Heat exchange type ventilation device, heat exchange type ventilation system, and control method for heat exchange type ventilation device

Abstract

To provide a heat exchange type ventilation device capable of inhibiting an outdoor unit that supplies a refrigerant to a temperature regulation coil from being broken due to temporary decline of supply air quantity.SOLUTION: A heat exchange type ventilation device 50 includes: an indoor unit 1 having a supply air blower 8 for generating a supply air current and a temperature regulation coil 2; and an outdoor unit 4 that sends a heated or cooled refrigerant to the temperature regulation coil 2. The indoor unit 1 includes a control section 71 having: an air quantity estimation section that estimates a supply air quantity that is a quantity of the supply air current; and a temperature regulation control section that controls temperature regulation of the supply air current with the temperature regulation coil 2 and the outdoor unit 4. The supply air blower 8 can be set to any of a plurality of air quantity notches. The temperature regulation control section performs temperature regulation of the supply air current with the temperature regulation coil 2 and the outdoor unit 4 when the supply air quantity estimated by the air quantity estimation section is a preset threshold value or larger, and forcedly stops the temperature regulation of the supply air current with the temperature regulation coil 2 and the outdoor unit 4 when the supply air quantity estimated by the air quantity estimation section is smaller than the threshold value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchange type ventilation device that regulates the temperature of an intake airflow using a temperature regulation coil that is a heat exchanger using a direct expansion coil, a heat exchange type ventilation system, and a control method for a heat exchange type ventilation device. [Background technology]

[0002] Conventionally, in order to maintain a comfortable indoor temperature while reducing energy loss due to air conditioning, a heat exchange type ventilation system has been used that performs heat exchange between supply air introduced from outside the room into the room by an intake air blower and exhaust air discharged from inside the room to the outside by an exhaust air blower, and then directs the supply air into the room.

[0003] Another type of heat exchange ventilation system regulates the temperature of the intake airflow by installing a heat exchanger using a direct expansion coil in the intake air duct, as disclosed in Patent Document 1, in which multiple fins are arranged on the outer surface of a heat transfer tube. A heat exchanger using a direct expansion coil is called a "temperature control coil."

[0004] The temperature control coil is connected to the outdoor unit by a refrigerant pipe. Refrigerant heated or cooled in the outdoor unit is sent to the temperature control coil through the refrigerant pipe and passes through the heat transfer tube, where heat is exchanged between the refrigerant flowing inside the heat transfer tube and the supply air flow passing through the fins, thereby controlling the temperature of the supply air flow.

[0005] In a heat-exchange type ventilation system with a temperature control coil, when the volume of the supply air flowing through the temperature control coil decreases, heat exchange in the temperature control coil becomes difficult. For example, during heating operation in winter, the pressure of the refrigerant returning to the outdoor unit increases, causing poor condensation in the refrigerant piping, putting a heavy load on the pump circulating the refrigerant and increasing the refrigerant pressure, increasing the risk of outdoor unit failure. Similarly, during cooling operation in summer, poor evaporation can occur, potentially causing the compressor to break down due to freezing of the direct expansion coil or backflow of refrigerant, increasing the risk of outdoor unit failure.

[0006] On the other hand, in recent years, the use of DC brushless motors and other devices in the fans of heat exchange type ventilation systems has made it possible to specify the operating point of the motor in detail, leading to a trend toward multiple air volume notches and the air volume of low air volume notches being set to a small value to improve energy efficiency.

[0007] For this reason, in a heat exchange type ventilation device having a temperature control coil and multiple air volume notches, in order to prevent the outdoor unit from breaking down when the supply air volume drops below a preset air volume notch, the outdoor unit may stop controlling the temperature of the supply airflow by the temperature control coil and the outdoor unit. The state in which the temperature control of the supply airflow by the temperature control coil and the outdoor unit is performed is called "thermo on," and the state in which the temperature control of the supply airflow by the temperature control coil and the outdoor unit is forcibly stopped is called "thermo off."

[0008] Some heat exchange type ventilation devices that allow thermo-on and thermo-off are designed so that, when priority is given to controlling the temperature of the intake airflow, the airflow volume notch of the intake air blower cannot be set to an airflow volume notch that is lower than the airflow volume notch that serves as the basis for switching between thermo-on and thermo-off. In such heat exchange type ventilation devices, when priority is given to controlling the temperature, the airflow volume notch of the intake air blower can only be set within a range that does not cause the thermo-off switch, making it possible to control the temperature of the intake airflow while preventing damage to the outdoor unit. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2018-91575 A Summary of the Invention [Problem to be solved by the invention]

[0010] However, if the outdoor intake airflow inlet or the indoor intake airflow outlet is temporarily blocked, the intake airflow rate may be lower than the airflow rate set at the set airflow notch. For example, if a foreign object blown by the wind adheres to the outdoor intake airflow inlet, the intake airflow rate will be reduced until the foreign object falls off the intake airflow inlet. For this reason, in a heat exchange type ventilator that can only set the blower airflow notch within a range that does not require thermostat off when prioritizing temperature control, even if the airflow notch is set to a value that does not require thermostat off, the actual intake airflow rate may be reduced to a level that results in insufficient heat exchange between the temperature control coil and the intake airflow, causing the outdoor unit to malfunction.

