Fresh air system

Abstract

The invention discloses a fresh air system, and belongs to the technical field of air purification. The fresh air system comprises an air duct, an electric check valve and a power supply circuit. The power supply circuit comprises an energy storage unit. The main power supply loop is electrically connected with the power supply end of the electric check valve and configured to be connected with an external power supply, and the external power supply is used for supplying power to the electric check valve; the charging loop is electrically connected with the energy storage unit and is configured to be connected with an external power supply, and the external power supply is used for charging the energy storage unit; and the discharge loop is electrically connected with the energy storage unit and the power supply end of the electric check valve, and is configured to utilize the energy storage unit to supply power to the electric check valve under the condition that the external power supply is abnormal. The independent power supply circuit is arranged for the electric check valve, the control circuit can detect power failure and control the discharging loop to work, electric energy stored in the energy storage unit is used for driving the electric check valve to complete the closing action, and the situation that the electric check valve stays in the opening state due to power failure is avoided.

Description

Technical Field

[0001] This application belongs to the field of air purification technology, and in particular relates to a fresh air system. Background Technology

[0002] In modern buildings, fresh air systems are mostly one-master-multiple-slave or multi-master cascade systems, designed to achieve precise airflow control across multiple rooms and ducts, thereby providing fresh air to different spaces as needed and expelling stale air. When some rooms need to operate while others do not, the system struggles to balance regional energy conservation with overall safety. Summary of the Invention

[0003] This application aims to at least solve one of the technical problems existing in the prior art. To this end, this application proposes a fresh air system that equips the electric check valve with an independent power supply circuit. The control circuit can detect power failure and control the discharge circuit to work. The electrical energy stored in the energy storage unit is used to drive the electric check valve to complete the closing action, thus preventing the electric check valve from remaining in the open state due to power failure.

[0004] In a first aspect, this application provides a fresh air system, which includes: Air ducts are used to bring fresh air from outdoors into the room; An electric check valve is installed inside the air duct and is used to open or close the air duct. The power supply circuit includes: Energy storage unit; The main power supply circuit is electrically connected to the power supply terminal of the electric check valve and is configured to connect to an external power source, and use the external power source to power the electric check valve. The charging circuit is electrically connected to the energy storage unit and is configured to connect to an external power source and use the external power source to charge the energy storage unit. The discharge circuit is electrically connected to the power supply terminals of the energy storage unit and the electric check valve, and is configured to use the energy storage unit to supply power to the electric check valve in the event of an external power failure.

[0005] According to the fresh air system of this application, by equipping the electric check valve with an independent power supply circuit, the external power supply is used to power the energy storage unit when the external power supply is normal. When the external power supply is cut off, the control circuit can detect the power failure and control the discharge circuit to work. The electrical energy stored in the energy storage unit is used to drive the electric check valve to complete the closing action, so as to prevent the electric check valve from remaining in the open state due to power failure.

[0006] According to one embodiment of this application, the fresh air system includes: The power detection circuit has its input terminal electrically connected to an external power source. The power detection circuit is configured to generate a first signal when the external power source is supplying power normally, or to generate a second signal when the external power source is in a power-off state. The control circuit is electrically connected to the output of the power detection circuit. The control circuit is configured to respond to a first signal to control the operation of the charging circuit and the main power supply circuit and control the discharge circuit to stop working, or to respond to a second signal to control the operation of the discharge circuit and control the operation of the charging circuit and the main power supply circuit to stop working.

[0007] According to one embodiment of this application, the power supply detection circuit includes: The first rectifier circuit has its AC side electrically connected to an external power supply. A current limiting circuit is included, with its input terminal electrically connected to the DC side of the first rectifier circuit. The optocoupler has its light-emitting diode electrically connected to the output terminal of the current-limiting circuit, its phototransistor's collector electrically connected to the power supply voltage node, and its emitter electrically connected to the ground node.

[0008] According to one embodiment of this application, the charging circuit includes: The second rectifier circuit has its AC side electrically connected to an external power source and its DC side electrically connected to an energy storage unit.

[0009] According to one embodiment of this application, the charging circuit further includes: The filter circuit has its input terminal electrically connected to the DC side of the second rectifier circuit, and its output terminal electrically connected to the control circuit. The control circuit is configured to control the charging circuit to operate and the discharging circuit to stop working when the external power supply is normal and the power quality is determined to be stable based on the output of the filter circuit.

[0010] According to one embodiment of this application, the discharge circuit includes: The boost circuit has its input terminal electrically connected to the energy storage unit and its output terminal connected to the power supply terminal of the electric check valve.

