Self-cleaning method of heat exchanger and air conditioner

Abstract

The present application relates to a self-cleaning method of an air conditioner, in particular to a self-cleaning method of a heat exchanger and an air conditioner, comprising three stages; in the first stage, the dew point temperature is increased, so that the dew point temperature is higher than the freezing point; in the second stage, the indoor unit is started, so that the heat exchanger surface condensation and frost; in the third stage, the frost layer on the surface of the heat exchanger is melted, in the first stage, the indoor unit heat exchanger is in heating mode, and the fan is started, in the first stage, the humidification module is started, the indoor unit further comprises a humidity sensor module, and the control system dynamically adjusts the heating power and the humidification intensity according to the dew point temperature provided by the humidity sensor module, the dew point is greater than 0 DEG C when the refrigeration mode is started, and the fan of the indoor unit is opened; by increasing the temperature and humidity, the dew point temperature is increased, the condensation amount is increased, and the condensation time is prolonged, so that the condensed water can fully penetrate into the ash layer, the water amount during defrosting is increased, and the cleaning effect is improved.

Description

Technical Field

[0001] This invention relates to a self-cleaning method for air conditioners, and particularly to a self-cleaning method for heat exchangers and an air conditioner. Background Technology

[0002] The evaporator is part of the heat exchange components of an air conditioner. The refrigerant absorbs heat in the evaporator and changes from a liquid state to a gas state. The temperature of the heat dissipation fins of the evaporator is relatively low compared to the surrounding environment. There is often condensation on the surface of the heat dissipation fins. Therefore, the evaporator often operates in a humid state. When dusty airflow passes over the surface of the evaporator fins, the dust layer will stick to the fins and form a shell, which will reduce the thermal conductivity of the evaporator fins.

[0003] The existing disclosure (CN1702406A) first frosts the surface of the evaporator, then defrosts it, allowing dust and dirt to flow away with the ice water to clean the evaporator fins;

[0004] The existing public disclosure (CN107166670A) uses two frosting and defrosting processes to make the condensate flow on the fins, thereby increasing the cleaning effect;

[0005] However, the above solution does not take into account the situation of low temperature and humidity. When the evaporator is working in winter, the temperature difference between the inside and outside is small and the air humidity is low, resulting in a low dew point temperature. The difference between the dew point temperature and the freezing point temperature is small, and the condensate will freeze quickly to form a frost layer that cannot flow. In addition, the amount of condensate generated is small and cannot completely wet the dust layer. Furthermore, the amount of water used for rinsing during the defrosting process is small, which will affect the cleaning efficiency and effect. Summary of the Invention

[0006] One of the objectives of this invention is to provide a self-cleaning method for heat exchangers and an air conditioner, so as to improve the cleaning efficiency and effect of the evaporator when the temperature and humidity are low.

[0007] A self-cleaning method for heat exchangers, comprising three stages;

[0008] In the first stage, the dew point temperature is increased to be higher than the freezing point.

[0009] In the second stage, turn on the indoor unit to allow condensation and frost to form on the surface of the heat exchanger;

[0010] In the third stage, the frost layer on the heat exchanger surface is melted.

[0011] Furthermore, in the first stage, the indoor unit heat exchanger is in heating mode and the fan is turned on.

[0012] Furthermore, the humidification module is activated in the first stage.

[0013] Furthermore, the indoor unit also includes a humidity sensing module, and the control system dynamically adjusts the heating power and humidification intensity based on the dew point temperature provided by the humidity sensing module.

[0014] Furthermore, when the cooling mode is activated, the dew point is greater than 0°C, and the indoor unit's fan is turned on.

[0015] Furthermore, the indoor unit also includes a fresh air module, and the first phase further comprises three steps:

[0016] S1, turn on the cooling function to make the evaporator surface frost up;

[0017] S2, turn on the heating function to melt the frost on the surface of the evaporator, forming water droplets that are stored in the indoor unit;

[0018] S3, turn on the fresh air function to expel dry indoor air and bring in humid outdoor air.

[0019] Furthermore, the indoor unit's fan is not turned on in S2.

[0020] Furthermore, the moisture inside the indoor unit of the S3 is introduced into the fresh air outlet.

[0021] The second objective of this invention is to provide an air conditioner for performing the above-described method.

[0022] Furthermore, it also includes a fresh air system.

