WO2023112428A1

WO2023112428A1 - Ventilator, air-conditioning system, ventilation method, and ventilation system

Info

Publication number: WO2023112428A1
Application number: PCT/JP2022/036876
Authority: WO
Inventors: 隆高橋; 維大大堂; 祥太鶴薗; 伸樹松井; 卓弥花田; 尚利藤田; 喜記山野井; 悠太井吉; 久美子佐伯; 猛宮崎; 敏行前田; 哲也岡本
Original assignee: ダイキン工業株式会社
Priority date: 2021-12-17
Filing date: 2022-09-30
Publication date: 2023-06-22

Abstract

This ventilator comprises: a compressor; a first heat exchanger; a first air flow path for causing air drawn in from outdoors to pass through the first heat exchanger and then supplying the air to an indoor space; a second heat exchanger; a second air flow path for causing air drawn in from the indoor space to pass through the second heat exchanger and then discharging the air to the outdoors; a refrigerant circuit that is configured by the compressor, the first heat exchanger, and the second heat exchanger being connected by refrigerant piping and circulates refrigerant therethrough; and a control unit. The control unit detects whether or not a predetermined criterion indicating the possibility of frost formation in the second heat exchanger is satisfied while the second heat exchanger is functioning as an evaporator, and upon detecting that the predetermined criterion is satisfied, the control unit adjusts the temperature of the second heat exchanger by controlling the temperature of the refrigerant flowing therethrough such that the second heat exchanger does not frost.

Description

Ventilation device, air conditioning system, ventilation method, and ventilation system

The present disclosure relates to a ventilation device, an air conditioning system, a ventilation method, and a ventilation system.

Conventionally, while ventilating indoors with an exhaust fan and an air supply fan, the outdoor air heat-exchanged with the refrigerant by the first heat exchanger is blown indoors, and the indoor air heat-exchanged with the refrigerant by the second heat exchanger. Ventilation and air-conditioning equipment that discharges to the outdoors is known (see Patent Documents 1 and 2).

Japanese Patent No. 5076745 JP-A-3-20573

The ventilation air conditioner described in Patent Document 1 proposes a technique of suppressing frost formation on the second heat exchanger by preheating air before being supplied to the second heat exchanger with a preheater. . However, various methods are conceivable as methods for suppressing frost formation.

The purpose of the present disclosure is to suppress frost formation and continue ventilation operation.

This disclosure is
a compressor;
a first heat exchanger functioning as a condenser or evaporator;
a first air flow path for supplying air taken in from outdoors to an indoor space after passing through the first heat exchanger;
a second heat exchanger functioning as a condenser or evaporator;
a second air flow path for exhausting the air taken in from the indoor space to the outdoors after passing through the second heat exchanger;
a refrigerant circuit in which the compressor, the first heat exchanger, and the second heat exchanger are connected by refrigerant pipes and in which refrigerant flows;
While the second heat exchanger is functioning as an evaporator, it is detected whether or not a predetermined criterion indicating the possibility of frost formation of the second heat exchanger is satisfied, and the predetermined criterion is satisfied. a control unit that controls the temperature of the refrigerant flowing through the second heat exchanger so that the second heat exchanger reaches a temperature at which frost does not form when it is detected that the refrigerant is satisfied;
to provide a ventilator comprising

According to the ventilation system, when a predetermined standard is satisfied, frost formation is suppressed by controlling the temperature of the refrigerant, and ventilation operation is continued by supplying air to the indoor space and exhausting it to the outdoors. realizable.

For the above ventilators,
The control unit detects whether or not a predetermined criterion indicating the possibility of frost formation in the second heat exchanger is satisfied while the second heat exchanger is functioning as an evaporator, Outputting a signal for controlling an air conditioner provided in the indoor space in order to control the temperature of the refrigerant flowing through the second heat exchanger when it is detected that the predetermined criterion is satisfied. You can also

According to the ventilator, the temperature of the indoor space is adjusted by operating the air conditioner according to the signal, and frost formation is suppressed by controlling the temperature of the refrigerant, so that frost formation can be efficiently suppressed. .

For the above ventilators,
The control unit may output a signal to an air conditioner installed in the indoor space to increase the temperature currently set for the air conditioner when the predetermined criterion is satisfied.

According to the ventilation system, the signal raises the temperature of the indoor space with the air conditioner, raises the temperature of the refrigerant, suppresses frost formation, and achieves efficient suppression of frost formation.

For the above ventilators,
The refrigerant circuit has a bypass pipe that flows the refrigerant to the second heat exchanger without passing through the first heat exchanger while the second heat exchanger is functioning as an evaporator,
The control unit may perform control to flow the refrigerant compressed by the compressor to the second heat exchanger through the bypass pipe when the predetermined criterion is satisfied.

According to this ventilator, by flowing the refrigerant through the second heat exchanger through the bypass pipe, the temperature of the refrigerant is raised, thereby suppressing frost formation and realizing efficient frost suppression.

For the above ventilators,
a third air flow path through which the air taken in from a room different from the second air flow path in the indoor space passes through the second heat exchanger;
a first guide mechanism that switches whether to guide air through the third air flow path to the second heat exchanger;
The controller may control the first guide mechanism to guide air through the third air flow path to the second heat exchanger when the predetermined criterion is satisfied.

According to the ventilation device, since the air is guided to the second heat exchanger through the third air flow path, frost formation is suppressed by increasing the temperature of the refrigerant flowing through the second heat exchanger, and efficiency is improved. It is possible to realize effective suppression of frost formation.

For the above ventilators,
further comprising a second ventilation unit that adjusts the amount of air flowing through the second air flow path to the second heat exchanger;
The control unit controls the second ventilation unit to increase the amount of air flowing through the second heat exchanger compared to before the predetermined criterion is satisfied when the predetermined criterion is satisfied. It's okay.

According to the ventilation device, by increasing the amount of air flowing through the second heat exchanger, the temperature of the refrigerant flowing through the second heat exchanger is increased to suppress frost formation, thereby effectively suppressing frost formation. realizable.

For the above ventilators,
a plurality of the second heat exchangers;
the second ventilation unit associated with each of the second heat exchangers;
The control unit responds to any one of the plurality of second heat exchangers when the predetermined criterion is satisfied while the plurality of second heat exchangers are functioning as evaporators. The attached second ventilation unit may be controlled to increase the amount of air flowing through the second heat exchanger compared to before the predetermined criterion is met.

According to the ventilation device, by increasing the amount of air flowing to the second heat exchanger in the second ventilation unit, the temperature of the refrigerant flowing through the second heat exchanger is increased to suppress frost formation, thereby improving efficiency. Suppression of frost formation can be realized.

For the above ventilators,
When performing control to increase the amount of air in the second ventilation unit associated with any one of the plurality of second heat exchangers, the controller controls the plurality of the second heat exchangers. Control for reducing the amount of air flowing to the second heat exchanger compared to before the predetermined criterion is satisfied, for the second ventilation unit associated with the other second heat exchanger among the exchangers can also be done.

According to the ventilation system, the comfort of the living room space can be maintained by adjusting the total amount of exhausted air.

For the above ventilators,
further comprising a first ventilation unit that adjusts the amount of air flowing through the first air flow path to the first heat exchanger;
The control unit controls the second ventilation unit associated with any one of the plurality of second heat exchangers to increase the amount of air, the second ventilation unit control the first ventilation unit to increase the amount of air flowing to the first heat exchanger compared to before the predetermined criterion is satisfied, based on the amount of air increased for the It's okay.

According to this ventilation device, when the air volume of the second air supply unit is increased, the air volume of the first ventilation unit is also increased to adjust the air volume to be supplied and the air volume to be exhausted. In this way, the comfort of the living room space can be maintained.

For the above ventilators,
a first ventilation unit that adjusts the amount of air flowing through the first air flow path to the first heat exchanger;
a second ventilation unit that adjusts the amount of air flowing through the second air flow path to the second heat exchanger;
While the second heat exchanger is functioning as an evaporator, the control unit receives a signal indicating that a defrosting operation is to be performed from an air conditioner provided in the indoor space. is satisfied, the amount of air flowing through the first heat exchanger for the first ventilation unit is increased compared to before the predetermined criterion is satisfied, and the amount of air flowing to the first heat exchanger for the second ventilation unit is increased. Control may be performed to increase the amount of air flowing through the second heat exchanger.

According to the ventilation device, when the air conditioner performs the defrosting operation, the amount of air in each of the first ventilation unit and the second ventilation unit is increased, thereby suppressing the reduction in heating performance and reducing the room space. You can stay comfortable.

For the above ventilators,
a bypass flow path that guides the air heat-exchanged by the first heat exchanger to the second heat exchanger;
a second guide mechanism that switches whether to guide air through the bypass flow path to the second heat exchanger;
The control unit may control the second guide mechanism to guide air through the bypass flow path to the second heat exchanger when the predetermined criterion is satisfied.

According to the ventilation device, by guiding the air through the bypass flow path to the second heat exchanger, the temperature of the refrigerant flowing through the second heat exchanger is increased to suppress frost formation, and efficient Suppression of frost formation can be realized.

For the above ventilators,
further comprising a second ventilation unit that adjusts the amount of air flowing through the second air flow path to the second heat exchanger;
The control unit stops the compressor when the predetermined criterion is satisfied, and instructs the second ventilation unit to allow the air passing through the second air flow path to flow into the second heat exchanger. Flow control may be performed.

According to the ventilation device, the compressor is stopped and air is allowed to flow through the second heat exchanger, thereby increasing the temperature of the refrigerant flowing through the second heat exchanger and suppressing frost formation. It is possible to realize the suppression of frost formation.

For the above ventilators,
a plurality of the second heat exchangers;
a second ventilation unit associated with each of the second heat exchangers;
The refrigerant circuit further has a first valve portion for adjusting the opening degree of the flow path flowing through the second heat exchanger for each of the second heat exchangers,
When the temperature information detected from the plurality of second heat exchangers satisfies the predetermined criterion, the control unit controls the plurality of heat exchangers corresponding to the second heat exchangers that satisfy the predetermined criterion. performing control to close the first valve portion in accordance with a predetermined order, and opening the second air flow path to the second ventilation unit corresponding to the second heat exchanger that satisfies the predetermined criteria; It is also possible to control the passing air to flow to the second heat exchanger.

According to the ventilator, by closing the valves in a predetermined order, it is possible to maintain the comfort of the living room space by suppressing the refrigerant from being stopped in the plurality of second heat exchangers at the same time.

For the above ventilators,
a first ventilation unit that adjusts the amount of air flowing through the first air flow path to the first heat exchanger;
a second ventilation unit that adjusts the amount of air flowing through the second air flow path to the second heat exchanger;
The controller controls, when the predetermined criterion is satisfied, that the amount of air discharged to the outdoors through the second air flow path is greater than the amount of air supplied to the indoor space through the first air flow path. Control the first ventilation unit and the second ventilation unit to increase.

According to the ventilation device, since the amount of air flowing into the second heat exchanger increases, the temperature of the refrigerant flowing through the second heat exchanger is increased to suppress frost formation, thereby effectively suppressing frost formation. realizable.

For the above ventilators,
When the predetermined criterion is satisfied, the control unit controls the air conditioner provided in the indoor space to increase the temperature of the air after passing through the first heat exchanger with respect to the first heat exchanger. Control the temperature to be lower than the set temperature.

According to the ventilator, the temperature of the refrigerant flowing through the second heat exchanger rises, so it is possible to efficiently suppress frost formation.

For the above ventilators,
a plurality of combinations of the compressor, the first heat exchanger, the second heat exchanger, the refrigerant circuit, and a second ventilation unit associated with the second heat exchanger;
When the temperature information detected from the plurality of second heat exchangers satisfies the predetermined criterion, the controller controls the compressor corresponding to the second heat exchanger that satisfies the predetermined criterion. are controlled to stop according to a predetermined order, and the air passing through the second air flow path is directed to the second ventilation unit corresponding to the second heat exchanger that meets the predetermined criteria. It controls the flow to the second heat exchanger.

According to the ventilation system, it is possible to maintain the comfort of the living room space by suppressing the refrigerant from being stopped in the plurality of second heat exchangers at the same time.

For the above ventilators,
a first casing housing at least part of the first heat exchanger and the first air flow path;
a second casing housing at least part of the second heat exchanger and the second air flow path;
The first casing and the second casing are separable.

According to the ventilation device, since the first casing and the second casing can be separated, the layout can be easily arranged, and the burden of installation can be reduced.

For the above ventilators,
The control unit performs control to lower the rotational speed of the compressor when the predetermined criterion is satisfied, compared to before the predetermined criterion is satisfied.

According to the ventilator, the temperature of the refrigerant flowing through the second heat exchanger rises by lowering the rotation speed of the compressor, so that frost formation can be efficiently suppressed.

For the above ventilators,
The refrigerant circuit is provided between the first heat exchanger and the second heat exchanger and has a second valve portion that adjusts the opening degree of the flow path,
The control unit performs control to increase the degree of opening of the second valve unit when the predetermined criterion is satisfied, compared to before the predetermined criterion is satisfied.

For the above ventilators,
further comprising a third valve portion downstream from the second heat exchanger in the flow of the refrigerant in the refrigerant circuit when the second heat exchanger functions as an evaporator;
Further, when the second heat exchanger functions as an evaporator, the control unit throttles the third valve unit when the predetermined criterion is satisfied compared to before the predetermined criterion is satisfied. control.

For the above ventilators,
a third heat exchanger functioning as a condenser or evaporator;
a third air flow path for exhausting, to the outdoors, air heat-exchanged with the outdoor air and the refrigerant flowing through the third heat exchanger;
The refrigerant circuit includes the compressor, the first heat exchanger, the second heat exchanger, and the third heat exchanger connected by the refrigerant pipe.

This disclosure is
A first heat exchanger that functions as a compressor or a condenser or an evaporator during heat recovery ventilation operation, and a first heat exchanger that supplies air taken in from the outdoors to an indoor space after passing through the first heat exchanger. an air flow path, a second heat exchanger that functions as a condenser or an evaporator, and a second air flow path that exhausts the air taken in from the indoor space to the outdoors after passing through the second heat exchanger and a refrigerant circuit in which the compressor, the first heat exchanger, and the second heat exchanger are connected by refrigerant pipes and a refrigerant flows therein;
An air conditioner having a third heat exchanger that functions as a condenser or an evaporator, and an air conditioner indoor unit that exhausts, into the indoor space, air heat-exchanged with the air in the indoor space and the refrigerant flowing through the third heat exchanger. and,
It is detected whether the second heat exchanger satisfies a predetermined criterion indicating the possibility of frost formation, and when it is detected that the predetermined criterion is satisfied, the second heat exchange is performed. The power consumption of the ventilation device and the air conditioner required when the temperature of the refrigerant flowing through the second heat exchanger is controlled so that the temperature of the second heat exchanger is not frosted, and the second heat exchanger is frosted. Based on the power consumption required for operation by the ventilation device and the air conditioner that later eliminates frosting of the second heat exchanger, the second heat exchanger is adjusted to a temperature at which frosting does not occur. a control unit that controls the temperature of the refrigerant flowing through the heat exchanger, or controls the operation of defrosting the second heat exchanger after the second heat exchanger is frosted;
To provide an air conditioning system comprising:

According to this air conditioning system, it is possible to effectively suppress frost formation by controlling the temperature of the refrigerant when a predetermined standard is met.

This disclosure is
a compressor, a first heat exchanger that functions as a condenser or an evaporator, and a first air flow path that supplies air taken in from the outdoors to an indoor space after passing through the first heat exchanger; a second heat exchanger that functions as a condenser or an evaporator; a second air flow path that exhausts the air taken in from the indoor space to the outdoors after passing through the second heat exchanger; and the compressor. and a refrigerant circuit in which the first heat exchanger and the second heat exchanger are connected by refrigerant pipes and a refrigerant flows therein, wherein the second heat exchanger is used as an evaporator While functioning, it is detected whether the second heat exchanger satisfies a predetermined criterion indicating the possibility of frost formation, and when it is detected that the predetermined criterion is satisfied. and controlling the temperature of the refrigerant flowing through the second heat exchanger so that the temperature at which the second heat exchanger does not form frost;
Provide a means of ventilation.

According to this ventilation method, it is possible to efficiently suppress frost formation by controlling the temperature of the refrigerant when a predetermined standard is met.

This disclosure is
A compressor, a first heat exchanger, and a second heat exchanger are connected by a refrigerant pipe, and outdoor air is supplied indoors through a refrigerant circuit in which refrigerant flows and the first heat exchanger. An air supply fan, an exhaust fan for exhausting the indoor air to the outdoors through the second heat exchanger, and a controller, wherein the controller causes the second heat exchanger to function as an evaporator. When the compressor is started, the low pressure of the refrigerant circuit, or the evaporation temperature of the second heat exchanger, the indoor temperature, or the outdoor temperature is reduced to the low pressure of the refrigerant circuit, or the second 2 When it is determined that the evaporation temperature of the heat exchanger, the indoor temperature, or the outdoor temperature has fallen below a first threshold, perform a first control to increase the low-pressure pressure of the refrigerant circuit,
Provide a ventilation system.

According to the ventilation system, in the ventilation system including the refrigerant circuit capable of recovering heat from the exhaust gas, the compressor can be reliably operated continuously when the second heat exchanger functions as an evaporator. .

For the above ventilation system,
The refrigerant circuit has a bypass pipe connecting a discharge pipe of the compressor, the second heat exchanger or a liquid pipe connected to the second heat exchanger, and a valve provided in the bypass pipe. , the control unit preferably opens the valve in the first control.

In this case, the high-temperature and high-pressure gas refrigerant can be supplied to the second heat exchanger in the first control. Thereby, frosting of the second heat exchanger can be suppressed.

For the above ventilation system,
The control unit, when the valve is opened, reduces the low pressure of the refrigerant circuit, the saturation temperature of the second heat exchanger, or the intake air temperature of the exhaust fan to the low pressure of the refrigerant circuit, or Preferably, the valve is closed when it is determined that a second threshold for the saturation temperature of the second heat exchanger or for the intake air temperature of the second heat exchanger has been exceeded.

In this case, when the conditions for the second heat exchanger to function as an evaporator are met during execution of the first control, the first control can be terminated.

For the above ventilation system,
Preferably, in the first control, the control unit causes the second heat exchanger to draw in air having a temperature higher than a second threshold for the intake air temperature.

In this case, air having a temperature higher than the second threshold can flow into the second heat exchanger during execution of the first control. Thereby, frosting of the second heat exchanger can be suppressed.

For the above ventilation system,
Preferably, in the first control, the controller adjusts the air blowing direction of the air supply fan so as to guide the air blown from the air supply fan to the suction side of the exhaust fan.

In this case, air having a temperature higher than the second threshold can flow into the second heat exchanger during execution of the first control.

For the above ventilation system,
The control unit further comprises an air conditioner that performs air conditioning of the indoor air, and the control unit controls the exhaust fan in the first control when the temperature of the indoor air becomes higher than the second threshold value due to the air conditioner. is preferably driven.

FIG. 1 is a diagram showing a configuration example of a ventilation device and an air conditioner according to the first embodiment. FIG. 2 is a flowchart showing frost suppression control performed by the exhaust unit of the ventilation system according to the first embodiment. FIG. 3 is a diagram showing a configuration example of a ventilation device and an air conditioner according to Modification 3 of the first embodiment. FIG. 4 is a diagram showing a configuration example of a ventilation device and an air conditioner according to the second embodiment. FIG. 5 is a diagram showing a refrigerant circuit according to Modification 1 of the second embodiment. FIG. 6 is a diagram showing a configuration example of a ventilation device, an air conditioner, and a host controller according to the third embodiment. FIG. 7 is a sequence diagram showing the flow of processing performed between a host controller, a ventilator, and an air conditioner when the defrosting operation of the air conditioner is started according to the third embodiment. FIG. 8 shows the flow of processing performed among the host controller, the compressor unit, and the exhaust unit group when there is a possibility of frost formation in each of the exhaust unit groups according to the fourth embodiment. It is a sequence diagram. FIG. 9 is a diagram exemplifying the arrangement of a device group including a host control device according to the seventh embodiment. FIG. 10 is a diagram exemplifying the arrangement of a device group including a host control device according to the eighth embodiment. FIG. 11 is a diagram showing a refrigerant circuit according to the eleventh embodiment. FIG. 12 is a diagram showing a refrigerant circuit according to a modification of the eleventh embodiment. FIG. 13 is a flow chart showing a processing procedure of a host controller according to the twelfth embodiment. FIG. 14 is a schematic configuration diagram of a ventilation system according to one embodiment. FIG. 15 is a control block diagram of the ventilation system according to one embodiment. FIG. 16 is a flow diagram illustrating operation of a ventilation system according to one embodiment. FIG. 17 is a schematic configuration diagram of a ventilation system according to the thirteenth embodiment. FIG. 18 is a schematic configuration diagram of a ventilation system according to the fourteenth embodiment. FIG. 19 is a schematic configuration diagram showing the installation state of the ventilation systems according to the fourteenth and fifteenth embodiments in a building. FIG. 20 is a schematic configuration diagram of a ventilation system according to the fifteenth embodiment. FIG. 21 is a schematic configuration diagram of a ventilation system according to the sixteenth embodiment. FIG. 22 is a schematic configuration diagram of a ventilation system according to the seventeenth embodiment. FIG. 23 is a schematic configuration diagram of a ventilation system according to the eighteenth embodiment.

