A duct air conditioner and a static pressure adaptive control method for an indoor unit thereof

Abstract

The present invention discloses a duct-type air conditioner and a static pressure adaptive control method for an indoor unit thereof. The duct-type air conditioner includes an indoor unit, an outdoor unit, and a controller. The indoor unit is equipped with an indoor heat exchanger, an indoor fan, an indoor ambient temperature sensor, an indoor coil temperature sensor, and an indoor humidity sensor. The controller is configured to detect the current indoor ambient temperature and indoor humidity of the indoor unit; detect a first time or a second time used for a change in the indoor unit coil temperature via the indoor coil temperature sensor; and calculate the current duct static pressure value of the indoor unit based on a preset correspondence between the indoor unit's duct static pressure and the indoor ambient temperature, the indoor humidity, the first time, and the second time. In an embodiment of the present invention, the duct static pressure of the indoor unit of the duct-type air conditioner is calculated from parameters of multiple dimensions without requiring an additional static pressure sensor or detecting motor current and power parameters, resulting in higher accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a duct type air conditioner and a static pressure adaptive control method of an indoor unit thereof. Background Art

[0002] Ducted air conditioners are widely used in hotels, restaurants, offices, conference centers, and other locations. Due to the diverse environments at each installation site, the static pressure requirements for the indoor unit of a ducted air conditioner vary. Improper static pressure can easily cause noise or excessive or insufficient airflow, impacting product stability and comfort.

[0003] The static pressure regulation method commonly used in the prior art for duct indoor units is: control the motor of the indoor unit to run at the fan speed corresponding to the preset static pressure for a first period of time, and then detect the operating current value; if the detected operating current value is within the target current range corresponding to the preset static pressure, the motor maintains the speed unchanged; if the operating current value does not fall within the target current range corresponding to the preset static pressure, the motor performs corresponding speed adjustment. This method uses the detection of whether the operating current value falls within the target current range corresponding to the preset static pressure as the only judgment condition for static pressure regulation control, which is relatively simple and has low accuracy, and may also cause misjudgment. In addition, if a static pressure sensor is used to detect the static pressure of the duct indoor unit, it is necessary to add a static pressure detection module to the air duct of the duct indoor unit and configure the corresponding control and power supply structure, which undoubtedly increases the manufacturing cost of the duct indoor unit and the complexity of the system. Summary of the Invention

[0004] The present invention provides a static pressure adaptive control method for a duct-type air conditioner and an indoor unit thereof, which does not require an additional static pressure sensor and does not require detection of motor current and power parameters. The duct static pressure of the indoor unit of the duct-type air conditioner is calculated from parameters in multiple other dimensions, thereby achieving higher accuracy.

[0005] The duct air conditioner provided in the first embodiment of the present invention includes:

[0006] Indoor unit, which is equipped with indoor heat exchanger, indoor fan, indoor ambient temperature sensor, indoor coil temperature sensor and indoor humidity sensor;

[0007] An outdoor unit is provided with an outdoor heat exchanger, an outdoor fan, a compressor, a flow regulating valve and a four-way valve, wherein the compressor, the flow regulating valve, the four-way valve, the outdoor heat exchanger and the indoor heat exchanger are connected by pipelines to form a refrigerant circulation loop;

[0008] The indoor heat exchanger is used to act as an evaporator or a condenser according to the operating state of the indoor unit, so as to perform heat exchange between the refrigerant flowing in the heat transfer tube and the air passing through the indoor heat exchanger;

[0009] The indoor ambient temperature sensor is used to detect the indoor ambient temperature of the indoor unit;

[0010] The indoor coil temperature sensor is used to detect the temperature of the indoor unit coil;

[0011] The indoor humidity sensor is used to detect the indoor humidity of the indoor unit;

[0012] The outdoor heat exchanger is used to act as a condenser or an evaporator according to the operating state of the outdoor unit, so that the refrigerant flowing in the heat transfer tube and the air passing through the outdoor heat exchanger can exchange heat;

[0013] The flow regulating valve is used to convert the medium-temperature and high-pressure liquid after the outdoor heat exchanger absorbs cold and releases heat into a low-temperature and low-pressure liquid;

[0014] The four-way valve is used to switch between cooling and heating by changing the flow direction of the refrigerant in the circulation loop;

[0015] The controller is configured to detect the current indoor ambient temperature and indoor humidity of the indoor unit through the indoor ambient temperature sensor and the indoor humidity sensor; detect the first time or the second time used for the indoor unit coil temperature change through the indoor coil temperature sensor; and calculate the current duct static pressure value of the indoor unit based on the preset correspondence between the duct static pressure of the indoor unit and the indoor ambient temperature, the indoor humidity, the first time and the second time.

[0016] In the duct air conditioner provided by the second embodiment of the present invention, the first time is the time taken for the indoor unit coil temperature to increase from the first temperature to the second temperature when the duct air conditioner operates in the cooling mode; the second time is the time taken for the indoor unit coil temperature to decrease from the third temperature to the fourth temperature when the duct air conditioner operates in the heating mode.

[0017] In the duct air conditioner provided in the third embodiment of the present invention, the controller is further configured as follows:

[0018] When the ducted air conditioner operates in cooling mode, the outdoor unit operates at a first frequency and the indoor unit operates at a first speed; when the indoor unit coil temperature drops to 0°C, the outdoor unit stops operating, the indoor unit continues to operate at the first speed, and the indoor unit coil temperature begins to rise; timing starts when the indoor unit coil temperature rises to a first temperature and ends when the indoor unit coil temperature rises to a second temperature.

[0019] In the duct air conditioner provided in the fourth embodiment of the present invention, the controller is further configured as follows:

[0020] When the ducted air conditioner operates in heating mode, the outdoor unit operates at a second frequency and the indoor unit operates at a second speed; when the indoor unit coil temperature rises to a fifth temperature, the outdoor unit stops operating, the indoor unit continues to operate at the second speed, and the indoor unit coil temperature begins to decrease; timing starts when the indoor unit coil temperature drops to a third temperature, and timing ends when the indoor unit coil temperature drops to a fourth temperature.

