Defrosting method and device of heat pump system and heat pump system

Abstract

The invention relates to the technical field of heat pump control, and discloses a defrosting method and device of a heat pump system and the heat pump system.The defrosting method comprises the steps that the temperature and humidity of gaps of a fin type heat exchanger are monitored in real time; and when the temperature is lower than or equal to the threshold value of the dynamic dew point temperature plus the safety margin and the humidity is higher than or equal to the threshold value, it is judged that the frosting prevention condition is met, the gap temperature is increased by adjusting the refrigerant bypass valve, the gap humidity is reduced by adjusting the airflow adjusting valve, and therefore frosting is actively prevented. And if the frost layer appears, short-time refrigeration interruption or low-power heating is started for defrosting according to the thickness of the frost layer or a pressure difference signal. And the formed ice layer is forcibly removed by switching the flow direction of the refrigerant and heating. By means of three-level linkage control, accurate defrosting in the whole process from prevention to removal is achieved, energy waste is effectively avoided, the defrosting efficiency and operation stability of the system are improved, and the user experience is improved.

Description

Technical Field

[0001] This invention relates to the field of heat pump control technology, and specifically to a defrosting method, apparatus, and heat pump system for a heat pump system. Background Technology

[0002] Finned heat exchangers are the core components for heat exchange in household and small commercial equipment (such as household air conditioners, refrigerators, and small heat pumps), and their performance directly affects the operating efficiency and stability of the equipment. Due to the limitations of existing processing equipment mold specifications, the finned heat exchangers used in these devices are usually limited to a fin height of 30cm-1.5m, which makes it difficult to meet the needs of larger heat exchange areas in some scenarios.

[0003] To overcome this height limitation, the industry's conventional approach is to use a spliced ​​fin structure, which extends the overall height by splicing multiple fin segments. However, this splicing solution has significant technical drawbacks: because it is difficult to ensure that the spacing between adjacent fin segments is perfectly aligned during the splicing process, irregular gaps are formed between the two layers of fins. During equipment operation, airflow within these gaps is obstructed, humidity easily accumulates, and the temperature easily drops below the dew point, leading to a continuous and intensified frost formation within the gap. As operating time progresses, the frost layer further condenses into ice, creating an ice buildup problem. The accumulation of ice not only significantly increases the thermal resistance of the fins, weakening the heat exchanger's heat exchange capacity, but also blocks airflow channels, resulting in reduced airflow, increased energy consumption, and ultimately a significant decline in the overall performance of heat pump systems and other equipment.

[0004] To address this frosting and ice buildup problem, existing technologies often employ either adding an electric heating device within the finned interlayer for defrosting, or introducing high-temperature refrigerant into the interlayer via hot gas bypass for defrosting. However, both of these solutions have significant drawbacks: adding an electric heating device directly increases the equipment's manufacturing cost and operating energy consumption, while the hot gas bypass method requires diverting the high-temperature refrigerant within the system, leading to a reduction in the heat pump system's heating efficiency, thus failing to balance the equipment's economic efficiency and energy performance. Summary of the Invention

[0005] In view of this, this invention addresses the technical problems of misalignment of the fins at the gaps in a heat pump system, the aggravation of frost buildup in the interlayer during operation, which leads to decreased equipment performance, and the increased costs and reduced energy efficiency of conventional electric heating or hot gas bypass defrosting solutions. This invention provides a defrosting method, apparatus, and system for a heat pump system that can prevent frost formation, quickly handle frost and ice after it appears, and simultaneously maintain the operating efficiency of the heat pump system.

[0006] In a first aspect, the present invention provides a defrosting method for a heat pump system, comprising the following steps:

[0007] The temperature and humidity values ​​at the gap between the two finned heat exchangers of the heat pump system are monitored in real time. When the temperature value is not higher than the first preset temperature threshold and the humidity value is not lower than the first preset humidity threshold, it is determined that the anti-frost condition is met. In response to meeting the anti-frost condition, the temperature at the gap is increased by adjusting the electric valve of the refrigerant pipeline, and the humidity at the gap is adjusted by adjusting the electric valve of the airflow regulating device.