[0011] According to one embodiment of this application, the discharge circuit includes: The voltage regulator circuit is electrically connected to the output terminal of the boost circuit and the power supply terminal of the electric check valve. The voltage regulator circuit is configured to regulate the voltage output by the boost circuit and output the working voltage to the power supply terminal of the electric check valve.

[0012] According to one embodiment of this application, the fresh air system further includes: The temperature detection module is electrically connected to the energy storage unit and the control circuit, and is configured to detect the temperature of the energy storage unit and transmit the detection result to the control circuit. The control circuit is also configured to stop the charging circuit from operating if the detection result is greater than the temperature threshold.

[0013] According to one embodiment of this application, the fresh air system further includes: The switching transistor has its first end electrically connected to the first power supply terminal of the electric check valve, the second power supply terminal of the electric check valve electrically connected to the energy storage unit, the second end of the switching transistor electrically connected to the grounding node, and the drive terminal of the switching transistor electrically connected to the control circuit. The control circuit is configured to disconnect the control switch when the external power supply is off.

[0014] According to one embodiment of this application, the fresh air system includes multiple air ducts, multiple electric check valves, and multiple power supply circuits. Each air duct and each electric check valve is connected in a corresponding manner, and each power supply circuit is electrically connected to the power supply terminal of the corresponding electric check valve.

[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0016] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a structural block diagram of the fresh air system provided in the embodiments of this application; Figure 2 This is a circuit diagram of the power detection circuit provided in an embodiment of this application; Figure 3 This is a circuit diagram of the charging circuit provided in an embodiment of this application; Figure 4 This is a circuit diagram of the discharge circuit provided in the embodiments of this application.

[0017] Figure label: Energy storage unit 10, charging circuit 20, filter circuit 21, second rectifier circuit 22, discharge circuit 30, external power supply 40, electric check valve 50, power detection circuit 60, first rectifier circuit 61, current limiting circuit 62, optocoupler 63, main power supply circuit 70, first to fifth resistors R1~R5, first to second capacitors C1~C2, power inductor L, power supply voltage node Vcc, ground node GND, power supply pin VCC, enable pin CE, output pin BAT, first to second diodes D1~D2. Detailed Implementation

[0018] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0019] In the following description, a "circuit" refers to a conductive loop consisting of at least one element or sub-circuit connected by an electrical or electromagnetic link. When an element or circuit is said to be "coupled to" or "connected to" another element, or when an element / circuit is said to be "coupled at" or "connected at" two nodes, it can be directly coupled to or connected to the other element, or there may be intermediate elements. The connection between elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there are no intermediate elements between them.

[0020] In the description, the terms "first," "second," etc., are used to distinguish similar objects, not to describe a specific order or sequence. It should be understood that such numerical descriptors can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] Furthermore, the use of terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicates that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0022] In modern buildings, fresh air systems are mostly one-master-multiple-slave or multi-master cascade systems, designed to achieve precise airflow control across multiple rooms and ducts, thereby providing fresh air to different spaces as needed and expelling stale air. When some rooms need to operate while others do not, the system struggles to balance regional energy conservation with overall safety.

[0023] To ensure safety, existing systems are generally designed for continuous power supply. Even if a fan coil unit in a room is not running, its control board and electric check valve remain on standby, ready to receive shutdown commands. The closing of the electric check valve depends on commands sent from the control board. If power is cut off directly to save electricity, the electric check valve will remain open due to power loss, causing backflow of exhaust air into the ductwork.

[0024] This application proposes a fresh air system that equips the electric check valve with an independent power supply circuit. The control circuit can detect power failure and control the discharge circuit to work. The electrical energy stored in the energy storage unit is used to drive the electric check valve to complete the closing action, thus preventing the electric check valve from remaining in the open state due to power failure.

[0025] Figure 1 A structural block diagram of a fresh air system provided in an embodiment of this application is shown. (Refer to...) Figure 1 One embodiment of this application proposes a fresh air system applied to an electrically operated check valve 50. The fresh air system includes: an air duct, an electrically operated check valve 50, and a power supply circuit. The air duct is used to introduce outdoor fresh air into the room; the electrically operated check valve 50 is connected to the air duct, and at least partially movable relative to the air duct to open and close the air duct; the power supply circuit includes: an energy storage unit 10, a main power supply circuit 70, a charging circuit 20, and a discharging circuit 30. The main power supply circuit 70 is electrically connected to the power supply terminal of the electrically operated check valve 50 and is configured to connect to an external power source 40, and use the external power source 40 to power the electrically operated check valve 50; the charging circuit is electrically connected to the energy storage unit 10 and is configured to connect to the external power source 40, and use the external power source 40 to charge the energy storage unit; the discharging circuit is electrically connected to the power supply terminals of the energy storage unit 10 and the electrically operated check valve 50, and is configured to use the energy storage unit 10 to power the electrically operated check valve 50 in the event of an abnormality in the external power source 40.

