Air conditioner

Abstract

The invention discloses an air conditioner, which comprises a refrigerant circulation loop, the draining pump is mounted in the water receiving plate and used for draining the condensate water in the water receiving plate to the outside; the water pump driving unit is used for driving the drainage pump to operate; the outlet air temperature sensor is used for detecting the outlet air temperature of indoor outlet air; the humidity sensor is used for detecting indoor air humidity; the main control unit is connected with the water pump driving unit and receives the air outlet temperature detected by the air outlet temperature sensor and the indoor air humidity detected by the humidity sensor; and after the generation amount of the condensate water and the displacement amount of the drainage pump are balanced, the main control unit obtains the indoor return air temperature based on the indoor air humidity, the air outlet volume in unit time, the air outlet temperature and the generation amount of the condensate water in unit time. The indoor return air temperature can be calculated through a software algorithm, an indoor return air temperature sensor is prevented from being additionally arranged, and the hardware input cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and particularly to an air conditioner. Background Art

[0002] During the control process of an air conditioner, the indoor temperature is often involved.

[0003] In the prior art, the temperature is usually obtained by a temperature sensor arranged indoors. This method requires an increase in the cost of sensor investment.

[0004] The above information disclosed in this background art is only used to increase the understanding of the background art of this application. Therefore, it may include prior art that is not known to those of ordinary skill in the art. Summary of the Invention

[0005] In view of the problems pointed out in the background art, the present application provides an air conditioner. When the drainage volume of the drainage pump is balanced with the generation amount of condensed water, the indoor return air temperature is calculated based on the generation amount of condensed water, the indoor air humidity, the outlet air temperature, and the air volume at the air outlet, so as to avoid adding an indoor return air temperature sensor and reduce the hardware investment cost.

[0006] To achieve the above-mentioned invention object, the present invention is implemented by the following technical solutions: The present application relates to an air conditioner, including: A refrigerant circulation circuit that circulates refrigerant in a compressor, a condenser, an expansion valve, and an evaporator. The compressor is used to compress low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas and discharge it to the condenser; A drainage pump installed in a water receiving tray for discharging the condensed water in the water receiving tray to the outside; A water pump driving unit for driving the drainage pump to operate; An outlet air temperature sensor for detecting the outlet air temperature of the indoor air outlet; A humidity sensor for detecting the indoor air humidity; A main control unit connected to the water pump driving unit and receiving the outlet air temperature detected by the outlet air temperature sensor and the indoor air humidity detected by the humidity sensor; After the generation amount of condensed water reaches balance with the drainage volume of the drainage pump, the main control unit obtains the indoor return air temperature based on the indoor air humidity RH out , the air volume of the outlet air per unit time V, the outlet air temperature, and the generation amount of condensed water per unit time Q1.

[0007] The air conditioner involved in this application utilizes the hardware structure of the original drainage pump, a humidity sensor for detecting the indoor air humidity, and an air outlet temperature sensor for detecting the air outlet temperature. Software-wise, it cooperates with the indoor air humidity RH out , the volume of the air outlet per unit time V, the air outlet temperature, and the amount of condensate generated per unit time Q1 to obtain the indoor return air temperature, avoiding the addition of an indoor return air temperature sensor and reducing the hardware investment cost.

[0008] In some embodiments of this application, it is determined that the amount of condensate generated is balanced with the drainage volume of the drainage pump. Specifically: Under the condition that the duty cycle of the PWM pulse drive signal sent to the water pump drive unit remains at a preset duty cycle and the installation structure of the drainage pump remains unchanged, the water pump current of the drainage pump is obtained; When the water pump current remains unchanged within a preset time period, the amount of condensate generated is balanced with the drainage volume of the drainage pump; After the amount of condensate generated and the drainage volume of the drainage pump reach balance, according to the pre-established relationship between the water pump current and the drainage volume, the drainage volume corresponding to the unchanged water pump current is determined; Make the drainage volume equal to the amount of condensate generated.