[0008] Monitor the frost thickness on the finned heat exchanger. When the frost thickness reaches a first preset thickness threshold or the pressure difference on both sides of the gap exceeds a set threshold, it is determined that the defrosting condition is met. In response to meeting the defrosting condition, short-term interruption of cooling or low-power heating is started to defrost.

[0009] The system monitors whether an ice layer forms on the finned heat exchanger. When the formation of the ice layer is confirmed, it is determined that the ice-melting condition is met. In response to meeting the ice-melting condition, the refrigerant flow direction is switched and heating is applied for strong removal.

[0010] The defrosting method provided in this invention achieves intelligent defrosting control with three-level linkage by real-time monitoring of the temperature and humidity, frost thickness, and ice state of the finned heat exchanger gap. Its beneficial effects are as follows: First, in the prevention stage, by adjusting the refrigerant and airflow, it actively suppresses the formation of frost conditions, fundamentally avoiding energy waste and ensuring continuous and efficient system operation. Second, it adopts a graded and precise removal strategy for frost and ice accumulation, significantly improving defrosting speed and effectiveness, and effectively preventing performance degradation. Finally, this method breaks through the limitations of traditional defrosting methods, which require system interruption, have high energy consumption, and result in a poor user experience. While significantly saving energy, it improves the stability and comfort of heat pump operation, extends equipment lifespan, and enhances the user experience.

[0011] In one optional embodiment, the first preset temperature threshold is the dew point temperature dynamically calculated based on environmental parameters plus a preset safety margin value. The step of increasing the temperature at the gap by adjusting the electric valve of the refrigerant pipeline and adjusting the humidity at the gap by adjusting the electric valve of the airflow regulating device includes: controlling the electric valve of the refrigerant pipeline to open the bypass branch, adjusting the refrigerant distribution flowing through the finned heat exchanger to raise the temperature at the gap above the first preset temperature threshold, and controlling the electric valve of the airflow regulating device to operate the airflow regulating device so that the air flows at the gap to reduce the humidity at the gap below the first preset humidity threshold.

[0012] This invention achieves advanced and accurate prediction of frost risk by dynamically calculating the dew point temperature and adding a safety margin value as a first preset temperature threshold. When the temperature and humidity at the gap reach critical conditions, the system intelligently opens the refrigerant bypass branch electric valve, rapidly raising the gap temperature above the safe value by optimizing refrigerant distribution; simultaneously, or independently, it controls the airflow regulating device to enhance airflow, effectively reducing the gap humidity below the threshold. This solution proactively intervenes before frost forms, fundamentally avoiding the increased thermal resistance and performance degradation caused by frost. It not only significantly improves heat exchange efficiency and system energy efficiency but also ensures the continuous and stable operation of the heat pump, completely eliminating the energy waste and operational interruption problems caused by traditional defrosting methods, achieving a dual breakthrough in energy saving and comfort.

[0013] In one optional implementation, the initiation of short-term interruption of cooling or low-power heating for defrosting includes: briefly interrupting the refrigerant flow to the area corresponding to the gap based on a preset time, and using the waste heat of the heat pump system for defrosting, and / or controlling the heating electric valve to start the auxiliary heating device for defrosting, until the temperature sensor detects that the fin temperature has reached the preset temperature and then stops.

[0014] This invention utilizes the waste heat of the heat pump system to defrost by briefly interrupting the local refrigerant flow for a preset time, eliminating the need for additional high-energy-consuming components. If necessary, an auxiliary heating device is activated, and the timing of its shutdown is precisely controlled by a temperature sensor to prevent overheating. Compared to conventional electric heating defrosting, this significantly reduces energy consumption. Intervention only targets the area corresponding to the gap, without affecting the operation of other areas of the system, preventing the frost layer from worsening into ice, thus avoiding increased difficulty in subsequent defrosting, ensuring the continuous and stable heat exchange performance of the heat pump system, and reducing equipment operating fluctuations.