[0026] In a fresh air system, the ductwork, as the physical path for air transport, is mainly used to reliably introduce treated fresh outdoor air into the room.

[0027] The electric check valve 50 is a one-way airflow control mechanism in the duct. It is mechanically connected to the duct, and its internal movable parts, such as valve discs and valve plates, can move relative to the duct, thereby achieving the "opening" and "closing" of the duct. The electric check valve 50 opens when the system is running, allowing fresh air to pass through; it closes when the system is shut down. Its core function is to prevent reverse airflow caused by pressure differences within the duct, thus avoiding the mixing of unfiltered outdoor air or polluted air from different rooms.

[0028] External power source 40 refers to the main power source that provides electrical energy to the fresh air system provided in this application, typically represented by mains power, i.e., AC power grid. Alternatively, external power source 40 can also be other forms of industrial power or distributed power.

[0029] Energy storage unit 10 refers to an energy storage component, which functions similarly to a backup battery. Energy storage unit 10 is the energy source for the entire circuit in the event of a power outage, and is mainly used to provide the power required to close the electric check valve 50 when the external power supply 40 is in a power outage state.

[0030] The specific type of energy storage unit 10 can be selected according to the actual application scenario, and is not limited here. For example, energy storage unit 10 can be a rechargeable battery.

[0031] The input terminal of the main power supply circuit 70 is used to connect to the external power supply 40, and the output terminal of the main power supply circuit 70 is connected to the power supply terminal of the electric check valve 50. The main power supply circuit 70 is configured to convert the electrical energy of the external power supply 40 into the working voltage of the electric check valve 50 when the external power supply 40 is normally powered, thereby driving its opening and closing action.

[0032] The input terminal of the charging circuit 20 is electrically connected to the external power supply 40, and the output terminal of the charging circuit 20 is electrically connected to the energy storage unit 10. The charging circuit 20 is configured to charge the energy storage unit 10 using the external power supply 40 when the external power supply 40 is supplying power normally. The charging circuit 20 may contain modules such as a rectifier circuit, a voltage regulator circuit, and a boost circuit to ensure that the electrical energy from the external power supply 40 is safely and efficiently converted into voltage and current suitable for charging the energy storage unit 10, avoiding overcharging or damage to the energy storage unit 10.

[0033] The input terminal of the discharge circuit 30 is electrically connected to the energy storage unit 10, and the output terminal of the discharge circuit 30 is electrically connected to the power supply terminal of the electric check valve 50. The discharge circuit 30 is configured to convert the electrical energy of the energy storage unit 10 into the working voltage of the electric check valve 50 in the event of an abnormal power supply from the external power supply 40, thereby driving the motor of the electric check valve 50 to perform a closing action.

[0034] Specifically, the power supply circuit proposed in this application operates as follows: When the external power supply 40 is operating normally, the main power supply circuit 70 and the charging circuit 20 function. A portion of the electrical energy from the external power supply 40 is converted and stored in the energy storage unit 10 through the charging circuit 20, ensuring it remains fully charged and ready to handle sudden power outages. The remaining electrical energy powers the electric check valve 50 and other electrical components in the fresh air system through the main power supply circuit 70. At this time, the electric check valve 50 is powered by the external power supply 40, and the energy storage unit 10 is only in a silent charging state as a backup power source. When the external power supply 40 fails, the pre-stored electrical energy in the energy storage unit 10 is released through the discharge circuit 30 and delivered to the power supply terminal of the electric check valve 50, providing it with emergency power. The powered electric check valve 50 can then perform a closing action to prevent backflow of air.

[0035] According to the fresh air system of this application, by equipping the electric check valve 50 with an independent power supply circuit, when the external power supply 40 is normally powered, the external power supply 40 is used to power the energy storage unit 10. When the external power supply 40 is cut off, the control circuit can detect the power failure and control the discharge circuit 30 to work. The electrical energy stored in the energy storage unit 10 is used to drive the electric check valve 50 to complete the closing action, so as to prevent the electric check valve 50 from remaining in the open state due to power failure.