The ventilation device, air conditioning system, ventilation method, and ventilation system according to this embodiment will be described below with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present disclosure, its applications, or its uses.

(First embodiment)
FIG. 1 is a diagram showing a configuration example of a ventilation device and an air conditioner according to the first embodiment. The example shown in FIG. 1 is an air conditioning system including a ventilator 1 and an air conditioner 2 for air conditioning an indoor space.

In the present embodiment, as an example of an indoor space, an example having a living room space R11 and a ceiling space R12 will be described, but the indoor space is not limited to the living room space R11 and the ceiling space R12. , it may be a space inside a building, and may have an underfloor space, for example.

The living room space R11 is, for example, a living room inside an office or a residence. The ceiling space R12 is a space that is adjacent to and above the living room space R11. Since the ceiling space R12 exists above the living room space R11, warm air tends to gather there.

The air conditioner 2 includes an outdoor unit 70 and two air conditioner

indoor units

81 and 82 . In this embodiment, the number of air conditioning indoor units is not limited to two, and may be one or three or more.

The air conditioner 2 is a device that performs a vapor compression refrigeration cycle to cool and heat the room space R11. The air conditioner 2 according to this embodiment is a device capable of both cooling and heating the living room space R11. However, this embodiment is not limited to an air conditioner capable of both cooling and heating, and may be an apparatus capable of only cooling, for example.

The outdoor unit 70 and the two air conditioning

indoor units

81 and 82 are connected by a connecting pipe F5. The communication pipe F5 includes a liquid refrigerant communication pipe and a gas refrigerant communication pipe (not shown). This implements a refrigerant circuit in which the refrigerant circulates between the outdoor unit 70 and the two air conditioning

indoor units

81 and 82 . When the refrigerant circulates in the refrigerant circuit, a vapor compression refrigeration cycle is performed in the air conditioner 2 .

The outdoor unit 70 is arranged outdoors. The outdoor unit 70 includes a heat exchanger and discharges to the outside the air heat-exchanged with the refrigerant flowing through the heat exchanger.

The air conditioning

indoor units

81 and 82 are provided with heat exchangers, and blow out air that has undergone heat exchange with the refrigerant flowing through the heat exchangers into the living room space R11. In this embodiment, the air conditioning

indoor units

81 and 82 are of a ceiling installation type installed on the ceiling of the living room space R11. In particular, the air conditioner

indoor units

81 and 82 of the present embodiment are ceiling-embedded air conditioner indoor units, and heat-exchanged air is blown out from the

ventilation openings

93A and 93B. In this embodiment, an example in which the

ventilation openings

93A and 93B are provided on the ceiling will be described, but the positions at which the

ventilation openings

93A and 93B are provided are not particularly limited. The air conditioning

indoor units

81 and 82 are not limited to the ceiling-embedded type, and may be of the ceiling-suspended type. Also, the air conditioning

indoor units

81 and 82 may be of a wall-mounted type, a floor-mounted type, or other type other than the ceiling-mounted type.

The ventilator 1 includes an exhaust unit 10, an air supply unit 20, a compressor unit 50, refrigerant circuits F1, F2, F3, F4, an air supply passage P1, and a return air passage P2.

The ventilation device 1 is a device that supplies outdoor air taken in to the living room space R11 and exhausts air taken in from the indoor space (including the living room space R11) to the outside. As a result, the ventilator 1 achieves replacement of the air in the living room space R11.

Furthermore, the ventilation device 1 according to the present embodiment exchanges heat between the exhaust unit 10 and the air supply unit 20, so that the temperature of the air taken in from the outside and the temperature of the living room space R11 It suppresses the temperature difference between

The air supply channel P1 (an example of the first air channel) supplies the air taken in from the outdoors through the air supply unit 20 having the first heat exchanger 22 and then through the ventilation port 92 to the living room space R11. It is a flow path for Although this embodiment describes an example in which the ventilation opening 92 is provided on the ceiling, the position of providing the ventilation opening 92 is not particularly limited.

A return air flow path P2 (an example of a second air flow path) passes the air (return air) taken in from the ventilation port 91 of the living room space R11 through the exhaust unit 10 having the second heat exchanger 12, and then to the outdoors. It is a channel for exhausting air. Although this embodiment describes an example in which the ventilation opening 91 is provided on the ceiling, the position of providing the ventilation opening 91 is not particularly limited.

The return air flow path P2 according to this embodiment is branched into two destinations for taking in air so that air can be taken in from a plurality of chambers. They are respectively referred to as a first return air branch passage P2A (an example of a second air flow path) and a second return air branch passage P2B (an example of a third air flow path).

The first return air branch path (an example of the second air flow path) P2A is provided for exhausting the air taken in from the living room space R11 to the outdoors after passing through the exhaust unit 10 having the second heat exchanger 12. air flow path. The first return air branch P2A takes in air from a ventilation port 91 provided in the ceiling of the living room space R11. In this embodiment, an example in which the ventilation port 91 is provided on the ceiling will be described, but it may be provided in another location such as under the floor or on the wall.

A second return air branch path (an example of a third air flow path) P2B is provided to exhaust the air taken in from the ceiling space R12 to the outdoors after passing through the exhaust unit 10 having the second heat exchanger 12. air flow path. An example in which the second return air branch P2B according to the present embodiment is the ceiling space R12 as a chamber to which air is taken in, which is different from that of the first return air branch P2A, will be described. However, the destination of air intake is not limited to the ceiling space R12, and may be the underfloor space. In this way, the destination of the air taken in by the second return air branch path P2B may be any room in the indoor space that is different from the living room space R11.

In addition, an opening/closing damper 40 is provided at the tip of the second return air branch passage. The opening/closing damper 40 is normally closed. The opening/closing damper 40 (an example of the first guide mechanism) can adjust the amount of air taken in from the ceiling space R12 by control from the control unit 13 provided in the exhaust unit 10 via the signal line S2.

Refrigerant circuits F1, F2, F3, and F4 connect the compressor unit 50, the first heat exchanger 22 of the air supply unit 20, and the second heat exchanger 12 of the exhaust unit 10 by refrigerant pipes, and have a refrigerant inside. is a circuit for flowing

The control section 52 of the compressor unit 50, the control section 23 of the air supply unit 20, and the control section 13 of the exhaust unit 10 are connected by a signal line S1 indicated by a dotted line in FIG. Accordingly, information can be transmitted and received among the controller 52 of the compressor unit 50, the controller 23 of the air supply unit 20, and the controller 13 of the exhaust unit 10. FIG. The processing indicated by the

control units

13, 23, and 52 shown below may be realized by reading a program by a CPU (not shown), or may be realized by hardware connection. The same applies to the control unit and host control device shown in subsequent embodiments.

The compressor unit 50 includes a driving motor 51 and a control unit 52, and compresses the refrigerant in any one of the refrigerant circuits F1, F2, F3, and F4, thereby compressing the refrigerant circuits F1, F2, F3, It controls the circulation of the refrigerant in F4. For example, when the second heat exchanger 12 in the exhaust unit 10 functions as an evaporator, the compressor unit 50 compresses the refrigerant in the refrigerant circuit F2 to Circulate the refrigerant.

The driving motor 51 is a motor for rotating (driving) the compressor for compressing the refrigerant.

The control unit 52 controls the internal configuration of the compressor unit 50 . For example, the controller 52 outputs a command to the drive motor 51 to rotate (drive) the compressor.

The air supply unit 20 includes a fan 21, a first heat exchanger 22, a control section 23, and a temperature detection section 24, takes in outside air (OA), and supplies the air (SA) to the living room space R11.

The fan 21 functions to supply (SA) the taken outside air (OA) to the living room space R11.

The first heat exchanger 22 functions as a condenser or an evaporator.

The temperature detection unit 24 detects the outdoor air temperature, the surface temperature of the first heat exchanger 22, and the temperature of the refrigerant flowing through the first heat exchanger 22.

The control unit 23 controls the configuration inside the air supply unit 20 . The control unit 23 performs various controls according to the detection results from the temperature detection unit 14 . For example, the controller 23 adjusts the function of the first heat exchanger 22 as a condenser or evaporator according to the detection result of the temperature detector 24 .

The exhaust unit 10 includes a fan 11, a second heat exchanger 12, a control unit 13, and a temperature detection unit 14, takes in return air (RA) in the room space R11, and exhausts it to the outside (EA). .

The fan 11 functions to exhaust (EA) the return air (RA) taken from the living room space R11 to the outside.

The second heat exchanger 12 functions as a condenser or evaporator.

The temperature detection unit 14 detects the indoor air temperature, the surface temperature of the second heat exchanger 12, and the temperature of the refrigerant flowing through the second heat exchanger 12. Furthermore, the indoor air temperature to be detected includes, for example, the temperature of the air in the living room space R11 and the temperature of the air in the ceiling space R12 via a sensor unit (not shown).

The control unit 13 controls the configuration inside the exhaust unit 10 . The control unit 13 performs various controls according to the detection results from the temperature detection unit 14 . For example, the control unit 13 adjusts the function of the second heat exchanger 12 as a condenser or an evaporator according to the detection result of the temperature detection unit 14 .

Furthermore, the control unit 13 according to the present embodiment can adjust the amount of air taken in from the ceiling space R12 by controlling the open/close damper 40 based on the detection result of the temperature detection unit 14.

The processing performed by the ventilation device 1 when the temperature is low will be explained. When the air temperature is low, the ventilator 1 warms the outside air (OA) taken in from the outdoors in the air supply unit 20, and then supplies air (SA) to the living room space R11, and takes in the air from the living room space R11 in the exhaust unit 10. After the return air (RA) is cooled, it is exhausted (EA) to the outside. That is, the first heat exchanger 22 in the air supply unit 20 functions as a condenser, and the second heat exchanger 12 in the exhaust unit 10 functions as an evaporator. Since the second heat exchanger 12 functions as an evaporator, the temperature of the refrigerant flowing through the second heat exchanger 12 is lowered, which may cause the second heat exchanger 12 to freeze (frost). Therefore, in the present embodiment, the freezing (frost formation) of the second heat exchanger 12 is avoided, or if frost is formed, control is performed so that the frost does not grow. In the embodiments described later, at least one of the control to avoid frost formation and the control to suppress the growth of frost if frost is formed is referred to as the control to suppress frost formation.

Specifically, while the second heat exchanger 12 is functioning as an evaporator, the control unit 13 of the exhaust unit 10 determines that the second heat exchanger 12 is frosted ( It is determined whether or not a predetermined criterion indicating the possibility of freezing is satisfied. The predetermined criterion indicating the possibility of frost formation (freezing) of the second heat exchanger 12 may be, for example, a criterion for determining whether or not the outdoor air temperature detected by the temperature detection unit 14 is 0° C. or less. . Further, in the present embodiment, the predetermined criterion is not limited to whether the outdoor air temperature is 0° C. or lower, but whether the outdoor air temperature is the lowest operating temperature of the second heat exchanger 12 or not. It may be used as a criterion for determination.

Also, the predetermined standard does not have to be a standard based on the temperature of the outside air. For example, whether or not the surface temperature of the second heat exchanger 12 is equal to or lower than a predetermined temperature (for example, 0 degrees) may be used as a determination criterion. As another example, whether or not the temperature of the refrigerant flowing through the second heat exchanger 12 is equal to or lower than a predetermined temperature (for example, 0 degrees) may be used as a determination criterion. An example of a predetermined criterion will be shown in the description below, but any criterion may be used as long as it indicates the possibility of frost formation (freezing) on the second heat exchanger 12 . For example, as shown in an embodiment to be described later, it may be used as a criterion for determining whether or not the low pressures of the refrigerant circuits F1, F2, F3, and F4 have fallen below a predetermined pressure threshold.

In this embodiment, an example will be described in which the outside air temperature, the surface temperature of the second heat exchanger, etc. are acquired, and whether or not the acquired temperature satisfies a predetermined standard is determined. However, this embodiment shows an example of information to be acquired, and the information to be acquired may be any information that can be used to determine whether or not it satisfies a predetermined criterion. For example, the surface temperature of the second heat exchanger 12, the temperature of the refrigerant, the pressure of the refrigerant, or the like may be acquired in addition to the temperature of the outside air. Also, it may be determined whether or not a predetermined criterion is satisfied by combining these pieces of information. It should be noted that the embodiments and modifications described below are examples of information to be acquired, and any information may be used as long as it can be determined whether or not it satisfies a predetermined criterion.

The control unit 13 of the exhaust unit 10 according to the present embodiment performs control to suppress frost formation on the second heat exchanger 12 when determining that the predetermined criteria are satisfied. is guided to the second heat exchanger 12 through the second return air branch passage P2B. That is, warm air gathers in the ceiling space R12 because it exists above the room space R11. Therefore, when there is a possibility that the second heat exchanger 12 is frosted, control is performed to open the open/close damper 40 . By this control, the warm air existing in the ceiling space R12 and the air existing in the living room space R11 are mixed and guided to the second heat exchanger 12 .

The control unit 13 according to the present embodiment controls the warm air in the ceiling space R12 to flow to the second heat exchanger 12 as an example of control for increasing the temperature of the refrigerant flowing through the second heat exchanger 12. Thereby, it can suppress that the 2nd heat exchanger 12 is frosted.

FIG. 2 is a flowchart showing frost formation suppression control performed by the exhaust unit 10 of the ventilation device 1 according to the present embodiment.

The control unit 13 of the exhaust unit 10 acquires the outside air temperature from the temperature detection unit 14 (S1201).

The control unit 13 of the exhaust unit 10 determines whether or not a predetermined criterion indicating the possibility of freezing of the second heat exchanger 12 is satisfied based on the obtained outside air temperature (S1202).

When the control unit 13 of the exhaust unit 10 determines that the predetermined criteria are not satisfied (S1202: NO), it ends without performing any particular processing.

On the other hand, when the control unit 13 of the exhaust unit 10 determines that the predetermined criteria are satisfied (S1202: YES), the temperature detection unit 14 detects the temperature of the air in the ceiling space R12 and the temperature of the air taken in from the living room space R11. and the temperature of (S1203).

The control unit 13 of the exhaust unit 10 determines whether the temperature of the air in the ceiling space R12 is higher than the temperature of the air in the living room space R11 (S1204). If it is determined that the temperature is equal to or lower than the temperature of the air in the living room space R11 (S1204: NO), the process ends without performing control of the opening/closing damper 40. FIG. In addition, when control regarding the opening/closing damper 40 is not performed, control for suppressing frost formation, which will be described in the following embodiments and modifications, may be performed.

On the other hand, when the control unit 13 determines that the temperature of the air in the ceiling space R12 is higher than the temperature of the air in the living room space R11 (S1204: YES), it controls the open/close damper 40 to open (S1205).

In the present embodiment, when there is a possibility that the second heat exchanger 12 is frosted by the above-described processing procedure, the air in the ceiling space R12, in which the air is warmer than that of the living room space R11, is used for the second heat exchange. It is guided to the vessel 12.

That is, since the temperature of the air flowing through the second heat exchanger 12 rises, the temperature of the refrigerant flowing through the second heat exchanger 12 can be raised. Thereby, the possibility that the second heat exchanger 12 is frosted can be reduced.

(Modification 1 of the first embodiment)
In the above-described first embodiment, as an example of control for increasing the temperature of the air flowing through the second heat exchanger 12, the air in the ceiling space R12 is guided to the second heat exchanger 12 so that the second A technique for reducing the possibility of frost formation on the heat exchanger 12 has been described. However, the control method for increasing the temperature of the air flowing through the second heat exchanger 12 is not limited to the method of guiding the air in the ceiling space R12 to the second heat exchanger 12, and other methods may be used. may Therefore, in Modified Example 1 of the first embodiment, the air conditioner 2 is controlled to increase the temperature (room temperature) of the air in the living room space R11.

In this modified example, the controller 13 of the exhaust unit 10 and the controller 71 of the outdoor unit 70 are connected by a signal line. Thereby, the controller 71 of the outdoor unit 70 can output a control signal to the controller 13 of the exhaust unit 10 .

In this modified example, an example in which the control unit 13 of the exhaust unit 10 and the control unit 71 of the outdoor unit 70 are connected by a signal line will be described as one mode in which information can be transmitted and received. However, the manner in which information can be transmitted and received is not limited to the example of connection with a signal line, and control signals may be transmitted and received via a host controller (not shown), or via a public network. Control signals may be transmitted and received via a connected cloud, server, or the like.

Then, the control unit 13 of the exhaust unit 10 according to the present modified example controls the predetermined reference indicating the possibility of the second heat exchanger 12 freezing while the second heat exchanger 12 is functioning as an evaporator. Detects whether or not the

If the control unit 13 determines that the predetermined criteria are satisfied, the control unit 13 causes the control unit 71 of the outdoor unit 70 of the air conditioner 2 to increase the temperature of the refrigerant flowing through the second heat exchanger 12 by: A control signal is output to increase the temperature currently set in the living room space R11. In this modification, since the temperature of the air flowing into the second heat exchanger 12 rises by raising the air temperature in the living room space R11, the temperature of the refrigerant flowing through the second heat exchanger 12 rises. can be done.

As described above, the control unit 13 according to the present modification instructs the control unit 71 to control the temperature currently set in the living room space R11 as an example of control for increasing the temperature of the refrigerant flowing through the second heat exchanger 12. output a control signal to increase the As a result, the room temperature of the living room space R11 rises, so warm air flows into the second heat exchanger 12, and the temperature of the refrigerant flowing through the second heat exchanger 12 rises. 12 can be suppressed from frosting.

In this modified example, an example of outputting a control signal for increasing the temperature currently set in the living room space R11 to the control unit 71 of the outdoor unit 70 of the air conditioner 2 has been described. However, in this modification, the control signal output to the control unit 71 of the outdoor unit 70 of the air conditioner 2 is not limited to a control signal for increasing the temperature currently set in the living room space R11. Any control signal for increasing the temperature of the refrigerant flowing through the exchanger 12 may be used. For example, the control unit 13 may output a control signal for increasing the air volume in order to circulate the air in the living room space R11.

(Modification 2 of the first embodiment)
The above-described first embodiment and modification are not limited to using the above-described method. Therefore, in Modification 2 of the first embodiment, a method of controlling the fan 11 to suppress frost formation will be described.

The control unit 13 of the exhaust unit 10 according to the present modification sets a predetermined standard indicating the possibility of frost formation on the second heat exchanger 12 while the second heat exchanger 12 is functioning as an evaporator. Determine whether or not it is satisfied.

When the control unit 13 determines that the predetermined criteria are satisfied, the control unit 13 controls the fan 11 (an example of the second ventilation unit) to increase the temperature of the refrigerant flowing through the second heat exchanger 12. Control is performed to increase the amount of air flowing through the second heat exchanger 12 compared to before the criterion of (1) is satisfied.

As described above, the control unit 13 according to the present modification controls the fan 11 (an example of the second ventilation unit) as an example of control for increasing the temperature of the refrigerant flowing through the second heat exchanger 12 by setting the fan 11 (an example of the second ventilation unit) to a predetermined standard A control signal is output to increase the amount of air flowing through the second heat exchanger 12 compared to before satisfying . As a result, the amount of warm air flowing into the second heat exchanger 12 increases, so that the temperature of the refrigerant can be raised and frost formation on the second heat exchanger 12 can be suppressed.

If the fan 11 is controlled to increase the amount of air flowing through the second heat exchanger 12, the interior of the living room space R11 may become negative pressure. Therefore, the controller 13 may output a control signal for increasing the air volume of the fan 21 to the controller 23 of the air supply unit 20 .

(Modification 3 of the first embodiment)
The above-described first embodiment and modification are not limited to using the above-described method. Therefore, in Modification 3 of the first embodiment, a method of providing a bypass flow path for direct air flow between the air supply unit and the exhaust unit will be described.

FIG. 3 is a diagram showing a configuration example of a ventilation device and an air conditioner according to Modification 3 of the first embodiment. In the example shown in FIG. 3, a ventilator 1A and an air conditioner 2 are provided to air-condition the indoor space. In addition, in this modification, the same code|symbol is assigned about the structure similar to 1st Embodiment, and description is abbreviate|omitted.

As shown in FIG. 3, a bypass flow path P102 is provided between the air supply unit 20 and the exhaust unit 110. As shown in FIG. The bypass flow path P102 includes a first bypass partial flow path P102A closer to the air supply unit 20 than the air supply flow path P101, a third bypass partial flow path P102C closer to the exhaust unit 110 than the return air flow path P103, and a first bypass partial flow path P102C. and a second bypass partial flow path P102B connecting the path P102A and the third bypass partial flow path P102C.

An opening/closing damper 140 is provided on the second bypass partial flow path P102B. The opening/closing damper 140 is normally closed. The open/close damper 140 (an example of a second guide mechanism) directs the air warmed by the air supply unit 20 to the exhaust unit 110 under the control of the control unit 113 provided in the exhaust unit 110 via the signal line S3. I can guide you.

After taking in outside air (OA), the air supply unit 20 normally supplies air (SA) to the living room space R11 via the first bypass partial flow path P102A and the air supply flow path P101.