[0011] The present disclosure has been made in consideration of the above, and aims to provide a heat exchange type ventilation device that prevents an outdoor unit that supplies refrigerant to a temperature control coil from failing due to a temporary decrease in supply air volume. [Means for solving the problem]

[0012] In order to solve the above-mentioned problems and achieve the object, a heat exchange type ventilation device according to the present disclosure includes an indoor unit having a supply air blower and a temperature control coil that generates a supply airflow, and an outdoor unit that sends heated or cooled refrigerant to the temperature control coil. The temperature of the supply airflow is controlled by the temperature control coil and the outdoor unit through heat exchange between the refrigerant and the supply airflow in the temperature control coil. The indoor unit includes a control unit having an air volume estimation unit that estimates the supply air volume, which is the air volume of the supply airflow, and a temperature control unit that controls the temperature control of the supply airflow by the temperature control coil and the outdoor unit. The supply air blower can be set to one of a plurality of air volume notches. The air volume estimation unit estimates the supply air volume at the air volume notch set in the supply air blower. When the supply air volume estimated by the air volume estimation unit is equal to or greater than a predetermined threshold, the temperature control control unit performs temperature control of the supply air flow using the temperature control coil and the outdoor unit, and when the supply air volume estimated by the air volume estimation unit is less than the threshold, the temperature control control unit forcibly stops temperature control of the supply air flow using the temperature control coil and the outdoor unit. [Effects of the Invention]

[0013] The present disclosure provides an advantage of providing a heat exchange type ventilation device that prevents an outdoor unit that supplies refrigerant to a temperature control coil from breaking down due to a temporary decrease in the supply air volume. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing the configuration of a heat exchange type ventilation device according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing the configuration of a control unit of an indoor unit of a heat exchange type ventilation device according to Embodiment 1. [Figure 3] 1 is a flowchart showing the flow of operation of the heat exchange type ventilation device according to the first embodiment. [Figure 4] 10 is a flowchart showing the flow of operation in a temperature control priority mode of a heat exchange type ventilation device according to a second embodiment. [Figure 5] FIG. 10 is a diagram showing the relationship between the airflow rate and the external static pressure of the heat exchange type ventilation device according to the second embodiment. [Figure 6] FIG. 10 is a diagram showing the configuration of a control unit of an indoor unit of a heat exchange type ventilation device according to a third embodiment. [Figure 7] FIG. 10 is a diagram showing the configuration of a heat exchange type ventilation system according to a fourth embodiment. [Figure 8] FIG. 1 is a diagram showing the hardware configuration of a control unit of an indoor unit according to Embodiments 1 to 4. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A heat exchanger ventilation device, a heat exchanger ventilation system, and a method for controlling a heat exchanger ventilation device according to embodiments will be described in detail below with reference to the accompanying drawings.

[0016] Embodiment 1 FIG. 1 is a diagram illustrating the configuration of a heat exchanger ventilator according to a first embodiment. The heat exchanger ventilator 50 includes an indoor unit 1 and an outdoor unit 4. The indoor unit 1 includes an intake air blower 8 that generates an intake airflow, an exhaust air blower 9 that generates an exhaust airflow, a heat exchange element 17 that exchanges heat between the intake airflow and the exhaust airflow, an air quality sensor 6 that measures the air quality of the exhaust airflow, a temperature control coil 2 connected to the outdoor unit 4 via refrigerant pipes 15 and 16, and a control unit 71 that controls the intake air blower 8, the exhaust air blower 9, and the temperature control coil 2. The intake air blower 8 can be set to one of several airflow notches. The temperature control coil 2 controls the temperature of the intake airflow by exchanging heat between the refrigerant and the intake airflow. The temperature control coil 2 includes a direct expansion coil with multiple fins arranged on the outer surface of a heat transfer tube. As the refrigerant passes through the inside of the heat transfer tube, heat is exchanged between the refrigerant and the intake airflow passing through the fins. The outdoor unit 4 sends the heated or cooled refrigerant to the temperature control coil 2.