[0021] In the duct air conditioner provided by the fifth embodiment of the present invention, the first time is positively correlated with the duct static pressure of the indoor unit, and the longer the first time is, the greater the duct static pressure is; the second time is positively correlated with the duct static pressure of the indoor unit, and the longer the second time is, the greater the duct static pressure is.

[0022] A sixth embodiment of the present invention provides a method for adaptively controlling static pressure in an indoor unit of a ducted air conditioner. The method is applied to a ducted air conditioner comprising an indoor heat exchanger, an indoor fan, an indoor ambient temperature sensor, an indoor coil temperature sensor, an indoor humidity sensor, an outdoor heat exchanger, an outdoor fan, a compressor, a flow regulating valve, and a four-way valve. The method comprises:

[0023] Detecting the current indoor ambient temperature and indoor humidity of the indoor unit by the indoor ambient temperature sensor and the indoor humidity sensor;

[0024] a first time or a second time used to detect a change in the temperature of the indoor unit coil by the indoor coil temperature sensor;

[0025] The current air duct static pressure value of the indoor unit is calculated according to the preset correspondence between the air duct static pressure of the indoor unit and the indoor ambient temperature, the indoor humidity, the first time and the second time.

[0026] In the static pressure adaptive control method for the indoor unit of a duct air conditioner provided in the seventh embodiment of the present invention, the first time is the time taken for the indoor unit coil temperature to increase from a first temperature to a second temperature when the duct air conditioner operates in a cooling mode; the second time is the time taken for the indoor unit coil temperature to decrease from a third temperature to a fourth temperature when the duct air conditioner operates in a heating mode.

[0027] In the static pressure adaptive control method for the indoor unit of a duct-type air conditioner provided in the eighth embodiment of the present invention, the method further includes:

[0028] When the ducted air conditioner operates in cooling mode, the outdoor unit operates at a first frequency and the indoor unit operates at a first speed; when the indoor unit coil temperature drops to 0°C, the outdoor unit stops operating, the indoor unit continues to operate at the first speed, and the indoor unit coil temperature begins to rise; timing starts when the indoor unit coil temperature rises to a first temperature and ends when the indoor unit coil temperature rises to a second temperature.

[0029] In the static pressure adaptive control method for an indoor unit of a duct-type air conditioner provided in a ninth embodiment of the present invention, the method further includes:

[0030] When the ducted air conditioner operates in heating mode, the outdoor unit operates at a second frequency and the indoor unit operates at a second speed; when the indoor unit coil temperature rises to a fifth temperature, the outdoor unit stops operating, the indoor unit continues to operate at the second speed, and the indoor unit coil temperature begins to decrease; timing starts when the indoor unit coil temperature drops to a third temperature, and timing ends when the indoor unit coil temperature drops to a fourth temperature.

[0031] In the static pressure adaptive control method for the indoor unit of a duct-type air conditioner provided in the tenth embodiment of the present invention, the first time is positively correlated with the duct static pressure of the indoor unit, and the longer the first time is, the greater the duct static pressure is; the second time is positively correlated with the duct static pressure of the indoor unit, and the longer the second time is, the greater the duct static pressure is.

[0032] Compared with the prior art, the embodiment of the present invention provides a duct-type air conditioner and a static pressure adaptive control method for an indoor unit thereof, which has the following beneficial effects: an indoor heat exchanger, an indoor fan, an indoor ambient temperature sensor, an indoor coil temperature sensor and an indoor humidity sensor are provided in the indoor unit of the duct-type air conditioner; an outdoor heat exchanger, an outdoor fan, a compressor, a flow regulating valve and a four-way valve are provided in the outdoor unit, and the compressor, the flow regulating valve, the four-way valve, the outdoor heat exchanger and the indoor heat exchanger are connected by pipelines to form a refrigerant circulation loop; the indoor heat exchanger is used to act as an evaporator or a condenser according to the operating state of the indoor unit, so that heat exchange is performed between the refrigerant flowing in the heat transfer pipe and the air passing through the indoor heat exchanger; the indoor ambient temperature sensor is used to detect the indoor ambient temperature of the indoor unit; the indoor coil temperature sensor is used to detect the temperature of the indoor unit coil; the indoor humidity sensor is used to detect The indoor humidity of the indoor unit; the outdoor heat exchanger, configured to function as a condenser or evaporator depending on the operating state of the outdoor unit, allowing heat exchange between the refrigerant flowing in the heat transfer tube and the air passing through the outdoor heat exchanger; the flow control valve, configured to convert the medium-temperature, high-pressure liquid after absorbing cold and releasing heat in the outdoor heat exchanger into a low-temperature, low-pressure liquid; the four-way valve, configured to switch between cooling and heating by changing the flow direction of the refrigerant within the circulation loop; the controller is configured to detect the current indoor ambient temperature and indoor humidity of the indoor unit via the indoor ambient temperature sensor and the indoor humidity sensor; detect the first time or the second time for the indoor unit coil temperature to change via the indoor coil temperature sensor; and calculate the current duct static pressure value of the indoor unit based on a preset correspondence between the duct static pressure of the indoor unit and the indoor ambient temperature, the indoor humidity, the first time, and the second time. This embodiment of the present invention does not require an additional static pressure sensor, does not require detection of motor current and power parameters, and calculates the duct static pressure of the indoor unit of the duct air conditioner based on parameters from multiple other dimensions, resulting in higher accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a perspective view of the appearance of a duct-type air conditioner provided by one embodiment of the present invention;

[0034] Figure 2 This is a structural diagram of a duct-type air conditioner provided by one embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of a refrigerant circulation circuit of a duct-type air conditioner provided by one embodiment of the present invention;

[0036] Figure 4 This is a schematic structural diagram of an indoor unit of a duct-type air conditioner with electric auxiliary heating provided by one embodiment of the present invention;