[0023] The beneficial effects achieved by the present invention using the above structure are as follows:

[0024] By increasing temperature and humidity, the dew point temperature is raised, the amount of condensation is increased, and the condensation time is extended, allowing the condensed water to fully penetrate the ash layer, increasing the amount of water used for defrosting, and improving the cleaning effect. Attached Figure Description

[0025] Figure 1 Here is a dew point temperature reference table;

[0026] Figure 2 This is a table showing the relationship between saturated water vapor pressure and temperature. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions shown in the attached diagram, while the terms “inside” and “outside” refer to the directions toward or away from the geometric center of a specific component, respectively.

[0029] To make the content of this invention easier to understand, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings.

[0030] This invention proposes a self-cleaning method for heat exchangers, which consists of three stages. In the first stage, the indoor temperature is increased to increase the amount of saturated water vapor in the air, and the water vapor content in the air is increased to increase the absolute humidity.

[0031] Preferably, increase relative humidity;

[0032] The higher the relative humidity of the air, the closer the water vapor in the air is to saturation, the closer the dew point temperature is to the current temperature, and the easier it is for water to condense on the evaporator surface. For example:

[0033] Assumption 1: When the temperature is 20℃ and the indoor relative humidity is 30%,

[0034] The saturated water vapor content of air at 20℃ is 17.3 g / m³. 3 At this time, the actual water vapor content in the air is 17.3 g / m³. 3 *30% = 5.19g / m 3 ;

[0035] Assumption 2: When the temperature is 20℃ and the indoor relative humidity is 50%,

[0036] The saturated water vapor content of the air remains unchanged; therefore, the actual water vapor content is 17.3 × 0.5 = 8.65 g / m³. 3 ;

[0037] According to the table,

[0038] For 5.19 g / m 3 The corresponding dew point is approximately 7°C;

[0039] For 8.65g / m 3 The corresponding dew point is approximately 10℃;

[0040] The above results indicate that the higher the relative humidity, the closer the dew point temperature is to the current temperature.

[0041] Preferably, increase the temperature;

[0042] Dew point temperature is affected not only by relative humidity but also by temperature. The example above illustrates that higher relative humidity leads to higher dew point temperature. In reality, higher temperatures result in a greater amount of saturated water vapor in the air, making it less likely to reach saturation, which also leads to an increase in dew point temperature. Examples are as follows:

[0043] Assumption 3: At 10℃ and 50% relative humidity,

[0044] According to the table, the saturated water vapor content of air is approximately 9.4 g / m³. 3 ;

[0045] According to the formula for calculating relative humidity, the actual moisture content at this time is 4.7 g / m³. 3 According to the table, the saturated water vapor pressure at 10℃ is approximately 1.228 kPa.

[0046] To condense the water vapor at this point, the temperature needs to be lowered to bring the relative humidity to 100%, while the relative humidity at this point is 50%. Therefore, the saturated water vapor pressure needs to be reduced by half to 0.614 kPa.

[0047] By referring to the common saturated water vapor pressure and temperature comparison table, we can find that...

[0048] A saturated water vapor pressure of 0.614 kPa corresponds to a temperature of approximately 0 °C.

[0049] Assumption 4, at 20℃ and 50% relative humidity.

[0050] According to the table, the saturated water vapor content of air is approximately 17.3 g / m³. 3 ;

[0051] According to the formula for calculating relative humidity, the actual moisture content at this time is 8.65 g / m³. 3 According to the table, the saturated water vapor pressure at 20℃ is approximately 2.3346 kPa.

[0052] To achieve a relative humidity of 100%, the saturated water vapor pressure also needs to be reduced by half to 1.1673 kPa.

[0053] By referring to the common saturated water vapor pressure and temperature comparison table, we can find that...

[0054] A saturated water vapor pressure of 1.1673 kPa corresponds to a temperature of approximately 10℃.

[0055] The above results indicate that, at the same relative humidity, the higher the temperature, the higher the dew point temperature will be.

[0056] Therefore, considering the above, increasing the temperature and absolute humidity in the first stage will inevitably lead to an increase in the dew point temperature.

[0057] In addition, as the dew point temperature rises, the absolute humidity in the air increases, which means that the water vapor content in the air increases. It also means that after reaching the dew point, as the evaporator continuously absorbs heat and the indoor temperature decreases, the saturated vapor pressure also continuously decreases, and more condensate will be generated on the surface of the evaporator.

[0058] Based on the above, in the first stage, it is necessary to activate the air conditioner's heating mode.

[0059] To increase the indoor temperature and thus the saturated vapor pressure, if the air conditioner includes a humidification function, the humidification function will be activated simultaneously. Alternatively, a separate humidifier can be used to humidify the indoor air.