[0017] Connected to the indoor unit 1 are an outdoor air intake duct 11 that leads to an intake air inlet 21 installed on an exterior wall 31, an indoor air outlet duct 12 that leads to an intake air outlet 22 installed on a ceiling 32 of the space to be ventilated, an indoor air intake duct 13 that leads to an exhaust air inlet 23 installed on the ceiling 32, and an outdoor air outlet duct 14 that leads to an exhaust air outlet 24 installed on the exterior wall 31. The intake air blower 8 draws in outdoor air OA through the intake air inlet 21 and the outdoor air intake duct 11 and blows out intake air SA into the space to be ventilated through the indoor air outlet duct 12 and the intake air outlet 22, thereby forming an intake airflow. The exhaust air blower 9 draws in indoor air RA through the exhaust air inlet 23 and the indoor air intake duct 13, and blows out exhaust air EA to the outdoors through the outdoor air outlet duct 14 and the exhaust air outlet 24, thereby forming an exhaust airflow.

[0018] The air quality sensor 6 detects, for example, the carbon dioxide concentration or the concentration of malodorous components in the exhaust flow. The air quality sensor 6 may be installed outside the indoor unit 1 as long as it is located in a position where it can detect the air quality of the indoor air flowing into the indoor air intake duct 13 from the room.

[0019] The outdoor unit 4 is equipped with a control unit 72 that controls whether a refrigerant is supplied to the temperature control coil 2 and controls the heating and cooling of the refrigerant supplied to the temperature control coil 2. The refrigerant heated or cooled in the outdoor unit 4 is sent to the temperature control coil 2 through refrigerant piping 15. The refrigerant that has exchanged heat with the supply air flow in the temperature control coil 2 is returned to the outdoor unit 4 through refrigerant piping 16.

[0020] The set value of the supply air volume varies depending on the user's setting or automatic adjustment of the air volume based on the measurement value of the air quality sensor 6. When automatic adjustment of the air volume based on the measurement value of the air quality sensor 6 is performed, the control unit 71 sets the supply air volume so that the carbon dioxide concentration or the concentration of malodorous components is kept below a preset reference value to maintain indoor comfort, and controls the supply air blower 8 so that ventilation is performed at the set supply air volume.

[0021] 2 is a diagram showing the configuration of a control unit of the indoor unit of the heat exchanger type ventilation system according to Embodiment 1. Control unit 71 includes motor control unit 711 that controls the motor of supply air blower 8, rotational speed detection unit 712 that detects the rotational speed of the motor of supply air blower 8, air volume estimation unit 713 that estimates the supply air volume, memory unit 714 that stores data table 714a, and temperature adjustment control unit 715 that controls temperature adjustment of the supply air flow by temperature adjustment coil 2 and outdoor unit 4. Data table 714a is a table that shows the relationship between the rotational speed of the motor of supply air blower 8 and the volume of the air flow generated by supply air blower 8 for each air volume notch.

[0022] Air volume estimation unit 713 estimates the current supply air volume based on information about the set air volume notch, information about the current rotation speed of the motor detected by rotation speed detection unit 712, and data table 714a.

[0023] Data table 714a may be a table that indicates, for each airflow rate notch, the relationship between the motor current of supply air blower 8 and the airflow rate of the airflow generated by supply air blower 8. In this case, control unit 71 may be configured to include a motor current detection unit instead of rotation speed detection unit 712, and airflow rate estimation unit 713 estimates the supply air flow rate based on the motor current instead of the motor rotation speed. Therefore, in both cases where the relationship between the rotation speed of the motor of supply air blower 8 and the airflow rate of the airflow generated by supply air blower 8 is indicated for each airflow rate notch, and where data table 714a indicates the relationship between the motor current of supply air blower 8 and the airflow rate of the airflow generated by supply air blower 8 for each airflow rate notch, airflow rate estimation unit 713 estimates the supply air flow rate at the set airflow rate notch.

[0024] The estimation of the supply air volume may be performed continuously or periodically at preset intervals, but the supply air volume is estimated immediately after the air volume notch is switched by a user instruction or an instruction based on the measurement value of the air quality sensor 6.

[0025] The temperature control control unit 715 outputs a thermo-off command to forcibly stop the temperature control of the intake air flow by the temperature control coil 2 and the outdoor unit 4, and a thermo-on command to allow the temperature control of the intake air flow by the temperature control coil 2 and the outdoor unit 4 to the control unit 72 of the outdoor unit 4.

[0026] When the control unit 72 receives a thermo-off command, it stops the supply of refrigerant to the temperature control coil 2 and the heating or cooling of the refrigerant. When the control unit 72 receives a thermo-on command while the thermo is off, it causes the supply of refrigerant to the temperature control coil 2 and the heating or cooling of the refrigerant to be executed.

[0027] FIG. 3 is a flowchart showing the flow of operation of the heat exchange type ventilation device according to the first embodiment. In step S101, the control unit 71 detects the rotation speed of the motor of the supply air blower 8. In step S102, the control unit 71 estimates the supply air volume. In step S103, the control unit 71 determines whether the estimated supply air volume is equal to or greater than a threshold Qmin. The threshold Qmin is a threshold corresponding to a minimum air volume for preventing failure of the outdoor unit 4 due to a decrease in the amount of heat exchanged between the supply air flow and the refrigerant, and is determined depending on the model of the outdoor unit 4. The threshold Qmin may be set arbitrarily by the user, provided that the value is such that failure of the outdoor unit 4 can be avoided.