[0037] Figure 5 This is a schematic structural diagram of an indoor unit without electric auxiliary heating in a duct-type air conditioner provided by one embodiment of the present invention;

[0038] Figure 6 This is a front view of an indoor unit of a duct-type air conditioner provided by one embodiment of the present invention;

[0039] Figure 7 This is a side view of an indoor unit of a duct-type air conditioner provided by one embodiment of the present invention;

[0040] Figure 8 This is a top view of an indoor unit of a duct-type air conditioner provided by one embodiment of the present invention;

[0041] Figure 9 This is a first working diagram of a controller in a duct-type air conditioner provided by one embodiment of the present invention;

[0042] Figure 10 This is a second working flow diagram of a controller in a duct-type air conditioner provided by one embodiment of the present invention;

[0043] Figure 11 The figure is a flow chart of a method for controlling a motor of a duct-type air conditioner provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0046] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0047] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0048] See also Figures 1 to 2 , Figure 1 This is a perspective view of the appearance of a duct-type air conditioner provided by one embodiment of the present invention. Figure 2 Schematic diagram of the structure of a duct air conditioner provided in one embodiment of the present invention. The duct air conditioner 1 provided in the embodiment of the present invention comprises:

[0049] Indoor unit 2, which is equipped with an indoor heat exchanger 21, an indoor fan 22, an indoor ambient temperature sensor 23, an indoor coil temperature sensor 24 and an indoor humidity sensor 25;

[0050] The outdoor unit 3 includes an outdoor heat exchanger 31, an outdoor fan 32, a compressor 33, a flow regulating valve 34, and a four-way valve 35. The compressor 33, the flow regulating valve 34, the four-way valve 35, the outdoor heat exchanger 31, and the indoor heat exchanger 21 are connected by pipes to form a refrigerant circulation loop.

[0051] The indoor heat exchanger 21 is used to act as an evaporator or a condenser according to the operating state of the indoor unit, so that the refrigerant flowing in the heat transfer tube and the air passing through the indoor heat exchanger can exchange heat;

[0052] The indoor ambient temperature sensor 23 is used to detect the indoor ambient temperature of the indoor unit;

[0053] The indoor coil temperature sensor 24 is used to detect the temperature of the indoor unit coil;

[0054] The indoor humidity sensor 25 is used to detect the indoor humidity of the indoor unit;

[0055] The outdoor heat exchanger 31 is used to act as a condenser or an evaporator according to the operating state of the outdoor unit, so that the refrigerant flowing in the heat transfer tube and the air passing through the outdoor heat exchanger can exchange heat;

[0056] The flow regulating valve 34 is used to convert the medium-temperature and high-pressure liquid after the outdoor heat exchanger absorbs cold and releases heat into a low-temperature and low-pressure liquid;

[0057] The four-way valve 35 is used to switch between cooling and heating by changing the flow direction of the refrigerant in the circulation loop;

[0058] The controller is configured to detect the current indoor ambient temperature and indoor humidity of the indoor unit through the indoor ambient temperature sensor 23 and the indoor humidity sensor 25; detect the first time or the second time used for the indoor unit coil temperature change through the indoor coil temperature sensor 24; and calculate the current duct static pressure value of the indoor unit based on the preset correspondence between the duct static pressure of the indoor unit and the indoor ambient temperature, the indoor humidity, the first time and the second time.

[0059] Specifically, the duct air conditioner 1 in the embodiment of the present invention includes an indoor unit 2. Taking the indoor wall mounted unit (shown in the figure) as an example, the indoor wall mounted unit is usually installed on the indoor wall. For another example, the indoor cabinet unit (not shown in the figure) is also a form of indoor unit. The outdoor unit 3 is usually set outdoors and used for heat exchange in the indoor environment. In addition, Figure 1In the illustration, the outdoor unit 3 is shown with a dashed line because it is located outdoors on the opposite side of the indoor unit 2, separated by a wall. The indoor unit 2 and the outdoor unit 3 are connected by a connecting pipe 4. The indoor unit 2 is equipped with an indoor heat exchanger 21, an indoor fan 22, an indoor ambient temperature sensor 23, an indoor coil temperature sensor 24, and an indoor humidity sensor 25. The indoor heat exchanger 21 is composed of a plurality of fins and a coil extending through the fins. Depending on the operating state of the indoor unit 2, the indoor heat exchanger 21 functions as an evaporator or a radiator, exchanging heat between the refrigerant flowing through the coil and the air passing through the indoor heat exchanger 21. The indoor fan 22 is located approximately in the center of the indoor unit casing. It is a cross-flow fan that is elongated in the longitudinal direction (left-right direction) of the indoor unit 2. As the indoor fan 22 rotates, indoor air is drawn in through the air inlet, passes through the air filter, and then passes through the indoor heat exchanger 21. The resulting conditioned air is then blown out through the outlet into the room. The higher the speed of the indoor fan 22, the greater the volume of conditioned air blown out of the air outlet. When the air conditioner is in cooling mode, the indoor heat exchanger 21 operates as an evaporator. Depending on the operating state of the indoor unit, the indoor heat exchanger 21 functions as either an evaporator or a radiator, exchanging heat between the refrigerant flowing through the heat transfer tubes and the air passing through the indoor heat exchanger. The indoor fan 22 generates an airflow of indoor air through the indoor heat exchanger 21 to promote heat exchange between the refrigerant flowing through the heat transfer tubes of the indoor heat exchanger 21 and the indoor air. The indoor ambient temperature sensor 23 detects the indoor ambient temperature of the indoor unit; the indoor coil temperature sensor 24 detects the temperature of the indoor unit coil; and the indoor humidity sensor 25 detects the indoor humidity of the indoor unit. The outdoor unit 3 includes an outdoor heat exchanger 31, an outdoor fan 32, a compressor 33, a flow control valve 34, and a four-way valve 35. The outdoor fan 32 generates an airflow of outdoor air through the outdoor heat exchanger 31, promoting heat exchange between the refrigerant flowing through the heat transfer tubes and the outdoor air. The outdoor fan 32 is driven by an outdoor motor with a variable speed. When the air conditioner is in cooling mode, the outdoor heat exchanger 31 functions as a condenser. The outdoor fan 32 generates an airflow of outdoor air through the outdoor heat exchanger 31, promoting heat exchange between the refrigerant flowing through the heat transfer tubes of the outdoor heat exchanger 31 and the outdoor air.