[0009] The drainage pump involved in this application, under the condition that the duty cycle of the PWM pulse drive signal is at a preset duty cycle and the installation structure of the drainage pump remains unchanged, the drainage volume is only related to the draft depth of the water inlet of the drainage pump.

[0010] The smaller the draft depth, the smaller the drainage volume, and the smaller the current of the drainage pump. The larger the draft depth, the larger the drainage volume, and the larger the current of the drainage pump. Therefore, the current drainage volume is deduced by detecting the water pump current.

[0011] In some embodiments of this application, the amount of condensate generated in the water receiving tray is related to the saturation humidity. Therefore, with the help of existing hardware devices (including a humidity sensor for detecting the indoor air humidity, an air outlet temperature sensor for detecting the indoor air outlet temperature, and a drainage pump), the indoor return air temperature is obtained.

[0012] According to the pre-established saturation humidity of air at different temperatures, the saturation humidity RH corresponding to the air outlet temperature is obtained max_out ; According to the formula Q1 = V * (RH max_out *RH out -RH max_in ), the saturation humidity RH corresponding to the indoor return air temperature is obtained max_in ; According to the pre-established saturation humidity of air at different temperatures, the indoor return air temperature corresponding to the saturation humidity RH is obtained max_in corresponding.

[0013] In some embodiments of the present application, the outlet air volume V per unit time is calculated based on the air outlet size and the wind speed information sent by the wire controller.

[0014] In some embodiments of the present application, the water pump driving unit includes: A water pump driving chip, which receives the PWM pulse driving signal sent by the main control unit, and the signal output by the speed feedback pin is fed back to the main control unit, for real-time detection of the speed of the drainage pump; An overcurrent protection circuit is disposed on the periphery of the water pump driving chip to provide overcurrent protection for the drainage pump motor.

[0015] The water pump driving chip involved in the present application has an overcurrent protection function, and can achieve overcurrent protection for the drainage pump motor by setting an overcurrent protection circuit on the periphery of the overcurrent protection pin.

[0016] In some embodiments of the present application, the water pump driving chip has a first pin, a second pin and a third pin, and the overcurrent protection circuit is connected between the first pin, the second pin and the third pin; The overcurrent protection circuit includes a first resistor, a second resistor and a third resistor, the first pin is grounded through the first resistor, the second pin is grounded through the second resistor, the third pin is connected to one end of the third resistor, and the other end of the third resistor is connected to the connection point between the second resistor and the second pin.

[0017] The overcurrent protection circuit may include a plurality of current limiting resistors. By setting different resistance values ​​of the current limiting resistors and setting current protection limits, overcurrent protection for different motor currents can be achieved.

[0018] In some embodiments of the present application, the air conditioner further comprises: A float switch is connected to the main control unit and is used to detect the water level in the water receiving tray. When the water level in the water receiving tray reaches the preset water level, the float switch sends a detection signal to the main control unit. The main control unit receives the detection signal and stops the indoor fan and controls the drainage pump to drain water.

[0019] By setting a float switch and a preset water level, when the drainage pump malfunctions and cannot drain water in time, a detection signal can be sent to the main control unit to stop the indoor fan and avoid further generation of condensed water.

[0020] In some embodiments of the present application, the air conditioner further comprises: An alarm unit is connected to the main control unit and is used to control the alarm unit to issue an alarm prompt when the main control unit receives the detection signal.

[0021] An alarm prompt is issued through the alarm unit to remind the user to drain water in time, avoiding safety risks caused by water overflow due to excessive water volume in the water receiving tray.

[0022] In some embodiments of the present application, the drainage pump is installed upside down in the water receiving tray and has a water inlet and a water outlet; The water inlet is communicated with the water receiving tray and has a draft depth with a first value; The water outlet is used to discharge the condensed water in the water receiving tray to the outside and has a drainage head with a second value.