[0028] If the estimated supply air volume is equal to or greater than the threshold Qmin, the answer is Yes in step S103, and in step S104, the control unit 71 outputs a thermo-on command to the control unit 72 of the outdoor unit 4. After step S104, the process returns to step S101.

[0029] If the estimated supply air flow rate is less than threshold Qmin, the result in step S103 is No, and in step S105, control unit 71 outputs a thermo-off command to control unit 72 of outdoor unit 4. After step S105, the process returns to step S101.

[0030] By performing the above operation, if the estimated supply air flow rate is equal to or greater than the threshold Qmin, the temperature of the supply airflow is controlled by the temperature control coil 2 and the outdoor unit 4, and if the estimated supply air flow rate is less than the threshold Qmin, the temperature control of the supply airflow by the temperature control coil 2 and the outdoor unit 4 can be forcibly stopped. Furthermore, after the temperature control of the supply airflow by the temperature control coil 2 and the outdoor unit 4 has been forcibly stopped, if the estimated supply airflow rate becomes equal to or greater than the threshold Qmin, the temperature control of the supply airflow by the temperature control coil 2 and the outdoor unit 4 can be resumed. Therefore, the heat exchange type ventilator 50 according to the first embodiment can prevent the outdoor unit 4, which supplies refrigerant to the temperature control coil 2, from breaking down due to a temporary decrease in the supply airflow rate.

[0031] Embodiment 2 The configuration of the heat exchanger ventilator 50 according to the second embodiment is the same as that of the heat exchanger ventilator 50 according to the first embodiment. The heat exchanger ventilator 50 according to the second embodiment operates in one of two operating modes: a temperature control priority mode in which the temperature of the supply airflow is controlled by the temperature control coil 2 and the outdoor unit 4, and an energy saving priority mode in which the temperature of the supply airflow is not controlled by the temperature control coil 2 and the outdoor unit 4. In the heat exchanger ventilator 50 according to the second embodiment, when controlling the temperature control of the supply airflow by the temperature control coil 2 and the outdoor unit 4, the temperature control control unit 715 controls the motor of the supply air blower 8 by the motor control unit 711 to change the airflow rate notch of the supply air blower 8 based on the estimated supply airflow rate.

[0032] 4 is a flowchart showing the flow of operation in the temperature control priority mode of the heat exchanger type ventilation apparatus according to embodiment 2. In the temperature control priority mode, processing starts in the thermo-on state, which allows temperature control of the supply airflow by the temperature control coil 2 and the outdoor unit 4. The processing from step S201 to step S203 is the same as the processing from step S101 to step S103 of the heat exchanger type ventilation apparatus 50 according to embodiment 1.

[0033] If the estimated supply airflow rate is equal to or greater than threshold Qmin, the result in step S203 is Yes, and in step S204, control unit 71 determines whether the most recent change in airflow rate notch was a change to increase the airflow rate notch. If the most recent change in airflow rate notch was a change to increase the airflow rate notch, the result in step S204 is Yes, and the process returns to step S201. If the most recent change in airflow rate notch was a change to decrease the airflow rate notch, the result in step S204 is No, and in step S205, control unit 71 decreases the airflow rate notch by one level. After step S205, the process returns to step S201.

[0034] If the estimated supply airflow rate is less than threshold Qmin, the result in step S203 is No, and in step S206, control unit 71 determines whether the current airflow rate notch is the maximum airflow rate notch. If the current airflow rate notch is the maximum airflow rate notch, the result in step S206 is Yes, and in step S207, control unit 71 outputs a thermo-off command to control unit 72 of outdoor unit 4, and ends the process. If the current airflow rate notch is not the maximum airflow rate notch, the result in step S206 is No, and in step S208, control unit 71 increases the airflow rate notch by one step. After step S208, the process returns to step S201.

[0035] By performing the above operations, in the temperature control priority mode, if the estimated supply airflow rate is equal to or greater than the threshold Qmin and no change to increase the airflow rate notch has been made recently, the airflow rate notch can be lowered to reduce the supply airflow rate. Furthermore, if the estimated supply airflow rate is less than the threshold Qmin and the current airflow rate notch is not the maximum airflow rate notch, the airflow rate notch can be raised to increase the ventilation airflow rate. Furthermore, if the estimated supply airflow rate is equal to or greater than the threshold Qmin and a change to increase the airflow rate notch has been made recently, the current airflow rate notch can be maintained. Furthermore, if the estimated supply airflow rate is less than the threshold Qmin and the current airflow rate notch is the maximum airflow rate notch, the thermostat can be turned off to forcibly stop temperature control of the supply airflow by the temperature control coil 2 and the outdoor unit 4. This ensures a minimum airflow rate to prevent failure of the outdoor unit 4 due to a decrease in the amount of heat exchange between the supply airflow and the refrigerant in the temperature control priority mode, thereby preventing failure of the outdoor unit 4, which supplies refrigerant to the temperature control coil 2, due to a temporary decrease in the supply airflow rate.