[0015] In one optional implementation, the powerful removal by switching the refrigerant flow direction and supplementing with heating includes: switching the refrigerant flow direction through the icing layer fins, so that the high-temperature refrigerant flows through the icing layer, and simultaneously starting the auxiliary heating device until the fin temperature rises to a preset temperature and the preset temperature state is maintained for a preset time and then stops.

[0016] In this embodiment of the invention, during the third defrosting action, the refrigerant flow direction is switched, allowing high-temperature refrigerant to preferentially flow through the ice layer. Simultaneously, an auxiliary heating device is activated. The two methods work synergistically, significantly improving the ice melting efficiency and solving the problem of ice being tightly adhered to the fins and difficult to remove. The stopping condition is clearly defined as "fin temperature reaching a preset temperature and remaining there for a preset duration," ensuring complete ice melting and preventing the re-accumulation of residual ice. Compared to conventional single-method ice melting, this method is more thorough and efficient, without affecting the overall operation of the heat pump system. This ensures reliable operation of household and small commercial equipment in low-temperature environments and reduces the risk of equipment failure due to ice.

[0017] In one optional implementation, monitoring whether an ice layer forms on the finned heat exchanger includes: monitoring the weight change of the fins using a weight sensor, or monitoring the duration of the temperature at the gap remaining at 0°C using a temperature sensor; when the weight increases beyond a preset threshold or the duration of the temperature remaining at 0°C exceeds a preset time threshold, it is confirmed that an ice layer has formed.

[0018] This invention provides accurate and quantifiable criteria for determining ice formation by monitoring fin weight changes with a weight sensor or monitoring the duration of 0°C with a temperature sensor. This makes the determination of ice-melting conditions more objective and reliable, ensuring that the third defrosting action is initiated in a timely manner at the initial stage of ice formation, improving ice-melting efficiency, reducing the damage of ice to the heat exchange efficiency of the finned heat exchanger, and further ensuring the stable operation of the heat pump system.

[0019] Secondly, the present invention provides a defrosting device for a heat pump system, comprising: a temperature sensor, a humidity sensor, a frost layer detection sensor, an ice layer detection sensor, an auxiliary heating device, a refrigerant pipeline, an airflow regulating device, and a controller, all disposed at the gap between two finned heat exchangers joined together in the heat pump system, wherein:

[0020] The auxiliary heating device is equipped with a heating electric valve;

[0021] The refrigerant pipeline is equipped with an electric valve that can adjust the flow rate;

[0022] The airflow regulating device is equipped with an electric valve that can adjust the flow rate;

[0023] The controller is electrically connected to the temperature sensor, humidity sensor, frost detection sensor, ice detection sensor, auxiliary heating device, electric valve of refrigerant pipeline, and electric valve of airflow regulating device, and is used to execute the defrosting method of the heat pump system described in any of the first aspects.

[0024] The defrosting device provided in this invention integrates multi-dimensional sensors, actuators, and a controller to form a complete defrosting control system. Sensors monitor the entire process from "pre-frost signs to frost layer to ice layer" in real time, providing precise trigger signals for defrosting actions. Actuators can flexibly perform operations such as temperature adjustment, humidity reduction, defrosting, and ice melting. The controller provides unified and coordinated control. Compared to decentralized defrosting components, this device has high integration and strong coordination, enabling automated control of the entire process from prevention to monitoring to defrosting without manual intervention. It is compatible with spliced ​​finned heat exchangers in household and small commercial equipment, effectively solving the problem of frost and ice buildup in the jacket, avoiding the increased costs and reduced energy efficiency of conventional defrosting solutions, and improving the operating efficiency and stability of heat pump systems.

[0025] In one optional implementation, the frost detection sensor is an infrared frost sensor or a differential pressure sensor.