[0060] See also Figure 3 , Figure 3The figure is a schematic diagram of a refrigerant circulation circuit for an air conditioner provided in one embodiment of the present invention. A compressor 33, a flow control valve 34, a four-way valve 35, an outdoor heat exchanger 31, and an indoor heat exchanger 21 are connected by pipes to form a refrigerant circulation circuit. The indoor heat exchanger 21 and the outdoor heat exchanger 31 function as a condenser or an evaporator. When the indoor heat exchanger 21 functions as a condenser and the outdoor heat exchanger 31 functions as an evaporator, the air conditioner functions as a heater in heating mode; when the indoor heat exchanger 21 functions as an evaporator and the outdoor heat exchanger 31 functions as a condenser, the air conditioner functions as a cooler in cooling mode. The four-way valve 35 is used to control the flow direction of the refrigerant in the refrigerant circulation circuit, so that the outdoor heat exchanger and the indoor heat exchanger can switch between functioning as a condenser and an evaporator. When the air conditioner is in cooling mode, the indoor heat exchanger 21 and the outdoor heat exchanger 31 function as an evaporator and a condenser, respectively. The refrigerant is compressed by the compressor and transformed into a high-temperature, high-pressure gas. It then passes through a four-way valve and enters the outdoor heat exchanger of the outdoor unit. There, it absorbs cold air and releases heat, becoming a medium-temperature, high-pressure liquid. After passing through a flow control valve, it becomes a low-temperature, low-pressure liquid. After absorbing heat and releasing heat in the indoor heat exchanger of the indoor unit, it becomes a low-temperature, low-pressure gas. It then passes through the four-way valve and returns to the compressor, continuing its cycle. The refrigerant circulation in the refrigerant circuit enables a vapor compression refrigeration cycle. The flow control valve can change its opening. Reducing the opening increases the flow resistance of the refrigerant through the flow control valve, while increasing the opening decreases the flow resistance. During cooling operation, this flow control valve expands and decompresses the refrigerant flowing from the indoor heat exchanger to the outdoor heat exchanger. Furthermore, even if the conditions of other components in the refrigerant circuit remain unchanged, changes in the opening of the flow control valve can change the flow rate of the refrigerant flowing through the refrigerant circuit.

[0061] See also Figures 4 to 8 , Figure 4 This is a structural diagram of an indoor unit of a duct-type air conditioner with electric auxiliary heating provided by one embodiment of the present invention; Figure 5 This is a schematic structural diagram of an indoor unit without electric auxiliary heating in a duct-type air conditioner provided by one embodiment of the present invention; Figure 6 This is a front view of an indoor unit of a duct-type air conditioner provided by one embodiment of the present invention; Figure 7 This is a side view of an indoor unit of a duct-type air conditioner provided by one embodiment of the present invention; Figure 8It is a top view of the indoor unit of a duct air conditioner provided by one embodiment of the present invention. The indoor unit of the duct air conditioner in the embodiment of the present invention has various forms, such as ceiling type, hidden ceiling type, etc. The characteristics of the duct air conditioner are that the condenser of the outdoor unit is air-cooled, and each outdoor unit is configured one-to-one with the indoor unit to form an independent system. The connection pipe between the condenser of the outdoor unit and the evaporator of the indoor unit can be up to 25 meters long. The hidden ceiling unit (indoor unit) can be connected to the air duct and the air outlet can be evenly arranged indoors according to the indoor space conditions. It can also be connected to the fresh air duct to introduce fresh air. The system completely relies on the refrigerant circulation to meet the air conditioning requirements. The system has both the use functions of a split air conditioner and the air supply effect of a central air conditioner. Compared with other forms of central air conditioners, the duct air conditioner has a smaller initial investment, is simple to design and use, is easy to install, and is flexible to use.

[0062] The outdoor fan draws in fresh outdoor air from the fresh air inlet, while the air drawn in from the indoor return air inlet is mixed in the new and old air mixing duct. The mixed air passes through a filter to remove impurities and is then delivered to the fan coil's return air inlet. The fan in the fan coil blows the air through the evaporator, where it undergoes heat exchange. The air that passes through the evaporator becomes cold air, which is then humidified by the humidification section of the fan coil. It is then delivered through the air outlet and enters the duct through the duct connector. The static pressure box applies static pressure to the cold air. After static pressure treatment, the cold air flows through the duct, first passing through the air volume control valve in the duct to adjust the amount of cold air, and then is delivered into the room through the air outlet (diffuser) to cool the indoor temperature. The low-temperature, low-pressure liquid refrigerant in the evaporator undergoes heat exchange with the air, transforming into a low-temperature, low-pressure gaseous refrigerant. This refrigerant is then piped into the outdoor unit, entering through port C of the solenoid four-way valve and then being fed into the compressor through port B, where it undergoes another refrigeration cycle. Ducted air conditioners utilize air ducts and diffusers for heat exchange at the user end, and can also incorporate fresh air and humidification devices. They also have two additional filters compared to conventional air conditioners to reduce dust ingress and ensure cleaner cooling air.

[0063] Specifically, in the embodiment of the present invention, the indoor ambient temperature T room , indoor humidity H room Under certain conditions, add an air duct with a static pressure of X Pa to the duct air conditioner. room When the temperature is ≥28℃, the whole machine runs in cooling mode. The outdoor unit runs at a fixed higher frequency, that is, the first frequency Y Hz, and the indoor unit runs at a fixed lower speed, that is, the first speed Z rpm / min. The indoor unit coil temperature is T coil Gradually decrease. When the indoor unit coil temperature T coil When the temperature drops to 0℃, the outdoor unit stops running and the indoor unit continues to run at a fixed lower speed, that is, the first speed Z rpm / min. The indoor unit coil temperature T coilWhen the indoor unit coil temperature T coil When the temperature rises to 2℃, the timer starts. The indoor unit coil temperature T coil When the temperature rises to 20℃, stop timing and record the indoor unit coil temperature T coil The first time T1 taken for the temperature to rise from 2°C to 20°C.