[0060] In addition, if the evaporator was originally operating in a humid environment, it will become a condenser in heating mode, continuously dissipating heat. The condensate on the fin surface will evaporate, making the dust on the surface looser. When the evaporator resumes cooling, the loose dust layer has a stronger water absorption capacity, and more condensate will clean the fin surface during the subsequent flushing process.

[0061] Air conditioners should be equipped with temperature and humidity sensors, and the control system should dynamically adjust the heating power and humidification intensity according to the target dew point temperature.

[0062] Based on the above, the following Example 1 is obtained when the temperature is greater than 10°C and the indoor relative humidity is less than 30%:

[0063] Phase 1: Increase the dew point temperature to be higher than the freezing point;

[0064] Heating mode activated: When the air conditioning system detects that the indoor temperature is greater than 10℃ and the relative humidity is less than 30%, it automatically switches to heating mode.

[0065] Heating and humidification:

[0066] Increase indoor temperature: The heating function raises the indoor temperature to 11-20℃, increasing the amount of saturated water vapor in the air.

[0067] Activate humidification function: If the air conditioner has a humidification function, it will start simultaneously; otherwise, a separate humidifier will be activated to increase the water vapor content in the air to 6g / m³. 3 above.

[0068] Dynamic adjustment: The central control unit dynamically adjusts the heating power and humidification intensity according to the target dew point temperature to ensure that the dew point temperature is raised to above 0°C.

[0069] Second stage: Turn on the indoor unit to allow condensation and frost to form on the surface of the heat exchanger;

[0070] Start the cooling mode: After the first stage is completed, switch to the cooling mode to start the cooling function of the evaporator, so that its surface temperature drops below the dew point temperature, promoting condensation and frosting.

[0071] Turn on the indoor unit fan: Start the indoor unit fan to circulate indoor air at medium speed, ensuring that high humidity air continuously flows over the evaporator surface, promoting the formation of condensate and frost.

[0072] Condensation and frost formation: Condensation condenses on the surface of the evaporator and gradually forms frost. Dust is collected and fixed in the frost layer along with the condensation.

[0073] The third stage: melts the frost on the surface of the heat exchanger and removes the dust;

[0074] Switch back to heating mode: After condensation and frosting are completed, the system automatically returns to heating mode to increase the indoor temperature and melt the frost on the evaporator surface.

[0075] Example 2: When the temperature is greater than 10℃ and the indoor relative humidity is greater than 30%;

[0076] Phase 1: Increase dew point temperature and absolute humidity;

[0077] Activate heating mode: When the indoor temperature is detected to be greater than 10℃ and the relative humidity is greater than 30%, the system will automatically switch to heating mode.

[0078] Heating and humidification:

[0079] Moderately increase indoor temperature: Raise the indoor temperature to between 11-24℃ to increase the amount of saturated water vapor in the air.

[0080] Activate humidification function: Activate the built-in humidification function of the air conditioner or a separate humidifier to increase the absolute humidity to 9g / m³. 3 above.

[0081] Dynamic adjustment: The central control unit dynamically adjusts the heating power and humidification intensity according to the target dew point temperature to ensure that the dew point temperature rises.

[0082] Second stage: Turn on the indoor unit to allow condensation and frost to form on the surface of the heat exchanger;

[0083] Turn on the evaporator's cooling function to lower its surface temperature below the dew point temperature (approximately 12°C), promoting condensation and frosting.

[0084] Condensate forms on the surface of the evaporator and gradually turns into frost.

[0085] The third stage: melts the frost on the heat exchanger surface and removes the dust;

[0086] After condensation and frosting are completed, the system returns to heating mode to further increase the indoor temperature to 22°C and melt the frost layer on the evaporator surface.

[0087] As the frost melts, the dust attached to it is carried away and discharged through the internal drainage system or stored in a designated location, ensuring the cleanliness of the condenser surface.

[0088] Example 3, at room temperature below 10°C:

[0089] Phase 1: Increase the dew point temperature to be higher than the freezing point;

[0090] Activate heating mode: Automatically switches to heating mode when the indoor temperature is detected to be below 10℃;

[0091] Activate humidification function: Increase absolute humidity to 5g / m³ using the humidifier. 3 Ensure that the dew point temperature is raised to above 2°C.

[0092] Second stage: Turn on the indoor unit to allow condensation and frost to form on the surface of the heat exchanger;

[0093] To start the cooling mode: Before starting, ensure that the indoor temperature is above 10℃ and the dew point temperature is above 0℃ to avoid sublimation.

[0094] Start the evaporator cooling function: Activate the evaporator's cooling function to lower its surface temperature below the dew point temperature (approximately 2°C), promoting condensation and frosting.