[0026] Infrared frost sensors can directly monitor frost thickness, accurately reflecting frost accumulation; differential pressure sensors indirectly determine frost thickening by monitoring the pressure difference at the gaps (frost increases airflow resistance, leading to a rise in pressure difference). Adaptable to different application scenarios and cost requirements, users can select the appropriate sensor type based on equipment specifications and operating environment, enhancing the flexibility and adaptability of the device.

[0027] In one alternative implementation, the ice layer detection sensor is a weight sensor or a temperature sensor.

[0028] Weight sensors directly reflect ice accumulation through weight changes (ice adds weight to the fins); temperature sensors indirectly determine ice formation through temperature changes (ice melts at a constant temperature of 0°C). These two sensor monitoring methods complement each other and can be flexibly selected based on factors such as equipment installation space and cost budget, improving the adaptability of the defrosting device.

[0029] In one alternative implementation, the airflow regulating device is a deflector or a miniature fan.

[0030] This invention specifies that the airflow regulating device is either a guide vane or a miniature fan, providing two feasible solutions to enhance airflow in the gap: the guide vane passively enhances airflow by guiding external airflow into the gap; the miniature fan actively enhances airflow by accelerating air circulation in the gap. Both devices are adaptable to different equipment structures and operational requirements. For example, a guide vane can be selected for equipment with limited space, while a miniature fan can be selected for scenarios requiring rapid dehumidification, improving the flexibility and adaptability of the method.

[0031] Thirdly, embodiments of the present invention provide a heat pump system including at least two layers of spliced ​​finned heat exchangers, with gaps formed between the spliced ​​finned heat exchangers, and a defrosting device as described in any of the second aspects.

[0032] The heat pump system provided in this invention addresses the problem of frost and ice buildup in spliced ​​finned heat exchangers caused by uneven fin spacing by integrating at least two layers of finned heat exchangers (forming gaps) with a defrosting device. The defrosting device achieves fully automated control of the prevention-monitoring-defrosting process, reducing frost and ice formation at the source, promptly removing frost and ice, and preventing frost and ice from affecting heat exchange efficiency. Compared to heat pump systems without this defrosting device, it has higher operating efficiency, lower energy consumption, and is less prone to performance fluctuations or malfunctions due to frost and ice in low-temperature environments. It is compatible with household air conditioners, small heat pumps, and other household and small commercial equipment, meeting their requirements for heat exchange efficiency and operational stability, improving user experience, and reducing equipment operation and maintenance costs. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a schematic flowchart of a defrosting method for a heat pump system according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the spliced ​​finned heat exchanger and the gap formed in the heat pump system according to an embodiment of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] This invention also provides a defrosting method for a heat pump system, including a frosting prevention stage: used to avoid the formation of frosting conditions, such as... Figure 1 As shown, the prevention, monitoring, and defrosting phases include the following steps:

[0038] S11, Prevention Phase: Real-time monitoring of the temperature and humidity values ​​at the gap between the two finned heat exchangers of the heat pump system. When the temperature value is not higher than a first preset temperature threshold and the humidity value is not lower than a first preset humidity threshold, it is determined that the anti-frost conditions are met. In response to meeting the anti-frost conditions, the temperature at the gap is increased by adjusting the electric valve of the refrigerant pipeline, and the humidity at the gap is adjusted by adjusting the electric valve of the airflow regulating device.

[0039] Specifically, the two-layer finned heat exchanger and its gap in the heat pump system are as follows: Figure 2As shown. The first preset temperature threshold in the prevention phase is the dew point temperature dynamically calculated based on environmental parameters plus a preset safety margin value; adjusting the temperature at the gap by regulating the electric valve of the refrigerant pipeline and adjusting the humidity at the gap by regulating the electric valve of the airflow regulating device includes: controlling the electric valve of the refrigerant pipeline to open the bypass branch, adjusting the refrigerant distribution flowing through the finned heat exchanger to raise the temperature at the gap above the first preset temperature threshold, and controlling the electric valve of the airflow regulating device to operate the airflow regulating device, so that the air flows at the gap to reduce the humidity at the gap below the first preset humidity threshold.