[0036] FIG. 5 is a diagram showing the relationship between air volume and external static pressure in a heat exchanger type ventilation device according to embodiment 2. Here, the air volume notches of supply air blower 8 can be set to four levels, and FIG. 5 shows only curves F01, F02, F03, and F04, which are air volume curves corresponding to each air volume notch. Note that the air volume notches of supply air blower 8 are not limited to four levels. Curves C00, C01, and C02 show pressure loss curves. Curve F04 is the air volume curve corresponding to the air volume notch that provides the maximum air volume.

[0037] The threshold Qmin, which is a threshold corresponding to the minimum air volume for preventing failure of the outdoor unit 4 due to a decrease in the amount of heat exchanged between the supply airflow and the refrigerant, is shown by a dashed line in FIG.

[0038] Here, a heat exchanger type ventilation device that turns off the thermostat at or below a preset air volume notch is defined as a heat exchanger type ventilation device according to a comparative example of embodiment 2. In the heat exchanger type ventilation device according to the comparative example of embodiment 2, curve F03 corresponds to the minimum air volume notch at which a thermo-on command is output to the outdoor unit.

[0039] For example, if the pressure loss in the air passage from the supply air inlet to the supply air outlet is represented by curve C00, in the heat exchange ventilator according to the comparative example of embodiment 2, the supply air flow rate at the airflow rate notch corresponding to curve F03 is the airflow rate corresponding to point P00. Also, if the pressure loss in the air passage from the supply air inlet to the supply air outlet is represented by curve C01, in the heat exchange ventilator according to the comparative example of embodiment 2, the supply air flow rate at the airflow rate notch corresponding to curve F03 is the airflow rate corresponding to point P01. Therefore, when the pressure loss in the air passage from the supply air inlet to the supply air outlet is represented by curve C00 or curve C01, the supply air flow rate will not continue to fall below threshold Qmin when supply air blower 8 is operating at the airflow rate notch corresponding to curve F03, and a supply air flow rate equal to or greater than Qmin will be ensured, so that outdoor unit 4 will not malfunction even if the thermostat is turned on.

[0040] On the other hand, when the pressure loss in the air passage from the supply air inlet to the supply air outlet is represented by curve C02, in a heat exchange ventilator according to a comparative example of embodiment 2, the supply air flow rate at the air flow rate notch corresponding to curve F03 is the air flow rate corresponding to point P05. Because the supply air flow rate at this time is less than Qmin, when the pressure loss in the air passage from the supply air inlet to the supply air outlet is represented by curve C02, operating the supply air blower at the air flow rate notch corresponding to curve F03 with thermostat on poses a risk of causing damage to the outdoor unit.

[0041] In heat exchanger ventilator 50 according to the second embodiment, when the pressure loss in the air passage from the supply air inlet to the supply air outlet is represented by curve C01, even if a user instruction or an instruction based on the measurement value of air quality sensor 6 is to operate at the airflow rate corresponding to point P02 at the airflow rate notch corresponding to curve F01, controller 71 changes the airflow rate notch from that corresponding to curve F01 to that corresponding to curve F02 in the temperature control priority mode, and operates supply air blower 8 at the airflow rate corresponding to point P04. Note that if the airflow rate notch between the airflow rate notch corresponding to curve F01 and the airflow rate notch corresponding to curve F02 can be continuously changed, controller 71 operates supply air blower 8 at the airflow rate corresponding to point P03.

[0042] In addition, when the pressure loss in the air path from the supply air inlet to the supply air outlet is represented by curve C02, even if the supply air blower 8 is operated at the air volume notch corresponding to curve F04, which is the maximum air volume, the supply air volume will not exceed the threshold Qmin, so the control unit 71 outputs a thermo-off command to the control unit 72 of the outdoor unit 4.