[0023] In some embodiments of the present application, the air conditioner further includes: A fan driving unit, which communicates with the main control unit through a communication unit and is used to drive the indoor fan to operate or stop operating.

[0024] Utilizing the communication unit to realize the communication loop between the main control unit and the fan driving unit can enable the main control unit to obtain the rotational speed (or wind gear) of the indoor fan. This communication unit can be a UART communication loop.

[0025] In some embodiments of the present application, the indoor return air temperature is fed back to the wired controller of the air conditioner and displayed on the wired controller.

[0026] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become clearer. Brief Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other accompanying drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a principle block diagram of an air conditioner in an air conditioner embodiment proposed according to the present application; Figure 2 It is a system block of an air conditioner embodiment proposed according to the present application Figure 1 ; Figure 3 It is a front view of a drainage pump in an air conditioner embodiment proposed according to the present application; Figure 4 It is a system block of an air conditioner embodiment proposed according to the present application Figure 2 ; Figure 5 It is a system block of an air conditioner embodiment proposed according to the present applicationFigure 3 ; Figure 6 It is the pin connection diagram of the air conditioner embodiment proposed according to the present application; Figure 7 It is the flowchart for judging when the drainage volume of the drainage pump and the generation amount of condensed water reach balance in the air conditioner embodiment proposed according to the present application; Figure 8 It is the detection schematic diagram of the float switch in the air conditioner embodiment proposed according to the present application; Figure 9 It is the control schematic diagram when the float switch emits a detection signal in the air conditioner embodiment proposed according to the present application; Figure 10 It is the schematic diagram for obtaining the indoor return air temperature in the air conditioner embodiment proposed according to the present application.

[0029] Reference numerals: 100, main control unit; 110, air volume calculation module; 120, information processing module; 200, water receiving tray; 300, drainage pump; 310, water pump driving unit; 320, water inlet; 330, drainage outlet; 400, humidity sensor; 500, outlet air temperature sensor; 600, wire controller; 700, communication unit; 700', fan driving unit; 800, indoor fan; 900, float switch. Detailed implementation manners

[0030] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without making creative efforts belong to the scope of protection of the present application.

[0031] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0032] 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 quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0033] In the description of the present application, it should be noted that, unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" should be construed broadly. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0035] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity and does not in itself indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0036] <Basic working principle of an air conditioner> See Figure 1 , the air conditioner performs a refrigeration cycle of the air conditioner by using a compressor, a condenser, an expansion valve and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion and evaporation to cool or heat the indoor space.

[0037] The low-temperature and low-pressure refrigerant enters the compressor, which compresses it into high-temperature and high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0038] The expansion valve expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the low-temperature and low-pressure refrigerant gas to the compressor. The evaporator can achieve a cooling effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. In the entire cycle, the air conditioner can adjust the temperature of the indoor space.

[0039] The outdoor unit of the air conditioner refers to a portion of a refrigeration cycle including a compressor and an outdoor heat exchanger, the indoor unit of the air conditioner includes an indoor heat exchanger, and an expansion valve may be provided in the indoor unit or the outdoor unit.

[0040] The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger functions as a condenser, the air conditioner functions as a heater in a heating mode, and when the indoor heat exchanger functions as an evaporator, the air conditioner functions as a cooler in a cooling mode.

[0041] Existing air conditioners are often equipped with a drainage pump, a temperature sensor for detecting the outlet temperature of indoor air, a humidity sensor for detecting the indoor air humidity, and a temperature sensor for detecting the return air temperature of indoor return air.

[0042] The drain pump is a component of the air conditioner indoor unit. In the cooling mode of the air conditioner, condensed water will be generated on the surface of the indoor heat exchanger serving as the evaporator when the air flow passes through it. Generally, a water collecting pan for receiving the condensed water is arranged under the indoor heat exchanger. The drain pump is installed in the water collecting pan and is used to draw the condensed water in the water collecting pan to the outside of the air conditioner indoor unit when the drain pump is started.