The exhaust unit 110 includes a fan 11, a second heat exchanger 12, a control unit 113, and a temperature detection unit 14, and is connected to the living room space R11 via the return air flow path P103 and the third bypass partial flow path P102C. of return air (RA) is taken in and exhausted to the outside (EA).

The control unit 113 of the exhaust unit 110 according to the present modification sets a predetermined standard indicating the possibility of frost formation on the second heat exchanger 12 while the second heat exchanger 12 is functioning as an evaporator. Detect whether it is satisfied or not.

When the control unit 13 determines that the predetermined criteria are satisfied, it controls the opening/closing damper 140 to increase the temperature of the refrigerant flowing through the second heat exchanger 12 .

In this way, the control unit 113 according to this modification guides air to the second heat exchanger 12 through the bypass flow path P102 as an example of control for increasing the temperature of the refrigerant flowing through the second heat exchanger 12. The opening/closing damper 140 is controlled to open. As a result, the air warmed in the exhaust unit 110 can flow directly to the second heat exchanger 12, so that frost formation on the second heat exchanger 12 can be suppressed.

(Second embodiment)
In the embodiment and modification described above, the example in which the temperature of the refrigerant flowing through the second heat exchanger 12 is increased by adjusting the air flowing through the second heat exchanger 12 has been described. However, another technique may be used as a technique for increasing the temperature of the refrigerant flowing through the second heat exchanger 12 . Therefore, in the present embodiment, a method of controlling the refrigerant flowing through the second heat exchanger 12 to raise the temperature of the refrigerant will be described.

FIG. 4 is a diagram showing a configuration example of a ventilation device and an air conditioner according to the second embodiment. In the example shown in FIG. 4, a ventilator 1B and an air conditioner 2 are provided to air-condition the indoor space. In addition, among the configurations according to the present embodiment, the configurations similar to those of the first embodiment are assigned the same reference numerals, and descriptions thereof are omitted.

Between the controller 52 of the compressor unit 50, the controller 23 of the first air supply unit 220A, the controller 23 of the second air supply unit 220B, and the controller 213 of the exhaust unit 210, a signal line S201 indicated by a dotted line is provided. connected with As a result, information can be transmitted and received between the controller 52 of the compressor unit 50, the controller 23 of the first air supply unit 220A, the controller 23 of the second air supply unit 220B, and the controller 213 of the exhaust unit 210. It becomes possible.

The ventilator 1B includes an exhaust unit 210, a first air supply unit 220A, a second air supply unit 220B, a compressor unit 50, refrigerant circuits F1, F2, F3, F4, and a first air supply flow path P201. , a second air supply passage P202 and a return air passage P203.

The first air supply passage P201 (an example of the first air passage) passes the air taken in from the outdoors through the first air supply unit 220A having the first heat exchanger 22, and then passes through the ventilation port 92A to the living room space R11. supply air to

The second air supply channel P202 (an example of the first air channel) passes the air taken in from the outdoors through the second air supply unit 220B having the first heat exchanger 22, and then passes through the ventilation port 92B to the living room space R11. supply air to

The return air flow path P203 (an example of the second air flow path) exhausts the air taken in from the indoor space to the outdoors after passing through the exhaust unit 210 having the second heat exchanger 12 .

The first air supply unit 220A and the second air supply unit 220B are provided with a fan 21, a first heat exchanger 22, a control unit 23, and a temperature detection unit 24, take in outside air (OA), and Air is supplied (SA) to R11.

The exhaust unit 210 includes a fan 11, a second heat exchanger 12, a control unit 213, and a temperature detection unit 14, takes in return air (RA) in the living room space R11, and exhausts it to the outside (EA). .

The control unit 213 of the exhaust unit 210 controls the configuration inside the exhaust unit 210 . For example, the controller 213 outputs a control signal to the controller 52 of the compressor unit 50 according to the detection result of the temperature detector 14 .

The processing performed by the ventilation device 1B when the temperature is low will be explained. Similar to the embodiment described above, the first heat exchangers 22 of the first air supply unit 220A and the second air supply unit 220B function as condensers, and the second heat exchanger 12 in the exhaust unit 210 functions as an evaporator. function as Since the second heat exchanger 12 functions as an evaporator, the temperature of the refrigerant flowing through the second heat exchanger 12 is lowered, so that the second heat exchanger 12 may be frosted. Therefore, in the present embodiment, control is performed to suppress frost formation on the second heat exchanger 12 .

Specifically, while the second heat exchanger 12 is functioning as an evaporator, the control unit 213 of the exhaust unit 210 determines that the second heat exchanger 12 is frosted based on the detection result of the temperature detection unit 14. It is determined whether or not a predetermined criterion indicating the possibility is satisfied. The predetermined criterion indicating the possibility of frost formation on the second heat exchanger 12 may be, for example, a criterion for determining whether or not the temperature of the refrigerant detected by the temperature detection unit 14 is 0 degrees or less. Further, in this embodiment, the predetermined criterion is not limited to the criterion based on the temperature of the refrigerant, but may be a criterion for determining whether or not the pressure of the refrigerant is equal to or less than a predetermined pressure.

Also, the predetermined standard does not have to be a standard based on the temperature or pressure of the refrigerant. For example, the reference may be based on the temperature of the outside air, or may be the reference based on the surface temperature of the second heat exchanger 12 .

The control unit 213 of the exhaust unit 210 according to the present embodiment controls the control unit 52 of the compressor unit 50 to suppress frost formation on the second heat exchanger 12 when it is determined that the predetermined criteria are satisfied. , a control signal is output for lowering the rotation speed of the compressor compared to before the predetermined criterion is satisfied.

Then, when receiving the control signal, the control unit 52 of the compressor unit 50 outputs a control signal for lowering the rotation speed of the compressor compared to before the predetermined criterion is satisfied. output to the motor 51 for use. This reduces the rotation speed of the compressor. Therefore, since the pressure of the refrigerant flowing through the refrigerant circuits F1, F2, F3, and F4 is lowered, the temperature (evaporation temperature) of the refrigerant flowing through the second heat exchanger 12 can be increased.

As an example of control for increasing the temperature of the refrigerant flowing through the second heat exchanger 12, the control unit 213 according to the present embodiment instructs the control unit 52 of the compressor unit 50 to , to output a control signal to reduce the rotation speed of the compressor. Thereby, it can suppress that the 2nd heat exchanger 12 is frosted.

(Modification 1 of the second embodiment)
In the second embodiment, the example in which the rotation speed of the compressor is lowered to raise the temperature (evaporation temperature) of the refrigerant flowing through the second heat exchanger 12 has been described. However, the technique of raising the temperature (evaporation temperature) of the refrigerant flowing through the second heat exchanger 12 is not limited to the technique of lowering the rotation speed of the compressor. Therefore, in Modification 1, an example in which a bypass flow path (an example of bypass piping) is provided in the refrigerant circuit will be described. As in the second embodiment, this modified example 1 is also provided with two air supply units and one exhaust unit.

FIG. 5 is a diagram showing a refrigerant circuit according to Modification 1 of the second embodiment. The example shown in FIG. 5 shows the flow of refrigerant when the second heat exchanger 12 of the exhaust unit 310 functions as an evaporator. In addition, the same code|symbol is assigned about the structure similar to embodiment mentioned above, and description is abbreviate|omitted.

In the example shown in FIG. 5,

air supply units

320A and 320B, an exhaust unit 310, and a compressor unit 350 are provided.

The

air supply units

320A and 320B include a fan 21, a first heat exchanger 22, a control section 23, a temperature detection section 24, a drive motor 25, and an electric valve 26.

The drive motor 25 controls the air volume of the fan 21 under the control of the controller 23 .

The motor-operated valve 26 functions as an expansion valve for reducing the pressure of the refrigerant, and switches whether to reduce the pressure based on control by the control unit 23 . The motor-operated valve 26 functions to reduce the pressure when the first heat exchanger 22 functions as an evaporator, and not to reduce the pressure when the first heat exchanger 22 functions as a condenser.

The exhaust unit 310 includes a fan 11 , a second heat exchanger 12 , a control section 313 , a temperature detection section 14 , a driving motor 15 and an electric valve 16 .

While the second heat exchanger 12 is functioning as an evaporator, the control unit 313 determines a predetermined criterion indicating the possibility of frost formation in the second heat exchanger 12 from the detection result of the temperature detection unit 14. Determine whether or not it is satisfied. Note that the predetermined criteria are the same as in the second embodiment, and the description thereof is omitted.

When the control unit 313 of the exhaust unit 310 according to this modification determines that the predetermined criteria are satisfied, the control unit 352 of the compressor unit 350 performs control to suppress frost formation on the second heat exchanger 12. , a control signal for causing the refrigerant to flow through the bypass flow path F6 is output.

The drive motor 15 controls the air volume of the fan 11 under the control of the controller 313 .

The motor-operated valve 16 functions as an expansion valve for reducing the pressure of the refrigerant, and switches whether to reduce the pressure based on control by the control unit 313 . The motor-operated valve 16 functions to reduce the pressure when the second heat exchanger 12 functions as an evaporator, and not to reduce the pressure when the second heat exchanger 12 functions as a condenser.

The compressor unit 350 is provided with a drive motor 51, a control section 352, a compressor 53, a four-way valve 54, an electric valve 55, and an electric bypass valve 56.

The compressor 53 compresses the refrigerant flowing through the refrigerant circuit.

The drive motor 51 is an actuator that drives the compressor 53 . The drive motor 51 according to the present embodiment drives the compressor 53 at a rotational speed controlled by the control section 352 .

The controller 352 controls the configuration inside the compressor unit 350 . For example, the controller 352 controls the driving motor 51 and the four-way valve 54 described below.

The four-way valve 54 functions as a valve that switches the outflow destination of the refrigerant compressed by the compressor 53 from the refrigerant circuit F1 and the refrigerant circuit F4. For example, when the second heat exchanger 12 functions as an evaporator under the control of the control unit 352, the four-way valve 54 is switched to flow the refrigerant compressed by the compressor 53 to the refrigerant circuit F1.

The motor-operated valve 55 functions as a valve that controls opening and closing of the refrigerant circuit according to control from the control unit 352 . When the second heat exchanger 12 functions as an evaporator, the motor-operated valve 55 is in a closed state in which no refrigerant flows.

In this modification, when the second heat exchanger 12 functions as an evaporator, in order to increase the temperature of the refrigerant flowing through the second heat exchanger 12, the refrigerant compressed by the compressor 53 is directly subjected to the second heat exchange. A bypass flow path F6 is provided for flowing to the vessel 12 .

The bypass flow path F6 is provided as a refrigerant flow path that bypasses between the compressor 53 and the four-way valve 54 and between the refrigerant circuit F3. In other words, while the second heat exchanger 12 is functioning as an evaporator, the bypass flow path F6 functions as a pipe that allows the refrigerant to flow through the second heat exchanger 12 without going through the first heat exchanger 22. .

The bypass motor-operated valve 56 functions as a valve for switching whether or not the refrigerant flows through the bypass flow path F6 according to control from the control unit 352 .

Specifically, first, when the controller 313 of the exhaust unit 310 determines that the second heat exchanger 12 satisfies a predetermined criterion indicating the possibility of frost formation, the controller 352 of the compressor unit 350 , a control signal for causing the refrigerant to flow through the bypass flow path F6 is output.

When the controller 352 of the compressor unit 350 receives a control signal for causing the refrigerant to flow through the bypass flow path F6 from the controller 313 of the exhaust unit 310, the controller 352 controls the bypass motor-operated valve 56 to open. conduct.

When the motor-operated valve 56 for bypass is in an open state, the refrigerant that has become a high-temperature, high-pressure gas as a result of being compressed by the compressor 53 flows through the bypass flow path F6 into the refrigerant circuit F3. This increases the temperature of the refrigerant flowing through the refrigerant circuit F3. Then, the refrigerant whose temperature has risen flows into the second heat exchanger 12 .

That is, in this modified example, when a predetermined criterion is satisfied, the refrigerant compressed by the compressor 53 is controlled to flow to the second heat exchanger 12 via the bypass flow path F6. Thereby, it can suppress that the 2nd heat exchanger 12 is frosted.

(Modification 2 of the second embodiment)
Also, other methods may be used as a method for increasing the temperature of the refrigerant flowing through the second heat exchanger 12 . Therefore, in Modification 2 of the second embodiment, an example of controlling the motor operated valve 16 inside the exhaust unit 310 will be described. Note that the configuration of Modification 2 of the second embodiment is a configuration in which the bypass flow path F6 is removed from the refrigerant circuit shown in FIG.

When the second heat exchanger 12 functions as an evaporator, the motor-operated valve 16 causes the high-pressure liquid refrigerant flowing out of the first heat exchanger 22 to be easily evaporated under the control of the control unit 313. It functions as a valve portion that reduces the pressure in order to Since the pressure is reduced as the degree of opening of the motor-operated valve 16 decreases, the temperature of the refrigerant decreases. In other words, the temperature of the refrigerant rises as the degree of opening of the motor-operated valve 16 increases.

Therefore, while the second heat exchanger 12 is functioning as an evaporator, the control unit 313 of the exhaust unit 310 detects the possibility of frost formation on the second heat exchanger 12 based on the detection result of the temperature detection unit 14. It is determined whether or not the indicated predetermined criteria are met. Note that the predetermined criteria are the same as in the second embodiment, and the description thereof is omitted.

Then, when it is determined that the predetermined standard is satisfied, the control unit 313 performs control for suppressing frost formation on the second heat exchanger 12 by increasing the motor-operated valve 16 (second (an example of a two-valve unit) is controlled to increase the opening degree.

That is, in this modification, when a predetermined criterion is satisfied, control is performed to increase the degree of opening of the motor-operated valve 16 and raise the temperature of the refrigerant flowing through the second heat exchanger 12 . Thereby, it can suppress that the 2nd heat exchanger 12 is frosted.

(Third embodiment)
In the above-described embodiment and modified example, the control unit in the exhaust unit determines whether or not the predetermined standard is satisfied, and controls are performed based on the result of the determination. However, the above-described embodiment and modifications are not limited to the method of control performed by the control section in the exhaust unit. For example, a host controller provided above the air conditioner and the ventilator may perform the control.

FIG. 6 is a diagram showing a configuration example of a ventilation device, an air conditioner, and a host controller according to the third embodiment. It should be noted that the same reference numerals are assigned to the same configurations as in the above-described embodiment, and the description thereof will be omitted.

In the example shown in FIG. 6, a host control device 400 is provided for cooperation between the ventilator 1C and the air conditioner 2C.

The air conditioner 2C includes an outdoor unit 470 and two air conditioner

indoor units

81 and 82. In this embodiment, the number of air conditioning indoor units is not limited to two, and may be one or three or more.

The outdoor unit 470 includes a heat exchanger (not shown) and a controller 471 .

The control unit 471 controls the entire air conditioner 2C. Also, the control unit 471 transmits and receives information to and from the host control device 400 . The control unit 471 performs various controls according to control signals from the host control device 400 .

The ventilator 1C includes a first exhaust unit 410A, a second exhaust unit 410B, a first air supply unit 420A, a second air supply unit 420B, a compressor unit 450, and refrigerant circuits F401, F402, F403, and F404. , a first air supply channel P401, a second air supply channel P402, a first return air channel P403, and a second return air channel P404.

The first air supply passage P401 supplies air taken in from the outdoors to the living room space R11 through the ventilation port 92A after passing through the first air supply unit 420A having the first heat exchanger 22.

The second air supply passage P402 supplies the air taken in from the outdoors to the living room space R11 through the ventilation port 92B after passing through the second air supply unit 420B having the first heat exchanger 22.

The first return air flow path P403 exhausts the air (return air) taken in from the ventilation port 91A of the indoor space to the outdoors after passing through the first exhaust unit 410A having the second heat exchanger 12.

The second return air flow path P404 exhausts the air (return air) taken in from the ventilation port 91B of the indoor space to the outdoors after passing through the second exhaust unit 410B having the second heat exchanger 12.

The refrigerant circuits F401, F402, F403, and F404 include the compressor unit 450, the first heat exchangers 22 of the first air supply unit 420A and the second air supply unit 420B, and the first exhaust unit 410 and the second exhaust unit 410B. It is a circuit in which the second heat exchangers 12 are connected by refrigerant pipes and the refrigerant flows therein.

Control section 452 of compressor unit 450, control section 423A of first air supply unit 420A, control section 423B of second air supply unit 420B, control section 413A of first exhaust unit 410A, and control section of second exhaust unit 410B 413B are connected by a signal line S401 indicated by a dotted line. This enables information to be transmitted and received among the control unit 452, the control unit 423A, the control unit 423B, the control unit 413A, and the control unit 413B.

The controller 452 of the compressor unit 450 transmits to the host controller 400 the status of the ventilator 1C received from the

controllers

423A, 423B, 413A, and 413B. As a result, the host controller 400 can implement control according to the situation of the ventilator 1C.

The first air supply unit 420A includes a fan 21, a first heat exchanger 22, a control section 423A, and a temperature detection section 24, takes in outside air (OA), and supplies it to the living room space R11 through the ventilation opening 92A. I feel (SA).

The second air supply unit 420B includes a fan 21, a first heat exchanger 22, a control section 423B, and a temperature detection section 24, takes in outside air (OA), and supplies it to the living room space R11 through the ventilation opening 92B. I feel (SA).

The control section 423A and the control section 423B control the internal configuration of each air supply unit. Further, the controllers 423A and 423B transmit detection results from the temperature detectors 24 and the like in the respective air supply units to the controller 452 of the compressor unit 450 . The controller 452 of the compressor unit 450 recognizes the current situation from the detection result and transmits the recognition result to the host controller 400 . This allows the host controller 400 to recognize the status of the first air supply unit 420A and the second air supply unit 420B.

The first exhaust unit 410A includes a fan 11 (an example of a second ventilation unit), a second heat exchanger 12, a control unit 413A, and a temperature detection unit 14, and exhausts air from the ventilation opening 91A of the living room space R11. Air (RA) is taken in and exhausted (EA) to the outside.

The second exhaust unit 410B includes a fan 11 (an example of a second ventilation unit), a second heat exchanger 12, a control unit 413B, and a temperature detection unit 14, and exhausts air from the ventilation port 91B of the living room space R11. Air (RA) is taken in and exhausted (EA) to the outside.

The control unit 413A and the control unit 413B control the configuration inside each exhaust unit. Further, the

controllers

413A and 413B transmit detection results from the temperature detectors 14 and the like in the respective exhaust units to the controller 452 of the compressor unit 450 . The controller 452 of the compressor unit 450 recognizes the current situation from the detection result and transmits the recognition result to the host controller 400 . This allows the host controller 400 to recognize the status of the first exhaust unit 410A and the second exhaust unit 410B.

The host controller 400 performs various controls to coordinate the operation of the ventilation device 1C and the operation of the air conditioner 2C.

The host controller 400 receives the status of the air conditioner 2C from the controller 471 of the outdoor unit 470, and receives the status of the ventilator 1C from the controller 452 of the compressor unit 450. Then, the host controller 400 performs various controls according to the conditions of the air conditioner 2C and the ventilator 1C.

For example, when the host controller 400 recognizes that the air conditioner 2C is performing the defrosting operation based on the information received from the controller 471 of the outdoor unit 470, the host controller 400 performs a control.

In other words, when the air conditioner 2C performs the defrosting operation, the temperature in the living room space R11 may decrease because the air conditioner 2C does not function as a heater. On the other hand, when the air supply temperature of the first air supply unit 420A and the second air supply unit 420B is increased in order to compensate for the functional deterioration of the air conditioner 2C when the air conditioner 2C performs the defrosting operation, the refrigerant circuit F401 , F402, F403, and F404, the temperature of the refrigerant flowing through the second heat exchangers 12 of the first exhaust unit 410A and the second exhaust unit 410B decreases. In this case, the possibility of frost formation on the second heat exchangers 12 of the first exhaust unit 410A and the second exhaust unit 410B is improved.

Therefore, when recognizing that the air conditioner 2C is performing the defrosting operation, the host controller 400 increases the air volume of the air supply and exhaust of the ventilation device 1C to improve the heating capacity, thereby Suppress temperature drop.

FIG. 7 is a sequence diagram showing the flow of processing performed among the host controller 400, the ventilator 1C, and the air conditioner 2C when the defrosting operation of the air conditioner 2C according to this embodiment is started. .

First, when the defrosting operation is started, the control unit 471 in the outdoor unit 470 of the air conditioner 2C transmits a signal indicating that the defrosting operation is to be performed to the host controller 400 (S1701).

Then, when the host controller 400 recognizes that the defrosting operation has started in the air conditioner 2C based on the received signal, it increases the air volume of the ventilation device 1C in order to compensate for the functional deterioration due to the defrosting operation. It is determined to perform control (S1702).

Then, the host controller 400 transmits a control signal instructing an increase in the air volume of the exhaust unit group (the first exhaust unit 410A and the second exhaust unit 410B) to the controller 452 of the compressor unit 450 (S1703).

Similarly, the controller 452 of the compressor unit 450 transmits a control signal instructing an air volume increase to each of the

controllers

413A and 413B of the exhaust unit group (the first exhaust unit 410A and the second exhaust unit 410B). (S1704).

Based on the received control signal, the

control units

413A and 413B of the exhaust unit group increase the amount of air flowing through the second heat exchanger 12 (increase the amount of air) compared to before the defrosting operation of the air conditioner 2C. Control is performed on the fan 11 (an example of the second ventilation unit) (S1705).