[0043] In the energy-saving priority mode, the control unit 71 operates the supply air blower 8 at the minimum airflow notch. In the example shown in FIG. 5, when the pressure loss in the air passage from the supply air inlet to the supply air outlet is represented by the curve C01, the supply air blower 8 is operated at the minimum airflow notch corresponding to the curve F01, resulting in the supply airflow corresponding to point P02. Because this airflow is below the threshold Qmin, the control unit 71 forcibly stops the temperature control of the supply airflow by the temperature control coil 2 and the outdoor unit 4. Note that when the supply air blower 8 can be set to an airflow notch corresponding to the airflow curves represented by the curves F02, F03, and F04, the minimum airflow notch is the airflow notch corresponding to the curve F02. In this case, when the pressure loss in the air passage from the supply air inlet to the supply air outlet is represented by the curve C01, the supply airflow corresponds to point P04. Because this air volume is equal to or greater than the threshold Qmin, the control unit 71 permits temperature control of the supply air flow by the temperature control coil 2 and the outdoor unit 4. That is, in the energy saving priority mode, regardless of the set air blowing notch, the thermo-on mode is set if the supply air volume is equal to or greater than the threshold Qmin, and the thermo-off mode is set if the supply air volume is less than the threshold Qmin.

[0044] It is also possible to provide a thermo-off mode in which the thermostat is always off, and operate the heat exchanger ventilator 50 in the thermo-off mode. When the heat exchanger ventilator 50 is operated in the thermo-off mode, the thermostat is never turned on regardless of the operating conditions, so there are no restrictions on automatic air volume control or air volume notch instructions by the user, enabling highly energy-efficient operation.

[0045] When the supply air flow rate estimated by air flow rate estimation unit 713 is less than threshold value Qmin, heat exchanger type ventilation device 50 according to embodiment 2 changes the air flow rate notch of supply air blower 8 so as to increase the supply air flow rate. This makes it possible to prevent failure of outdoor unit 4 not only when the decrease in supply air flow rate is due to a transient cause, but also when the decrease in supply air flow rate is due to clogging of heat exchange element 17 or a filter (not shown).

[0046] Furthermore, if the supply airflow rate estimated by airflow rate estimator 713 is equal to or greater than preset threshold Qmin, the airflow rate notch is lowered by one step unless the most recent change in airflow rate notch was a change to increase the airflow rate notch. Therefore, if the supply airflow rate is greater than the design value because the duct lengths of outdoor air intake duct 11 and indoor air discharge duct 12 are shorter than the design value, the airflow rate notch of supply air blower 8 can be lowered within a range that does not cause the supply airflow rate to fall below threshold Qmin. Therefore, heat exchanger-type ventilator 50 according to embodiment 2 can reduce energy consumption while preventing failure of outdoor unit 4.

[0047] Embodiment 3 6 is a diagram showing the configuration of a control unit of an indoor unit of a heat exchanger type ventilation apparatus according to embodiment 3. The control unit 71 of the indoor unit 1 of the heat exchanger type ventilation apparatus 50 according to embodiment 3 differs from the control unit 71 of the indoor unit 1 of the heat exchanger type ventilation apparatus 50 according to embodiment 1 in that it includes a notification unit 716. Other than this, it is the same as the control unit 71 of the indoor unit 1 of the heat exchanger type ventilation apparatus 50 according to embodiment 1.

[0048] The notification unit 716 displays, on a remote controller (not shown) or a user terminal (not shown) installed in the room, a message notifying that the thermostat has been turned off during the temperature control priority mode and a message notifying that the supply airflow rate has increased from less than the threshold Qmin to equal to or greater than the threshold Qmin due to a change in the airflow rate notch during the temperature control priority mode. Examples of the user terminal include, but are not limited to, a smartphone terminal and a tablet terminal.

[0049] In the heat exchanger type ventilation device 50 according to the third embodiment, the notification unit 716 sends a message to notify that the thermostat has been turned off during the temperature control priority mode, and also notifies that the supply air volume has increased from less than the threshold Qmin to greater than or equal to the threshold Qmin due to a change in the air volume notch during the temperature control priority mode. This allows the user of the heat exchanger type ventilation device 50 to know that temperature control is not possible despite the temperature control priority mode, and that the state has changed from one in which temperature control is not possible to one in which temperature control is possible.

[0050] Embodiment 4 7 is a diagram showing the configuration of a heat exchanger ventilation system according to embodiment 4. The heat exchanger ventilation system 100 according to embodiment 4 includes a heat exchanger ventilation device 50 and a temperature control coil unit 3. The temperature control coil unit 3 includes a temperature control coil 2. The temperature control coil unit 3 is connected to the supply air outlet 22 by an indoor air outlet duct 12, and is connected to the indoor unit 1 by a connecting duct 5. The temperature control coil unit 3 controls the temperature of the supply air flow blown out from the indoor unit 1 to the connecting duct 5.

[0051] The indoor unit 1 has a configuration in which the temperature control coil 2 is omitted from the indoor unit 1 of the heat exchanger ventilation device 50 according to embodiment 1. In other words, the heat exchanger ventilation system 100 according to embodiment 4 is configured as a system in which the temperature control coil 2 is separated from the indoor unit 1 of the heat exchanger ventilation device 50 according to embodiment 1 and is combined with the heat exchanger ventilation device 50 and a temperature control coil unit 3.