[0036] In some embodiments, the fresh air system includes a power detection circuit 60 and a control circuit. The input terminal of the power detection circuit 60 is electrically connected to an external power supply 40. The power detection circuit 60 is configured to generate a first signal when the external power supply 40 is supplying power normally, or to generate a second signal when the external power supply 40 is in a power-off state. The control circuit is electrically connected to the output terminal of the power detection circuit 60. The control circuit is configured to control the charging circuit 20 and the main power supply circuit 70 to operate and control the discharging circuit 30 to stop operating in response to the first signal, or to control the discharging circuit 30 to operate and control the charging circuit 20 and the main power supply circuit 70 to stop operating in response to the second signal.

[0037] The power detection circuit 60 is electrically connected to the external power supply 40. The power detection circuit 60 is mainly used to continuously monitor the status of the external power supply 40 and convert this physical status into an electrical signal that can be recognized and processed by subsequent control circuits. When the external power supply 40 is supplying power normally, the power detection circuit 60 generates and outputs a first signal. The first signal can be a specific high level (e.g., 3.3V or 5V) or a specific pulse signal. When the external power supply 40 loses power, the power detection circuit 60 switches the output signal to a second signal, which is different from the first signal. The second signal can be a low-level signal.

[0038] Upon receiving the first signal, the control circuit determines that the main power supply is normal, activates the charging circuit 20, allowing it to draw power from the external power source 40 and charge the energy storage unit 10. Simultaneously, it controls the discharging circuit 30 to stop operating, effectively cutting off the connection between the energy storage unit 10 and the electric check valve 50 to maintain the charge level of the energy storage unit 10 and ensure system safety during standby. Upon receiving the second signal: the control circuit determines that the main power supply is lost, activates the discharging circuit 30, connecting the power supply path between the energy storage unit 10 and the electric check valve 50, and immediately stops the charging circuit 20. This allows the backup power supply to drive the electric check valve 50 to complete the shut-off action.

[0039] By setting up a dedicated power detection circuit 60, hardware-level direct sampling and judgment of the main power supply status is achieved. This circuit can accurately capture the moment when the external power supply 40 is turned on and off, and convert this physical state into a logic signal, thereby improving the response speed and anti-interference capability of status detection.

[0040] Figure 2 A circuit diagram of the power detection circuit 60 provided in an embodiment of this application is shown. (Refer to...) Figure 2 In some embodiments, the power detection circuit 60 includes: a first rectifier circuit 61, a current limiting circuit 62, and an optocoupler 63. The AC side of the first rectifier circuit 61 is electrically connected to the external power supply 40; the input terminal of the current limiting circuit 62 is electrically connected to the DC side of the first rectifier circuit 61; the light-emitting diode of the optocoupler 63 is electrically connected to the output terminal of the current limiting circuit 62, the collector of the phototransistor of the optocoupler 63 is electrically connected to the power supply voltage node Vcc, and the emitter of the phototransistor is electrically connected to the ground node GND.

[0041] The first rectifier circuit 61 is electrically connected between the external power supply 40 and the current limiting circuit 62, and is mainly used to convert the high-voltage AC power provided by the external power supply 40 into a DC signal suitable for subsequent circuit processing.

[0042] The specific structure of the first rectifier circuit 61 can be selected according to the actual application scenario, and is not limited here. For example, the first rectifier circuit 61 can be a full-bridge rectifier circuit or a half-bridge rectifier circuit, etc.

[0043] The input terminal of the current limiting circuit 62 is electrically connected to the DC side of the first rectifier circuit 61, thereby receiving the rectified pulsating DC power. The current limiting circuit 62 can be composed of multiple resistors connected in series or a single resistor. The current limiting circuit 62 is mainly used to limit the current flowing to the LED of the subsequent optocoupler 63 within a safe rated value, preventing the LED from burning out due to excessive current.

[0044] Optocoupler 63's LED is electrically connected to the output of current-limiting circuit 62, primarily used to receive the current output from current-limiting circuit 62. When the external power supply 40 is normal, current flows through the LED, causing it to emit light. The collector of the phototransistor in optocoupler 63 is connected to the power supply voltage node Vcc, and the emitter can be connected to the ground node GND through a pull-down resistor. The specific type of power supply voltage node Vcc can be selected according to the actual application scenario and is not limited here. For example, the power supply voltage node Vcc can be derived from the microcontroller's 3.3V or 5V power supply.