[0043] In some embodiments of the present application, commonly configured hardware devices are used to calculate the return air temperature using a software algorithm to avoid installing a return air temperature sensor for detecting the return air temperature as described above, thereby reducing hardware investment costs.

[0044] The air conditioner involved in the present application is mainly used in places with floor heating, such as in the north. In this way, there is no need to use the air conditioner for heating in winter, and the air conditioner is basically used for cooling in summer. Therefore, the water receiving pan 200 will receive condensed water when the air conditioner is in cooling mode. In this way, the drain pump 300 will be turned on to discharge the condensed water from the water receiving pan 200.

[0045] See also Figure 2, the air conditioner includes a water receiving tray 200, a drain pump 300, a water pump driving unit 310, an air outlet temperature sensor 500, a humidity sensor 400, a remote controller 600, and a main control unit 100.

[0046] The water receiving tray 200 is located inside the air conditioner indoor unit and is used to receive the condensed water generated when the air flow passes through the surface of the low-temperature indoor heat exchanger during the refrigeration operation of the air conditioner.

[0047] See Figure 3 , the drain pump 300 has a water inlet 320 and a water outlet 330, where the water outlet 330 is connected to the water inlet 320 and is used to drain the water in the water receiving tray 200.

[0048] The drain pump 300 is installed inside the water receiving tray 200, for example, installed upside down inside the water receiving tray 200, so that the water inlet 320 of the drain pump 300 faces the water receiving tray 200, for example, is in contact with the condensed water in the water receiving tray 200.

[0049] When the drain pump 300 is working, the water inlet 320 of the drain pump 300 can extract the condensed water collected in the water receiving tray 200.

[0050] See Figures 4 to 6 , the water pump driving unit 310 is connected to the main control unit 100, is used to receive the PWM pulse driving signal sent by the main control unit 100, and controls the operation of the drain pump 300 based on this PWM.

[0051] The larger the duty ratio of the PWM pulse driving signal, the faster the operating speed of the drain pump 300, and thus the faster the drainage speed; the smaller the duty ratio of the PWM pulse driving signal, the slower the operating speed of the drain pump 300, and thus the slower the drainage speed.

[0052] In some embodiments of the present application, see Figure 3 , when the installation structure of the drain pump 300 remains unchanged (that is, the draft depth of the water inlet 320 of the drain pump 300 is h, and the drainage head is H), when the duty ratio of the PWM pulse driving signal input from the main control unit 100 to the water pump driving unit 310 is the preset duty ratio, the drainage volume Q2 of the drain pump 300 is only related to the draft depth h of the water inlet 320 of the drain pump 300.

[0053] The smaller the draft depth h, the smaller the drainage volume Q2, and the smaller the water pump current I; the larger the draft depth h, the larger the drainage volume Q2, and the larger the water pump current I. Therefore, the current drainage volume Q2 can be estimated by detecting the water pump current I.

[0054] When the pump current I of the drain pump 300 remains unchanged within a preset time period (e.g., 10 seconds), it indicates that the drainage volume Q2 of the current drain pump 300 reaches equilibrium with the condensate generation volume Q1. At this time, the condensate generation volume Q1 is obtained by using the drainage volume Q2.

[0055] In some embodiments of the present application, referring to Figures 4 to 6 , the air conditioner further includes a humidity sensor 400 and an air outlet temperature sensor 500.

[0056] The humidity sensor 400 is disposed indoors and is used to detect the indoor air humidity RH out .

[0057] The humidity sensor 400 is connected to the main control unit 100 and is used to transmit the indoor air humidity detected by the humidity sensor 400 to the main control unit 100.

[0058] In some embodiments of the present application, the main control unit 100 employs an integrated MCU chip, which has a first input pin for receiving the indoor air humidity RH fed back by the humidity sensor 400 out .

[0059] The air outlet temperature sensor 500 is disposed at the air outlet or near the indoor heat exchanger and is used to detect the air outlet temperature.