[0040] The first preset temperature threshold of this invention is the dew point temperature dynamically calculated based on environmental parameters plus a preset safety margin value. Specifically, the dew point temperature is dynamically calculated based on the ambient temperature and wet-bulb temperature. The real-time dew point temperature can be expressed in a table, while the preset safety margin value + 2° is a fixed value, and the first preset humidity threshold is 60%. When the anti-frost conditions are met, the electric valve in the refrigerant pipeline is triggered: it opens the bypass branch, increasing the refrigerant flow to the layer of fins prone to frosting (raising the temperature of that layer to ≥ the dew point temperature), or reducing the flow to another layer (avoiding overcooling), thus preventing condensation through temperature regulation. By controlling the airflow regulating electric valve to open the deflector / micro fan, the airflow between the two layers is enhanced, carrying away trapped water vapor (reducing local humidity to <60%).

[0041] This invention significantly advances the defrosting process, ensuring the system remains in a highly efficient heat exchange state, resulting in more continuous and stable operation. Furthermore, the control logic, triggered by precise sensor data, directly targets specific gaps prone to frosting (adjusting refrigerant distribution and enhancing local airflow), avoiding global, energy-intensive defrosting operations. It only invests the minimum necessary energy when needed, resulting in significant energy savings. Because it is a preventative, localized fine-tuning intervention, it does not interrupt the normal operation of the main unit. The refrigerant adjustment and airflow enhancement are smooth and virtually imperceptible to the user, thereby improving the comfort and user experience of the heat pump system.

[0042] S12, Monitoring Phase: Monitor the frost thickness on the finned heat exchanger. When the frost thickness reaches a first preset thickness threshold or the pressure difference on both sides of the gap exceeds a set threshold, it is determined that the defrosting condition is met. In response to meeting the defrosting condition, short-term interruption of cooling or low-power heating is initiated to defrost.

[0043] Specifically, when the infrared sensor detects a frost layer thickness ≥ 0.5 mm (or a pressure difference exceeding a set threshold, such as 15 Pa; in the gaps of the finned heat exchanger, as the frost layer gradually thickens, it leads to increased airflow resistance within the gaps. At this time, the pressure difference value across the gap, monitored by the pressure difference sensor installed at the gap, exceeds the preset pressure difference threshold for determining initial frost formation), a mild defrosting mode is activated. This includes: briefly interrupting the refrigerant flow to the corresponding area of ​​the gap for a preset time, utilizing the waste heat of the heat pump system for defrosting, and / or controlling the heating electric valve to activate the auxiliary heating device for defrosting, until the temperature sensor detects that the fin temperature has reached the preset temperature, then stopping. Specifically:

[0044] 1. Briefly close the refrigerant flow in the corresponding area of ​​the finned jacket (i.e., the local piping of the finned jacket; closing the local piping has almost no impact on other areas) by controlling the refrigerant electric valve (10-30 seconds). Use the system's waste heat (such as the exhaust heat of the compressor) to heat the fins in reverse, raising the local temperature to 5-10℃ and melting the initial frost layer.

[0045] 2. Control the auxiliary heating electric valve. If an electric heating wire is provided at the gap, the electric valve will be turned on to heat (power ≤ 500W, to avoid excessive energy consumption) for 30 seconds to 1 minute until the frost melts (confirmed by temperature sensor T≥5℃).

[0046] The monitoring phase provided in this invention involves a brief interruption of local refrigerant flow at a preset time, utilizing the waste heat of the heat pump system for defrosting without the need for additional high-energy-consuming components. If necessary, an auxiliary heating device is activated, and the timing of shutdown is precisely controlled by a temperature sensor to avoid overheating. Compared to conventional electric heating defrosting, this significantly reduces energy consumption. Intervention only targets the area corresponding to the gap, without affecting the operation of other areas of the system, preventing the frost layer from worsening into ice, thus avoiding increased difficulty in subsequent defrosting, ensuring the continuous and stable heat exchange performance of the heat pump system, and reducing equipment operating fluctuations.