[0064] When T room When the temperature is less than 28℃, the whole unit operates in heating mode. The outdoor unit operates at a fixed higher frequency, that is, the second frequency Y Hz, and the indoor unit operates at a fixed lower speed, that is, the second speed Z rpm / min. The indoor unit coil temperature T coil Gradually increases. Indoor unit coil temperature T coil When the temperature rises to 52℃, the outdoor unit stops running and the indoor unit continues to run at a fixed lower speed, that is, the second speed Z rpm / min. The indoor unit coil temperature T coil When the indoor unit coil temperature T coil When the temperature drops to 50℃, the timer starts. coil When it drops to 32℃, stop timing and record the indoor unit coil temperature T coil The second time T2 used to drop from 50°C to 32°C.

[0065] It should be noted that, at the indoor ambient temperature T room , indoor humidity H room Under certain circumstances:

[0066] ① The cooling capacity released when the indoor unit coil temperature rises from 2°C to 20°C is basically constant;

[0067] ②The heat released when the indoor unit coil temperature drops from 50℃ to 32℃ is basically constant;

[0068] ③ If the indoor fan speed is constant and the duct static pressure X is constant, the air output volume is basically constant in this case;

[0069] ④ Under the above conditions, the time T1 and T2 used for the indoor unit coil temperature to change are corresponding to the duct static pressure XPa.

[0070] For example, for a certain duct air conditioner, the indoor ambient temperature is 35° C. and the indoor relative humidity is 50%. In this case, the relationship between time T1 and duct static pressure XPa is shown in Table 1 below.

[0071] Table 1

[0072] Serial number Time T1 Static pressure value 1 15S 10Pa 2 16S 15Pa 3 17S 20Pa 4 18S 25Pa 5 19S 30Pa 6 20S 35Pa 7 21S 40Pa 8 22S 45Pa 9 23S 50Pa 10 24S 55Pa

[0073] The indoor ambient temperature is 20°C and the indoor relative humidity is 30%. In this case, the relationship between time T2 and duct static pressure XPa is shown in Table 2 below.

[0074] Table 2

[0075] Serial number Time T2 Static pressure value 1 10S 10Pa 2 11S 15Pa 3 12S 20Pa 4 13S 25Pa 5 14S 30Pa 6 15S 35Pa 7 16S 40Pa 8 17S 45Pa 9 18S 50Pa 10 19S 55Pa

[0076] According to the above method, at different indoor ambient temperatures T room , indoor humidity H room , duct static pressure X, record the time T used for the indoor unit coil temperature change, record the corresponding data under different conditions, form a multi-dimensional database, and store the database in the indoor unit program. When the indoor unit of the duct air conditioner starts to automatically test the duct static pressure, the indoor ambient temperature sensor and indoor humidity sensor detect the current indoor ambient temperature T of the indoor unit. room and indoor humidity H room The indoor coil temperature sensor detects the first time T1 or the second time T2 used for the indoor unit coil temperature change, and then calculates the current duct static pressure value X Pa of the indoor unit based on the correspondence between the indoor unit's duct static pressure and the indoor ambient temperature, indoor humidity, the first time and the second time pre-stored in the database.

[0077] The embodiment of the present invention does not require an additional static pressure sensor, does not need to detect the current and power parameters of the motor, and calculates the duct static pressure of the indoor unit of the duct air conditioner from parameters of other multiple dimensions, with higher accuracy.

[0078] As one of the optional embodiments, the first time is the time taken for the indoor unit coil temperature to increase from a first temperature to a second temperature when the ducted air conditioner operates in a cooling mode; the second time is the time taken for the indoor unit coil temperature to decrease from a third temperature to a fourth temperature when the ducted air conditioner operates in a heating mode.

[0079] Specifically, in the embodiment of the present invention, when the ducted air conditioner operates in cooling mode, the indoor unit coil temperature T coil First gradually decrease, when the indoor unit coil temperature T coil When the temperature drops to 0℃, the outdoor unit stops running and the indoor unit continues to run at a fixed lower speed. The indoor unit coil temperature T coil The first time is the time it takes for the indoor unit coil temperature to rise from the first temperature to the second temperature when the ducted air conditioner is in cooling mode. coil When the temperature rises to 2℃, the timer starts. The indoor unit coil temperature T coil When the temperature rises to 20℃, stop timing and record the indoor unit coil temperature T coil The first time T1 is used to increase the temperature from 2℃ to 20℃. When the ducted air conditioner is running in heating mode, the indoor unit coil temperature T coilFirst gradually increase, when the indoor unit coil temperature T coil When the temperature rises to 52℃, the outdoor unit stops running and the indoor unit continues to run at a fixed lower speed. The indoor unit coil temperature T coil The second time is the time it takes for the indoor unit coil temperature to decrease from the third temperature to the fourth temperature when the ducted air conditioner is in heating mode. coil When the temperature drops to 50℃, the timer starts. coil When it drops to 32℃, stop timing and record the indoor unit coil temperature T coil The second time T2 used to drop from 50°C to 32°C.

[0080] As one of the optional embodiments, the controller is further configured to:

[0081] When the ducted air conditioner operates in cooling mode, the outdoor unit operates at a first frequency and the indoor unit operates at a first speed; when the indoor unit coil temperature drops to 0°C, the outdoor unit stops operating, the indoor unit continues to operate at the first speed, and the indoor unit coil temperature begins to rise; timing starts when the indoor unit coil temperature rises to a first temperature and ends when the indoor unit coil temperature rises to a second temperature.