Furthermore, the host controller 400 transmits a control signal instructing an air volume increase of the air supply unit group (the first air supply unit 420A and the second air supply unit 420B) to the controller 452 of the compressor unit 450 (S1706). ).

Then, the controller 452 of the compressor unit 450 sends a control signal to each of the controllers 423A and 423B of the air supply unit group (the first air supply unit 420A and the second air supply unit 420B) to instruct the air volume to increase. is transmitted (S1707).

Based on the received control signal, each of the control units 423A and 423B of the air supply unit group increases the amount of air flowing through the first heat exchanger 22 (air volume control is performed on the fan 21 (an example of the first ventilation unit) (S1708).

In this embodiment, the heating capacity of the ventilation device 1C is increased by increasing the air supply/exhaust air volume without increasing the supply air temperature of the ventilation device 1C, thereby suppressing a decrease in the room temperature of the living room space R11. Further, in the present embodiment, by suppressing an increase in the supply air temperature of the ventilation device 1C, it is possible to reduce the possibility of frost formation on the second heat exchanger 12 due to a decrease in the evaporation temperature.

The host controller 400 according to the present embodiment increases the air supply/exhaust amount of the ventilation device 1C in order to compensate for the deterioration in performance due to the frosting operation of the air conditioner 2C, so that the second heat exchanger 12 can be frosted. In addition to reducing the heat resistance, the heating capacity can be increased to suppress the decrease in room temperature.

The upper control device 400 according to this embodiment can perform various controls other than the above-described cooperative control.

For example, when the host controller 400 receives the temperature of outside air from the controller 413A or the controller 413B of the exhaust unit group via the controller 452 of the compressor unit 450, the second heat exchanger 12 is It may be determined whether or not a predetermined criterion indicating the possibility of frost is met. Then, when the host controller 400 determines that a predetermined criterion is satisfied, control may be performed to suppress frost formation on the second heat exchanger 12 . As a control to suppress frost formation on the second heat exchanger 12, for example, the host controller 400 sends a control signal to the controller 471 of the outdoor unit 470 to raise the current set temperature of heating. You may

Also, the configuration of the host controller 400 shown in this embodiment may be included as the configuration of the ventilation device. In other words, the processing performed by the host controller 400 may be a function of the ventilator. The same applies to subsequent embodiments.

(Fourth embodiment)
In the third embodiment, cooperative control when the host controller 400 performs the defrosting operation with the air conditioner 2C has been described. However, the host controller 400 performs various cooperative controls. Therefore, in the fourth embodiment, control when there is a possibility of frost formation in the second heat exchangers 12 of the plurality of exhaust units 410 will be described.

When there is a possibility of frost formation in the second heat exchangers 12 of the plurality of exhaust units 410, it may be difficult to control frost formation in the second heat exchangers 12 of the plurality of exhaust units 410 at the same time. exist. Therefore, the host controller 400 makes adjustments so that the second heat exchangers 12 of the plurality of exhaust units 410 are not controlled to suppress frost formation at the same time.

In the present embodiment, the frost formation suppression control of the ventilation device 1C performs control to increase the amount of air flowing to the second heat exchanger 12 . When control to increase the amount of air flowing to the second heat exchanger 12 is performed simultaneously by the plurality of

exhaust units

410A and 410B, the room space R11 may become negative pressure.

Therefore, in the present embodiment, one of the plurality of

exhaust units

410A and 410B is controlled to suppress defrosting by increasing the amount of air, and the other is decreased in amount of air. That is, in the present embodiment, one of the plurality of

exhaust units

410A and 410B is preferentially subjected to the defrosting suppression operation. Furthermore, the host controller 400 controls the negative pressure in the living room space R11 by making adjustments so as to maintain the total amount of discharged air.

FIG. 8 shows the flow of processing performed among the host controller 400, the compressor unit 450, and the exhaust unit group when there is a possibility of frost formation in each of the exhaust unit groups according to this embodiment. It is a sequence diagram.

First, the controller 413A of the first exhaust unit 410A acquires the temperature of the outside air from the temperature detector 14 (S1801).

Then, the controller 413A notifies the controller 452 of the compressor unit 450 of the detected outside air temperature (1802).

Also, the controller 413B of the second exhaust unit 410B acquires the temperature of the outside air from the temperature detector 14 (S1811).

Then, the controller 413B notifies the controller 452 of the compressor unit 450 of the detected outside air temperature (1812).

The controller 452 of the compressor unit 450 controls the first exhaust unit 410A and the second exhaust unit 410A based on the detected outside air temperature received from the first exhaust unit 410A controller 413A and the second exhaust unit 410B controller 413B. It is determined whether or not the second heat exchanger 12 of the exhaust unit 410B satisfies a predetermined criterion for the possibility of frost formation (S1821). In the example shown in FIG. 8, it is determined that each of the second heat exchangers 12 of the first exhaust unit 410A and the second exhaust unit 410B satisfies the predetermined criteria. Note that the predetermined criteria are the same as in the above-described embodiment, and the description thereof is omitted.

The controller 452 of the compressor unit 450 notifies the host controller 400 of the determination result indicating the possibility of frost formation (S1822).

Based on the received determination results, the host controller 400 determines the order of performing frost formation suppression control for the first exhaust unit 410A and the second exhaust unit 410B (S1831). Any method may be used as a method for determining the order. For example, control may be performed so that frost formation is suppressed first in the one with a higher possibility of frost formation, or determination may be made according to the priority assigned in advance to the first exhaust unit 410A and the second exhaust unit 410B. good. The example shown in FIG. 8 is an example in which it is determined to perform frost formation suppression in the order of the first exhaust unit 410A and the second exhaust unit 410B.

The host controller 400 transmits a signal indicating an instruction to increase the air volume of the first exhaust unit 410A to the controller 452 of the compressor unit 450 (S1832).

Then, the controller 452 of the compressor unit 450 transmits a signal indicating an instruction to increase the air volume to the controller 413A of the first exhaust unit 410A (S1823).

As a result, the control unit 413A of the first exhaust unit 410A controls the fan 11 to increase the amount of air flowing through the second heat exchanger 12 (increase the amount of air) compared to before the temperature is detected in S1801. (S1803).

After increasing the amount of air flowing through the second heat exchanger 12 by the control described above, the host controller 400 controls the compressor unit 450 after a predetermined period of time (predetermined period of time for suppressing frost formation) has elapsed. A signal indicating an instruction to decrease the air volume of the second exhaust unit 410B is transmitted to the controller 452 (S1833).

Then, the controller 452 of the compressor unit 450 transmits a signal indicating an instruction to decrease the air volume to the controller 413B of the second exhaust unit 410B (S1824).

As a result, the control unit 413B of the second exhaust unit 410B controls the fan 11 to decrease the amount of air flowing through the second heat exchanger 12 (reduce the amount of air) compared to before the temperature is detected in S1811. (S1813).

In this embodiment, the total air discharge amount is maintained by increasing the air volume of the first exhaust unit 410A and decreasing the air volume of the second exhaust unit 410B. After that, the host controller 400 replaces the exhaust unit that suppresses frost formation.

The host controller 400 transmits a signal indicating an instruction to decrease the air volume of the first exhaust unit 410A to the controller 452 of the compressor unit 450 (S1834).

Then, the controller 452 of the compressor unit 450 transmits a signal indicating an instruction to decrease the air volume to the controller 413A of the first exhaust unit 410A (S1825).

As a result, the control unit 413A of the first exhaust unit 410A controls the fan 11 to reduce the amount of air flowing through the second heat exchanger 12 (reduce the amount of air) compared to before the temperature is detected in S1801. (S1804).

The host controller 400 transmits a signal indicating an instruction to increase the air volume of the second exhaust unit 410B to the controller 452 of the compressor unit 450 (S1835).

Then, the controller 452 of the compressor unit 450 transmits a signal indicating an instruction to increase the air volume to the controller 413B of the second exhaust unit 410B (S1826).

As a result, the control unit 413B of the second exhaust unit 410B controls the fan 11 to increase the amount of air flowing through the second heat exchanger 12 (increase the amount of air) compared to before the temperature is detected in S1811. (S1814).

Thus, the controller 452 of the compressor unit 450 and the host controller 400 according to the present embodiment determine that the predetermined criteria are met while the plurality of second heat exchangers 12 are functioning as evaporators. increase the amount of air flowing through the second heat exchanger 12 compared to before the predetermined criterion is met, for the fan 11 associated with one of the plurality of second heat exchangers 12. control to allow As a result, since the amount of (warm) air flowing into any one of the second heat exchangers 12 increases, frost formation can be suppressed.

Furthermore, when the host controller 400 controls to increase the air amount of the fan 11 associated with one of the plurality of second heat exchangers 12, the other second heat exchangers Control is performed on the fan 11 associated with 12 so as to reduce the amount of air flowing through the second heat exchanger compared to before the predetermined criterion is satisfied. As a result, it is possible to maintain the amount of air discharged from the plurality of exhaust unit groups, thereby avoiding negative pressure in the living room space R11.

Furthermore, according to the present embodiment, by performing frost formation suppression control according to a predetermined order for each of the plurality of exhaust units, it is possible to suppress frost formation on the second heat exchangers 12 of the plurality of exhaust units.

(Fifth embodiment)
In the fourth embodiment, an example has been described in which, when performing frost formation suppression control, adjustment is performed so as to maintain the amount of air discharged from a plurality of exhaust unit groups. However, the method of avoiding negative pressure is not limited to the method of adjusting so as to maintain the amount of air discharged from a plurality of exhaust unit groups. Therefore, in the fifth embodiment, when increasing the amount of air exhausted from the exhaust unit group, the amount of air taken in by the air supply unit group from the outside will be increased. It should be noted that the configuration of this embodiment is assumed to be similar to that of the fourth embodiment.

As in the fourth embodiment, the controller 452 of the compressor unit 450 according to the present embodiment controls the second heat exchangers of the first exhaust unit 410A and the second exhaust unit 410B based on the received outside air temperature. 12 is determined whether or not it satisfies a predetermined criterion for the possibility of frost formation.

Then, when the controller 452 of the compressor unit 450 determines that one of the first exhaust unit 410A and the second exhaust unit 410B satisfies the predetermined criteria, the host controller 400 controls the exhaust Instruct the unit to increase the air volume. The instruction method is the same as in the fourth embodiment, and description thereof is omitted.

When the host controller 400 determines that each of the first exhaust unit 410A and the second exhaust unit 410B satisfies the predetermined criteria, the host controller 400 determines the order of frost formation suppression for the first exhaust unit 410A and the second exhaust unit 410B. to decide. Then, the host controller 400 instructs each of the first exhaust unit 410A and the second exhaust unit 410B to increase the air volume according to the order.

The host control device 400 according to the present embodiment, instead of instructing to decrease the air volume as shown in the fourth embodiment, performs one or more of the first air supply unit 420A and the second air supply unit 420B. to increase the air volume. An instruction to increase the air volume is sent from the host controller 400 via the controller 452 of the compressor unit 450 to either the controller 423A of the first air supply unit 420A or the controller 423B of the second air supply unit 420B. It is done for the above.

The target for instructing an increase in air volume may be either one of the first air supply unit 420A and the second air supply unit 420B, or each of the first air supply unit 420A and the second air supply unit 420B. However, the host controller 400 makes the amount of air discharged in the first exhaust unit 410A and the second exhaust unit 410B equal to the amount of air taken in by the first air supply unit 420A and the second air supply unit 420B. Adjust so that

As described above, the host controller 400 according to the present embodiment performs the second heat exchange with respect to the fan 11 associated with any one of the plurality of second heat exchangers 12 included in the exhaust unit group. When control is performed to increase the amount of air flowing through the unit 12, the fan 21 included in the air supply unit group is compared to before the predetermined criterion is satisfied, based on the increased amount of air. Control is performed to increase the amount of air flowing through the exchanger 22 . As a result, in this embodiment, the amount of air taken in substantially matches the amount of air exhausted, so that it is possible to suppress negative pressure in the living room space R11.

(Sixth embodiment)
The method of suppressing frost formation is not limited to the above-described embodiment, and other methods may be used. Therefore, in the sixth embodiment, an example of suppressing frost formation by stopping the operation of the compressor of the compressor unit and allowing air to flow through the second heat exchanger 12 will be described.

The configuration of this embodiment may be of any configuration, and may be a case in which a host controller 400 as shown in FIG. 6 of the third embodiment is provided. In the example shown in FIG. 6, two exhaust units and two air supply units are provided, but one exhaust unit and one air supply unit may be provided. Thus, the number of exhaust units and air supply units may be arbitrary.

While the second heat exchanger 12 is functioning as an evaporator, the controller 413A of the first exhaust unit 410A and the controller 413B of the second exhaust unit 410B detect the second heat exchange from the temperature detector . Acquire the surface temperature of the vessel 12 . Then, the controller 413 A and the controller 413 B of the second exhaust unit 410 B transmit the detected surface temperature of the second heat exchanger 12 to the controller 452 of the compressor unit 450 .

Then, based on the surface temperature of the second heat exchanger 12, the controller 452 of the compressor unit 450 determines whether the second heat exchanger 12 satisfies a predetermined criterion indicating the possibility of frost formation. judge. The predetermined criterion indicating the possibility of frost formation on the second heat exchanger 12 may be, for example, a criterion for determining whether or not the surface temperature of the second heat exchanger 12 is 0 degrees or less. The predetermined criterion may be any criterion as long as it indicates the possibility of frost formation on the second heat exchanger 12 . For example, the predetermined criterion may be a criterion such as that of the embodiment described above, or may be a criterion based on the temperature or pressure of the refrigerant, for example.

When determining that the predetermined criteria are satisfied, the control unit 452 of the compressor unit 450 according to the present embodiment outputs the determination result indicating that the second heat exchanger 12 may be frosted. The controller 400 is notified.

Based on the determination result, the host controller 400 transmits a control signal instructing to stop the compressor to the controller 452 of the compressor unit 450 . Accordingly, the controller 452 of the compressor unit 450 performs control to stop the compressor.

In addition, based on the determination result, the host controller 400 controls each of the control section 413A of the first exhaust unit 410A and the control section 413B of the second exhaust unit 410B via the control section 452 of the compressor unit 450. , outputs a control signal to continue the control of flowing air to the second heat exchanger 12 of the fan 11 . Also, the host controller 400 may perform control to increase the air volume of the fan 11 as in the fourth embodiment.

In this embodiment, the compressor inside the compressor unit 450 is stopped, and the air in the living room space R11 is allowed to flow through the second heat exchanger 12, thereby increasing the temperature of the surface of the second heat exchanger 12, It is possible to suppress the formation of frost on the second heat exchanger 12 .

(Seventh embodiment)
In the sixth embodiment, an example in which the host controller 400 controls one compressor unit 450 has been described. However, the number of compressor units controlled by the host controller 400 is not limited to one. Therefore, in the seventh embodiment, an example in which the host controller 400 controls three compressor units will be described.

FIG. 9 is a diagram exemplifying the arrangement of a device group including the upper control device 500 according to the seventh embodiment. The example shown in FIG. 9 includes at least living room spaces R501, R502, R503, restrooms R511, R512, and a pipe shaft R521.

The restrooms R511 and R512 are provided with

ventilation openings

595A and 595B, respectively.

Also, the air conditioner 2D includes three

outdoor units

571, 572, 573 and eight air conditioner

indoor units

581, 582, 583, 584, 585, 586, 587, 588. The three outdoor units 571 to 573 and the eight air conditioning indoor units 581 to 588 are connected by connecting pipes (not shown).

Also, the three outdoor units 571 to 573 are connected to the host controller 500 via signal lines. As a result, the three outdoor units 571 to 573 can perform air conditioning control under the control of the host controller 500. FIG.

The first ventilation device 1D_1 is a ventilation device provided in the living room space R501, and includes a first compressor unit 550A, a first air supply unit 520A, and a first exhaust unit 510A.

The first air supply unit 520A supplies air (SA) from the ventilation port 592A. The first exhaust unit 510A returns air (RA) from the ventilation port 591A. The first compressor unit 550A, the first air supply unit 520A, and the first exhaust unit 510A are connected by a connecting pipe F501. The communication pipe F501 includes a plurality of refrigerant communication pipes. Thereby, the refrigerant can be circulated among the first compressor unit 550A, the first air supply unit 520A, and the first exhaust unit 510A.

Also, the first compressor unit 550A, the first air supply unit 520A, and the first exhaust unit 510A are connected by signal lines (not shown). This enables information to be transmitted and received between units. Also, the internal configurations of the first compressor unit 550A, the first air supply unit 520A, and the first exhaust unit 510A are the same as the compressor unit 450A, the first air supply unit 420A, and the first exhaust unit 410A shown in FIG. The description is omitted assuming that the configuration is the same as that of FIG.

The second ventilation device 1D_2 is a ventilation device provided in the living room space R502, and includes a second compressor unit 550B, a second air supply unit 520B, and a second exhaust unit 510B.

The second air supply unit 520B supplies air (SA) from the ventilation port 592B. The second exhaust unit 510B returns air (RA) from the ventilation port 591B. The second compressor unit 550B, the second air supply unit 520B, and the second exhaust unit 510B are connected by a connecting pipe F502. The communication pipe F502 includes a plurality of refrigerant communication pipes. Thereby, the refrigerant can be circulated among the second compressor unit 550B, the second air supply unit 520B, and the second exhaust unit 510B.

Also, the second compressor unit 550B, the second air supply unit 520B, and the second exhaust unit 510B are connected by signal lines (not shown). This enables information to be transmitted and received between units. Also, the configurations inside the second compressor unit 550B, the second air supply unit 520B, and the second exhaust unit 510B are similar to the compressor unit 450A, the first air supply unit 420A, and the first exhaust unit 410A shown in FIG. The description is omitted assuming that the configuration is the same as that of FIG.

The third ventilation device 1D_3 is a ventilation device provided in the living room space R503, and includes a third compressor unit 550C, a third air supply unit 520C, and a third exhaust unit 510C.

The third air supply unit 520C supplies air (SA) from the ventilation port 592C. The third exhaust unit 510C returns air (RA) from the ventilation port 591C. The third compressor unit 550C, the third air supply unit 520C, and the third exhaust unit 510C are connected by a connecting pipe F503. The communication pipe F503 includes a plurality of refrigerant communication pipes. Thereby, the refrigerant can be circulated among the third compressor unit 550C, the third air supply unit 520C, and the third exhaust unit 510C.

Also, the third compressor unit 550C, the third air supply unit 520C, and the third exhaust unit 510C are connected by signal lines (not shown). This enables information to be transmitted and received between units. Further, the internal configurations of the third compressor unit 550C, the third air supply unit 520C, and the third exhaust unit 510C are similar to the compressor unit 450A, the first air supply unit 420A, and the first exhaust unit 410A shown in FIG. The description is omitted assuming that the configuration is the same as that of FIG.

As described above, in this embodiment, a plurality of combinations of compressor units, air supply units, exhaust units, and connecting pipes are provided. The first compressor unit 550A, the second compressor unit 550B, and the third compressor unit 550C are arranged on the pipe shaft R521.

The host controller 500 is connected to the first compressor unit 550A, the second compressor unit 550B, and the third compressor unit 550C by signal lines. As a result, the host controller 500 can recognize the state of each of the first ventilator 1D_1 to the third ventilator 1D_3 and control each of the devices.

With the above-described configuration, while the second heat exchangers 12 of the first exhaust unit 510A to the third exhaust unit 510C are functioning as evaporators, the first compressor unit 550A to the third compressor unit 550C A controller (not shown) receives the surface temperature of the second heat exchanger 12 from each of the first to third exhaust units 510A to 510C.

Then, the control units of the first compressor unit 550A to the third compressor unit 550C according to the present embodiment control the surface of the second heat exchanger 12 while the second heat exchanger 12 functions as an evaporator. Based on the temperature, it is determined whether or not the second heat exchanger 12 satisfies a predetermined criterion indicating the possibility of frost formation. Note that the predetermined criteria are the same as in the above-described embodiment, and the description thereof is omitted.

The controllers of the first compressor unit 550A to the third compressor unit 550C notify the upper controller 400 of the determination result indicating whether or not the predetermined criteria are met.

Based on the determination result, the host controller 500 selects the compressor units (for example, the first compressor unit 550A to the third compressor unit 550C) connected to the second heat exchanger 12 that satisfies the predetermined criteria by connecting pipes. When it is determined that a plurality of are present, as a control to suppress frost formation on the second heat exchanger 12, for the plurality of compressor units (for example, the first compressor unit 550A to the third compressor unit 550C) and outputs a control signal to stop the compressor in accordance with a predetermined order. This prevents a plurality of compressor units from stopping their compressors at the same time. Further, the predetermined order may be any order, such as the lowest surface temperature order, or may be based on the preset priority of the compressor units.

In addition, the host controller 500 causes the fan 11 corresponding to the second heat exchanger 12 that satisfies a predetermined criterion to maintain control of flowing air from the living room spaces R501 to R503 to the second heat exchanger 12. . Thereby, the temperature of the refrigerant flowing through the second heat exchanger 12 can be increased.

In the present embodiment, by performing the control described above, the refrigerant flowing through the second heat exchanger 12 is stopped, and by maintaining the flow of air through the second heat exchanger 12, the second heat exchanger 12 frost formation can be suppressed.

