Indoor fan control method and system without communication unit

Abstract

The communication-unit-free indoor fan control method comprises the steps that 1, the temperature of an indoor temperature sensor is collected, and the initial rotating speed of an indoor fan is set according to the interval where the temperature is located; 2, after operation is conducted for a first set time according to the initial rotating speed set in the step 1, the indoor air inlet temperature TI and the indoor air outlet temperature TO are detected, the current operation modes of the unit are judged, and the operation modes comprise the refrigeration mode, the heating mode and the air supply mode; 3, in the refrigeration mode, TI and TO are detected with third set time as a period, according to the value of TI-TO, the refrigeration interval to which TI and TO belong is judged, and the refrigeration rotating speed mode is switched; 4, in the heating mode, TI and TO are detected with the fourth set time as the period, according to the value of TO-TI, the heating interval to which the TI and TO belong is judged, and the heating rotating speed mode is switched; and 5, when the mode is the air supply mode, the rotating speed is not switched, and the step 2 is returned again. Variable wind gears are achieved by presetting the temperature interval, and the unit energy efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of non-communication air conditioning units, and in particular relates to a method and system for controlling indoor fans in non-communication units. Background Technology

[0002] Due to the high labor costs and complex installation involved in replacements, many users tend to replace only the outdoor unit when an air conditioning unit malfunctions. This approach has led to the gradual emergence of air conditioning units without communication capabilities in the market. In these units, the indoor and outdoor units are controlled via a wired controller or thermostat. Air conditioning units with communication capabilities can automatically select the indoor fan speed based on the difference between the set temperature and the indoor temperature. In contrast, air conditioning units without communication capabilities have a constant indoor fan speed and cannot adjust the fan speed.

[0003] Existing technologies disclose a control method for a communication-free air conditioning system, a communication-free air conditioning system, and a computer storage medium, including the following steps: acquiring command signals from a thermostat, including power-on commands, power-off commands, and mode selection commands, whereby the mode selection commands include either a cooling mode command or a heating mode command. Based on the power-on command and mode selection command, the air conditioning unit is controlled to operate in the corresponding mode, and the capacity output of the air conditioning unit is adjusted according to the temperature difference between the target temperature and the actual indoor temperature. During the operation of the air conditioning unit, if a power-off command or a switching command between cooling and heating modes is acquired from the thermostat, the current actual indoor temperature is stored, and the target temperature is changed to a first temperature, which is the current actual indoor temperature. However, the shortcomings of this existing technology are that it requires frequent adjustment of the indoor fan speed, resulting in high unit energy consumption and low energy efficiency. Therefore, there is an urgent need to propose a control method that enables the indoor fan of a communication-free unit to change its fan speed to meet different capacity requirements. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for controlling indoor fans in air conditioning units without communication capabilities. By presetting a temperature range, the air conditioning unit can achieve variable fan speeds based on capacity requirements, thereby improving unit energy efficiency.

[0005] The present invention adopts the following technical solution.

[0006] The first aspect of this invention provides a method for controlling an indoor fan without communication, comprising: Step 1: Collect the indoor temperature sensor temperature and set the initial speed of the indoor fan according to the temperature range; Step 2: After running for a first set time according to the initial speed set in Step 1, detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O to determine the current operating mode of the unit, wherein the operating mode includes cooling mode, heating mode and air supply mode. Step 3: Based on the determination in Step 2 that the unit is currently in the cooling mode, the indoor air inlet temperature T_I and the indoor air outlet temperature T_O are detected at a third set time interval. Based on the difference between the indoor air inlet temperature T_I and the indoor air outlet temperature T_O, the cooling range is determined, and the cooling speed mode is switched. Step 4: Based on the determination in Step 2 that the unit is currently in the heating mode, the indoor air inlet temperature T_I and the indoor air outlet temperature T_O are detected at a fourth set time interval. The heating range is determined according to the difference between the indoor air outlet temperature T_O and the indoor air inlet temperature T_I, and the heating speed mode is switched. Step 5: If the unit is currently in the air supply mode as determined in Step 2, do not switch the speed and return to Step 2.

[0007] Preferably, the current operating mode of the unit is determined as follows: If T_I > T_O + N, then the unit is currently operating in cooling mode. If T_I < T_O + N, then the unit is currently operating in heating mode. If |T_I-T_O|≤N, then the unit is currently operating in the air supply mode. Where N is the set temperature value.

[0008] Preferably, the cooling zone includes a first cooling zone, a second cooling zone, and a third cooling zone; the cooling speed mode includes a low-speed cooling mode, a medium-speed cooling mode, and a high-speed cooling mode.