[0082] For details, please refer to Figure 9 , Figure 9 This is a first working diagram of a controller in a duct air conditioner provided by one embodiment of the present invention. room When the temperature is ≥28℃, the whole machine runs in cooling mode, the outdoor unit runs at a fixed higher frequency, that is, the first frequency Y Hz, and the indoor unit runs at a fixed lower speed, that is, the first speed Zrpm / min. The indoor unit coil temperature T coil Gradually decrease. When the indoor unit coil temperature T coil When the temperature drops to 0℃, the outdoor unit stops running and the indoor unit continues to run at a fixed lower speed, that is, the first speed Z rpm / min. The indoor unit coil temperature T coil When the indoor unit coil temperature T coil When the temperature rises to 2℃, the timer starts. The indoor unit coil temperature T coil When the temperature rises to 20℃, stop timing and record the indoor unit coil temperature T coil The first time T1 taken for the temperature to rise from 2°C to 20°C.

[0083] As one of the optional embodiments, the controller is further configured to:

[0084] When the ducted air conditioner operates in heating mode, the outdoor unit operates at a second frequency and the indoor unit operates at a second speed; when the indoor unit coil temperature rises to a fifth temperature, the outdoor unit stops operating, the indoor unit continues to operate at the second speed, and the indoor unit coil temperature begins to decrease; timing starts when the indoor unit coil temperature drops to a third temperature, and timing ends when the indoor unit coil temperature drops to a fourth temperature.

[0085] For details, please refer to Figure 10 , Figure 10 This is a second working diagram of a controller in a duct air conditioner provided by one embodiment of the present invention. room When the temperature is less than 28℃, the whole unit operates in heating mode. The outdoor unit operates at a fixed higher frequency, that is, the second frequency Y Hz, and the indoor unit operates at a fixed lower speed, that is, the second speed Zrpm / min. The indoor unit coil temperature T coil Gradually increases. Indoor unit coil temperature T coil When the temperature rises to 52℃, the outdoor unit stops running and the indoor unit continues to run at a fixed lower speed, that is, the second speed Z rpm / min. The indoor unit coil temperature T coil When the indoor unit coil temperature T coil When the temperature drops to 50℃, the timer starts. coil When it drops to 32℃, stop timing and record the indoor unit coil temperature T coil The second time T2 used to drop from 50°C to 32°C.

[0086] As one of the optional embodiments, the first time is positively correlated with the duct static pressure of the indoor unit, and the longer the first time is, the greater the duct static pressure is; the second time is positively correlated with the duct static pressure of the indoor unit, and the longer the second time is, the greater the duct static pressure is.

[0087] Specifically, referring to Table 1 and Table 2, the embodiment of the present invention is in the indoor environment temperature T room , indoor humidity H room Under certain conditions, the first time is positively correlated with the duct static pressure of the indoor unit. The longer the first time is, the greater the duct static pressure is. The second time is positively correlated with the duct static pressure of the indoor unit. The longer the second time is, the greater the duct static pressure is.

[0088] See also Figure 11 , Figure 11This is a flow chart of a static pressure adaptive control method for an indoor unit of a duct air conditioner provided by an embodiment of the present invention. The static pressure adaptive control method for an indoor unit of a duct air conditioner provided in an embodiment of the present invention is applied to a duct air conditioner comprising an indoor heat exchanger, an indoor fan, an indoor ambient temperature sensor, an indoor coil temperature sensor, an indoor humidity sensor, an outdoor heat exchanger, an outdoor fan, a compressor, a flow regulating valve, and a four-way valve; the indoor heat exchanger is used to act as an evaporator or a condenser according to the operating state of the indoor unit, so that heat exchange is performed between the refrigerant flowing in the heat transfer tube and the air passing through the indoor heat exchanger; the indoor ambient temperature sensor is used to detect the indoor ambient temperature of the indoor unit; the indoor coil temperature sensor is used to detect the indoor ambient temperature of the indoor unit; and the indoor heat exchanger is used to detect the indoor ambient temperature of the indoor unit. The sensor is used to detect the temperature of the indoor unit coil; the indoor humidity sensor is used to detect the indoor humidity of the indoor unit; the outdoor heat exchanger is used to act as a condenser or an evaporator according to the operating state of the outdoor unit, so that the refrigerant flowing in the heat transfer tube exchanges heat with the air passing through the outdoor heat exchanger; the flow regulating valve is used to convert the medium-temperature and high-pressure liquid after absorbing cold and releasing heat in the outdoor heat exchanger into a low-temperature and low-pressure liquid; the four-way valve is used to achieve switching between cooling and heating by changing the flow direction of the refrigerant in the circulation loop; the static pressure adaptive control method of the indoor unit of the duct air conditioner includes:

[0089] S1. Detecting the current indoor ambient temperature and indoor humidity of the indoor unit by the indoor ambient temperature sensor and the indoor humidity sensor;

[0090] S2, detecting the first time or the second time for the indoor unit coil temperature change by the indoor coil temperature sensor;

[0091] S3. Calculate a current duct static pressure value of the indoor unit according to a preset correspondence between the duct static pressure of the indoor unit and the indoor ambient temperature, the indoor humidity, the first time, and the second time.

[0092] Specifically, in the embodiment of the present invention, the indoor ambient temperature T room , indoor humidity H room Under certain conditions, add an air duct with a static pressure of X Pa to the duct air conditioner. room When the temperature is ≥28℃, the whole machine runs in cooling mode. The outdoor unit runs at a fixed higher frequency, that is, the first frequency Y Hz, and the indoor unit runs at a fixed lower speed, that is, the first speed Z rpm / min. The indoor unit coil temperature is T coil Gradually decrease. When the indoor unit coil temperature T coil When the temperature drops to 0℃, the outdoor unit stops running and the indoor unit continues to run at a fixed lower speed, that is, the first speed Z rpm / min. The indoor unit coil temperature T coilWhen the indoor unit coil temperature T coil When the temperature rises to 2℃, the timer starts. The indoor unit coil temperature T coil When the temperature rises to 20℃, stop timing and record the indoor unit coil temperature T coil The first time T1 taken for the temperature to rise from 2°C to 20°C.