[0060] The air outlet temperature sensor 500 is connected to the main control unit 100 and is used to transmit the air outlet temperature detected by the air outlet temperature sensor 500 to the main control unit 100.

[0061] In some embodiments of the present application, the main control unit 100 employs an integrated MCU chip, which has a second input pin for receiving the air outlet temperature fed back by the air outlet temperature sensor 500.

[0062] In some embodiments of the present application, when the drainage volume Q2 of the drain pump 300 reaches equilibrium with the condensate generation volume Q1, the main control unit 100 calculates the indoor return air temperature by using the condensate generation volume Q1 per unit time, the air volume V per unit time, the air outlet temperature, and the indoor air humidity RH out to calculate the indoor return air temperature.

[0063] In some embodiments of the present application, Q1 = V * (RH max_out *RH out -RH max_in ) is adopted to obtain the saturation humidity RH corresponding to the indoor return air temperature max_in , and then according to the pre-established saturation humidity of air at different temperatures, the indoor return air temperature corresponding to the saturation humidity RH max_in is obtained.

[0064] In some embodiments of the present application, referring toFigure 5 The main control unit 100 is communicatively connected to the fan drive unit 700' through the communication unit 700, and the fan drive unit 700' outputs a drive signal to the indoor fan 800 to make the indoor fan 800 operate or stop operating.

[0065] The communication unit 700 can adopt a UART communication loop.

[0066] When the indoor fan 800 is operating, the main control unit 100 can obtain the air volume information of the indoor fan 800 through the communication unit 700, and can also send the air volume information to the main control unit 100 through the wired controller 600 (see Figure 4 ).

[0067] In some embodiments of the present application, according to the air volume information and the air outlet size, the main control unit 100 can calculate the volume of air passing through the air outlet per unit time V.

[0068] This calculation method is a prior art and will not be elaborated in detail here.

[0069] See Figure 6 , the MCU chip also has a first output pin, and outputs a PWM pulse drive signal to the water pump drive unit 310 at the first output pin.

[0070] Among them, the duty cycle of the PMW pulse drive signal can be preset, that is, the rotation speed of the drain pump 300 is preset.

[0071] See Figure 6 , the water pump drive unit 310 includes a water pump drive chip, which has a PWM pin for receiving the PWM pulse drive signal output from the first output pin of the MCU chip.

[0072] The water pump drive chip also has an overcurrent protection function, and realizes current limiting protection for the motor of the drain pump 300 by setting an overcurrent protection circuit around it.

[0073] In some embodiments of the present application, see Figure 6 , the water pump drive chip has a first pin, a second pin and a third pin, and the overcurrent protection circuit is arranged between the first pin, the second pin and the third pin.

[0074] The overcurrent protection circuit includes a first resistor R1, a second resistor R2 and a third resistor R3.

[0075] The first pin is grounded through the first resistor R1, the second pin is grounded through the second resistor R2, and the third pin is connected to the connection point where the second pin and the second resistor R2 are connected through the third resistor R3.

[0076] By setting the values of each resistor, the overcurrent protection limit value of the motor of the drain pump 300 can be set, and by changing the values of each resistor, different overcurrent protection limit values can be set.

[0077] See Figure 6 , the water pump driving chip further has a speed feedback pin, and the MCU chip has a fourth input pin.

[0078] The speed feedback pin is connected to the fourth input pin, and is used for the main control unit 100 to detect the speed of the drain pump 300 in real time and perform closed-loop control on the speed to achieve stable and controllable speed.

[0079] In some embodiments of the present application, in order to achieve a balanced state between the drainage volume Q2 of the drain pump 300 and the generation amount Q1 of the condensate water, a fixed duty cycle of the PWM pulse driving signal is set.

[0080] And at the same time, the installation structure of the drain pump 300 remains unchanged, that is, see Figure 3 The shown draft depth h remains unchanged and the drainage head H remains unchanged.