(Eighth embodiment)
In the seventh embodiment, an example has been described in which the host controller 500 stops a plurality of compressor units in a predetermined order. In contrast, in the eighth embodiment, an example in which a plurality of air supply units and a plurality of exhaust units are connected to one compressor will be described.

FIG. 10 is a diagram exemplifying the arrangement of a device group including the host controller 600 according to the eighth embodiment. Among the configurations shown in FIG. 10, configurations similar to those of the above-described embodiment are assigned the same reference numerals, and descriptions thereof are omitted.

As shown in FIG. 10, the compressor unit 650 is connected to the first air supply unit 520A and the first exhaust unit 510A via a communication pipe F601, and communicates with the second air supply unit 520B and the second exhaust unit 510B. It is connected via piping F602, and connected to the third air supply unit 520C and the third exhaust unit 510C via communication piping F603. As a result, the refrigerant circulates through the units connected by the connecting pipes F601, F602, and F603.

Since the compressor unit 650, the first air supply unit 520A to the third air supply unit 520C, and the first exhaust unit 510A to the third exhaust unit 510C are connected by signal lines (not shown), information can be exchanged between the units. can be sent and received. Moreover, since the host controller 500 and the compressor unit 650 are also connected by a signal line, information can be transmitted and received.

The first air supply unit 520A, the second air supply unit 520B, and the third air supply unit 520C are provided with the electric valve 26 (an example of the first valve portion) as shown in FIG. Similarly, the first exhaust unit 510A, the second exhaust unit 510B, and the third exhaust unit 510C are provided with the electric valve 16 (an example of the first valve portion) as shown in FIG.

When the second heat exchangers 12 of the first exhaust unit 510A, the second exhaust unit 510B, and the third exhaust unit 510C function as evaporators, the motor-operated valve 16 opens the flow path to the second heat exchangers 12. It functions as a valve that adjusts the temperature (regulates the pressure of the refrigerant).
(Example of valve part)

As a result, the host controller 600 individually stops the inflow of refrigerant by controlling the motor-operated valves 16 to the closed state for each of the first exhaust unit 510A, the second exhaust unit 510B, and the third exhaust unit 510C. You can control it.

The controller (not shown) of the compressor unit 650 according to the present embodiment controls the second It is determined whether or not the heat exchanger 12 satisfies a predetermined criterion indicating the possibility of frost formation. Note that the predetermined criteria are the same as in the above-described embodiment, and the description thereof is omitted. Then, the controller 652 (not shown) of the compressor unit 650 notifies the upper controller 600 of the determination result.

In the present embodiment, the host controller 600 suppresses frost formation on the second heat exchangers 12 when recognizing that there are a plurality of the second heat exchangers 12 that satisfy the predetermined criteria based on the determination result. As a control to perform the electric A control signal is output to close the valve 16 . This prevents the refrigerant from flowing into the plurality of second heat exchangers 12 from stopping at the same time. Further, the predetermined order may be any order, such as the lowest surface temperature order, or may be based on the preset priority of the compressor units.

In addition, the host controller 500 causes the fan 11 corresponding to the second heat exchanger 12 that satisfies a predetermined criterion to maintain control of flowing air from the living room spaces R501 to R503 to the second heat exchanger 12. .

In the present embodiment, by performing the above-described control, the refrigerant flowing to the second heat exchanger 12 is stopped and the air is kept flowing to the second heat exchanger 12, so frost formation is suppressed. be able to.

(Ninth embodiment)
You may suppress frost formation of the 2nd heat exchanger 12 using methods other than embodiment mentioned above. Therefore, in the ninth embodiment, an example of adjusting between the air supply volume and the exhaust volume will be described.

The configuration of the ninth embodiment may be any configuration of the embodiments described above, and may be, for example, the configuration shown in FIG. Therefore, in the present embodiment, a case in which the configuration shown in FIG. 6 is provided will be described.

Then, while the second heat exchanger 12 is functioning as an evaporator, the controller 452 of the compressor unit 450 according to the present embodiment controls the second heat based on the surface temperature of the second heat exchanger 12. It is determined whether or not the exchanger 12 satisfies a predetermined criterion indicating the possibility of frost formation. Note that the predetermined criteria are the same as in the above-described embodiment, and the description thereof is omitted.

In this embodiment, the controller 452 of the compressor unit 450 notifies the upper controller 400 of the determination result. Then, when the host controller 400 recognizes that there are a plurality of second heat exchangers 12 that satisfy a predetermined criterion, the exhaust unit group (For example, the first exhaust unit 410A and the second exhaust unit 410B) the total amount of air supplied by the fan 11 (an example of the second ventilation unit), the air supply unit group (for example, the first air supply unit 420A and the second A control signal for controlling the fan 11 and the fan 21 is output so that the amount of air exhausted by the fan 21 (an example of the first ventilation unit) of the air supply unit 420B) is larger than the total amount of exhaust air.

In the present embodiment, by setting the air volume of the exhaust air to be larger than the air volume of the air supply, the condensation capacity of the air supply unit group is suppressed, and the evaporation temperature of the second heat exchanger 12 of the exhaust unit group is increased. , frost formation can be suppressed.

(Tenth embodiment)
You may suppress frost formation of the 2nd heat exchanger 12 using methods other than embodiment mentioned above. Therefore, in the tenth embodiment, an example of adjusting the temperature of the air after passing through the first heat exchanger 22 will be described.

The configuration of the tenth embodiment may be any configuration of the embodiments described above, and may be, for example, the configuration shown in FIG. Therefore, in the present embodiment, a case in which the configuration shown in FIG. 6 is provided will be described.

Then, while the second heat exchanger 12 is functioning as an evaporator, the controller 452 of the compressor unit 450 according to the present embodiment controls the second heat based on the surface temperature of the second heat exchanger 12. It is determined whether or not the exchanger 12 satisfies a predetermined criterion indicating the possibility of frost formation. Note that the predetermined criteria are the same as in the above-described embodiment, and the description thereof is omitted. Then, the controller 452 of the compressor unit 450 notifies the host controller 400 of the determination result.

In this embodiment, when the host controller 400 recognizes that there are a plurality of second heat exchangers 12 that satisfy a predetermined criterion, the control for suppressing frost formation on the second heat exchangers 12 includes: With respect to the first heat exchangers of the air supply unit group (for example, the first air supply unit 420A and the second air supply unit 420B), the temperature of the air after passing through the first heat exchanger 22 is the room space R11. output a control signal to make the temperature lower than the temperature set in the air conditioner 2C. The temperature set in the air conditioner 2C is obtained from the control section 471 of the outdoor unit 470. FIG.

In this embodiment, the temperature of the air after passing through the first heat exchanger 22 of the air supply unit group (supply air temperature) is lower than the indoor set temperature. As a result, the compressor of the compressor unit 450 operates at a low rotational speed, so that a decrease in the evaporation temperature of the second heat exchanger 12 can be suppressed.

(Eleventh embodiment)
You may suppress frost formation of the 2nd heat exchanger 12 using methods other than embodiment mentioned above. Therefore, in the eleventh embodiment, an example in which the pressure of the refrigerant is adjusted by an electrically operated valve (an example of the third valve portion) provided downstream of the exhaust unit will be described.

The configuration of the eleventh embodiment may be any configuration of the embodiments described above, and may be, for example, the configuration shown in FIG. Therefore, in the present embodiment, a case in which the configuration shown in FIG. 6 is provided will be described.

FIG. 11 is a diagram showing a refrigerant circuit according to the eleventh embodiment. The example shown in FIG. 11 shows the refrigerant flow when the second heat exchangers 12 of the

exhaust units

410A and 410B function as evaporators. In addition, the same code|symbol is assigned about the structure similar to embodiment mentioned above, and description is abbreviate|omitted.

In the example shown in FIG. 11, when the second heat exchangers 12 of the

exhaust units

410A and 410B are functioning as evaporators, the motor-operated valves are downstream of the second heat exchangers 12 of the exhaust units 410A and 410B. 601, 602 are provided.

Then, while the second heat exchanger 12 is functioning as an evaporator, the controller 452 of the compressor unit 450 according to the present embodiment controls the second heat based on the surface temperature of the second heat exchanger 12. It is determined whether or not the exchanger 12 satisfies a predetermined criterion indicating the possibility of frost formation. Note that the predetermined criteria are the same as in the above-described embodiment, and the description thereof is omitted. The controller 452 of the compressor unit 450 notifies the upper controller 400 of the determination result.

In this embodiment, when the host controller 400 recognizes that there is a second heat exchanger 12 that satisfies a predetermined criterion, the exhaust unit (for example, the first exhaust unit 410A) including the second heat exchanger 12 Or output a control signal to the control unit (control unit 413A or control unit 413B) of the second exhaust unit 410B) to throttle the motor-operated valve (motor-operated valve 601 or 602) compared to before a predetermined criterion is satisfied. .

By reducing the degree of opening of the expansion valve (expansion valve 161 or expansion valve 162), the pressure of the refrigerant flowing through the second heat exchanger 12 upstream of the expansion valve (expansion valve 161 or expansion valve 162) is increased. can be made Thereby, the evaporation temperature of the refrigerant flowing through the second heat exchanger 12 can be increased. Therefore, frost formation on the second heat exchanger 12 can be suppressed.

Although the bypass flow path F6 is shown in FIG. 11, in the present embodiment, it may be combined with the control using the bypass flow path F6 shown in the embodiment described above, or may not be combined. .

(Modification of the eleventh embodiment)
In the eleventh embodiment, the example of suppressing frosting by using the technique of throttling the motor-operated

valves

601 and 602 downstream from the second heat exchanger 12 has been described. In the eleventh embodiment, in addition to the method of adjusting the motor-operated

valves

601 and 602 downstream of the second heat exchanger 12, an exhaust unit 730 for the outdoor unit is further provided in the refrigerant circuit, and the exhaust unit 730 is controlled. will be explained.

FIG. 12 is a diagram showing a refrigerant circuit according to a modified example of the eleventh embodiment. The example shown in FIG. 12 is an example in which the refrigerant circuit shown in FIG. 11 is further provided with an exhaust unit 730 . Note that the configuration is the same as that of the eleventh embodiment except that an exhaust unit 730 is provided, and description thereof is omitted.

The exhaust unit 730 includes a fan 11 , a third heat exchanger 732 , a control section 733 , a temperature detection section 14 , a drive motor 15 and an electric valve 16 .

The exhaust unit 730 functions as an outdoor unit. That is, the exhaust unit 730 is provided on a flow path (an example of a fourth air flow path) for exhausting to the outdoors the air that has undergone heat exchange with the outdoor air and the refrigerant flowing through the third heat exchanger 732. .

In this embodiment, when the host controller 400 recognizes that there is a second heat exchanger 12 that satisfies the predetermined criteria, it performs the same control as in the eleventh embodiment, When the heat exchanger 732 performs heat exchange, it is controlled to perform heat exchange at a lower evaporation temperature than the second heat exchanger 12 .

As shown in FIG. 12, the refrigerant flow through the third heat exchanger 732 of the exhaust unit 730 and the refrigerant flow through the second heat exchangers 12 of the

exhaust units

410A, 410B are connected. Therefore, by lowering the evaporation temperature of the third heat exchanger 732, the evaporation temperature of the second heat exchanger 12 can be increased. Thereby, frost formation on the second heat exchanger 12 can be suppressed.

In addition, in the above-described embodiment and modification, a method of sharing processing by the control unit 452 of the compressor unit 450 and the host controller 500 has been described. It is not limited to the method of sharing and processing, and either one of the control unit 452 of the compressor unit 450 and the host control device 500 may perform determination and control of other devices. Furthermore, the method of performing the processing by the control unit 452 of the compressor unit 450 and the host controller 500 is not limited, and the processing of the above-described embodiment may be performed by a centrally managed server or in the cloud.

(Twelfth embodiment)
You may suppress frost formation of the 2nd heat exchanger 12 using methods other than embodiment mentioned above. Therefore, in the twelfth embodiment, an example of switching control in consideration of power consumption will be described.

The configuration of the twelfth embodiment may be any configuration of the embodiments described above, and may be, for example, the configuration shown in FIG. Therefore, in the present embodiment, a case in which the configuration shown in FIG. 6 is provided will be described. The host controller 400 performs the following controls during the heat recovery ventilation operation.

Then, while the second heat exchanger 12 is functioning as an evaporator, the controller 452 of the compressor unit 450 according to the present embodiment controls the second heat based on the surface temperature of the second heat exchanger 12. It is determined whether or not the exchanger 12 satisfies a predetermined criterion indicating the possibility of frost formation. The controller 452 of the compressor unit 450 notifies the upper controller 400 of the determination result.

The predetermined criterion may be determined based on the temperature of the refrigerant flowing through the second heat exchanger 12 or the pressure of the refrigerant, or may be the same as in the embodiment described above.

In the present embodiment, when the host controller 400 recognizes that there are a plurality of second heat exchangers 12 that satisfy a predetermined criterion, the host controller 400 controls frost formation, or allows frost formation and allows frost formation. It is determined whether the defrosting operation is to be performed later. Then, according to the determination result of the host controller 400, the exhaust unit group (for example, the first exhaust unit 410A and the second exhaust unit 410B) performs frost formation suppression control, or permits frost formation and after frost formation Perform defrosting operation.

FIG. 13 is a flow chart showing the processing procedure of the host controller 400 according to this embodiment.

First, the control unit 452 of the compressor unit 450 according to the present embodiment receives detection results regarding the second heat exchanger 12 from each of the exhaust unit group (S2101). The detection results are the temperature of the refrigerant flowing through the second heat exchanger 12 and the pressure of the refrigerant.

The controller 452 of the compressor unit 450 determines whether or not a predetermined criterion is satisfied based on the detection result (S2102). For example, the predetermined criterion indicating the possibility of frost formation on the second heat exchanger 12 may be whether or not the detected (evaporation) temperature of the refrigerant is lower than a predetermined temperature t. The criterion is whether the (evaporation) pressure of the refrigerant is lower than a predetermined pressure p. If it is determined that the predetermined criteria are not satisfied (S2102: NO), the process is repeated from S2101. It should be noted that the predetermined temperature t and pressure p are values determined depending on the embodiment as criteria for determining whether or not there is a possibility of frost formation, and the description thereof will be omitted. It is conceivable that the determination is made every predetermined time (for example, x minutes).

When the controller 452 of the compressor unit 450 determines that the predetermined criteria are met (S2102: YES), it notifies the upper controller 400 of the determination result.

Then, the host controller 400 controls the temperature of the refrigerant flowing through the second heat exchanger 12 to suppress frost formation, and calculates the power consumption E1 for maintaining the current temperature of the living room space R11. (S2103).

Furthermore, the host controller 400 performs the defrosting operation and calculates the power consumption E2 for maintaining the current temperature and the like of the living room space R11 (S2104).

For example, in the present embodiment, the host controller 500 stores in advance a power consumption calculation model that is set in advance to calculate the power consumption E1 and the power consumption E2. Then, the host controller 500 inputs input information (for example, room temperature/outdoor temperature, air volume of

fans

11 and 21, refrigerant pressure, compressor rotation speed, etc.: an example of the state of the living room space) to the power consumption calculation model. By inputting, the power consumption is calculated. Note that the power consumption calculation method is not limited to the method using the calculation model, and other methods may be used.

After that, the host controller 400 determines whether or not the power consumption E1 is smaller than the power consumption E2 (S2105). When the host controller 400 determines that the power consumption E1 is smaller than the power consumption E2 (S2105: YES), it outputs a control signal for suppressing frost formation to the exhaust unit group (S2106). Note that the method for suppressing frost formation may be the processing shown in the above-described embodiment, and the description thereof is omitted. After that, the host controller 500 performs the processing from S2101 again.

Thereafter, when the host controller 400 determines that the power consumption E1 is greater than or equal to the power consumption E2 (not smaller) (S2105: NO), the host controller 400 allows frost formation on the exhaust unit group. , outputs a control signal for executing the defrosting operation (S2107). It should be noted that the method of performing the defrosting operation is not limited to any well-known method, and description thereof will be omitted as any method may be used.

After that, the host controller 400 according to the present embodiment receives detection results regarding the second heat exchanger 12 from each of the exhaust unit groups via the controller 452 of the compressor unit 450 (S2108). The detection results are the temperature of the refrigerant flowing through the second heat exchanger 12 and the pressure of the refrigerant.

The host controller 400 determines whether or not the defrosting end criteria are satisfied based on the detection result (S2109). For example, the defrosting end criterion for the second heat exchanger 12 may be whether or not the detected (evaporation) temperature of the refrigerant is greater than a predetermined temperature t+α, or whether the detected (evaporation) pressure of the refrigerant is The criterion is whether or not the pressure is smaller than a predetermined pressure p+β. Any standard may be used as the defrosting end standard as long as it can be used to determine whether the defrosting has been completed. It should be noted that the variables α and β are positive numbers determined according to the embodiment, and the description thereof is omitted. It is determined whether or not the defrosting end criteria are met (S2109). If it is determined that the defrosting end criterion is not met (S2109: NO), the process is repeated from S2108. It is conceivable that the determination is made every predetermined time (for example, y minutes).

On the other hand, when the upper controller 400 determines that the defrosting end criteria are satisfied based on the detection result (S2109: YES), it outputs a control signal for terminating the defrosting operation to the exhaust unit group (S2110 ) and terminate the process. After that, the host controller 500 performs the processing from S2101 again.

By performing the control described above, the host controller 500 according to the present embodiment adjusts the second The power consumption required when controlling the temperature of the refrigerant flowing through the heat exchanger 12, and the power consumption required for the operation of defrosting the second heat exchanger 12 after frosting on the second heat exchanger 12 Based on this, the temperature of the refrigerant flowing through the second heat exchanger 12 is controlled so that the second heat exchanger 12 is not frosted, or the second heat exchanger 12 is frosted and then the second heat exchanger 12 can be controlled to eliminate frost formation.

As a result, in the present embodiment, it is possible to suppress power consumption when suppressing or defrosting the exhaust unit group.

In the above-described embodiments and modifications, the air supply unit includes the first heat exchanger 22 and a casing (an example of the first casing) that houses at least part of the air flow path (an example of the first air flow path). and the exhaust unit is a casing (an example of a second casing) that houses at least a part of the second heat exchanger 12 and an air flow path (an example of the second air flow path), each of which is separated from the casing I explained an example of

This makes it possible to arrange the exhaust unit and the air supply unit at separate positions. As a result, it is possible to increase the degree of freedom in arranging the ventilator capable of recovering heat compared to the conventional art.

However, the embodiments and modifications described above are not limited to examples in which the casings of the air supply unit and the exhaust unit are separated, and the air supply unit and the exhaust unit may be integrated. That is, the first heat exchanger 22 and the second heat exchanger 12 are connected by a refrigerant circuit, and the fan 21 corresponding to the first heat exchanger 22 and the fan corresponding to the second heat exchanger 12 are provided. In this case, it is possible to apply the air volume adjustment and the refrigerant temperature adjustment as shown in the above-described embodiment and modifications. In this way, the techniques shown in the above-described embodiments and modifications may be applied to the case where the air supply unit and the exhaust unit are integrated.

(Overview of ventilation system)
By the way, the air conditioning system starts the compressor, uses the first heat exchanger of the supply air unit as a condenser, and the second heat exchanger of the exhaust unit as an evaporator, thereby supplying the exhaust air (indoor air ) can be recovered by the refrigerant in the refrigerant circuit, and the indoor can be ventilated. In an air conditioning system, when the second heat exchanger into which the exhaust gas flows is used as an evaporator, if the temperature of the exhaust gas (indoor air) is lower than a predetermined value, the second heat exchanger will be frosted, and the pressure in the refrigerant circuit will drop. pressure drops. In this case, it becomes difficult to continue the operation of the started compressor.

The embodiments shown below enable reliable continuous operation of the compressor when using the heat exchanger as an evaporator for a ventilation system with a refrigerant circuit.

FIG. 14 is a schematic configuration diagram of the ventilation system of the present disclosure. FIG. 15 is a control block diagram of the ventilation system of the present disclosure; In the following description, the ventilation system 1E (see FIG. 17) according to the thirteenth embodiment is referred to as the thirteenth ventilation system 1F, and the ventilation system 1E (see FIGS. 18 and 19) according to the fourteenth embodiment is referred to as the thirteenth ventilation system 1F. The ventilation system 1E according to the fifteenth embodiment (see FIG. 20) is called the fifteenth ventilation system 1H, and the ventilation system 1E (see FIG. 21) according to the sixteenth embodiment is called the sixteenth ventilation system 1G. The ventilation system 1I according to the seventeenth embodiment (see FIG. 22) is called the seventeenth ventilation system 1J, and the ventilation system 1E (see FIG. 23) according to the eighteenth embodiment is called the eighteenth ventilation system. Call it 1K. In the following description, when simply referred to as "ventilation system 1E", it describes the configuration common to each of the 13th to 18th ventilation systems 1F to 1K.

A ventilation system 1E shown in FIG. 14 is one embodiment of the ventilation device of the present disclosure, and is installed in a building such as a building or a factory to realize ventilation of a target space in the building. The ventilation system 1</b>E includes an air supply unit 1020 , an exhaust unit 1030 , a compressor unit 1040 and a refrigerant circuit 1050 .