[0047] S13, Defrosting stage: Monitor whether an ice layer has formed on the finned heat exchanger. When it is confirmed that the ice layer has formed, it is determined that the ice melting condition is met. In response to meeting the ice melting condition, the refrigerant flow direction is switched and heating is used for strong removal.

[0048] This invention monitors the rate of temperature recovery by installing a weight sensor (the ice layer adds weight) or a temperature sensor at the gap (the temperature remains at 0°C when the ice melts until it completely melts and then rises). Monitoring whether an ice layer forms on the finned heat exchanger includes: monitoring the weight change of the fins using a weight sensor, or monitoring the duration of the temperature at the gap remaining at 0°C using a temperature sensor; when the weight increase exceeds a preset threshold or the duration of the temperature remaining at 0°C exceeds a preset time threshold, ice layer formation is confirmed. If the temperature remains at 0°C for more than 5 minutes, or the weight sensor reading increases sharply, a strong defrosting mode is activated for de-icing, including: switching the refrigerant flow direction through the fins with the ice layer, allowing high-temperature refrigerant to flow through the ice layer, and simultaneously activating an auxiliary heating device until the fin temperature rises to a preset temperature and remains at the preset temperature for a preset duration. Specifically, this includes:

[0049] 1. Control the refrigerant electric valve to switch the flow direction of the two layers of refrigerant (similar to the defrosting logic of a heat pump), so that the high-temperature refrigerant flows first through the fins of the ice layer, and continues until the temperature rises above 5°C.

[0050] 2. Control the auxiliary heating electric valve to simultaneously open the heating wire, and work with the refrigerant to accelerate ice melting. The water produced by ice melting is discharged through the guide channel (to avoid secondary freezing).

[0051] This invention employs targeted monitoring (such as a sudden increase in weight detected by a weight sensor or a temperature sensor reading of 0°C for more than 5 minutes) to accurately identify ice formation, preventing increased thermal resistance and worsening ice buildup due to delayed detection. This fundamentally reduces the damage to heat exchange efficiency caused by ice, ensuring stable heat exchanger operation. Furthermore, the third defrosting action utilizes a combined mode of switching refrigerant flow and synchronous auxiliary heating, prioritizing the flow of high-temperature refrigerant through the ice layer. This, coupled with the auxiliary heating device, significantly accelerates ice melting compared to conventional single-method defrosting, addressing the challenge of removing ice tightly bound to the fins. The defrosting process is explicitly defined as stopping when the fin temperature reaches a preset temperature (≥5°C) and remains at that temperature for a preset duration (30 seconds), ensuring complete ice melting while avoiding overheating and energy waste, thus balancing defrosting effectiveness and heat pump efficiency. Additionally, water generated during defrosting can be discharged through a drainage channel, effectively preventing secondary icing and further reducing subsequent defrosting frequency, thus lowering equipment operation and maintenance costs.

[0052] Traditional defrosting only begins after frost has already formed and significantly impacted heat exchange efficiency, resulting in high energy consumption and interrupted heating. This invention employs a three-stage precise intervention for defrosting: In the prevention stage, real-time monitoring of the temperature and humidity at the gap between the two-layer finned heat exchanger triggers the first defrosting action when frost formation conditions are met, preventing frost formation at its source and reducing subsequent defrosting needs; in the monitoring stage, frost is identified by its thickness or gap pressure difference, triggering the second defrosting action to promptly remove thin frost and prevent it from deteriorating into difficult-to-handle ice; in the defrosting stage, a third defrosting action is executed after precise ice formation to efficiently melt the ice, preventing ice from damaging heat exchange efficiency. The entire process does not rely on energy-intensive conventional electric heating or hot gas bypass solutions, balancing defrosting effectiveness with heat pump efficiency, ensuring stable equipment operation, reducing performance fluctuations, and adapting to the needs of residential and small commercial applications.