[0052] The operation of the heat exchanger ventilation system 100 according to the fourth embodiment is similar to that of the heat exchanger ventilation device 50 according to the first embodiment, and therefore a duplicated description will be omitted. Note that it is also possible to make the heat exchanger ventilation system 100 configured by separating the temperature control coil 2 from the indoor unit 1 of the heat exchanger ventilation device 50 according to the second or third embodiment perform the same operation as the heat exchanger ventilation device 50 according to the second or third embodiment.

[0053] Next, the hardware configuration of the control unit 71 of the indoor unit 1 according to the first to fourth embodiments will be described.

[0054] Figure 8 is a diagram showing the hardware configuration of the control unit of the indoor unit according to Embodiments 1 to 4. The control unit 71 is realized by a computer system including a processor 91 that executes various processes, a memory 92 that is a main memory, and a storage device 93 that stores information.

[0055] The processor 91 may be a computing device such as a microprocessor, microcomputer, CPU (Central Processing Unit), or DSP (Digital Signal Processor). The memory 92 may be a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory). The storage device 93 stores programs for estimating and changing the supply air volume by the supply air blower 8 and for switching the thermostat on and off.

[0056] In the computer system described above, the processor 91 reads into the memory 92 programs stored in the storage device 93 and executes the programs corresponding to the processing of each component, thereby realizing the functions of the control unit 71. The memory 92 is also used as a temporary memory for each process executed by the processor 91. The programs executed by the processor 91 may be provided in a state stored in a storage medium, or may be provided via a network.

[0057] The configurations shown in the above embodiments are merely examples of the content, and may be combined with other known technologies, or parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0058] 1 indoor unit, 2 temperature control coil, 3 temperature control coil unit, 4 outdoor unit, 5 connecting duct, 6 air quality sensor, 8 supply air blower, 9 exhaust air blower, 11 outdoor air intake duct, 12 indoor air outlet duct, 13 indoor air intake duct, 14 outdoor air outlet duct, 15, 16 refrigerant piping, 17 heat exchange element, 21 supply air intake port, 22 supply air outlet, 23 exhaust air intake port, 24 exhaust air outlet, 31 exterior wall, 32 ceiling, 50 heat exchange type ventilation device, 71, 72 control unit, 91 processor, 92 memory, 93 storage device, 100 heat exchange type ventilation system, 711 motor control unit, 712 rotation speed detection unit, 713 air volume estimation unit, 714 memory unit, 714a data table, 715 temperature control control unit, 716 Notification Department.

Claims

1. A heat exchange type ventilation device comprising an indoor unit having a supply air blower and a temperature control coil that generate a supply air flow, and an outdoor unit that sends a heated or cooled refrigerant to the temperature control coil, wherein the temperature of the supply air flow is controlled by the temperature control coil and the outdoor unit through heat exchange between the refrigerant and the supply air flow in the temperature control coil, the indoor unit includes a control unit having an air volume estimation unit that estimates a supply air volume, which is the air volume of the supply airflow, and a temperature adjustment control unit that controls the temperature adjustment of the supply airflow by the temperature adjustment coil and the outdoor unit; The supply air blower can be set to one of a plurality of air volume notches; the air volume estimation unit estimates the supply air volume at an air volume notch set in the supply air blower, The temperature control control unit controls the temperature of the supply air flow using the temperature control coil and the outdoor unit when the supply air flow rate estimated by the air volume estimation unit is equal to or greater than a predetermined threshold, and forcibly stops the temperature control of the supply air flow using the temperature control coil and the outdoor unit when the supply air flow rate estimated by the air volume estimation unit is less than the threshold.

2. The heat exchange type ventilation device according to claim 1, characterized in that the control unit includes an alarm unit that performs processing to notify that the temperature control of the supply air flow by the temperature control coil and the outdoor unit has been forcibly stopped.

3. A heat exchange type ventilation device comprising an indoor unit having a supply air blower and a temperature control coil that generate a supply air flow, and an outdoor unit that sends a heated or cooled refrigerant to the temperature control coil, wherein the temperature of the supply air flow is controlled by the temperature control coil and the outdoor unit through heat exchange between the refrigerant and the supply air flow in the temperature control coil, the indoor unit includes a control unit having an air volume estimation unit that estimates a supply air volume, which is the air volume of the supply airflow, and a temperature adjustment control unit that controls the temperature adjustment of the supply airflow by the temperature adjustment coil and the outdoor unit; The supply air blower can be set to one of a plurality of air volume notches; the air volume estimation unit estimates the supply air volume at an air volume notch set in the supply air blower, The heat exchange type ventilation device is characterized in that when the supply air volume estimated by the air volume estimation unit is equal to or greater than a predetermined threshold, the temperature control control unit controls the temperature of the supply air flow using the temperature control coil and the outdoor unit, and when the supply air volume estimated by the air volume estimation unit is less than the threshold, the air volume notch of the supply air blower is changed so as to increase the supply air volume.

