation system according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a plan view of a heat exchange type ventilation system according to Embodiment 1 of the present invention, and shows the configuration of the main parts of the heat exchange type ventilation system.

The heat exchange type ventilation device 1 is installed in a ceiling, inside a side wall, or under a floor in a building, and the case where it is installed in a ceiling will be described below. The heat exchange type ventilation device 1 has a rectangular parallelepiped shape, and has a heat exchange element 2, an outdoor suction port 3, an indoor air supply port 4, an indoor suction port 5, and an outdoor exhaust port 6. .

A heat exchange element 2 built into the heat exchange type ventilation device 1 has a function of recovering heat from air exhausted from indoors and giving heat to air supplied from outdoors. This heat exchange element 2 has a function of recovering exhaust heat from the exhaust air flow and applying heat to the supply air flow, and has an air path made up of a plurality of heat transfer plates stacked at predetermined intervals. ing.

This heat exchanger plate has gas shielding properties and moisture permeability, and by allowing indoor air and outdoor air to flow alternately between the heat exchanger plates, heat exchange and moisture can be achieved through the heat exchanger plate while providing ventilation. The configuration allows for the exchange of That is, inside the heat exchange element 2, a heat exchange air supply air passage A and a heat exchange exhaust air passage B are alternately stacked with heat exchanger plates in between. Heat exchange can be performed without mixing the air flow and the exhaust flow.

The outdoor suction port 3 and the indoor air supply port 4 communicate with each other through a heat exchange air supply air path A, and an air supply fan is installed near the indoor air supply port 4 in the heat exchange air supply path A to generate a supply air flow. It has 7. Further, the indoor suction port 5 and the outdoor exhaust port 6 communicate with each other through a heat exchange exhaust air path B, and an exhaust fan 8 for generating an exhaust flow is provided near the outdoor exhaust port 6 of the heat exchange exhaust air path B. It is equipped with

Further, inside the heat exchange type ventilation device 1, an outdoor air supply shutter 9 is provided adjacent to the outdoor suction port 3, and a circulation port 10 that communicates the heat exchange air supply air path A and the heat exchange exhaust air path B is provided. , and an exhaust circulation damper 11. The outdoor air supply shutter 9 is a partition wall that can be opened and closed and has a fulcrum at the end of the outdoor suction port 3, and operates to open and close the outdoor suction port 3. The exhaust circulation damper 11 operates to close either the outdoor exhaust port 6 or the circulation port 10.

In the heat exchange operation in which heat is exchanged between the supply air flow and the exhaust air flow, the circulation port 10 is closed by the exhaust circulation damper 11, and control is performed so that a heat exchange supply air passage A passing through the heat exchange element 2 is formed.

Therefore, by operating the air supply fan 7 in the heat exchange air supply air path A, the outside air sucked in from the outdoor suction port 3 can be passed through the heat exchange element 2, and air can be supplied from the indoor air supply port 4. .

On the other hand, as shown in FIG. 2, by closing the outdoor exhaust port 6 with the exhaust circulation damper 11 and forming the heat exchanger circulation air path C, the air supply from the outdoors to the room via the heat exchanger air supply air path A and the heat A mixed air operation is performed in which circulation is simultaneously carried out from room to room through the alternating circulation air path C. In addition, if the circulating air volume from indoors at this time is 60 CFM (Cubic feet per minute) and the outside air air volume from outside is 40 CFM, the air volume of exhaust fan 8 will be the circulating air volume, and the air volume of supply air fan 7 will be the outside air volume. Since this is the sum of the circulating air volume, the air volume of the air supply fan 7 is controlled to be 100 CFM, and the air volume of the exhaust fan 8 is controlled to be 60 CFM. In this way, the circulating air volume and the outside air volume during mixed air operation can be determined by controlling the air supply fan 7 and the exhaust fan 8. At this time, the air volume of the supply air fan 7 and the exhaust fan 8 can be set arbitrarily, and by making the air volume of the air supply fan 7 and the exhaust fan 8 the same, the outside air volume from outside is 0, which is equivalent to circulation operation. Become.

However, in a general heat exchange type ventilation system, when the outside air temperature decreases during mixed air operation, the temperature of the air supply flowing through the indoor air supply port decreases below the dew point temperature, and the indoor air supply of the heat exchange element 2 decreases in temperature. There is a possibility that condensation may occur from the air vent 4 side.