[0009] Preferably, if T_I-T_O belongs to the first cooling range, the indoor fan switches to the low-speed cooling mode; If T_I-T_O belongs to the second cooling range, the indoor fan switches to the medium-speed cooling mode. If T_I-T_O belongs to the third cooling zone, the indoor fan switches to the high-speed cooling mode.

[0010] Preferably, the heating range includes a first heating range, a second heating range, and a third heating range; the heating speed mode includes a low-speed heating mode, a medium-speed heating mode, and a high-speed heating mode.

[0011] Preferably, if T_O-T_I belongs to the first heating range, the indoor fan switches to the low-speed heating mode; If T_O-T_I belongs to the second heating range, the indoor fan switches to the medium-speed heating mode. If T_O-T_I belongs to the third heating range, the indoor fan switches to the high-speed heating mode.

[0012] A second aspect of the present invention provides a communication-free indoor fan control system, employing the above-described method, comprising: Initial speed setting module, operating mode judgment module, cooling speed switching module, heating speed switching module and air supply speed switching module; The initial speed setting module is used to collect the temperature from the indoor temperature sensor and set the initial speed of the indoor fan according to the temperature range. The operation mode determination module is used to detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O after running for a first set time, and determine the current operation mode of the unit, wherein the operation mode includes cooling mode, heating mode and air supply mode. The cooling speed switching module is used to detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O at a third set time period, and determine the cooling range based on the difference between the indoor air inlet temperature T_I and the indoor air outlet temperature T_O, and switch the cooling speed mode accordingly. The heating speed switching module is used to detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O at a fourth set time period, and determine the heating range based on the difference between the indoor air outlet temperature T_O and the indoor air inlet temperature T_I, and switch the heating speed mode accordingly. The air supply speed switching module is used to not switch the speed and return to the operating mode judgment module.

[0013] A third aspect of the present invention provides a communication-free air conditioning unit: This includes the aforementioned indoor fan control system without communication units.

[0014] A fourth aspect of the present invention provides a terminal, including a processor and a storage medium; The storage medium is used to store instructions; The processor is used to perform the steps of the above method according to the instructions.

[0015] The fifth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the above-described method.

[0016] The beneficial effects of this invention are compared with those of the prior art: This invention can improve the stability and reliability of air conditioning systems; and improve the energy efficiency and comfort of air conditioning systems.

[0017] This invention provides a method for controlling indoor fans in air conditioning units without communication capabilities. By setting a preset temperature range, the air conditioning unit can achieve variable fan speed according to capacity requirements, thereby improving unit energy efficiency and enhancing energy saving and comfort.

[0018] In non-communication units, the internal fan speed is generally constant. Switching the fan speed or the fan speed requires changing the unit's DIP switch. The variable fan speed provided by this invention can realize the internal fan speed conversion according to capacity requirements, improve unit energy efficiency, save energy, improve comfort, and realize the advantages of unit frequency conversion control. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the system of the present invention; Figure 2 This is a diagram of the refrigeration operation system of the unit of the present invention; Figure 3 This is a diagram of the heating operation system of the unit of the present invention; Figure 4 The process of this invention Figure 1 ; Figure 5 The process of this invention Figure 2 . Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0021] Example 1 like Figure 1-3 As shown, Embodiment 1 of the present invention provides a communication-free air conditioning unit system, comprising: Outdoor unit and indoor unit.

[0022] The outdoor unit is a variable frequency unit, which includes at least a compressor, condenser, outdoor fan, four-way valve and electronic expansion valve. It also contains an outdoor temperature sensor, a pressure sensor and a first controller for detection and control, as well as a variable frequency drive to drive the compressor.

[0023] The condenser includes a condenser inlet pipe and a condenser outlet pipe; the compressor includes a compressor inlet pipe and a compressor outlet pipe; the electronic expansion valve includes a first electronic expansion valve (…). Figure 1 Electronic expansion valve 1) and second electronic expansion valve ( Figure 1The electronic expansion valve 2); the pressure sensor includes a first pressure sensor (pressure sensor 1) and a second pressure sensor (pressure sensor 2); the outdoor temperature sensor includes an ambient temperature sensor, a condenser inlet pipe temperature sensor, and a condenser outlet pipe temperature sensor. The variable fan speed is achieved by the indoor air inlet temperature sensor and its controller, the indoor air outlet temperature sensor and its controller, the indoor unit controller, and the indoor unit fan speed control.