[0081] To determine the balanced state between the drainage volume Q2 of the drain pump 300 and the generation amount Q1 of the condensate water, specifically refer to Figure 7 for description.

[0082] (1) Obtain the pump current I of the drain pump 300 and send it to the main control unit 100.

[0083] (2) Determine whether the pump current changes within a preset time period (for example, 10 s). If it remains unchanged, the generation amount Q1 of the condensate water reaches balance with the drainage volume Q2 of the drain pump 300. If it changes, continuously monitor the pump current I.

[0084] (3) After the generation amount Q1 of the condensate water and the drainage volume Q2 of the drain pump 300 reach balance, according to the pre-established relationship between the pump current I and the drainage volume Q2, determine the drainage volume Q2 corresponding to the unchanged pump current I.

[0085] Therefore, in some embodiments of the present application, the relationship between the pump current I and the drainage volume Q2 is pre-established.

[0086] Among them, when the duty cycle of the PWM pulse driving signal, the pump head H and the draft depth h of the drain pump 300 are fixed, there is a corresponding relationship between the pump current I and the drainage volume Q2. When the pump current I is high, the corresponding drainage volume Q2 is large, and when the pump current I is low, the corresponding drainage volume Q2 is small.

[0087] Based on this principle, the relationship between the preset pump current I and the drainage volume Q2 is set.

[0088] This relationship can be pre-written in a preset data table or pre-written as multiple commands, where each command describes the relationship between the pump current I and the drainage volume Q2.

[0089] The number of the pump current I and the number of the drainage volume Q2 can be set as needed.

[0090] The preset data table as described above can be stored in a storage unit (not shown), which is connected to the main control unit 100.

[0091] During use, the main control unit 100 calls the data table from the storage unit and queries the data table based on the obtained pump current I to determine the drainage volume Q2.

[0092] Determine the drainage volume Q2 for different pump currents I.

[0093] (4) Make the drainage volume Q2 equal to the condensate generation amount Q1, so as to obtain the condensate generation amount Q1 at equilibrium.

[0094] In some embodiments of the present application, the air outlet temperature sensor 500 can obtain the air outlet temperature.

[0095] Different temperatures correspond to different saturation humidities of air, and there is a corresponding table for querying between different temperatures and their corresponding saturation humidities of air.

[0096] After knowing the air outlet temperature, the saturation humidity RH of the air corresponding to the air outlet temperature can be queried according to the known table. max_out 。

[0097] Obtain the condensate generation amount Q1, saturation humidity RH max_out , air volume V and indoor air humidity RH out , and then use Q1 = V * (RH max_out * RH out - RH max_in ) to obtain the saturation humidity RH max_in 。

[0098] According to the saturation humidity RH max_in , query the table of the relationship between the temperature and its saturation humidity as described above, and the temperature corresponding to the obtained saturation humidity RH max_in is the indoor return air temperature.

[0099] The indoor return air temperature can be returned to the display interface of the line controller 600 for display.

[0100] In order to avoid the problem that when the drain pump 300 malfunctions, the condensate water in the water receiving tray 200 overflows due to excessive amount, resulting in potential safety hazards. In some embodiments of the present application, refer to Figure 6, Figure 8 and Figure 9 , the air conditioner further includes a float switch 900.

[0101] The float switch 900 is disposed in the water receiving tray 200 for detecting the water level of the condensed water in the water receiving tray 200, and a preset water level is preset inside the float switch 900, and the preset water level is the maximum water receiving level in the water receiving tray 200.

[0102] When the water level in the water receiving tray 200 reaches the preset water level, the float switch 900 operates and sends a detection signal, and the sent detection signal is transmitted to the main control unit 100.

[0103] Generally, the float switch 900 is in a normally closed state, and once the water level in the water receiving tray 200 reaches the preset water level, the float switch 900 disconnects, that is, it is in an open state. Therefore, the opening and closing state information of the float switch 900 includes a closed state and an open state.