[0053] Simultaneously, based on multi-dimensional sensor signals such as temperature, humidity, frost thickness, pressure difference, and ice weight, the system status is accurately determined and different levels of defrosting actions are triggered. This "on-demand defrosting" mode avoids the drawbacks of traditional fixed-cycle defrosting methods, such as "defrosting when there is no frost" or "defrosting only when the frost is thick," and greatly reduces unnecessary energy consumption.

[0054] This invention also provides a defrosting device for a heat pump system, comprising: a temperature sensor, a humidity sensor, a frost detection sensor, an ice detection sensor, an auxiliary heating device, a refrigerant pipeline, an airflow regulating device, and a controller, all disposed at the gap between two finned heat exchangers joined together in the heat pump system. The auxiliary heating device is equipped with a heating electric valve; the refrigerant pipeline is equipped with an adjustable flow electric valve; the airflow regulating device is equipped with an adjustable flow electric valve; and the controller is electrically connected to the temperature sensor, humidity sensor, frost detection sensor, ice detection sensor, auxiliary heating device, refrigerant pipeline electric valve, and airflow regulating electric valve, for executing the defrosting method of the heat pump system described in the above embodiment.

[0055] Specifically, the frost detection sensor is an infrared frost sensor or a differential pressure sensor; the ice detection sensor is a weight sensor or a temperature sensor; and the airflow regulation device is a deflector or a miniature fan.

[0056] The frost detection sensor in this invention is either an infrared frost sensor or a differential pressure sensor. Each sensor has its advantages: the infrared frost sensor can directly monitor the frost thickness, accurately reflecting the frost accumulation; the differential pressure sensor indirectly determines frost thickening by monitoring the pressure difference at the gap (frost causes increased airflow resistance, leading to a rise in pressure difference). Adaptable to different usage scenarios and cost requirements, users can choose the appropriate sensor type based on equipment specifications and operating environment, improving the flexibility and adaptability of the device. Simultaneously, both sensors can accurately capture the frost state, providing a reliable trigger for the second defrosting action, ensuring timely frost removal, preventing frost deterioration, guaranteeing efficient heat exchange in the finned heat exchanger, and maintaining the performance of the heat pump system.

[0057] The ice layer detection sensor can be either a weight sensor or a temperature sensor. These two types of sensors monitor ice layer from different perspectives: the weight sensor directly reflects ice accumulation through weight changes (ice layer increases the weight of the fins); the temperature sensor indirectly determines ice formation through temperature changes (ice layer melts at a constant temperature of 0℃). These two sensor monitoring methods complement each other and can be flexibly selected based on factors such as equipment installation space and cost budget, improving the adaptability of the defrosting device.

[0058] The airflow regulation device, consisting of a deflector or a miniature fan, offers two feasible solutions for enhancing airflow in gaps: the deflector passively enhances airflow by guiding external airflow into the gap; the miniature fan actively enhances airflow by accelerating air circulation within the gap. Both devices are adaptable to different equipment structures and operational requirements. For example, a deflector can be chosen for equipment with limited space, while a miniature fan can be selected for scenarios requiring rapid dehumidification, thus improving the flexibility and adaptability of the method.

[0059] The device provided in this invention, through the coordinated configuration of sensors, auxiliary heating devices, refrigerant pipelines, airflow regulating devices, and controllers, significantly addresses the problems of interlayer frost and ice buildup and performance degradation caused by uneven fin spacing in spliced ​​finned heat exchangers (fin height 30cm-1.5m) used in household and small commercial equipment, as well as the high consumption and low efficiency of conventional defrosting solutions.