Therefore, in such a case, as shown in FIG. The indoor dew point temperature is calculated based on the indoor temperature and indoor humidity.

After calculating the indoor dew point temperature, if the supply air temperature detected by the temperature sensor 15 is lower than the indoor dew point temperature, the control unit 13 increases the circulation air volume by increasing the rotation speed of the exhaust fan. If the temperature detected by the temperature detection means is higher than the indoor dew point temperature, the rotation speed of the exhaust fan is reduced to reduce the circulating air volume. Controls to increase the amount of outside air supplied.

Determination of the operating state of the heat exchange type ventilation system of the present invention will be explained below using the flowcharts of FIGS. 2 and 3. Note that S in FIG. 3 means a step.
When the operation is started, the control unit 13 selects mixed air operation (S01). Here, as the initial air volume state of the mixed air operation, the air volume of the supply fan is 100 CFM, the air volume of the exhaust fan is 60 CFM, and the fan rotation speed is controlled so that the circulating air volume is 60 CFM and the outside air volume is 40 CFM. The initial state of the protection flag for mixed air operation is OFF. Further, the outdoor exhaust port 6 is closed by the exhaust circulation damper 11, and the outdoor air supply shutter 9 is opened.

The protection flag is used for conditional branching (S02) to determine whether to proceed to mixed air operation control (S03) or to internal circulation operation (S04). Note that changes in the state of the protection flag will be explained later.

The mixed air operation control (S03) will be explained using the timing chart of FIG. 4.

In the timer process (S101), a 1-minute elapsed flag is turned on every time one minute elapses, and a five-minute elapsed flag is turned on every five minutes. If the one-minute elapsed flag is ON, the one-minute elapsed flag is turned off (S103), and the indoor temperature and humidity detected by the temperature/humidity sensor 14 and the supply air temperature detected by the temperature sensor 15 are acquired ( S104). After calculating the indoor dew point temperature based on the indoor temperature and indoor humidity (S105), the process proceeds to a step of determining the temperature (S106). If the supply air temperature is below the indoor dew point temperature, the step of increasing the circulating air volume (S1
07, proceed to S108). Specifically, check whether the circulating air volume is at the upper limit and set the circulating air volume to 5CF.
Increase M. Further, in the temperature determination, if the supply air temperature is higher than the indoor dew point temperature +5° C., the process proceeds to steps for reducing the circulating air volume (S109 to S112). First, check the state of the 5-minute elapsed flag, and if the 5-minute elapsed flag is ON, turn off the 5-minute elapsed flag (S110
), it is confirmed whether the circulating air volume is at the upper limit or not, and the circulating air volume is decreased by 5 CFM (S111, S112).

Changes in the circulating air volume will be explained using the graph in FIG. 5. Control is started with a circulating air volume of 60 CFM from the start of operation, but when the supply air temperature enters temperature range D, the supply air temperature is increased by 5 CFM every minute. Then, as the outside air flow rate decreases by 5 CFM, the supply air temperature increases. When the supply air temperature eventually enters temperature range E, the supply air flow rate is maintained (here, 90 CFM). When the supply air temperature further increases and enters temperature range F, the circulating air volume is decreased by 5 CFM every 5 minutes.

Thereby, the heat exchange type ventilation device can reduce the concentration of particulates in the indoor air through mixed air operation while suppressing the occurrence of dew condensation inside the air passage of the heat exchange type ventilation device.
Furthermore, since the time interval for increasing or decreasing the circulating air volume and the value for increasing or decreasing the air volume can be set arbitrarily, for example, when increasing the rotation speed of an exhaust fan, it is possible to shorten the time it takes to reach a predetermined rotation speed. , the circulating air volume increases immediately, while the external air volume decreases relatively immediately. Therefore, it is possible to improve the condition where condensation occurs more quickly.

A change in the state of the protection flag from the OFF state to the ON state is determined in the flow of S115 in FIG. 4. If the supply air temperature continues to be below the indoor dew point temperature, the circulating air volume is increased to 5 CFM every minute, but when the circulating air volume reaches the upper limit (for example, 95 CFM), the time measurement step (S113) is performed. ). Here, the time during which the supply air temperature is below the indoor dew point temperature and the circulating air volume is operated at the upper limit value is measured. This value is a certain time threshold (here, 5
minutes), the protection flag is turned ON (S114, S115).