4. The heat exchange type ventilation device described in claim 3, characterized in that, when the supply air volume estimated by the air volume estimation unit is less than a predetermined threshold, the temperature adjustment control unit gradually changes the air volume notch of the supply air blower until the supply air volume estimated by the air volume estimation unit becomes equal to or greater than the threshold.

5. The heat exchange type ventilation device described in claim 3 or 4, characterized in that the control unit is provided with an alarm unit that performs processing to notify that the supply air volume has changed from below the threshold to above the threshold due to a change in the air volume notch of the supply air blower.

6. A heat exchange type ventilation system comprising an indoor unit having a supply air blower that generates a supply air flow, a temperature control coil unit having a temperature control coil that exchanges heat between a refrigerant and the supply air flow, and an outdoor unit that sends heated or cooled refrigerant to the temperature control coil unit, wherein the temperature of the supply air flow is controlled by the temperature control coil unit and the outdoor unit by exchanging heat between the refrigerant and the supply air flow in the temperature control coil unit, the indoor unit includes a control unit having an air volume estimation unit that estimates a supply air volume, which is the air volume of the supply airflow, and a temperature adjustment control unit that controls the temperature adjustment of the supply airflow by the temperature adjustment coil unit and the outdoor unit; The supply air blower can be set to one of a plurality of air volume notches; the air volume estimation unit estimates the supply air volume at an air volume notch set in the supply air blower, The temperature control control unit controls the temperature of the supply air flow using the temperature control coil unit and the outdoor unit when the supply air flow estimated by the air volume estimation unit is equal to or greater than a predetermined threshold, and forcibly stops the temperature control of the supply air flow using the temperature control coil unit and the outdoor unit when the supply air flow estimated by the air volume estimation unit is less than the threshold.

7. A heat exchange type ventilation system comprising an indoor unit having a supply air blower that generates a supply air flow, a temperature control coil unit having a temperature control coil that exchanges heat between a refrigerant and the supply air flow, and an outdoor unit that sends heated or cooled refrigerant to the temperature control coil unit, wherein the temperature of the supply air flow is controlled by the temperature control coil unit and the outdoor unit by exchanging heat between the refrigerant and the supply air flow in the temperature control coil unit, the indoor unit includes a control unit having an air volume estimation unit that estimates a supply air volume, which is the air volume of the supply airflow, and a temperature adjustment control unit that controls the temperature adjustment of the supply airflow by the temperature adjustment coil unit and the outdoor unit; The supply air blower can be set to one of a plurality of air volume notches; the air volume estimation unit estimates the supply air volume at an air volume notch set in the supply air blower, The temperature control control unit controls the temperature of the supply air flow using the temperature control coil unit and the outdoor unit when the supply air volume estimated by the air volume estimation unit is equal to or greater than a predetermined threshold, and when the supply air volume estimated by the air volume estimation unit is less than the threshold, changes the air volume notch of the supply air blower so as to increase the supply air volume.

8. A control method for a heat exchange type ventilation device including an indoor unit having a supply air blower and a temperature control coil that can be set to any one of a plurality of air volume notches, and an outdoor unit that sends heated or cooled refrigerant to the temperature control coil, wherein the temperature of the supply air flow is controlled by the temperature control coil and the outdoor unit by exchanging heat in the temperature control coil between the refrigerant and a supply air flow generated by the supply air blower, the indoor unit estimates a supply airflow rate, which is the airflow rate of the supply airflow at an airflow rate notch set in the supply air blower; determining whether the estimated supply air volume is equal to or greater than a preset threshold; When the estimated supply air volume is equal to or greater than a predetermined threshold, performing temperature control of the supply air flow by the temperature control coil and the outdoor unit; A control method for a heat exchange type ventilation device, characterized by comprising a step of forcibly stopping the temperature control of the supply air flow by the temperature control coil and the outdoor unit when the estimated supply air volume is less than the threshold value.

9. A control method for a heat exchange type ventilation device including an indoor unit having a supply air blower and a temperature control coil that can be set to any one of a plurality of air volume notches, and an outdoor unit that sends heated or cooled refrigerant to the temperature control coil, wherein the temperature of the supply air flow is controlled by the temperature control coil and the outdoor unit by exchanging heat in the temperature control coil between the refrigerant and a supply air flow generated by the supply air blower, the indoor unit estimates a supply airflow rate, which is the airflow rate of the supply airflow at an airflow rate notch set in the supply air blower; When the estimated supply air volume is equal to or greater than a predetermined threshold, performing temperature control of the supply air flow by the temperature control coil and the outdoor unit; A control method for a heat exchange type ventilation device, characterized by comprising a step of changing the air volume notch of the supply air blower so as to increase the supply air volume when the estimated supply air volume is less than the threshold value.

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