[0093] When T room When the temperature is less than 28℃, the whole unit operates in heating mode. The outdoor unit operates at a fixed higher frequency, that is, the second frequency Y Hz, and the indoor unit operates at a fixed lower speed, that is, the second speed Z rpm / min. The indoor unit coil temperature T coil Gradually increases. Indoor unit coil temperature T coil When the temperature rises to 52℃, the outdoor unit stops running and the indoor unit continues to run at a fixed lower speed, that is, the second speed Z rpm / min. The indoor unit coil temperature T coil When the indoor unit coil temperature T coil When the temperature drops to 50℃, the timer starts. coil When it drops to 32℃, stop timing and record the indoor unit coil temperature T coil The second time T2 used to drop from 50°C to 32°C.

[0094] At different indoor ambient temperatures T room , indoor humidity H room , duct static pressure X, record the time T used for the indoor unit coil temperature change, record the corresponding data under different conditions, form a multi-dimensional database, and store the database in the indoor unit program. When the indoor unit of the duct air conditioner starts to automatically test the duct static pressure, the indoor ambient temperature sensor and indoor humidity sensor detect the current indoor ambient temperature T of the indoor unit. room and indoor humidity H room The indoor coil temperature sensor detects the first time T1 or the second time T2 used for the indoor unit coil temperature change, and then calculates the current duct static pressure value X Pa of the indoor unit based on the correspondence between the indoor unit's duct static pressure and the indoor ambient temperature, indoor humidity, the first time and the second time pre-stored in the database.

[0095] The embodiment of the present invention does not require an additional static pressure sensor, does not need to detect the current and power parameters of the motor, and calculates the duct static pressure of the indoor unit of the duct air conditioner from parameters of other multiple dimensions, with higher accuracy.

[0096] As one of the optional embodiments, the first time is the time taken for the indoor unit coil temperature to increase from a first temperature to a second temperature when the ducted air conditioner operates in a cooling mode; the second time is the time taken for the indoor unit coil temperature to decrease from a third temperature to a fourth temperature when the ducted air conditioner operates in a heating mode.

[0097] As an optional embodiment, the method further includes:

[0098] When the ducted air conditioner operates in cooling mode, the outdoor unit operates at a first frequency and the indoor unit operates at a first speed; when the indoor unit coil temperature drops to 0°C, the outdoor unit stops operating, the indoor unit continues to operate at the first speed, and the indoor unit coil temperature begins to rise; timing starts when the indoor unit coil temperature rises to a first temperature and ends when the indoor unit coil temperature rises to a second temperature.

[0099] As an optional embodiment, the method further includes:

[0100] When the ducted air conditioner operates in heating mode, the outdoor unit operates at a second frequency and the indoor unit operates at a second speed; when the indoor unit coil temperature rises to a fifth temperature, the outdoor unit stops operating, the indoor unit continues to operate at the second speed, and the indoor unit coil temperature begins to decrease; timing starts when the indoor unit coil temperature drops to a third temperature, and timing ends when the indoor unit coil temperature drops to a fourth temperature.

[0101] As one of the optional embodiments, the first time is positively correlated with the duct static pressure of the indoor unit, and the longer the first time is, the greater the duct static pressure is; the second time is positively correlated with the duct static pressure of the indoor unit, and the longer the second time is, the greater the duct static pressure is.

[0102] An embodiment of the present invention provides a duct-type air conditioner and a static pressure adaptive control method for an indoor unit thereof, wherein the indoor unit of the duct-type air conditioner is provided with an indoor heat exchanger, an indoor fan, an indoor ambient temperature sensor, an indoor coil temperature sensor and an indoor humidity sensor; the outdoor unit is provided with an outdoor heat exchanger, an outdoor fan, a compressor, a flow regulating valve and a four-way valve, and the compressor, the flow regulating valve, the four-way valve, the outdoor heat exchanger and the indoor heat exchanger are connected by pipelines to form a refrigerant circulation loop; the indoor heat exchanger is used to act as an evaporator or a condenser according to the operating state of the indoor unit, so that heat exchange is performed between the refrigerant flowing in the heat transfer pipe and the air passing through the indoor heat exchanger; the indoor ambient temperature sensor is used to detect the indoor ambient temperature of the indoor unit; the indoor coil temperature sensor is used to detect the temperature of the indoor unit coil; the indoor humidity sensor is used to detect the indoor humidity of the indoor unit humidity; the outdoor heat exchanger is configured to function as a condenser or evaporator, depending on the operating state of the outdoor unit, to exchange heat between the refrigerant flowing in the heat transfer tube and the air passing through the outdoor heat exchanger; the flow control valve is configured to convert the medium-temperature, high-pressure liquid after the outdoor heat exchanger absorbs cold and releases heat into a low-temperature, low-pressure liquid; the four-way valve is configured to switch between cooling and heating by changing the flow direction of the refrigerant within the circulation loop; the controller is configured to detect the current indoor ambient temperature and indoor humidity of the indoor unit via the indoor ambient temperature sensor and the indoor humidity sensor; detect the first time or second time for the indoor unit coil temperature to change via the indoor coil temperature sensor; and calculate the current duct static pressure value of the indoor unit based on a preset correspondence between the duct static pressure of the indoor unit and the indoor ambient temperature, the indoor humidity, the first time, and the second time. This embodiment of the present invention does not require an additional static pressure sensor or motor current or power parameters, and calculates the duct static pressure of the indoor unit of the duct air conditioner from parameters in multiple dimensions, resulting in higher accuracy.

[0103] It should be noted that the system embodiment described above is merely illustrative, wherein the units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed across multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the system embodiment provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art can understand and implement the present invention without inventive work.