[0045] When the external power supply 40 is supplying power normally, the electrical energy provided by the external power supply 40 flows through the current limiting circuit 62 after being rectified by the first rectifier circuit 61. The LED of the optocoupler 63 receives the current output from the current limiting circuit 62 and emits light, causing the phototransistor to conduct. At this time, the collector and emitter of the phototransistor are effectively short-circuited, pulling the output signal high to the voltage provided by the supply voltage node Vcc, generating a high-level signal. This high-level signal is the first signal indicating that the external power supply 40 is supplying power normally. When the external power supply 40 is in a de-energized state, the LED is off, the phototransistor is cut off, and its output signal is pulled down to a low-level signal by the pull-down resistor. This low-level signal is the second signal indicating that the external power supply 40 is in a de-energized state.

[0046] The use of optocoupler 63 achieves complete electrical isolation between the input high-voltage side and the output low-voltage side, preventing external power grid surges, high-voltage faults, and other issues from flowing into the downstream control circuitry, thus improving system safety. Furthermore, the entire detection process is based on photoelectric conversion, resulting in extremely fast response speeds and the ability to detect instantaneous power outages without delay, thereby enhancing system reliability.

[0047] In some embodiments, the charging circuit 20 includes a second rectifier circuit 22. The AC side of the second rectifier circuit 22 is electrically connected to an external power supply 40, and the DC side of the second rectifier circuit 22 is electrically connected to the energy storage unit 10.

[0048] The AC side of the second rectifier circuit 22 is directly connected to the external power supply 40 (such as 220V / 50Hz mains power), and its DC side is connected to the energy storage unit 10. It is mainly used to rectify the AC power from the external power supply 40 and provide DC power to the energy storage unit 10 to charge the DC energy storage unit 10.

[0049] The specific structure of the second rectifier circuit 22 can be selected according to the actual application scenario, and is not limited here. For example, the second rectifier circuit 22 can be a full-bridge rectifier circuit or a half-bridge rectifier circuit, etc.

[0050] An independent second rectifier circuit 22 is used as the front end of the charging circuit 20, which can handle all the power required for charging, provide sufficient power to the energy storage unit 10, and ensure a high charging rate and energy conversion efficiency.

[0051] In some embodiments, the charging circuit 20 further includes a filter circuit 21. The input terminal of the filter circuit 21 is electrically connected to the DC side of the second rectifier circuit 22, and the output terminal of the filter circuit 21 is electrically connected to the control circuit. The control circuit is configured to control the charging circuit 20 to operate and control the discharging circuit 30 to stop working when the external power supply 40 is supplying power normally and the power quality is determined to be stable based on the output of the filter circuit 21.

[0052] The filter circuit 21 is electrically connected between the DC side of the second rectifier circuit 22 and the control circuit. The filter circuit 21 can smooth and filter the pulsating DC power output by the second rectifier circuit 22, reduce its AC ripple component, and the voltage waveform characteristics at its output terminal can also reflect the quality and stability of the external power supply 40.

[0053] The specific structure of the filter circuit 21 can be selected according to the actual application scenario, and is not limited here. For example, the filter circuit 21 can be an RC filter network composed of capacitors and resistors.

[0054] The specific structure of the charging circuit 20 can be selected according to the actual application scenario, and is not limited here.

[0055] Figure 3 A circuit diagram of the charging circuit 20 provided in an embodiment of this application is shown. (Refer to...) Figure 3 As an example, the charging circuit 20 includes a first power conversion chip, which has a power supply pin VCC, an enable pin CE, and an output pin BAT. The power supply pin VCC is electrically connected to the DC side of the second rectifier circuit 22 through a first diode D1. The anode of the first diode D1 is electrically connected to the DC side of the second rectifier circuit 22, and the cathode of the first diode D1 is electrically connected to the power supply pin VCC. The enable pin CE is electrically connected to the control circuit, and the output pin BAT is electrically connected to the energy storage unit 10. The filter circuit 21 includes a first resistor R1, a second resistor R2, a third resistor R3, and a first capacitor C1. The first resistor R1 and the second resistor R2 are connected in series between the DC side of the second rectifier circuit 22 and the ground node GND, forming a voltage divider circuit. The first end of the third resistor R3 is electrically connected to the connection node of the first resistor R1 and the second resistor R2, and the second end of the third resistor R3 is electrically connected to the first end of the first capacitor C1. The second end of the first capacitor C1 is electrically connected to the ground node GND. The connection node of the third resistor R3 and the first capacitor C1 serves as the output terminal of the filter circuit 21. The voltage output from the DC side of the second rectifier circuit 22 is divided by the first resistor R1 and the second resistor R2 and then transmitted to the filter circuit 21 composed of the third resistor R3 and the first capacitor C1. After being filtered by the filter circuit 21, the voltage is transmitted to the control circuit.