As shown in FIG. 14, the air supply unit 1020 includes a first casing 1021, an air supply fan 1022, and a first heat exchanger 1023. The first casing 1021 of the present embodiment is a cubic box made of heat-insulating panel members, and has a suction port 1024 and a discharge port 1025 formed on its side surfaces. The air supply fan 1022 and the first heat exchanger 1023 are arranged inside the first casing 1021 . When the air supply unit 1020 drives the air supply fan 1022, the air (outside air OA) of the outdoors (hereinafter referred to as outdoor 1000S2, see FIGS. 17 and 19) is taken into the inside of the first casing 1021, and the taken air is After exchanging heat with the refrigerant in the first heat exchanger 1023, the air (supply air SA) is supplied from the outlet 1025 indoors (hereinafter referred to as indoor 1000S1, see FIGS. 17 and 19). . The ventilation system 1E has an air supply flow path P1001 (an example of a first air flow path) for supplying the taken outside air OA to the indoor space 1000S1 from the outlet 1025 via the first casing 1021.

The first heat exchanger 1023 constitutes a refrigerant circuit 1050 which will be described later. The first heat exchanger 1023 is a cross-fin tube type or microchannel type heat exchanger, and is used to heat-exchange the refrigerant flowing in the first heat exchanger 1023 with the air (outside air OA) of the outdoor 1000S2. .

The air supply unit 1020 includes a supply air temperature sensor 1026 and an outside air temperature sensor 1027 . The supply air temperature sensor 1026 is arranged in the flow of air after passing through the first heat exchanger 1023 in the first casing 1021, and detects the temperature T1 of the supply air SA (hereinafter referred to as the blown air temperature T1). to detect Outside air temperature sensor 1027 is arranged in the flow of air before passing through first heat exchanger 1023 in first casing 1021, and detects temperature T2 of outside air OA (hereinafter referred to as outside air temperature T2). .

The air supply unit 1020 includes a first heat exchange temperature sensor 1055 and a first coolant temperature sensor 1056 . First heat exchange temperature sensor 1055 detects temperature Tb1 of first heat exchanger 1023 (in other words, the refrigerant in first heat exchanger 1023). The first refrigerant temperature sensor 1056 detects the temperature Ta2 of the refrigerant after passing through the first heat exchanger 1023 (outlet). Note that the first heat exchanger temperature sensor 1055 may be a pressure sensor that detects the pressure in the first heat exchanger 1023. In this case, the refrigerant temperature in the first heat exchanger 1023 is determined from the pressure detection value. Convert.

The exhaust unit 1030 includes a second casing 1031, an exhaust fan 1032, and a second heat exchanger 1033. The second casing 1031 of the present embodiment is a cubic box made of heat-insulating panel members, and has a suction port 1034 and a discharge port 1035 formed on its side surfaces. The exhaust fan 1032 and the second heat exchanger 1033 are arranged inside the second casing 1031 . When the exhaust unit 1030 drives the exhaust fan 1032, the indoor 1000S1 air (return air RA) is taken into the second casing 1031, and the taken air is heat-exchanged with the refrigerant in the second heat exchanger 1033. , the air (exhaust EA) is discharged from the outlet 1035 toward the outdoors 1000S2. The ventilation system 1E has a return air flow path P1002 (an example of a second air flow path) for releasing the air (return air RA) of the indoor 1000S1 through the second casing 1031 and the outlet 1035 to the outdoors 1000S2.

The second heat exchanger 1033 constitutes a refrigerant circuit 1050 which will be described later. The second heat exchanger 1033 is a cross-fin tube type or microchannel type heat exchanger, and is used to heat-exchange the refrigerant flowing in the second heat exchanger 1033 with the indoor 1000S1 air (return air RA). be done.

The exhaust unit 1030 includes a return air temperature sensor 1036. The return air temperature sensor 1036 is arranged in the flow of air before passing through the second heat exchanger 1033 inside the second casing 1031, and detects the temperature T3 of the air flowing into the second heat exchanger 1033. . In the following description, this temperature T3 will be referred to as intake air temperature T3. In the present disclosure, the intake air temperature T3 when only the air taken in from the indoor 1000S1 is allowed to pass through the second heat exchanger 1033 is the temperature of the air in the indoor 1000S1. The temperature of the indoor 1000S1 may be detected by a sensor (not shown) provided in the indoor 1000S1.

The exhaust unit 1030 includes a second heat exchanger temperature sensor 1057 and a second coolant temperature sensor 1058 . Second heat exchanger temperature sensor 1057 detects temperature Tb2 of second heat exchanger 1033 (in other words, the refrigerant in second heat exchanger 1033). The second refrigerant temperature sensor 1058 detects the temperature Tb3 of the refrigerant after passing through the second heat exchanger 1033 (outlet). The second heat exchanger temperature sensor 1057 may be a pressure sensor that detects the pressure in the second heat exchanger 1033. In this case, the refrigerant temperature in the first heat exchanger 1023 can be determined from the pressure detection value. Convert.

The compressor unit 1040 includes a third casing 1041, a compressor 1042, a four-way switching valve 1043, and an expansion valve 1044. Although the compressor unit 1040 of this embodiment includes the third casing 1041, the third casing 1041 may be omitted. In this case, it is preferable to accommodate the compressor 1042 and the four-way switching valve 1043 in the first casing 1021 of the air supply unit 1020 or the second casing 1031 of the exhaust unit 1030 . In the ventilation system 1E of this embodiment, the expansion valve 1044 is housed in the compressor unit 1040. may be accommodated.

The compressor unit 1040 includes a low pressure sensor 1052, a discharge pressure sensor 1053, and a discharge temperature sensor 1054. Low-pressure sensor 1052 detects pressure PL of the refrigerant sucked into compressor 1042 . In the following description, this pressure PL will also be referred to as the low pressure PL. A discharge pressure sensor 1053 detects the pressure PH of the refrigerant discharged from the compressor 1042 . In the following description, this pressure PH is also referred to as high pressure PH. Discharge temperature sensor 1054 detects temperature Ta1 of refrigerant discharged from compressor 1042 .

The compressor 1042 sucks in low-pressure gaseous refrigerant and discharges high-pressure gaseous refrigerant. Compressor 1042 includes a motor whose operating speed can be adjusted by inverter control. The compressor 1042 is of a variable capacity type (capacity variable type) whose capacity (capacity) can be changed by inverter-controlling the motor. However, the compressor 1042 may be of the constant capacity type. Note that the compressor 1042 used in the ventilation system 1E of the present disclosure may be configured by connecting two or more compressors in parallel.

The four-way switching valve 1043 reverses the flow of the refrigerant in the refrigerant pipe, switches the refrigerant discharged from the compressor 1042 to one of the first heat exchanger 1023 and the second heat exchanger 1033, and supplies the refrigerant. As a result, the ventilation system 1E has a cooling operation mode for cooling the outside air OA (hereinafter also referred to as a first operation mode M1) and a heating operation mode for heating the outside air OA (hereinafter also referred to as a second operation mode M2). It can be done by switching. The expansion valve 1044 is composed of an electrically operated valve capable of adjusting the flow rate and pressure of the refrigerant. In the ventilation system 1E, the opening degree of the expansion valve 1044 is controlled to adjust the pressure of the refrigerant supplied to the first heat exchanger 1023 or the second heat exchanger 1033.

The refrigerant circuit 1050 includes a compressor 1042, a four-way switching valve 1043, an expansion valve 1044, a first heat exchanger 1023, a second heat exchanger 1033, and refrigerant pipes 1051 (a liquid pipe 1051L and a gas pipe 1051G) connecting these. contains. Refrigerant circuit 1050 circulates the refrigerant between first heat exchanger 1023 and second heat exchanger 1033 .

In the ventilation system 1E configured as described above, when the outside air OA is cooled and supplied by the air supply unit 1020 (in the first operation mode M1), the four-way switching valve 1043 is held in the state indicated by the solid line in FIG. The high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1042 flows into the second heat exchanger 1033 of the exhaust unit 1030 via the four-way switching valve 1043 . At this time, the second heat exchanger 1033 functions as a condenser, and the refrigerant flowing through the second heat exchanger 1033 exchanges heat with the return air RA due to the operation of the exhaust fan 1032 to condense and liquefy. The liquefied refrigerant is decompressed by the expansion valve 1044 and flows into the first heat exchanger 1023 . At this time, the first heat exchanger 1023 functions as an evaporator, and in the first heat exchanger 1023, the refrigerant exchanges heat with the outside air OA and evaporates. The outside air OA cooled by the evaporation of the refrigerant is supplied by the air supply fan 1022 as the supply air SA to the indoor 1000S1. The refrigerant evaporated in first heat exchanger 1023 returns to compressor unit 1040 through refrigerant pipe 1051 (gas pipe 1051G) and is sucked into compressor 1042 through four-way switching valve 1043 .

In the ventilation system 1E configured as described above, when the air supply unit 1020 heats and supplies the outside air OA (in the second operation mode M2), the four-way switching valve 1043 is held in the state indicated by the dashed line in FIG. The high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1042 passes through the four-way switching valve 1043 and flows into the first heat exchanger 1023 of the air supply unit 1020 . At this time, the first heat exchanger 1023 functions as a condenser, and in the first heat exchanger 1023, the refrigerant exchanges heat with the outside air OA to condense and liquefy. The outside air OA heated by condensation of the refrigerant is supplied to the indoor 1000S1 by the air supply fan 1022 . The refrigerant liquefied in the first heat exchanger 1023 passes through the refrigerant pipe 1051 (liquid pipe 1051L), reaches the compressor unit 1040, is decompressed to a predetermined low pressure by the expansion valve 1044, and further flows into the second heat exchanger 1033. do. At this time, the second heat exchanger 1033 functions as an evaporator, and in the second heat exchanger 1033, the refrigerant evaporates by exchanging heat with the return air RA. The refrigerant evaporated/vaporized in the second heat exchanger 1033 is sucked into the compressor 1042 via the four-way switching valve 1043 .

(Regarding the control unit)
FIG. 15 is a control block diagram of the ventilation system 1E. As shown in FIG. 15, the ventilation system 1E has a controller 1018. As shown in FIG. The control unit 1018 is a device that controls the operation of the ventilation system 1E, and is configured by, for example, a microcomputer having a processor such as a CPU and a memory such as RAM and ROM. The control unit 1018 may be implemented as hardware using LSI, ASIC, FPGA, or the like. Control unit 1018 exhibits a predetermined function when the processor executes a program installed in the memory.

The controller 1018 is connected to the air supply fan 1022, the exhaust fan 1032, the compressor 1042, the four-way switching valve 1043, and the expansion valve 1044. The control unit 1018 includes a supply air temperature sensor 1026, an outside air temperature sensor 1027, a return air temperature sensor 1036, a low pressure sensor 1052, a discharge pressure sensor 1053, a discharge temperature sensor 1054, a first heat exchanger temperature sensor 1055, and a first refrigerant temperature sensor. 1056 , a second heat exchanger temperature sensor 1057 and a second coolant temperature sensor 1058 . The control unit 1018 controls the operation of the air supply fan 1022, the exhaust fan 1032, the compressor 1042, the four-way switching valve 1043, the expansion valve 1044, and the low pressure increasing means 1080 based on the detected values of the respective sensors.

Control unit 1018 calculates saturation temperature TS of second heat exchanger 1033 functioning as an evaporator based on the value (high pressure PH) detected by discharge pressure sensor 1053 during operation in second operation mode M2. . Control unit 1018 acquires low pressure PL of refrigerant circuit 1050 from the detection value of low pressure sensor 1052 . Control unit 1018 acquires evaporation temperature TE of second heat exchanger 1033 from the value detected by second heat exchanger temperature sensor 1057 (temperature Tb2). Alternatively, the control unit 1018 acquires the evaporation temperature TE of the second heat exchanger 1033 from the acquired low pressure PL.

As described above, the ventilation system 1E of the present disclosure has the first operation mode M1 and the second operation mode M2 as user-selectable operation modes. When the user selects the first operation mode M1 and starts the operation of the ventilation system 1E, the first heat exchanger 1023 can be used as an evaporator and the second heat exchanger 1033 can be used as a condenser. Thus, the controller 1018 switches the four-way selector valve 1043 . When the user selects the second operation mode M2 to start the operation of the ventilation system 1E, the first heat exchanger 1023 can be used as a condenser and the second heat exchanger 1033 can be used as an evaporator. Thus, the controller 1018 switches the four-way selector valve 1043 . In this description, "when the user selects the second operation mode M2 and starts the operation of the ventilation system 1E", the four-way switching valve 1043 has already been switched. and when the switching of valve 1043 has not yet been completed.

When the ventilation system 1E of the present disclosure is started by selecting the second operation mode M2, the control unit 1018 may perform the low pressure increase control (first control). In the following description, the operation mode of the ventilation system 1E when the control unit 1018 executes the low pressure increase control is referred to as a low pressure increase mode M3. When the user selects the second operation mode M2 and the operation of the ventilation system 1E is started, the control unit 1018 activates the compressor 1042 to increase the low pressure PL of the refrigerant circuit 1050 or the evaporation of the second heat exchanger 1033. Detect temperature TE. When the control unit 1018 determines that the low pressure PL or the evaporating temperature TE has fallen below the respective set threshold values (referred to as first threshold values in this description), the operation mode of the ventilation system 1E is changed to the low pressure increase mode M3. to perform low-pressure pressure rise control. Note that the control unit 1018 does not switch the operation mode of the ventilation system 1E to the low pressure increase mode M3 (low pressure increase control ).

The ventilation system 1E having the refrigerant circuit 1050 operates in the second operation mode M2 by using the first heat exchanger 1023 as a condenser and the second heat exchanger 1033 as an evaporator. , the heat of the exhaust EA can be recovered in the refrigerant in the refrigerant circuit 1050 . In the ventilation system 1E in this case, when the temperature of the exhaust EA drops, frost may occur in the second heat exchanger 1033. In this case, the low-pressure pressure PL of the refrigerant circuit 1050 drops, and the compressor 1042 continues to operate. becomes difficult. In such a case, the control unit 1018 selects the low pressure increase mode M3 to enable continuous operation of the compressor 1042 . In addition, "continuous operation of the compressor" here means that after the compressor starts, it does not reach a state where operation cannot be continued (has no choice but to stop) due to a decrease in the low pressure of the refrigerant circuit, etc. can be continued.

The control unit 1018 has a first threshold value X for judging whether or not the conditions for operating in the second operation mode M2 are met when the ventilation system 1E is activated by selecting the second operation mode M2. remembered. In the ventilation system 1E of the present disclosure, the first threshold X is the pressure threshold X1, which is the first threshold X for the low pressure PL of the refrigerant circuit 1050, and the first threshold X for the evaporation temperature TE of the second heat exchanger 1033. , the indoor temperature threshold X3 that is the first threshold X for the intake air temperature T3 that is the temperature of the air in the indoor 1000S1, and the first threshold for the outside temperature T2 that is the temperature of the air in the outdoor 1000S2 An outside air temperature threshold value X4, which is X, is stored. Note that the control unit 1018 of the present embodiment stores the pressure threshold X1, the refrigerant temperature threshold X2, the indoor temperature threshold X3, and the outdoor temperature threshold X4 as the first threshold X, but the ventilation system 1E of the present disclosure, Any one of the threshold values X1 to X4 may be stored in the control unit 1018. FIG.

In the control unit 1018, when the control unit 1018 is executing the low pressure increase control (in other words, when the ventilation system 1E is operated in the low pressure increase mode M3), the second operation mode M2 A second threshold value Y is stored for judging whether or not the drivable conditions are met. In the ventilation system 1E of the present disclosure, the second threshold Y is the pressure threshold Y1, which is the second threshold Y for the low pressure PL of the refrigerant circuit 1050, and the second threshold Y for the saturation temperature TS of the second heat exchanger 1033. and the air temperature threshold Y3, which is the second threshold Y for the intake air temperature T3 of the second heat exchanger 1033, are stored. Note that the control unit 1018 of the present embodiment stores the pressure threshold value Y1, the saturation temperature threshold value Y2, and the air temperature threshold value Y3 as the second threshold value Y, but the ventilation system 1E of the present disclosure stores the , pressure threshold Y1, saturation temperature threshold Y2, or air temperature threshold Y3 may be stored.

(Regarding control at the start of operation of the ventilation system)
In the ventilation system 1E, the controller 1018 controls the operation at the start of operation according to the flow shown in FIG.

As shown in FIG. 16, when the operation of the ventilation system 1E is started, the control unit 1018 first determines whether or not the second operation mode M2 has been selected and started (S2501). In step (S2501), when the control unit 1018 determines that the second operation mode M2 has been selected and started (YES), the next step (S2502) is executed. In step (S2501), if the control unit 1018 determines that the second operation mode M2 has not been selected and started (NO), the control unit 1018 ends the control at the start of operation. In step (S2502), control unit 1018 activates compressor 1042, and proceeds to the next step (S2503).

In step (S2503), the control unit 1018 determines the low pressure PL of the refrigerant circuit 1050. In step (S2503), if the control unit 1018 determines that the low pressure PL is not lower than the first threshold value X (pressure threshold value X1) for the low pressure PL (NO), proceed to the next step (S2504). Execute. In step (S2503), if the control unit 1018 determines that the low pressure PL is lower than the first threshold value X (pressure threshold value X1) (YES), the next step (S2507) is executed.

At step (S2504), the control unit 1018 determines the evaporation temperature TE of the second heat exchanger 1033. In step (S2504), if the control unit 1018 determines that the evaporation temperature TE is not lower than the first threshold value X (refrigerant temperature threshold value X2) for the evaporation temperature TE (NO), the next step (S2505). to run. In step (S2504), if the control unit 1018 determines that the evaporation temperature TE has fallen below the first threshold value X (refrigerant temperature threshold value X2) (YES), the next step (S2507) is executed.

At step (S2505), the control unit 1018 makes a determination about the intake air temperature T3, which is the air temperature of the indoor 1000S1. In step (S2505), if control unit 1018 determines that intake air temperature T3 is not lower than first threshold value X (indoor temperature threshold value X3) for intake air temperature T3 (NO), the next step ( S2506) is executed. In step (S2505), if control unit 1018 determines that intake air temperature T3 has fallen below first threshold value X (indoor temperature threshold value X3) (YES), the next step (S2507) is executed.

In step (S2506), the control unit 1018 makes a determination about the outside air temperature T2, which is the air temperature of the outdoor 1000S2. In step (S2506), if the control unit 1018 determines that the outside temperature T2 is not lower than the first threshold value X (outside temperature threshold value X4) for the outside temperature T2 (NO), the next step (S2512). to run. In step (S2506), if the control unit 1018 determines that the outside temperature T2 is lower than the first threshold value X (the outside temperature threshold value X4) (YES), the next step (S2507) is executed.

At step (S2507), the control unit 1018 executes low-pressure pressure increase control. Specifically, in step (S2507), the control unit 1018 switches the operation mode of the ventilation system 1E to the low pressure increase mode M3 to operate the ventilation system 1E. When the control unit 1018 executes the low pressure increase control, the ventilation system 1E uses the low pressure increase means 1080 which will be described later. After starting the execution of the low-pressure pressure increase control, the control unit 1018 further executes step (S2508).

In step (S2508), the control unit 1018 determines the low pressure PL of the refrigerant circuit 1050 during execution of the low pressure increase control. In step (S2508), when the control unit 1018 determines that the low pressure PL does not exceed the second threshold value Y (pressure threshold value Y1) (NO), step (S2509) is executed. In step (S2508), if control unit 1018 determines that low pressure PL exceeds pressure threshold value Y1 (YES), step (S2511) is executed.

In step (S2509), the control unit 1018 determines the saturation temperature TS of the second heat exchanger 1033. If it is determined in step (S2509) that the saturation temperature TS does not exceed the second threshold Y (saturation temperature threshold Y2) for the saturation temperature TS (NO), step (S2510) is executed. If it is determined in step (S2509) that the saturation temperature TS has exceeded the saturation temperature threshold value Y2 (YES), step (S2511) is executed.

At step (S2510), the control unit 1018 makes a determination about the intake air temperature T3 of the second heat exchanger 1033. If it is determined in step (S2510) that the intake air temperature T3 does not exceed the second threshold value Y (air temperature threshold value Y3) for the intake air temperature T3 (NO), the process returns to step (S2508). In step (S2510), when control unit 1018 determines that intake air temperature T3 has exceeded air temperature threshold value Y3 (YES), step (S2511) is executed.

At step (S2511), the control unit 1018 terminates the low pressure increase control. After completing the low pressure increase control, the control unit 1018 executes step (S2512). In step (S2512), the control unit 1018 switches the operation mode of the ventilation system 1E to the second operation mode M2 to operate the ventilation system 1E. Thus, the control of the operation at the start of operation by the control unit 1018 (the flow shown in FIG. 16) ends.