[0104] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A duct type air conditioner, characterized in that: include: Indoor unit, which is equipped with indoor heat exchanger, indoor fan, indoor ambient temperature sensor, indoor coil temperature sensor and indoor humidity sensor; An outdoor unit is provided with an outdoor heat exchanger, an outdoor fan, a compressor, a flow regulating valve and a four-way valve, wherein the compressor, the flow regulating valve, the four-way valve, the outdoor heat exchanger and the indoor heat exchanger are connected by pipelines to form a refrigerant circulation loop; The indoor heat exchanger is used to act as an evaporator or a condenser according to the operating state of the indoor unit, so as to perform heat exchange between the refrigerant flowing in the heat transfer tube and the air passing through the indoor heat exchanger; The indoor ambient temperature sensor is used to detect the indoor ambient temperature of the indoor unit; The indoor coil temperature sensor is used to detect the temperature of the indoor unit coil; The indoor humidity sensor is used to detect the indoor humidity of the indoor unit; The outdoor heat exchanger is used to act as a condenser or an evaporator according to the operating state of the outdoor unit, so that the refrigerant flowing in the heat transfer tube and the air passing through the outdoor heat exchanger can exchange heat; The flow regulating valve is used to convert the medium-temperature and high-pressure liquid after the outdoor heat exchanger or the indoor heat exchanger absorbs cold and releases heat into a low-temperature and low-pressure liquid; The four-way valve is used to switch between cooling and heating by changing the flow direction of the refrigerant in the circulation loop; The controller is configured to detect the current indoor ambient temperature and indoor humidity of the indoor unit through the indoor ambient temperature sensor and the indoor humidity sensor; detect the first time or the second time used for the indoor unit coil temperature change; and calculate the current duct static pressure value of the indoor unit based on a preset correspondence between the duct static pressure of the indoor unit and the indoor ambient temperature, the indoor humidity, the first time, and the second time: Among them, the first time is the time taken for the indoor unit coil temperature to rise from the first temperature to the second temperature after the outdoor unit stops running when the ducted air conditioner operates in the cooling mode; the second time is the time taken for the indoor unit coil temperature to drop from the third temperature to the fourth temperature after the outdoor unit stops running when the ducted air conditioner operates in the heating mode.

2. The duct type air conditioner according to claim 1, wherein: The controller is further configured to: When the ducted air conditioner operates in cooling mode, the outdoor unit operates at a first frequency and the indoor unit operates at a first speed; when the indoor unit coil temperature drops to 0°C, the outdoor unit stops operating, the indoor unit continues to operate at the first speed, and the indoor unit coil temperature begins to rise; timing starts when the indoor unit coil temperature rises to a first temperature and ends when the indoor unit coil temperature rises to a second temperature.

3. The duct type air conditioner according to claim 2, wherein: The controller is further configured to: When the ducted air conditioner operates in heating mode, the outdoor unit operates at a second frequency and the indoor unit operates at a second speed; when the indoor unit coil temperature rises to a fifth temperature, the outdoor unit stops operating, the indoor unit continues to operate at the second speed, and the indoor unit coil temperature begins to decrease; timing starts when the indoor unit coil temperature drops to a third temperature, and timing ends when the indoor unit coil temperature drops to a fourth temperature.

4. The duct type air conditioner according to claim 3, wherein: The first time is positively correlated with the air duct static pressure of the indoor unit. The longer the first time is, the greater the air duct static pressure is. The second time is positively correlated with the air duct static pressure of the indoor unit. The longer the second time is, the greater the air duct static pressure is.

5. A static pressure adaptive control method for an indoor unit of a ducted air conditioner, characterized in that: The method is applied to a duct-type air conditioner comprising an indoor unit and an outdoor unit; the indoor unit is equipped with an indoor heat exchanger, an indoor fan, an indoor ambient temperature sensor, an indoor coil temperature sensor, and an indoor humidity sensor; the outdoor unit is equipped with an outdoor heat exchanger, an outdoor fan, a compressor, a flow regulating valve, and a four-way valve. The static pressure adaptive control method of the indoor unit of the duct-type air conditioner comprises: Detecting the current indoor ambient temperature and indoor humidity of the indoor unit by the indoor ambient temperature sensor and the indoor humidity sensor; The first time or second time used to detect changes in the indoor unit coil temperature; Calculating a current duct static pressure value of the indoor unit according to a preset correspondence between the duct static pressure of the indoor unit and the indoor ambient temperature, the indoor humidity, the first time, and the second time; Among them, the first time is the time taken for the indoor unit coil temperature to rise from the first temperature to the second temperature after the outdoor unit stops running when the ducted air conditioner operates in the cooling mode; the second time is the time taken for the indoor unit coil temperature to drop from the third temperature to the fourth temperature after the outdoor unit stops running when the ducted air conditioner operates in the heating mode.

6. The static pressure adaptive control method for the indoor unit of a ducted air conditioner according to claim 5, wherein: The method further comprises: When the ducted air conditioner operates in cooling mode, the outdoor unit operates at a first frequency and the indoor unit operates at a first speed; when the indoor unit coil temperature drops to 0°C, the outdoor unit stops operating, the indoor unit continues to operate at the first speed, and the indoor unit coil temperature begins to rise; timing starts when the indoor unit coil temperature rises to a first temperature and ends when the indoor unit coil temperature rises to a second temperature.

7. The static pressure adaptive control method for the indoor unit of a ducted air conditioner according to claim 6, wherein: The method further comprises: When the ducted air conditioner operates in heating mode, the outdoor unit operates at a second frequency and the indoor unit operates at a second speed; when the indoor unit coil temperature rises to a fifth temperature, the outdoor unit stops operating, the indoor unit continues to operate at the second speed, and the indoor unit coil temperature begins to decrease; timing starts when the indoor unit coil temperature drops to a third temperature, and timing ends when the indoor unit coil temperature drops to a fourth temperature.

8. The static pressure adaptive control method for the indoor unit of a ducted air conditioner according to claim 7, wherein: The first time is positively correlated with the air duct static pressure of the indoor unit. The longer the first time is, the greater the air duct static pressure is. The second time is positively correlated with the air duct static pressure of the indoor unit. The longer the second time is, the greater the air duct static pressure is.

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