[0056] The control circuit continuously samples the voltage signal output by the filter circuit 21 and analyzes it using an internal algorithm. Judgment criteria may include voltage level and ripple magnitude. For example, it can determine whether the voltage level is within the expected normal range and whether the AC ripple component is below an acceptable threshold. The control circuit only activates the charging circuit 20 and disables the discharging circuit 30 when both of the following conditions are met simultaneously.

[0057] The control circuit determines that the current power supply is available and safe only after confirming that the monitoring signal from the filter circuit 21 is stable within the preset quality acceptable range, and then issues a command to control the operation of the charging circuit 20. Conversely, if the power supply voltage is detected to be too low, too high, or the ripple is too large, even if there is power macroscopically, the control circuit will consider it an abnormal power supply and prohibit the charging circuit 20 from starting. This avoids possible circuit malfunctions or failures caused by forcibly charging under poor power quality conditions, and ensures the stable operation of the system in various complex power grid environments.

[0058] Figure 4 A circuit diagram of the discharge circuit 30 provided in an embodiment of this application is shown. (Refer to...) Figure 4 In some embodiments, the discharge circuit 30 includes a boost circuit, the input of which is electrically connected to the energy storage unit 10, and the output of which is connected to the power supply terminal of the electric check valve 50.

[0059] The boost circuit is mainly used to raise the relatively low DC voltage of the energy storage unit 10 to the DC voltage required for the rated operation of the electric check valve 50. Furthermore, the boost circuit, through voltage conversion, ensures that even when the backup power supply voltage drops, it can still provide sufficient driving capability to the load, maximizing the utilization of the energy stored in the energy storage unit 10.

[0060] The specific structure of the boost circuit can be selected according to the actual application scenario, and is not limited here. For example, the boost circuit may include a power inductor L, a power switching transistor, and a second diode D2.

[0061] When the power switch is turned on, current flows from the energy storage unit 10, through the inductor, and stores magnetic energy. When the power switch is turned off, since the inductor current cannot change abruptly, it generates an induced electromotive force (EMF). This EMF, combined with the voltage of the energy storage unit 10, supplies power to the electric check valve 50 through the diode, thereby producing an output voltage higher than the input voltage. By controlling the duty cycle of the switch, the output voltage can be stably maintained at the design target value.

[0062] The embodiments of this application use energy storage unit 10 with a lower voltage level, which helps to reduce costs, reduce circuit size and improve safety. At the same time, it can drive electric check valve 50, which requires a higher operating voltage, through boost circuit, thus enhancing the configurability and adaptability of the solution.

[0063] In some embodiments, the discharge circuit 30 includes a voltage regulator circuit, which is electrically connected to the output terminal of the boost circuit and the power supply terminal of the electric check valve 50, respectively. The voltage regulator circuit is configured to regulate the voltage output by the boost circuit and output a working voltage to the power supply terminal of the electric check valve 50.

[0064] The specific structure of the voltage regulator circuit can be selected according to the actual application scenario, and is not limited here. For example, the voltage regulator circuit can be a linear regulator.

[0065] The specific structure of the discharge circuit 30 can be selected according to the actual application scenario, and is not limited here.

[0066] As an example, the discharge circuit 30 includes a power inductor L, a second diode D2, a fourth resistor R4, a fifth resistor R5, a second capacitor C2, and a second power conversion chip. The second power conversion chip has a switching pin and a feedback pin. The first terminal of the power inductor L and the first terminal of the second capacitor C2 are both electrically connected to the energy storage unit 10. The second terminal of the second capacitor C2 is electrically connected to the ground node GND. The second terminal of the power inductor L is electrically connected to both the switching pin and the anode of the second diode D2. The cathode of the second diode D2 is electrically connected to the power supply terminal of the electric check valve 50, forming a boost network. The fourth resistor R4 and the fifth resistor R5 are connected in series between the power supply terminal of the electric check valve 50 and the ground node GND. The connection node of the fourth resistor R4 and the fifth resistor R5 is electrically connected to the feedback pin. The second power conversion chip adjusts the switching duty cycle according to the voltage received by the feedback pin to stabilize the output voltage at the rated operating voltage of the electric check valve 50.