Now, return to the timing chart of FIG. 3.
If the protection flag is ON, internal circulation operation is selected (S04). Here, the air volume of the supply air fan is 100 CFM, the air volume of the exhaust fan is 100 CFM, and the fan rotation speed is controlled so that the circulating air volume is 100 CFM and the outside air volume is 0 CFM. Further, the outdoor exhaust port 6 is closed by the exhaust circulation damper 11, and the outdoor air supply shutter 9 is closed. This internal circulation operation allows the outside air to be completely shut off, and the heat exchanger circulation air path C allows the warm indoor air to suppress the occurrence of condensation more quickly. After performing the internal circulation operation for 10 minutes (S05), the mixed air operation is selected (S06) to return to the initial state at the start of the mixed air operation, and the operation can be continued.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and it is readily understood that various improvements and modifications can be made without departing from the spirit of the present invention. This can be inferred.

Further, the numerical values listed in each of the above embodiments are merely examples, and it is of course possible to employ other numerical values.

INDUSTRIAL APPLICABILITY The present invention is used for mixed air operation control in a heat exchange type ventilation system.

1 Heat exchange type ventilation device 2 Heat exchange element 3 Outdoor suction port 4 Indoor air supply port 5 Indoor suction port 6 Outdoor exhaust port 7 Air supply fan 8 Exhaust fan 9 Outdoor air supply shutter 10 Circulation port 11 Exhaust circulation damper 12 Air cleaning filter 13 Control part 14 Temperature and humidity sensor 15 Temperature sensor A Heat exchange air supply air path B Heat exchange exhaust air path C Heat exchange circulation air path 101 Main body 102 Outdoor suction port 103 Indoor air supply port 104 Heat exchange air supply air path 105 Indoor suction port 106 Outdoor exhaust port 107 Heat exchanger exhaust air path 108 Circulation port 109 Heat exchanger circulation air path 110 Heat exchange element 111 Air supply fan 112 Exhaust fan

Claims (3)

a heat exchange element that exchanges heat between outside air taken in from the outdoor suction port and inside air taken in from the indoor suction port;
a heat exchange air supply air passage through which outside air sucked from the outdoor suction port is supplied into the room from the indoor air supply port via the heat exchange element;
a heat exchange exhaust air passage in which internal air sucked from the indoor suction port is exhausted to the outside from the outdoor exhaust port via the heat exchange element;
an air supply fan that is provided in the heat exchange air supply air passage and supplies outside air;
an exhaust fan provided in the heat exchanger exhaust air passage to exhaust internal air;
an exhaust circulation damper provided at the outdoor exhaust port;
a heat exchange circulation air passage that closes the outdoor exhaust port with the exhaust circulation damper and circulates the inside air sucked from the indoor suction port via the heat exchange element to the indoor air supply port by the exhaust fan;
temperature and humidity detection means for detecting the temperature and humidity of the indoor air passing through the indoor air intake;
temperature detection means for detecting the temperature of the airflow passing through the indoor air supply port;
A heat exchange type ventilation device comprising a control unit that controls the rotation speed of the air supply fan and the exhaust fan,
When the heat exchange circulation air path and the heat exchange air supply air path are configured, the control unit calculates the indoor dew point temperature based on the temperature and humidity detected by the temperature and humidity detection means, and the control unit: If the temperature detected by the temperature detection means is lower than the indoor dew point temperature, the rotation speed of the exhaust fan is increased; if the temperature detected by the temperature detection means is higher than the indoor dew point temperature, the A heat exchange type ventilation device characterized by reducing the rotation speed of an exhaust fan. 2. The heat exchange type ventilation device according to claim 1, wherein the control unit is capable of changing the time period during which the rotation speed of the exhaust fan is increased to a predetermined number. The control unit may close an outdoor air supply shutter provided at the outdoor suction port when the temperature detected by the temperature detection means continues to be lower than the indoor dew point temperature for a predetermined period of time. The heat exchange type ventilation device according to claim 1 or claim 2.

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