[0095] The third stage: melts the frost on the heat exchanger surface and removes the dust;

[0096] Switch back to heating mode: After condensation and frosting are completed, return to heating mode to raise the indoor temperature to 14°C and melt the frost on the evaporator surface.

[0097] Furthermore, if the air conditioner includes a fresh air function, and the goal is also to increase the dew point temperature and absolute humidity, then the first stage is improved to obtain the following embodiment:

[0098] Example 4: In the first stage, the indoor absolute humidity was increased according to the following method:

[0099] S1, turn on the cooling function to make the evaporator surface frost up;

[0100] S2, turn on the heating function to melt the frost on the surface of the evaporator, forming water droplets that are stored in the indoor unit;

[0101] S3, turn on the fresh air function to expel dry indoor air and bring in humid outdoor air.

[0102] In S1, the evaporator continuously absorbs heat and cools down, causing the surrounding air to reach the dew point and then the freezing point, causing water vapor in the indoor air to frost on the surface of the evaporator and accumulating water vapor in the indoor air on the surface of the evaporator.

[0103] When the heating mode is activated in S2, the frost layer on the evaporator surface can be melted.

[0104] Preferably, the indoor unit's fan is not turned on in S2;

[0105] Not turning on the fan can reduce the evaporation of water droplets produced by melting, and keep the water produced by melting in the indoor unit of the air conditioner as much as possible;

[0106] In S3, when the fresh air mode of the air conditioner is turned on, the dry indoor air will be exhausted from the exhaust vent, and the humid outdoor air will be introduced into the room through the heat exchange module.

[0107] Preferably, in S3, the moisture inside the indoor unit in S2 is introduced into the fresh air outlet;

[0108] The airflow through the fresh air outlet allows the water produced by the evaporator to evaporate quickly.

[0109] Using the above method, the dew point is guaranteed to be greater than 0℃. The evaporator absorbs heat and cools down. At this time, condensate is generated first. There are dry and wet areas in the ash layer. The condensate that has not been frosted will be evenly distributed in the ash layer through infiltration.

[0110] In addition, after the first stage, during the second stage of evaporator cooling, the absolute humidity and temperature in the room are initially high. As the evaporator works, the temperature of the indoor air continuously decreases, which leads to a continuous decrease in the saturated water vapor pressure of the indoor air. Before frosting, compared to the lower room temperature and relative humidity, more condensate will be generated on the evaporator fins.

[0111] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A self-cleaning method for a heat exchanger, characterized in that, It includes three stages: In the first stage, the dew point temperature is increased to be higher than the freezing point. Increasing the dew point temperature includes increasing the indoor temperature and increasing the indoor absolute humidity. In the second stage, turn on the indoor unit to allow condensation and frost to form on the surface of the heat exchanger; In the third stage, the frost layer on the surface of the heat exchanger is melted.

2. The self-cleaning method for a heat exchanger according to claim 1, characterized in that, In the first stage, increasing the indoor temperature involves turning on the indoor unit's heat exchanger to heating mode and turning on the fan.

3. The self-cleaning method for a heat exchanger according to claim 2, characterized in that, In the first stage, increasing absolute humidity means turning on the humidification module.

4. The self-cleaning method for a heat exchanger according to claim 3, characterized in that, The indoor unit also includes a humidity sensing module, and the control system dynamically adjusts the heating power and humidification intensity based on the dew point temperature provided by the humidity sensing module.

5. The self-cleaning method for a heat exchanger according to claim 4, characterized in that, When the cooling mode is turned on, the dew point is greater than 0°C and the indoor unit's fan is turned on.

6. The self-cleaning method for a heat exchanger according to claim 1, characterized in that, The indoor unit also includes a fresh air module, and the process of increasing indoor absolute humidity as described in the first stage includes the following three steps: S1, turn on the cooling function to make the evaporator surface frost up; S2, turn on the heating function to melt the frost on the surface of the evaporator, forming water droplets that are stored in the indoor unit; S3, turn on the fresh air function to expel dry indoor air and bring in humid outdoor air.

7. A self-cleaning method for a heat exchanger according to claim 6, characterized in that, In S2, the indoor unit's fan is not turned on.

8. A self-cleaning method for a heat exchanger according to claim 6, characterized in that, Moisture inside the indoor unit of the S3 is introduced into the fresh air outlet.

9. An air conditioner, characterized in that, Perform the method as described in any one of claims 1-5.

10. An air conditioner, characterized in that, It also includes a fresh air system that performs the method as described in any one of claims 6-8.

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