[0067] As the discharge progresses, the voltage of the energy storage unit 10 gradually decreases, which may cause a slight shift in the output voltage of the boost circuit. The presence of the voltage regulator circuit effectively isolates the impact of this upstream voltage change on the load, ensuring that the electric check valve 50 operates at its rated voltage throughout the entire discharge cycle.

[0068] In some embodiments, the fresh air system further includes a temperature detection module, which is electrically connected to the energy storage unit 10 and the control circuit respectively. The temperature detection module is configured to detect the temperature of the energy storage unit 10 and transmit the detection result to the control circuit. The control circuit is also configured to control the charging circuit 20 to stop working when the detection result is greater than the temperature threshold.

[0069] The temperature detection module is mainly used to detect the surface temperature of the energy storage unit 10 in real time and convert the physical temperature value into an electrical signal that the control circuit can recognize and process, so that the control circuit can execute temperature-related protection strategies.

[0070] The specific structure of the temperature detection module can be selected according to the actual application scenario, and is not limited here. For example, the temperature detection module may include a negative temperature coefficient thermistor. The resistance value of a negative temperature coefficient thermistor decreases as the temperature increases, and the temperature can be calculated by measuring its voltage drop.

[0071] The control circuit continuously receives detection results from the temperature detection module and compares them with an internally preset temperature threshold. Once the control circuit determines that the temperature of the energy storage unit 10 is too high, it can control the charging circuit 20 to stop working and cut off the charging current.

[0072] The temperature of energy storage unit 10 is too high, meaning the temperature detection module detects that the temperature of energy storage unit 10 exceeds the temperature threshold. The specific value of the temperature threshold can be selected according to the actual application scenario and is not limited here. For example, the temperature threshold can be 50℃ or 60℃, etc.

[0073] The embodiments of this application, by introducing a temperature detection module and integrating corresponding protection logic into the control circuit, can effectively prevent the risk of thermal runaway caused by overheating of the energy storage unit 10, extend its cycle life and maintenance cycle, and improve safety and reliability.

[0074] In some embodiments, the fresh air system further includes a switch tube, the first end of which is electrically connected to the first power supply terminal of the electric check valve 50, the second power supply terminal of the electric check valve 50 is electrically connected to the energy storage unit 10, the second end of which is electrically connected to the grounding node GND, and the drive end of which is electrically connected to the control circuit; the control circuit is configured to control the switch tube to disconnect when the external power supply 40 is in a power-off state.

[0075] A switching transistor is electrically connected between the power supply terminal of the electric check valve 50 and the energy storage unit 10, serving as a drive circuit for switching the electric check valve 50 between an energized and de-energized state. When the control circuit applies a high-level signal to the drive terminal of the switching transistor, the transistor conducts, and the electrical energy provided by the energy storage unit 10 sequentially passes through the first and second power supply terminals of the electric check valve 50 to form a circuit, energizing the electric check valve 50. When the control circuit applies a low-level signal to the drive terminal of the switching transistor, the transistor de-energizes, disconnecting the power supply circuit between the energy storage unit 10 and the electric check valve 50, and the electric check valve 50 stops operating.

[0076] The specific type of switching transistor can be selected based on the actual application scenario, and is not limited here. For example, the switching transistor can be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), an IGBT (Insulated-Gate Bipolar Transistor), or a bipolar transistor, etc.

[0077] The control circuit indirectly controls the electric check valve 50 to switch between energized and de-energized states by driving the switching transistor, thus achieving effective isolation between the control circuit and the power circuit and improving the system's safety and anti-interference capabilities.

[0078] One embodiment of this application proposes a fresh air system, which includes multiple air ducts, multiple electric check valves 50, and multiple power supply circuits. Each air duct and each electric check valve 50 is connected in a one-to-one correspondence, and each power supply circuit is electrically connected to the power supply terminal of the corresponding electric check valve 50.

[0079] The fresh air system comprises multiple air ducts, each responsible for introducing treated fresh air into a specific room or area. Each air duct is integrated with an electric check valve 50, which is connected to the air duct one by one to form an independent air supply terminal responsible for controlling the flow of air in that area.

[0080] In the embodiments of this application, each electric check valve 50 is equipped with an independent power supply circuit. When a room is unoccupied, the user or the central management system can directly cut off the power supply to the air supply terminal of that room, thereby achieving regional energy saving. Its main power supply circuit 70 stops working when the external power supply 40 is cut off. At the same time, the discharge circuit 30 starts to operate, using the electrical energy stored in the energy storage unit 10 to drive the corresponding electric check valve 50 to perform a closing action.