The determination conditions of steps (S2508) to (S2510) are conditions for determining whether or not the compressor 1042 can be reliably operated continuously in the second operation mode M2. In other words, if any of the conditions in steps (S2508) to (S2510) are satisfied, the conditions are met to ensure continuous operation of the compressor 1042 in the second operation mode M2. By executing the low-pressure pressure increase control (first control), the ventilation system 1E is able to prepare conditions for reliably allowing the compressor 1042 to continue operating. The ventilation system 1E prepares the conditions for ensuring the continuous operation of the compressor 1042, and then starts operation in the second operation mode M2, thereby ensuring the continuous operation of the compressor 1042. Become. In the present disclosure, the determination of whether to proceed to step (S2507) is based on the low pressure PL in step (S2503), the evaporation temperature TE in step (S2504), and the Judgment based on intake air temperature T3 and judgment based on outside air temperature T2 in step (S2506) are made, but judgment may be made in only one of steps (S2503) to (S2506). . In the present disclosure, the determination of whether to proceed to step (S2511) is based on the low pressure PL in step (S2508), the saturation temperature TS in step (S2509), and the intake air The determination is made based on the temperature T3, but the determination may be made by only one of steps (S2508) to (S2510).

(For a detailed embodiment of the ventilation system)
As shown in FIG. 15, the ventilation system 1E of the present disclosure includes low pressure pressure increasing means 1080. As shown in FIG. Each of the first to sixth ventilation systems 1F to 1K described below differs in the configuration of the low-pressure pressure increasing means 1080, respectively. When the ventilation system 1E is activated by selecting the second operation mode M2, the low pressure increase means 1080 is used when executing the low pressure increase control (see FIG. 16) described above. In the following description, the same reference numerals are given to the parts common to the first to sixth ventilation systems 1F to 1K, and the repeated explanation of the parts given the same reference numerals will be omitted.

(About the 13th ventilation system 1F)
FIG. 17 shows a thirteenth ventilation system 1F according to a thirteenth embodiment of the ventilation system 1E of the present disclosure. The thirteenth ventilation system 1F shown in FIG. 17 includes an air supply unit 1020, an exhaust unit 1030 and a compressor unit 1040. The thirteenth ventilation system 1F is configured integrally with an air supply unit 1020, an exhaust unit 1030, and a compressor unit 1040. As shown in FIG. Note that the thirteenth ventilation system 1F shown in the present embodiment is configured integrally with the air supply unit 1020, the exhaust unit 1030, and the compressor unit 1040, but the ventilation system 1E of the present disclosure includes the air supply unit 1020 (the 1 heat exchanger 1023 and air supply fan 1022), exhaust unit 1030 (second heat exchanger 1033 and exhaust fan 1032), and compressor unit 1040 (compressor 1042) may be arranged separately.

The thirteenth ventilation system 1F can be placed outdoors, for example, 1000S2. In the thirteenth ventilation system 1F shown in FIG. 17, the outlet 1025 of the air supply unit 1020 and the inlet 1034 of the exhaust unit 1030 are directly attached to the outer wall surface of the building 1000B. In this embodiment, the case where the thirteenth ventilation system 1F is placed outdoors 1000S2 is exemplified, but the whole or part of the thirteenth ventilation system 1F may be placed indoors 1000S1.

As shown in FIG. 17, the thirteenth ventilation system 1F includes an air conditioner 1081 that is the first low-pressure pressure increasing means 1080 . The air conditioner 1081 includes an indoor unit 1081a, an outdoor unit 1081b, and a refrigerant circuit 1081d including a refrigerant pipe 1081c.

(About air conditioners)
The air conditioner 1081 is installed in the building 1000B and realizes air conditioning of the air-conditioned space (indoor 1000S1). The air conditioner 1081 cools and heats the air-conditioned space by performing vapor compression refrigeration cycle operation. In this embodiment, the air conditioner 1081 that performs vapor compression refrigeration cycle operation is exemplified, but the system of the air conditioner as the low pressure pressure increasing means 1080 is not limited to this. It may be an air conditioner that realizes air conditioning of the target space with cold water/hot water that is supplied.

The air conditioner 1081 has an indoor unit 1081a arranged indoors 1000S1 and an outdoor unit 1081b arranged outdoors 1000S2. The indoor unit 1081a and the outdoor unit 1081b are connected by a refrigerant pipe 1081c. The air conditioner 1081 has an air conditioning refrigerant circuit 1081d. The air-conditioning refrigerant circuit 1081d includes a compressor, a four-way switching valve, an outdoor heat exchanger, an expansion valve, an indoor heat exchanger, and the like (all not shown). The air-conditioning refrigerant circuit 1081d circulates the refrigerant between the indoor unit 1081a and the outdoor unit 1081b via the refrigerant pipe 1081c. The air-conditioning refrigerant circuit 1081d is separated from the refrigerant circuit 1050 of the thirteenth ventilation system 1F and constitutes an independent circuit. Air conditioner 1081 detects the temperature of indoor 1000S1.

In the thirteenth ventilation system 1F, the temperature of the indoor 1000S1 is raised by operating the air conditioner 1081 when executing the low-pressure pressure increase control. In the thirteenth ventilation system 1F, when the control unit 1018 determines that the temperature of the air in the indoor 1000S1 detected by the air conditioner 1081 exceeds the second threshold Y (air temperature threshold Y3 for the intake air temperature T3) (Fig. 15), the operation of the exhaust fan 1032 is started. In the thirteenth ventilation system 1F, this causes the second heat exchanger 1033 to suck in air having a temperature higher than the air temperature threshold Y3 for the suction air temperature T3. In the thirteenth ventilation system 1F, frosting of the second heat exchanger 1033 is suppressed by operating the air conditioner 1081 . In the thirteenth ventilation system 1F, the air conditioner 1081 can increase the intake air temperature T3 of the second heat exchanger 1033 functioning as an evaporator, thereby suppressing frosting of the second heat exchanger 1033. At the same time, a decrease in the low pressure PL of the refrigerant circuit 1050 can be suppressed.

In the thirteenth ventilation system 1F, when the second operation mode M2 is selected and activated, the control unit 1018 may forcibly activate the air conditioner 1081. In the thirteenth ventilation system 1F, when the second operation mode M2 is selected and activated, the control unit 1018 provides the user with information prompting activation of the air conditioner 1081, and the user activates the air conditioner 1081. may be In addition, when the thirteenth ventilation system 1F and the air conditioner 1081 are not interlocked, the control unit 1018 provides the user with information prompting the activation of the air conditioner 1081, and after a predetermined time has passed, the exhaust fan 1032 is turned on. The intake air temperature T3 may be measured during operation, and the control unit 1018 may activate the air conditioner 1081 based on the measured value. In the thirteenth ventilation system 1F, the control unit 1018 is configured to detect the operating state of the air conditioner 1081, and when the second operation mode M2 is selected and activated, the air conditioner 1081 is in operation. When the control unit 1018 detects that there is a problem, the control unit 1018 may execute the low pressure increase control.

In the thirteenth ventilation system 1F, when the low-pressure pressure increase control ends, the control unit 1018 may stop the air conditioner 1081, or the control unit 1018 may continue the operation of the air conditioner 1081.

(About the 14th ventilation system 1G)
FIG. 18 is a schematic configuration diagram of a ventilation system according to a fourteenth embodiment of the present disclosure; FIG. 19 is a schematic configuration diagram showing the installation state of the ventilation system in the building according to the fourteenth and fifteenth embodiments of the present disclosure. A fourteenth ventilation system 1G shown in FIGS. 18 and 19 is a fourteenth embodiment of the ventilation system 1E of the present disclosure. The fourteenth ventilation system 1G is different from the thirteenth ventilation system 1F in that it includes a second low pressure increase means 1082 which is the second low pressure increase means 1080 .

As shown in FIG. 18, the 14th ventilation system 1G includes a second low-pressure pressure increasing means 1082. The second low-pressure pressure increasing means 1082 is composed of a bypass pipe 1082a and a valve 1082b. The valve 1082b is, for example, an electric valve, an electromagnetic valve, or the like. The bypass pipe 1082a is a pipe that bypasses the discharge pipe 45 of the compressor 1042 and the liquid pipe 1051L. The bypass pipe 1082a can supply the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1042 to the second heat exchanger 1033 via the liquid pipe 1051L. Valve 1082b can switch the flow of refrigerant in bypass pipe 1082a. When the valve 1082b is opened, the gaseous refrigerant can flow through the bypass pipe 1082a, and when the valve 1082b is closed, the flow of the gaseous refrigerant in the bypass pipe 1082a can be stopped.

The fourteenth ventilation system 1G opens the valve 1082b and supplies gaseous refrigerant to the second heat exchanger 1033 through the bypass pipe 1082a, thereby increasing the temperature of the refrigerant flowing through the second heat exchanger 1033, Thereby, frosting of the second heat exchanger 1033 can be suppressed. In the fourteenth ventilation system 1G, the second low pressure pressure increasing means 1082 can increase the saturation temperature TS at the outlet of the second heat exchanger 1033 functioning as an evaporator, thereby increasing the temperature of the second heat exchanger 1033. As well as suppressing frosting, a decrease in the low pressure PL of the refrigerant circuit 1050 can be suppressed.

In the 14th ventilation system 1G, the control unit 1018 closes the valve 1082b to terminate the low pressure increase control.

(Regarding the 15th ventilation system 1H)
FIG. 20 is a schematic configuration diagram of a ventilation system according to a fifteenth embodiment of the present disclosure; A fifteenth ventilation system 1H shown in FIGS. 19 and 20 is a fifteenth embodiment of the ventilation system 1E of the present disclosure. As shown in FIG. 20, the fifteenth ventilation system 1H differs from the thirteenth and

fourteenth ventilation systems

1F and 1G in that it includes a third low pressure increase means 1083 which is a third low pressure increase means 1080. FIG.

The fifteenth ventilation system 1H includes a third low-pressure pressure increasing means 1083. The third low-pressure pressure increasing means 1083 is composed of a bypass duct 1083a and a damper 1083b. The bypass duct 1083a is formed inside the third casing 1041 and communicates the discharge side of the first casing 1021 and the suction side of the second casing. Bypass duct 1083 a can supply part of the air flow (supply air SA) generated in air supply unit 1020 to the suction side of exhaust fan 1032 in exhaust unit 1030 . The damper 1083b includes a valve body and an opening/closing mechanism that can open/close the flow of the supply air SA in the bypass duct 1083a. When the damper 1083b is opened, the supply air SA can flow through the bypass duct 1083a, and when the damper 1083b is closed, the flow of the supply air SA in the bypass duct 1083a can be stopped.

In the fifteenth ventilation system 1H, when the control unit 1018 determines that the blown air temperature T1 detected by the supply air temperature sensor 1026 exceeds the second threshold value Y (air temperature threshold value Y3 for the intake air temperature T3) (FIG. 15 ), and the damper 1083b is opened. The fifteenth ventilation system 1H opens the damper 1083b and supplies the intake air SA to the intake side of the second heat exchanger 1033 through the bypass duct 1083a, thereby reducing the intake air temperature T3 of the second heat exchanger 1033 to can be raised. In the fifteenth ventilation system 1H, the intake air temperature T3 of the second heat exchanger 1033 functioning as an evaporator can be raised by the third low-pressure pressure raising means 1083. In addition to suppressing sticking, a decrease in the low pressure PL of the refrigerant circuit 1050 can be suppressed.

In the fifteenth ventilation system 1H, the control unit 1018 closes the damper 1083b to terminate the low pressure increase control.

(About the 16th ventilation system 1I)
FIG. 21 is a schematic configuration diagram of a ventilation system according to a sixteenth embodiment of the present disclosure; A sixteenth ventilation system 1I shown in FIG. 21 is a sixteenth embodiment of the ventilation system 1E of the present disclosure. As shown in FIG. 21, the sixteenth ventilation system 1I differs from the thirteenth to fifteenth ventilation systems 1F to 1H in the configuration of the low pressure increasing means 1080 . The sixteenth ventilation system 1I differs from the above-mentioned thirteenth to fifteenth ventilation systems 1F to 1H in that the air supply unit 1020, the exhaust unit 1030, and the compressor unit 1040 are separated and arranged indoors 1000S1. ing. In the 16th ventilation system 1I, the air supply unit 1020, the exhaust unit 1030, and the compressor unit 1040 are arranged in the space behind the ceiling of the room R1, which is the ventilation target space of the indoor 1000S1 (hereinafter referred to as the ceiling space R2). be. Although the sixteenth ventilation system 1I is placed indoors 1000S1 in this embodiment, the sixteenth ventilation system 1I may be placed entirely or partially outdoors 1000S2.

In the 16th ventilation system 1I, the air supply unit 1020 constitutes part of the air supply air passage 1028 . The supply air passage 1028 is an air passage that connects the indoor 1000S1 and the outdoor 1000S2. The air supply air passage 1028 is composed of a first air supply duct 1028a, a second air supply duct 1028b, and an air supply unit 1020. As shown in FIG. First air supply duct 1028a connects outdoor 1000S2 and air supply unit 1020 . Specifically, the first air supply duct 1028a has a suction port 1028c at one end, and the suction port 1028c is connected to an opening in the outer wall of the building 1000B and communicates with the outdoors 1000S2. The other end of first air supply duct 1028a is connected to air supply unit 1020 . The second air supply duct 1028b connects the air supply unit 1020 and the indoor space 1000S1. Specifically, the second air supply duct 1028b has an air outlet 1028d at one end, and the air outlet 1028d is connected to an opening in the ceiling surface of the indoor 1000S1 and communicates with the indoor 1000S1. The other end of second air supply duct 1028b is connected to air supply unit 1020 .

In the sixteenth ventilation system 1I, the exhaust unit 1030 constitutes part of the exhaust air passage 1038. The exhaust air passage 1038 is an air passage that communicates the indoor 1000S1 and the outdoor 1000S2. The exhaust air passage 1038 is composed of a first exhaust duct 1038 a , a second exhaust duct 1038 b and an exhaust unit 1030 . The first exhaust duct 1038a connects the outdoor 1000S2 and the exhaust unit 1030 . Specifically, the first exhaust duct 1038a has an exhaust port 1038c at one end, and the exhaust port 1038c is connected to an opening in the outer wall of the building 1000B and communicates with the outdoors 1000S2. The other end of first exhaust duct 1038 a is connected to exhaust unit 1030 . The second exhaust duct 1038b connects the exhaust unit 1030 and the indoor space 1000S1. Specifically, the second exhaust duct 1038b has a suction port 1038d at one end, and the suction port 1038d is connected to an opening in the ceiling surface of the indoor space 1000S1 and communicates with the indoor space 1000S1. The other end of second exhaust duct 1038b is connected to exhaust unit 1030 .

The 16th ventilation system 1I is equipped with a fourth low pressure pressure increasing means 1084. The fourth low pressure pressure increasing means 1084 is composed of a bypass duct 1084a and a damper 1084b. Bypass duct 1084 a communicates second air supply duct 1028 b connected to the blowout side of air supply unit 1020 and second exhaust duct 1038 b connected to the suction side of exhaust unit 1030 . Bypass duct 1084 a can supply part of the air flow (supply air SA) generated in air supply unit 1020 to the suction side of exhaust fan 1032 in exhaust unit 1030 . The damper 1084b includes a valve element and an opening/closing mechanism that can open and close the flow of the supply air SA in the bypass duct 1084a. When the damper 1084b is opened, the supply air SA can flow through the bypass duct 1084a, and when the damper 1084b is closed, the flow of the supply air SA in the bypass duct 1084a can be stopped.

In the sixteenth ventilation system 1I, when the control unit 1018 determines that the blowing air temperature T1 detected by the supply air temperature sensor 1026 exceeds the second threshold value Y (air temperature threshold value Y3 for the intake air temperature T3), the damper 1084b open. The sixteenth ventilation system 1I opens the damper 1084b and supplies the intake air SA to the intake side of the second heat exchanger 1033 through the bypass duct 1084a, thereby reducing the intake air temperature T3 of the second heat exchanger 1033 to can be raised. In the sixteenth ventilation system 1I, the fourth low-pressure pressure increasing means 1084 can increase the intake air temperature T3 of the second heat exchanger 1033 functioning as an evaporator. In addition to suppressing sticking, a decrease in the low pressure PL of the refrigerant circuit 1050 can be suppressed.

In the 16th ventilation system 1I, the control unit 1018 closes the damper 1084b to terminate the low pressure increase control.

(About the 17th ventilation system 1J)
FIG. 22 is a schematic configuration diagram of a ventilation system according to a seventeenth embodiment of the present disclosure; A seventeenth ventilation system 1J shown in FIG. 22 is a seventeenth embodiment of the ventilation system 1E of the present disclosure. As shown in FIG. 22, the 17th ventilation system 1J differs from the 16th ventilation system 1I in the configuration of the low-pressure pressure increasing means 1080 . The seventeenth ventilation system 1J is provided with fifth low-pressure increasing means 1085 which is the fifth low-pressure increasing means 1080 .

The fifth low-pressure pressure increasing means 1085 is composed of an intake duct 1085a, a damper 1085b, and a ceiling space temperature sensor 1085c. The intake duct 1085a is connected to the second exhaust duct 1038b and is open in the ceiling space R2. In the seventeenth ventilation system 1J, the air in the ceiling space R2 taken into the exhaust unit 1030 can be circulated to the second heat exchanger 1033. The damper 1085b is a valve that can open and close the flow of air in the intake duct 1085a. When the damper 1085b is opened, the air in the ceiling space R2 can be sucked into the intake duct 1085a, and when the damper 1085b is closed, the air circulation in the intake duct 1085a can be stopped.

In the 17th ventilation system 1J, the ceiling space temperature sensor 1085c is connected to the control unit 1018. The ceiling space temperature sensor 1085c can detect the temperature of the air in the ceiling space R2. In the seventeenth ventilation system 1J, when the control unit 1018 determines that the temperature T4 of the air in the ceiling space R2 exceeds the second threshold value Y (the air temperature threshold value Y3 for the intake air temperature T3), the damper 1085b is opened, The air in the ceiling space R2 is circulated to the second heat exchanger 1033 via the intake duct 1085a.

The seventeenth ventilation system 1J opens the damper 1085b and supplies the air in the ceiling space R2 to the suction side of the second heat exchanger 1033 through the intake duct 1085a. T3 can be elevated. In the seventeenth ventilation system 1J, the fifth low-pressure pressure increasing means 1085 can increase the intake air temperature T3 of the second heat exchanger 1033 functioning as an evaporator. In addition to suppressing sticking, a decrease in the low pressure PL of the refrigerant circuit 1050 can be suppressed.

In the 17th ventilation system 1J, the control unit 1018 closes the damper 1085b, thereby ending the low pressure increase control.

(About the 18th ventilation system 1K)
FIG. 23 is a schematic configuration diagram of a ventilation system according to an eighteenth embodiment of the present disclosure; An eighteenth ventilation system 1K shown in FIG. 23 is an eighteenth embodiment of the ventilation system 1E of the present disclosure. As shown in FIG. 23, the 18th ventilation system 1K differs from the 16th and

17th ventilation systems

1I and 1J in the configuration of the low-pressure pressure increasing means 1080 .

The 18th ventilation system 1K is provided with a sixth low pressure increase means 1086 which is the sixth low pressure increase means 1080 . The sixth low-pressure pressure increasing means 1086 includes a louver 1086a configured to be rotatable about a rotation axis and a mechanism (not shown) for rotating the louver 1086a. The louver 1086a is arranged near the outlet 1028d in the indoor space 1000S1. The louver 1086a rotates between a storage position 1000P1 in which the blowing direction of the supply air SA blown out from the blowout port 1028d is not changed, and an operating position 1000P2 in which the blowing direction of the supply air SA blown out from the blowout port 1028d is changed. configured to be movable.

In the eighteenth ventilation system 1K, when the controller 1018 determines that the blown air temperature T1 detected by the supply air temperature sensor 1026 exceeds the second threshold value Y (the air temperature threshold value Y3 for the intake air temperature T3), the louvers 1086a is rotated from the retracted position 1000P1 to the operating position 1000P2. In the eighteenth ventilation system 1K, the supply air SA blown out from the outlet 1028d hits the louver 1086a, changes its blowing direction, and flows toward the suction port 1038d. In the eighteenth ventilation system 1K, the intake air temperature T3 of the second heat exchanger 1033 is raised by actively sucking the supply air SA, which has a higher temperature than the air in the indoor space 1000S1, from the suction port 1038d. In the eighteenth ventilation system 1K, the sixth low-pressure pressure increasing means 1086 can increase the intake air temperature T3 of the second heat exchanger 1033 functioning as an evaporator. In addition to suppressing sticking, a decrease in the low pressure PL of the refrigerant circuit 1050 can be suppressed.

In the 18th ventilation system 1K, the control unit 1018 changes the rotational position of the louver 1086a from the operating position 1000P2 to the retracted position 1000P1, thereby completing the low pressure increase control.

[Action and effect of the embodiment]
(1) The ventilation system 1E shown in the above embodiment has a refrigerant circuit in which a compressor 1042, a first heat exchanger 1023, and a second heat exchanger 1033 are connected by a refrigerant pipe 1051, and a refrigerant flows therein. 1050, an air supply fan 1022 that supplies the air of the outdoor 1000S2 to the indoor 1000S1 through the first heat exchanger 1023, an exhaust fan 1032 that exhausts the air of the indoor 1000S1 to the outdoor 1000S2 through the second heat exchanger 1033, and control a portion 1018; When causing the second heat exchanger 1033 to function as an evaporator, the control unit 1018 activates the compressor 1042 to reduce the low pressure PL of the refrigerant circuit 1050, the evaporation temperature TE of the second heat exchanger 1033, or the indoor 1000S1. The temperature (intake air temperature T3) or the temperature of the outdoor 1000S2 (outside temperature T2) is the low pressure PL of the refrigerant circuit 1050, the evaporation temperature TE of the second heat exchanger 1033, the intake air temperature T3, or the outside temperature T2. is below the first threshold value X, low-pressure pressure increase control is performed to increase the low-pressure pressure PL of the refrigerant circuit 1050 .