[0104] In some embodiments of the present application, referring to Figure 8 , the power supply +5V is connected to the input end of a voltage dividing circuit (not shown) connected by the float switch 900, that is, one end of the float switch 900 is connected to +5V and the other end is connected to the input end of the voltage dividing circuit.

[0105] For example, the voltage dividing circuit may include a first resistor, a second resistor, and a third resistor. One end of the first resistor is respectively connected to the other end of the float switch 900 and one end of the second resistor. The other end of the first resistor is grounded. The other end of the second resistor is respectively connected to the third input pin of the MCU chip and one end of the third resistor, and the other end of the third resistor is grounded.

[0106] Thus, referring to Figure 6 and Figure 9 , when the float switch 900 is in a normally closed state because the water level does not reach the preset water level, the third input pin of the MCU chip receives a high-level detection signal, and when the float switch 900 disconnects because the water level reaches the preset water level, the third input pin of the MCU chip receives a low-level detection signal.

[0107] After receiving the detection signal, the MCU chip outputs a control signal to the fan driving unit 700' to make the indoor fan 800 operate or stop operating.

[0108] That is, when the MCU chip receives a high-level detection signal, it outputs a control signal to the fan driving unit 700' to make the indoor fan 800 operate; when the MCU chip receives a low-level detection signal, it outputs a control signal to the fan driving unit 700' to make the indoor fan 800 stop operating, so as to prevent the indoor fan 800 from continuing to operate and continue to generate condensed water.

[0109] As described above, when the float switch 900 is turned off, it indicates that the water level in the water receiving tray 200 has reached the preset water level. This situation indicates that there is an abnormality in the drainage of the drainage pump 300. Therefore, at this time, manual drainage should be carried out in a timely manner.

[0110] To remind the user to drain the water in a timely manner, the air conditioner further includes an alarm unit (not shown), which is used to control the alarm unit to issue an alarm prompt when the main control unit 100 receives a low-level detection signal, so as to visually remind the user to drain the water in a timely manner.

[0111] The alarm prompt can also be fed back to the wired controller 600 and displayed on the display interface of the wired controller 600.

[0112] See Figure 10 , the entire operation process of the air conditioner can be described as follows.

[0113] The user controls the air conditioner indoor unit to enter the cooling mode and sets the indoor fan 800 to start running at a certain gear. At this time, the air conditioner begins to generate condensate.

[0114] After the air conditioner has been running for a period of time, the drainage pump 300 is turned on. By obtaining the pump current I of the drainage pump 300, it is judged whether the drainage volume of the drainage pump 300 is balanced with the condensate generation volume.

[0115] If the balance is achieved, the air volume calculation module 120 in the main control unit 100 obtains the air volume V per unit time by obtaining the air outlet size and the wind gear information.

[0116] The air volume V is transmitted to the information processing module 110 of the main control unit 100.

[0117] The current indoor air humidity RH is detected by the humidity sensor 400 out and transmitted to the information processing module 110, and the current air outlet temperature is detected by the air outlet temperature sensor 500 and transmitted to the information processing module 110.

[0118] The information processing module 110 queries the saturation temperature RH corresponding to the air outlet temperature according to the preset table between the air outlet temperature and the temperature and the saturation humidity. max_out .

[0119] The information processing module 110 obtains the saturation humidity RH according to Q1 = V * (RH max_out * RH out - RH max_in ). max_in .

[0120] After that, by calling the preset table between the temperature and the saturation humidity and querying, the indoor return air temperature corresponding to the saturation humidity RH max_in is obtained.

[0121] The main control unit 100 can send the indoor return air temperature to the remote controller 600 for display.

[0122] In this way, the indoor return air temperature can be obtained by using existing hardware devices without setting a return air temperature sensor, reducing the hardware investment cost.

[0123] In the description of the above embodiments, the specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner.