[0024] The indoor unit includes an indoor fan, an evaporator, an indoor temperature sensor, and a second controller for detection and control. The indoor temperature sensor includes an evaporator inlet pipe temperature sensor, an evaporator outlet pipe temperature sensor, an indoor air inlet temperature sensor, and an indoor air outlet temperature sensor; the evaporator includes an evaporator inlet pipe and an evaporator outlet pipe; the indoor fan includes an indoor fan return air vent and an indoor fan outlet.

[0025] The condenser inlet pipe is connected to the compressor outlet pipe or compressor inlet pipe via a four-way valve. The condenser inlet pipe is connected to the evaporator inlet pipe via a first electronic expansion valve and a second electronic expansion valve. The evaporator outlet pipe is connected to the compressor inlet pipe or compressor outlet pipe via a four-way valve. A temperature sensor is installed on the condenser inlet pipe and the temperature sensor is installed on the condenser outlet pipe. The outdoor fan is located on one side of the condenser, and the indoor fan is located on the one side of the evaporator. A temperature sensor is installed on the evaporator inlet pipe and the temperature sensor is installed on the evaporator outlet pipe. An indoor return air temperature sensor is installed at the indoor fan return air inlet. An indoor outlet air temperature sensor is installed at the indoor fan outlet.

[0026] In a preferred but non-limiting embodiment of the invention, a filter is further included, comprising a first filter and a second filter, wherein the first filter is disposed between the condenser and the first electronic expansion valve, and the second filter is disposed between the evaporator and the second electronic expansion valve.

[0027] A first pressure sensor is located at the compressor outlet pipe, and a second pressure sensor is located at the compressor inlet pipe. In a preferred but non-limiting embodiment of the present invention, a compressor heating belt is also included, located at the compressor.

[0028] When running in cooling mode, the refrigerant is compressed in the compressor and then flows through the four-way valve into the condenser to condense and release heat. After being throttled by the second electronic expansion valve, it enters the evaporator to evaporate and absorb heat. Then, it flows through the four-way valve back to the compressor to start a new cycle.

[0029] When running in heating mode, the refrigerant is compressed in the compressor and flows through the four-way valve into the evaporator to condense and release heat. It then flows through the first electronic expansion valve for throttling, enters the condenser to evaporate and absorb heat, flows through the four-way valve, and returns to the compressor to start a new cycle.

[0030] In cooling mode, the second electronic expansion valve is throttled while the first electronic expansion valve is fully open; in heating mode, the first electronic expansion valve is throttled while the second electronic expansion valve is fully open.

[0031] Example 2 like Figure 4-5 As shown, Embodiment 2 of the present invention provides a method for controlling indoor fans without communication units, including: Step 1: Collect the indoor temperature sensor temperature and set the initial speed of the indoor fan according to the temperature range; The relationship between the initial speed of the indoor fan and the temperature range can be derived from engineering practice.

[0032] Step 2: After running for the first set time according to the initial speed set in Step 1, detect the indoor air inlet temperature and indoor air outlet temperature to determine the current operating mode of the unit, which includes cooling mode, heating mode and air supply mode. Wherein, the indoor air inlet temperature T_I is the temperature value measured by the indoor air inlet temperature sensor, and the indoor air outlet temperature T_O is the temperature value measured by the indoor air outlet temperature sensor.

[0033] After the air conditioning unit without communication is turned on, after a first set time, the indoor inlet air temperature T_I measured by the indoor inlet air temperature sensor and the indoor outlet air temperature T_O measured by the indoor outlet air temperature sensor are detected. If T_I > T_O + N, it is in cooling mode, and the indoor unit operates in cooling mode; if T_I < T_O + N, it is in heating mode, and the indoor unit operates in heating mode; if |T_I - T_O| ≤ N, it is in air supply mode, and the indoor unit operates in air supply mode.

[0034] Where N is a set temperature value, and in a preferred but non-limiting embodiment of the present invention, N is 3.

[0035] In a preferred but non-limiting embodiment of the present invention, after the air conditioning unit without communication is turned on, the indoor inlet air temperature T_I and the indoor outlet air temperature T_O are detected once every 2-5 minutes. If T_I > T_O + 3, it is in cooling mode, and the indoor unit operates in cooling mode; if T_I < T_O + 3, it is in heating mode, and the indoor unit operates in heating mode; if |T_I - T_O| ≤ 3, it is in air supply mode, and the indoor unit operates in air supply mode. Step 3: Based on the determination in step 2 that the unit is currently in cooling mode, the indoor inlet air temperature and the indoor outlet air temperature are detected at a third set time interval. Based on the difference between the indoor inlet air temperature and the indoor outlet air temperature, the cooling range is determined, and the cooling speed mode is switched accordingly. The cooling zones include the first cooling zone, the second cooling zone, and the third cooling zone; the cooling speed modes include low-speed cooling mode, medium-speed cooling mode, and high-speed cooling mode.