According to the ventilation system 1E having such a configuration, in the ventilation system including the refrigerant circuit 1050 capable of recovering heat from the exhaust EA, when the second heat exchanger 1033 functions as an evaporator, the compressor 1042 can be reliably operated continuously.

(2) In the fourteenth ventilation system 1G shown in the above embodiment, the refrigerant circuit 1050 includes the discharge pipe 45 of the compressor 1042, the second heat exchanger 1033, or the liquid pipe 1051L connected to the second heat exchanger 1033. and a valve 1082b provided in the bypass pipe 1082a. In the fourteenth ventilation system 1G, the controller 1018 opens the valve 1082b in the low-pressure pressure increase control (first control).

In this case, high-temperature and high-pressure gas refrigerant can be supplied to the second heat exchanger 1033 in the low-pressure pressure increase control. Thereby, frosting of the second heat exchanger 1033 can be suppressed.

(3) In the fourteenth ventilation system 1G shown in the above embodiment, when the valve 1082b is opened, the control unit 1018 controls the low pressure PL of the refrigerant circuit 1050, or the saturation temperature TS of the second heat exchanger 1033, Alternatively, the intake air temperature T3 of the exhaust fan 1032 exceeds the low pressure PL of the refrigerant circuit 1050, the saturation temperature TS of the second heat exchanger 1033, or the second threshold value Y for the intake air temperature T3 of the second heat exchanger 1033. When it is determined that it exceeds, the valve 1082b is closed.

In this case, when the conditions for the second heat exchanger 1033 to function as an evaporator are met during execution of the low-pressure pressure increase control, the low-pressure pressure increase control can be terminated.

(4) In each of the

ventilation systems

1F, 1H to 1K shown in the above embodiments, the control unit 1018 controls the intake air temperature T3 to the second heat exchanger 1033 in the low-pressure pressure increase mode M3 in which the low-pressure pressure increase control is performed. Air having a temperature higher than the second threshold value Y (air temperature threshold value Y3) is sucked.

In this case, air having a temperature higher than the second threshold value Y (air temperature threshold value Y3) can flow into the second heat exchanger 1033 during execution of the low-pressure pressure increase control. Thereby, frosting of the second heat exchanger 1033 can be suppressed.

(5) In the eighteenth ventilation system 1K shown in the above embodiment, the control unit 1018 moves the air blown out from the air supply fan 1022 to the suction side of the exhaust fan 1032 in the low pressure pressure increase mode M3 in which the low pressure pressure increase control is performed. Adjust the air blowing direction of the air supply fan 1022 so as to lead to the air.

In this case, air having a temperature higher than the second threshold value Y (air temperature threshold value Y3) for the intake air temperature T3 can flow into the second heat exchanger 1033 during execution of the low-pressure pressure increase control.

(6) The thirteenth ventilation system 1F shown in the above embodiment further includes an air conditioner 1081 that air-conditions the indoor 1000S1, and the control unit 1018 controls the air The exhaust fan 1032 is driven when the air temperature of the indoor 1000S1 becomes higher than the second threshold value Y (air temperature threshold value Y3) by the air conditioner 1081 .

The above-described embodiment and modifications are examples of techniques for suppressing frost formation. The techniques shown in the above-described embodiments and modifications are not limited to using only those techniques, and may be used in combination with one or more techniques shown in other embodiments and modifications.

According to the above-described embodiment and modification, by performing the above-described control, frost formation (for example, on the second heat exchanger) is suppressed, and air is supplied to the indoor space and to the outdoors. To make it possible to continue ventilation operation by exhaust without stopping. Suppression of frost formation is not limited to avoiding frost formation, but means to control frost growth even if frost formation occurs. In the ventilation device or ventilation system according to the embodiment and modifications, it is possible to maintain the comfort of the living room space by suppressing frost formation and continuing the ventilation operation.

The numbers of air supply units and exhaust units shown in the above-described embodiment and modifications are shown as an example. The number of air supply units and the number of exhaust units may be determined according to the living room space. For example, the number of air supply units may be one or more, and the number of exhaust units may also be one or more. Also, the control unit shown in the above-described embodiment and modified example is shown as one aspect, and may be included in any device.

Although the embodiments have been described above, it will be understood that various changes in form and detail are possible without departing from the spirit and scope of the claims. Various modifications and improvements such as combination or replacement with part or all of other embodiments are possible.

This application claims priority based on Japanese Patent Application Nos. 2021-204798 and 2021-205609 filed on December 17, 2021, and the entire contents of these Japanese Patent Applications are incorporated herein by reference. do.

1, 1A, 1B, 1C, 1D_1, 1D_2, 1D_3 ventilator 2, 2C air conditioner 10, 110, 210, 310, 410A, 410B, 510A, 510B, 510C, 730 exhaust unit 11 fan 12 second heat exchanger 13 , 113, 213, 313, 413A, 413B Control unit 14 Temperature detection unit 15 Driving motor 16 Electric valve 20, 220A, 220B, 320A, 320B, 420A, 420B, 520A, 520B, 520C Air supply unit 21 Fan 22 First Heat exchanger 23, 423A, 423B Control unit 24 Temperature detection unit 25 Driving motor 26 Electric valve 40 Opening/closing damper 50, 350, 450, 550A, 550B, 550C, 650 Compressor unit 51 Driving motor 52, 452 Control unit 53 Compressor 54 Four-way valve 55 Motor operated valve 56 Motor operated valve for bypass 70, 470, 571, 572, 573 Outdoor unit 71, 471 Control unit 81, 82, 581, 582, 583, 584, 585, 586, 587, 588 Air-conditioned room Machines 400, 500, 600 Upper controllers 601, 602 Electric valves 732 Third heat exchanger 733 Control units F1, F2, F3, F4, F401, F402, F403, F404 Refrigerant circuits F5, F501, F502, F503, F601, F602, F603 Connecting pipe F6 Bypass flow path P1, P101 Air supply flow path P2, P103 Return air flow path P2A First return air branch path P2B Second return air branch path P102 Bypass flow path P201, P401 First air supply flow path P202, P402 Second Supply air passage P203 Return air passage P403 First return air passage P404 Second return air passage 1E Ventilation system 1F 13th ventilation system 1G 14th ventilation system 1H 15th ventilation system 1I 16th ventilation system 1J 17th ventilation system 1K 18th Ventilation system 1018 Control unit 1022 Air supply fan 1023 First heat exchanger 1032 Exhaust fan 1033 Second heat exchanger 1042 Compressor 1045 Discharge pipe 1050 Refrigerant circuit 1051 Refrigerant pipe 1051L Liquid pipe 1080 Low pressure pressure increasing means 1081 Air conditioner 1082a Bypass Piping 1082b Valve 1000S1 Indoor 1000S2 Outdoor PL Low pressure TE Evaporation temperature TS Saturation temperature T2 Outside air temperature T3 Intake air temperature X First threshold Y Second threshold Y3 Air temperature threshold (second threshold for intake air temperature)
SA Air supply (air blown out from the air supply fan)

Claims

a compressor;
a first heat exchanger functioning as a condenser or evaporator;
a first air flow path for supplying air taken in from outdoors to an indoor space after passing through the first heat exchanger;
a second heat exchanger functioning as a condenser or evaporator;
a second air flow path for exhausting the air taken in from the indoor space to the outdoors after passing through the second heat exchanger;
a refrigerant circuit in which the compressor, the first heat exchanger, and the second heat exchanger are connected by refrigerant pipes and in which refrigerant flows;
While the second heat exchanger is functioning as an evaporator, it is detected whether or not a predetermined criterion indicating the possibility of frost formation of the second heat exchanger is satisfied, and the predetermined criterion is satisfied. a control unit that controls the temperature of the refrigerant flowing through the second heat exchanger so that the second heat exchanger reaches a temperature at which frost does not form when it is detected that the refrigerant is satisfied;
ventilation system.
The control unit detects whether the predetermined criterion is satisfied while the second heat exchanger is functioning as an evaporator, and it is detected that the predetermined criterion is satisfied. In this case, outputting a signal for controlling an air conditioner provided in the indoor space in order to control the temperature of the refrigerant flowing through the second heat exchanger;
2. Ventilation device according to claim 1.
When the predetermined criterion is satisfied, the control unit outputs a signal to an air conditioner provided in the indoor space to increase the temperature currently set for the air conditioner.
3. Ventilation device according to claim 2.
further comprising a second ventilation unit that adjusts the amount of air flowing through the second air flow path to the second heat exchanger;
After outputting a signal for controlling the air conditioner, the control unit drives the second ventilation unit when the air temperature in the indoor space becomes higher than a second threshold.
3. Ventilation device according to claim 2.
The refrigerant circuit has a bypass pipe that flows the refrigerant to the second heat exchanger without passing through the first heat exchanger while the second heat exchanger is functioning as an evaporator,
The control unit controls the flow of the refrigerant compressed by the compressor to the second heat exchanger via the bypass pipe when the predetermined criterion is satisfied.
2. Ventilation device according to claim 1.
After controlling the flow to the second heat exchanger through the bypass pipe, the control unit controls the low pressure of the refrigerant circuit, or the saturation temperature of the second heat exchanger, or the second heat exchanger When it is determined that the intake air temperature of the refrigerant circuit exceeds the low pressure pressure, or the saturation temperature of the second heat exchanger, or the second threshold for the intake air temperature of the second heat exchanger, the compressor Control to close the valve for flowing the refrigerant compressed in the bypass pipe to the second heat exchanger,
6. Ventilation device according to claim 5.
a third air flow path through which the air taken in from a room different from the second air flow path in the indoor space passes through the second heat exchanger;
a first guide mechanism that switches whether to guide air through the third air flow path to the second heat exchanger;
The control unit controls the first guide mechanism to guide air through the third air flow path to the second heat exchanger when the predetermined criterion is satisfied.
2. Ventilation device according to claim 1.
further comprising a second ventilation unit that adjusts the amount of air flowing through the second air flow path to the second heat exchanger;
The control unit controls the second ventilation unit to increase the amount of air flowing through the second heat exchanger compared to before the predetermined criterion is satisfied when the predetermined criterion is satisfied. ,
2. Ventilation device according to claim 1.
a plurality of the second heat exchangers;
the second ventilation unit associated with each of the second heat exchangers;
The control unit responds to any one of the plurality of second heat exchangers when the predetermined criterion is satisfied while the plurality of second heat exchangers are functioning as evaporators. controlling the attached second ventilation unit to increase the amount of air flowing to the second heat exchanger compared to before the predetermined criterion is satisfied;
9. Ventilation device according to claim 8.
When performing control to increase the amount of air in the second ventilation unit associated with any one of the plurality of second heat exchangers, the controller controls the plurality of the second heat exchangers. Control for reducing the amount of air flowing to the second heat exchanger compared to before the predetermined criterion is satisfied, for the second ventilation unit associated with the other second heat exchanger among the exchangers I do,
10. Ventilation device according to claim 9.
further comprising a first ventilation unit that adjusts the amount of air flowing through the first air flow path to the first heat exchanger;
The control unit controls the second ventilation unit associated with any one of the plurality of second heat exchangers to increase the amount of air, the second ventilation unit control the first ventilation unit to increase the amount of air flowing to the first heat exchanger compared to before the predetermined criterion is satisfied, based on the amount of air increased for the ,
10. Ventilation device according to claim 9.
a first ventilation unit that adjusts the amount of air flowing through the first air flow path to the first heat exchanger;
a second ventilation unit that adjusts the amount of air flowing through the second air flow path to the second heat exchanger;
While the second heat exchanger is functioning as an evaporator, the control unit receives a signal indicating that a defrosting operation is to be performed from an air conditioner provided in the indoor space. is satisfied, the amount of air flowing through the first heat exchanger for the first ventilation unit is increased compared to before the predetermined criterion is satisfied, and the amount of air flowing to the first heat exchanger for the second ventilation unit is increased. 2 Control to increase the amount of air flowing through the heat exchanger,
2. Ventilation device according to claim 1.
a bypass flow path that guides the air heat-exchanged by the first heat exchanger to the second heat exchanger;
a second guide mechanism that switches whether to guide air through the bypass flow path to the second heat exchanger;
The control unit controls the second guide mechanism to guide air to the second heat exchanger through the bypass flow path when the predetermined criterion is satisfied.
2. Ventilation device according to claim 1.
The control unit causes the flow adjustment mechanism to guide the air blown into the indoor space from the first air flow path to the suction side of the second air flow path when the predetermined criterion is satisfied. regulate the air flow,
2. Ventilation device according to claim 1.
further comprising a second ventilation unit that adjusts the amount of air flowing through the second air flow path to the second heat exchanger;
The control unit stops the compressor when the predetermined criterion is satisfied, and instructs the second ventilation unit to allow the air passing through the second air flow path to flow into the second heat exchanger. to control the flow,
2. Ventilation device according to claim 1.
a plurality of the second heat exchangers;
a second ventilation unit associated with each of the second heat exchangers;
The refrigerant circuit further has a first valve portion for adjusting the opening degree of the flow path flowing through the second heat exchanger for each of the second heat exchangers,
When the temperature information detected from the plurality of second heat exchangers satisfies the predetermined criterion, the control unit controls the plurality of heat exchangers corresponding to the second heat exchangers that satisfy the predetermined criterion. performing control to close the first valve portion in accordance with a predetermined order, and opening the second air flow path to the second ventilation unit corresponding to the second heat exchanger that satisfies the predetermined criteria; Control the flow of the passed air to the second heat exchanger,
2. Ventilation device according to claim 1.
a first ventilation unit that adjusts the amount of air flowing through the first air flow path to the first heat exchanger;
a second ventilation unit that adjusts the amount of air flowing through the second air flow path to the second heat exchanger;
The controller controls, when the predetermined criterion is satisfied, that the amount of air discharged to the outdoors through the second air flow path is greater than the amount of air supplied to the indoor space through the first air flow path. controlling the first ventilation unit and the second ventilation unit to increase;
2. Ventilation device according to claim 1.
When the predetermined criterion is satisfied, the control unit controls the air conditioner provided in the indoor space to increase the temperature of the air after passing through the first heat exchanger with respect to the first heat exchanger. control the temperature to be lower than the set temperature,
2. Ventilation device according to claim 1.
a plurality of combinations of the compressor, the first heat exchanger, the second heat exchanger, the refrigerant circuit, and a second ventilation unit associated with the second heat exchanger;
When the temperature information detected from the plurality of second heat exchangers satisfies the predetermined criterion, the controller controls the compressor corresponding to the second heat exchanger that satisfies the predetermined criterion. are controlled to stop according to a predetermined order, and the air passing through the second air flow path is directed to the second ventilation unit corresponding to the second heat exchanger that meets the predetermined criteria. controlling the flow to the second heat exchanger;
2. Ventilation device according to claim 1.
The control unit uses the low pressure of the refrigerant circuit, the evaporation temperature of the second heat exchanger, or the temperature of the indoor space as a predetermined criterion indicating the possibility of frost formation on the second heat exchanger, or determining whether the outdoor temperature is below the low pressure of the refrigerant circuit, or the evaporation temperature of the second heat exchanger, or the temperature of the indoor space, or a first threshold for the outdoor temperature. ,
20. Ventilation device according to any one of the preceding claims.
a first casing housing at least part of the first heat exchanger and the first air flow path;
a second casing housing at least part of the second heat exchanger and the second air flow path;
The first casing and the second casing are separable,
21. Ventilation device according to any one of the preceding claims.
When the predetermined criterion is satisfied, the control unit performs control to lower the rotation speed of the compressor compared to before the predetermined criterion is satisfied.
22. Ventilation device according to claim 21.
The refrigerant circuit is provided between the first heat exchanger and the second heat exchanger and has a second valve portion that adjusts the opening degree of the flow path,
When the predetermined criterion is satisfied, the control unit performs control to increase the degree of opening of the second valve unit compared to before the predetermined criterion is satisfied.
22. Ventilation device according to claim 21.
further comprising a third valve portion downstream from the second heat exchanger in the flow of the refrigerant in the refrigerant circuit when the second heat exchanger functions as an evaporator;
Further, when the second heat exchanger functions as an evaporator, the control unit throttles the third valve unit when the predetermined criterion is satisfied compared to before the predetermined criterion is satisfied. control,
2. Ventilation device according to claim 1.
a third heat exchanger functioning as a condenser or evaporator;
a fourth air flow path for exhausting to the outdoors the air heat-exchanged with the outdoor air and the refrigerant flowing through the third heat exchanger;
In the refrigerant circuit, in addition to the compressor, the first heat exchanger and the second heat exchanger, the third heat exchanger is connected by the refrigerant pipe,
25. Ventilation device according to claim 24.
A first heat exchanger that functions as a compressor or a condenser or an evaporator during heat recovery ventilation operation, and a first heat exchanger that supplies air taken in from the outdoors to an indoor space after passing through the first heat exchanger. an air flow path, a second heat exchanger that functions as a condenser or an evaporator, and a second air flow path that exhausts the air taken in from the indoor space to the outdoors after passing through the second heat exchanger and a refrigerant circuit in which the compressor, the first heat exchanger, and the second heat exchanger are connected by refrigerant pipes and a refrigerant flows therein;
An air conditioner having a third heat exchanger that functions as a condenser or an evaporator, and an air conditioner indoor unit that exhausts, into the indoor space, air heat-exchanged with the air in the indoor space and the refrigerant flowing through the third heat exchanger. and,
It is detected whether the second heat exchanger satisfies a predetermined criterion indicating the possibility of frost formation, and when it is detected that the predetermined criterion is satisfied, the second heat exchange is performed. The power consumption of the ventilation device and the air conditioner required when the temperature of the refrigerant flowing through the second heat exchanger is controlled so that the temperature of the second heat exchanger is not frosted, and the second heat exchanger is frosted. Based on the power consumption required for operation by the ventilation device and the air conditioner that later eliminates frosting of the second heat exchanger, the second heat exchanger is adjusted to a temperature at which frosting does not occur. a control unit that controls the temperature of the refrigerant flowing through the heat exchanger, or controls the operation of defrosting the second heat exchanger after the second heat exchanger is frosted;
air conditioning system.
a compressor, a first heat exchanger that functions as a condenser or an evaporator, and a first air flow path that supplies air taken in from the outdoors to an indoor space after passing through the first heat exchanger; a second heat exchanger that functions as a condenser or an evaporator; a second air flow path that exhausts the air taken in from the indoor space to the outdoors after passing through the second heat exchanger; and the compressor. and a refrigerant circuit in which the first heat exchanger and the second heat exchanger are connected by refrigerant pipes and a refrigerant flows therein, wherein the second heat exchanger is used as an evaporator While functioning, it is detected whether the second heat exchanger satisfies a predetermined criterion indicating the possibility of frost formation, and when it is detected that the predetermined criterion is satisfied. and controlling the temperature of the refrigerant flowing through the second heat exchanger so that the temperature at which the second heat exchanger does not form frost;
ventilation method.
a refrigerant circuit in which the compressor, the first heat exchanger, and the second heat exchanger are connected by refrigerant pipes and in which the refrigerant flows;
An air supply fan for supplying outdoor air indoors through the first heat exchanger, and an exhaust fan for exhausting the indoor air to the outdoors through the second heat exchanger;
a control unit;
When the second heat exchanger functions as an evaporator, the control unit starts the compressor, and the low pressure of the refrigerant circuit, the evaporation temperature of the second heat exchanger, or the indoor temperature, or when it is determined that the outdoor temperature has fallen below the low pressure of the refrigerant circuit, or the evaporation temperature of the second heat exchanger, or the indoor temperature, or a first threshold for the outdoor temperature, the refrigerant A ventilation system with a first control to increase the low pressure pressure in the circuit.
The refrigerant circuit has a bypass pipe connecting a discharge pipe of the compressor, the second heat exchanger or a liquid pipe connected to the second heat exchanger, and a valve provided in the bypass pipe. ,
29. The ventilation system according to claim 28, wherein said control section opens said valve in said first control.
When the valve is opened, the control unit causes the low pressure of the refrigerant circuit, the saturation temperature of the second heat exchanger, or the intake air temperature of the second heat exchanger to rise to the low pressure of the refrigerant circuit. 30. Ventilation according to claim 29, wherein the valve is closed when it is determined that a second threshold for the pressure or the saturation temperature of the second heat exchanger or the intake air temperature of the second heat exchanger has been exceeded. system.
29. The ventilation system according to claim 28, wherein, in the first control, the control unit causes the second heat exchanger to draw in air having a temperature higher than a second threshold for intake air temperature.
32. The ventilation according to claim 31, wherein in the first control, the control unit adjusts the blowing direction of the air supply fan so as to guide the air blown from the air supply fan to the suction side of the exhaust fan. system.
Further comprising an air conditioner for air conditioning the indoor,
32. The ventilation system according to claim 31, wherein in the first control, the control unit drives the exhaust fan when the indoor air temperature becomes higher than the second threshold value due to the air conditioner.