[0124] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An air conditioner, characterized in that, Comprising: A refrigerant circulation circuit that circulates refrigerant through a compressor, a condenser, an expansion valve, and an evaporator. The compressor compresses low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas and discharges it to the condenser. A drain pump installed in a water receiving tray for discharging the condensed water in the water receiving tray to the outside. A water pump driving unit for driving the drain pump to operate. An outlet air temperature sensor for detecting the outlet air temperature of the indoor air. A humidity sensor for detecting the indoor air humidity. A main control unit connected to the water pump driving unit and receiving the outlet air temperature detected by the outlet air temperature sensor and the indoor air humidity detected by the humidity sensor. After the amount of condensed water generated reaches equilibrium with the drainage volume of the drainage pump, the main control unit determines the indoor return air temperature based on the indoor air humidity RH out , the volume of air blown out per unit time V, the blown-out air temperature, and the amount of condensed water generated per unit time Q1.

2. The air conditioner according to claim 1, characterized in that, Determining that the generation amount of the condensed water and the drainage amount of the drain pump reach a balance, specifically: Under the condition that the duty ratio of the PWM pulse driving signal sent to the water pump driving unit is a preset duty ratio and the installation structure of the drain pump remains unchanged, obtaining the water pump current of the drain pump. When the water pump current remains unchanged within a preset time period, the generation amount of the condensed water and the drainage amount of the drain pump reach a balance. After the generation amount of the condensed water and the drainage amount of the drain pump reach a balance, according to the pre-established relationship between the water pump current and the drainage amount, determining the drainage amount corresponding to the unchanged water pump current. Making the drainage amount equal to the generation amount of the condensed water.

3. The air conditioner according to claim 1, wherein Obtain the saturation humidity RH corresponding to the outlet air temperature according to the pre-established saturation humidity of air at different temperatures max_out ; According to the formula Q1 = V * (RH max_out *RH out -RH max_in ), obtain the saturation humidity RH corresponding to the indoor return air temperature max_in ; Obtain the saturation humidity RH according to the pre-established saturation humidity of air at different temperatures max_in The corresponding indoor return air temperature 4. The air conditioner according to claim 1, wherein Based on the outlet size and the wind speed information sent by the wire controller, calculating the volume V of the outlet air per unit time.

5. The air conditioner according to claim 1, characterized in that, The water pump driving unit includes: A water pump driving chip that receives the PWM pulse driving signal sent by the main control unit, and the signal output by the rotation speed feedback pin is fed back to the main control unit for real-time detection of the rotation speed of the drain pump. An overcurrent protection circuit is provided around the water pump driving chip for overcurrent protection of the drain pump motor.

6. The air conditioner according to claim 5, characterized in that, The water pump driving chip has a first pin, a second pin, and a third pin, and the overcurrent protection circuit is connected between the first pin, the second pin, and the third pin. The overcurrent protection circuit includes a first resistor, a second resistor, and a third resistor. The first pin is grounded through the first resistor, the second pin is grounded through the second resistor, the third pin is connected to one end of the third resistor, and the other end of the third resistor is connected to the connection point between the second resistor and the second pin.

7. The air conditioner according to claim 1, characterized in that The air conditioner further includes: A float switch connected to the main control unit for detecting the water level in the water receiving tray. When the water level in the water receiving tray reaches a preset water level, the float switch sends a detection signal to the main control unit. The main control unit receives the detection signal and stops the operation of the indoor fan, and controls the drain pump to drain water.

8. The air conditioner according to claim 7, wherein The air conditioner further includes: An alarm unit connected to the main control unit for controlling the alarm unit to give an alarm prompt when the main control unit receives the detection signal.

9. The air conditioner according to claim 1, characterized in that, The drain pump is installed upside down in the water receiving tray and has a water inlet and a water outlet. The water inlet is communicated with the water receiving tray and has a water depth of a first value; The drain outlet is used to drain the condensed water in the water receiving tray to the outside and has a drainage head of a second value.

10. The air conditioner according to claim 1, wherein The indoor return air temperature is fed back to the line controller of the air conditioner and displayed on the line controller.

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