[0036] After the non-communication air conditioning unit is turned on, after the second set time, when it is running in cooling mode, T_I and T_O are checked once at the third set time interval.

[0037] In a preferred but non-limiting embodiment of the present invention, when the air conditioning unit without communication is turned on and running in cooling mode for 3-5 minutes, T_I and T_O are detected once every 5-6 minutes.

[0038] In a preferred but non-limiting embodiment of the present invention, it is determined whether T_I-T_O belongs to the first cooling zone. If yes, the indoor fan switches to low-speed cooling mode; if no, it is determined whether T_I-T_O belongs to the second cooling zone. If yes, the indoor fan switches to medium-speed cooling mode; if no, that is, T_I-T_O belongs to the third cooling zone, the indoor fan switches to high-speed cooling mode.

[0039] At this point, the first cooling range can be below 5°C, the second cooling range can be 5~10°C, and the third cooling range can be 10~15°C. The low-speed mode can operate at 500 rpm, the medium-speed mode at 1000 rpm, and the high-speed mode at 1500 rpm. These values ​​and ranges can be adjusted according to the unit's cooling capacity and actual speed. The number of speed modes can also be increased or decreased as needed.

[0040] Step 4: Based on the determination in Step 2 that the unit is currently in heating mode, the indoor air inlet temperature and indoor air outlet temperature are detected at the fourth set time interval. Based on the difference between the indoor air outlet temperature and the indoor air inlet temperature, the heating range is determined and the heating speed mode is switched. The heating range includes a first heating range, a second heating range, and a third heating range; the heating speed modes include low-speed heating mode, medium-speed heating mode, and high-speed heating mode.

[0041] In a preferred but non-limiting embodiment of the present invention, after the non-communication air conditioning unit is turned on for 3 minutes, when running in heating mode, T_I and T_O are checked every 5 minutes. It is determined whether T_O-T_I belongs to the first heating range. If yes, the indoor fan switches to low-speed heating mode; otherwise, it is determined whether T_O-T_I belongs to the second heating range. If yes, the indoor fan switches to medium-speed heating mode; otherwise, if T_O-T_I belongs to the third heating range, the indoor fan switches to high-speed heating mode.

[0042] In a preferred but non-limiting embodiment of the present invention, the first heating range can be below 7°C, the second heating range can be 7~12°C, the third heating range can be 12~18°C, the low-speed heating mode can have a rotation speed of 500 rpm, the medium-speed heating mode can have a rotation speed of 1000 rpm, and the high-speed heating mode can have a rotation speed of 1500 rpm. These values ​​and ranges can be adjusted according to the unit's cooling capacity and actual rotation speed. The number of rotation speed modes can also be increased or decreased as needed.

[0043] Step 5: If the unit is currently in air supply mode as determined in Step 2, do not switch the speed and return to Step 2. Example 3 Embodiment 3 of the present invention discloses a communication-free indoor fan control system, comprising: Initial speed setting module, operating mode judgment module, cooling speed switching module, heating speed switching module and air supply speed switching module; The initial speed setting module is used to collect the temperature from the indoor temperature sensor and set the initial speed of the indoor fan according to the temperature range. The operation mode determination module is used to detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O after running for the first set time, and determine the current operation mode of the unit. The operation mode includes cooling mode, heating mode and air supply mode. The cooling speed switching module is used to detect the indoor inlet air temperature T_I and the indoor outlet air temperature T_O at a third set time period. Based on the difference between the indoor inlet air temperature T_I and the indoor outlet air temperature T_O, it determines the cooling range and switches the cooling speed mode. The heating speed switching module is used to detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O at a fourth set time period. Based on the difference between the indoor air inlet temperature T_O and the indoor air outlet temperature T_I, it determines the heating range and switches the heating speed mode. The air supply speed switching module is used to avoid switching the speed and return to the operating mode judgment module.

[0044] Example 4 Embodiment 4 of the present invention provides a non-communication air conditioning unit, including the non-communication indoor fan control system of Embodiment 3.

[0045] The beneficial effects of this invention are compared with those of the prior art: This invention can improve the stability and reliability of air conditioning systems; and improve the energy efficiency and comfort of air conditioning systems.