[0081] While the room is powered off to conserve energy, its electric check valve 50 closes, preventing backflow caused by pressure differences in the ductwork due to the operation of fans in other rooms. Meanwhile, the fresh air systems in other rooms that are still powered on remain completely unaffected.

[0082] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0083] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A fresh air system, characterized in that The new air system comprises: an air duct for guiding outdoor fresh air into a room; an electric check valve arranged in the air duct, the electric check valve being used to open or close the air duct; a power supply circuit comprising: an energy storage unit; a main power supply loop electrically connected to a power supply end of the electric check valve, configured to be connected to an external power source, and supply power to the electric check valve by using the external power source; a charging loop electrically connected to the energy storage unit, configured to be connected to the external power source, and supply charging power to the energy storage unit by using the external power source; a discharging loop electrically connected to the energy storage unit and the power supply end of the electric check valve, configured to supply power to the electric check valve by using the energy storage unit in the case of abnormality of the external power source.

2. The fresh air system of claim 1, wherein, The new air system comprises: a power supply detection circuit, an input end of the power supply detection circuit being electrically connected to the external power source, the power supply detection circuit being configured to generate a first signal in the case of normal power supply of the external power source, or generate a second signal in the case of power-off of the external power source; a control circuit electrically connected to an output end of the power supply detection circuit, the control circuit being configured to control the charging loop and the main power supply loop to operate and control the discharging loop to stop working in response to the first signal, or control the discharging loop to operate and control the charging loop and the main power supply loop to stop working in response to the second signal.

3. The fresh air system of claim 2, wherein, The power supply detection circuit comprises: a first rectifier circuit, an alternating current side of the first rectifier circuit being electrically connected to the external power source; a current limiting circuit, an input end of the current limiting circuit being electrically connected to a direct current side of the first rectifier circuit; an optocoupler, a light emitting diode of the optocoupler being electrically connected to an output end of the current limiting circuit, a collector of a light sensitive transistor of the optocoupler being electrically connected to a power supply voltage node, and an emitter of the light sensitive transistor being electrically connected to a ground node.

4. The fresh air system of claim 2, wherein, The charging loop comprises: a second rectifier circuit, an alternating current side of the second rectifier circuit being electrically connected to the external power source, and a direct current side of the second rectifier circuit being electrically connected to the energy storage unit.

5. The fresh air system of claim 4, wherein, The charging loop further comprises: a filter circuit, an input end of the filter circuit being electrically connected to the direct current side of the second rectifier circuit, and an output end of the filter circuit being electrically connected to the control circuit; the control circuit being configured to control the charging loop to operate and control the discharging loop to stop working in the case of normal power supply of the external power source and stable power supply quality determined according to the output of the filter circuit.

6. The fresh air system of claim 1, wherein, The discharging loop comprises: a boost circuit, an input end of the boost circuit being electrically connected to the energy storage unit, and an output end of the boost circuit being electrically connected to the power supply end of the electric check valve.

7. The fresh air system according to claim 6, c h a r a c t e r i z e d i n that The discharging loop comprises: a voltage stabilizing circuit, the voltage stabilizing circuit being electrically connected to the output end of the boost circuit and the power supply end of the electric check valve respectively, the voltage stabilizing circuit being configured to perform voltage stabilizing processing on the voltage output by the boost circuit, and output a working voltage to the power supply end of the electric check valve.

8. The fresh air system of claim 2, wherein, The new air system further comprises: A temperature detection module, which is electrically connected with the energy storage unit and the control circuit respectively, is configured to detect the temperature of the energy storage unit and transmit the detection result to the control circuit; The control circuit is further configured to control the charging circuit to stop working when the detection result is greater than a temperature threshold.

9. The fresh air system of claim 2, wherein, The fresh air system further comprises: A switch tube, a first end of the switch tube is electrically connected with a first power supply end of the electric check valve, a second power supply end of the electric check valve is electrically connected with the energy storage unit, a second end of the switch tube is electrically connected with a grounding node, and a driving end of the switch tube is electrically connected with the control circuit; The control circuit is configured to control the switch tube to be turned off when the external power supply is in a power-off state.

10. A fresh air system according to any one of claims 1-7, characterized in that, The fresh air system comprises a plurality of air ducts, a plurality of electric check valves and a plurality of power supply circuits, each air duct and each electric check valve are connected one by one, and each power supply circuit is electrically connected with the power supply end of the corresponding electric check valve.

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