[0046] This invention provides a method for controlling indoor fans in air conditioning units without communication capabilities. By setting a preset temperature range, the air conditioning unit can achieve variable fan speed according to capacity requirements, thereby improving unit energy efficiency and enhancing energy saving and comfort.

[0047] In non-communication units, the internal fan speed is generally constant. Switching the fan speed or the fan speed requires changing the unit's DIP switch. The variable fan speed provided by this invention can realize the internal fan speed conversion according to capacity requirements, improve unit energy efficiency, save energy, improve comfort, and realize the advantages of unit frequency conversion control.

[0048] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0049] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0050] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0051] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for controlling an indoor fan without communication unit, characterized in that, include: Step 1: Collect the indoor temperature sensor temperature and set the initial speed of the indoor fan according to the temperature range; Step 2: After running for a first set time according to the initial speed set in Step 1, detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O to determine the current operating mode of the unit, wherein the operating mode includes cooling mode, heating mode and air supply mode. Step 3: Based on the determination in Step 2 that the unit is currently in the cooling mode, the indoor air inlet temperature T_I and the indoor air outlet temperature T_O are detected at a third set time interval. Based on the difference between the indoor air inlet temperature T_I and the indoor air outlet temperature T_O, the cooling range is determined, and the cooling speed mode is switched. Step 4: Based on the determination in Step 2 that the unit is currently in the heating mode, the indoor air inlet temperature T_I and the indoor air outlet temperature T_O are detected at a fourth set time interval. The heating range is determined according to the difference between the indoor air outlet temperature T_O and the indoor air inlet temperature T_I, and the heating speed mode is switched. Step 5: If the unit is currently in the air supply mode as determined in Step 2, do not switch the speed and return to Step 2.

2. The indoor fan control method for non-communication units according to claim 1, characterized in that: The current operating mode of the unit is determined to be: If T_I > T_O + N, then the unit is currently operating in cooling mode. If T_I < T_O + N, then the unit is currently operating in heating mode. If |T_I-T_O|≤N, then the unit is currently operating in the air supply mode. Where N is the set temperature value.

3. The indoor fan control method for non-communication units according to claim 1, characterized in that: The cooling zones include a first cooling zone, a second cooling zone, and a third cooling zone; the cooling speed modes include a low-speed cooling mode, a medium-speed cooling mode, and a high-speed cooling mode.

4. The indoor fan control method for non-communication units according to claim 3, characterized in that: If T_I-T_O belongs to the first cooling range, the indoor fan switches to the low-speed cooling mode; If T_I-T_O belongs to the second cooling range, the indoor fan switches to the medium-speed cooling mode. If T_I-T_O belongs to the third cooling zone, the indoor fan switches to the high-speed cooling mode.

5. The indoor fan control method for non-communication units according to claim 1, characterized in that: The heating range includes a first heating range, a second heating range, and a third heating range; the heating speed mode includes a low-speed heating mode, a medium-speed heating mode, and a high-speed heating mode.

6. The indoor fan control method for non-communication units according to claim 5, characterized in that: If T_O-T_I belongs to the first heating range, the indoor fan switches to the low-speed heating mode; If T_O-T_I belongs to the second heating range, the indoor fan switches to the medium-speed heating mode. If T_O-T_I belongs to the third heating range, the indoor fan switches to the high-speed heating mode.

7. A communication-free indoor fan control system, employing the method described in any one of claims 1-6, characterized in that, include: Initial speed setting module, operating mode judgment module, cooling speed switching module, heating speed switching module and air supply speed switching module; The initial speed setting module is used to collect the temperature from the indoor temperature sensor and set the initial speed of the indoor fan according to the temperature range. The operation mode determination module is used to detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O after running for a first set time, and determine the current operation mode of the unit, wherein the operation mode includes cooling mode, heating mode and air supply mode. The cooling speed switching module is used to detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O at a third set time period, and determine the cooling range based on the difference between the indoor air inlet temperature T_I and the indoor air outlet temperature T_O, and switch the cooling speed mode accordingly. The heating speed switching module is used to detect the indoor air inlet temperature T_I and the indoor air outlet temperature T_O at a fourth set time period, and determine the heating range based on the difference between the indoor air outlet temperature T_O and the indoor air inlet temperature T_I, and switch the heating speed mode accordingly. The air supply speed switching module is used to not switch the speed and return to the operating mode judgment module.

8. A non-communication air conditioning unit, characterized in that: Includes the communication-free indoor fan control system as described in claim 7.

9. A terminal, comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1-7.

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