[0060] From a monitoring perspective, the temperature and humidity sensors at the gap between the two-layer finned heat exchangers can capture the temperature and humidity environment prone to frost in real time. The frost layer detection sensor can accurately identify the frost layer (e.g., frost layer thickness ≥ 0.5 mm or pressure difference exceeding 15 Pa). The ice layer detection sensor at the gap can promptly determine the formation of ice layer (e.g., temperature 0℃ for 5 minutes or sudden increase in weight). The multi-dimensional sensors work together to achieve accurate monitoring of the entire process from "frost precursors to frost layer to ice layer", avoiding a sharp drop in heat exchange efficiency caused by the accumulation of frost and ice that is not dealt with in time, and providing accurate triggering basis for subsequent defrosting actions.

[0061] From an execution perspective, the electric valves in the refrigerant piping can flexibly adjust flow distribution and direction. This allows for temperature regulation and condensation prevention via bypass branches during the prevention phase, and for switching flow direction during defrosting to prioritize ice melting by high-temperature refrigerant. The electric valves in the airflow regulating device enhance intermittent airflow for dehumidification, while the auxiliary heating device and heating electric valves provide low-power (≤500W) supplemental heating as needed, avoiding excessive energy consumption. All execution components are uniformly controlled by a controller, strictly adhering to the three-level logic of "prevention-monitoring-defrosting." Intervention is only applied to specific problem areas (e.g., shutting down one of multiple refrigerant branches) without affecting the overall system operation. This ensures effective defrosting (e.g., complete ice melting and prevention of secondary icing), significantly reduces defrosting costs, improves heat pump efficiency, minimizes equipment operational fluctuations, and optimizes the user experience in residential and small commercial settings.

[0062] The present invention also provides a heat pump system, including at least two layers of spliced ​​finned heat exchangers, with gaps formed between the spliced ​​finned heat exchangers, and the defrosting device described in the above embodiments.

[0063] The heat pump system provided in this invention is applicable to household and small commercial equipment such as household air conditioners and small heat pumps. Its core configuration includes at least two layers of spliced ​​finned heat exchangers and the defrosting device described in the above embodiment. The specific structure and operating logic are as follows:

[0064] Finned heat exchanger: It adopts a splicing structure (due to the limitations of the processing equipment mold, the height of a single fin is 30cm-1.5m, and the splicing is used to meet the requirement of a larger heat exchange area). After the two layers of fins are spliced, an irregular gap is formed, and the heat exchanger is equipped with a guide groove (to drain the water generated by melting ice).

[0065] The defrosting device comprises multi-dimensional sensors, actuators, and a controller. The sensors include temperature sensors, humidity sensors, and frost detection sensors (infrared frost sensors or differential pressure sensors) installed in the gaps, as well as ice detection sensors (weight sensors or temperature sensors) installed in the gaps. The actuators include refrigerant line electric valves (the refrigerant lines have dozens of branch structures, each corresponding to a local area of ​​the fins), airflow regulating electric valves (connected to a deflector plate or a miniature fan), and auxiliary heating electric valves (connected to an electric heating wire in the gap, with a power ≤500W). The controller is electrically connected to all sensors and electric valves, and has a preset three-level control logic of prevention, monitoring, and defrosting.

[0066] Taking the operation of a small heat pump for heating in winter as an example: When changes in ambient temperature and humidity cause the temperature and humidity sensor at the gap to detect T≤0℃ (real-time dew point temperature is calculated as 0℃)+2℃ and H≥60%, the controller triggers the prevention phase action: the electric valve of the refrigerant pipeline opens the bypass branch, increases the refrigerant flow to the easily frosted fin layer, and raises the gap temperature to >0℃; at the same time, the electric valve of the airflow regulation opens the guide plate, enhances the airflow in the gap, and reduces the humidity to <60%, avoiding condensation and frosting.

[0067] If the subsequent frost layer detection sensor detects that the frost layer thickness in the gap is ≥0.5mm (or the pressure difference exceeds 15Pa), the system enters the monitoring stage: the controller controls the refrigerant electric valve to briefly close the single refrigerant branch in the area corresponding to the gap (duration 10-30 seconds), and uses the waste heat from the compressor exhaust to heat the fins in reverse, so that the local temperature rises to 5-10℃; if the frost layer is not completely melted, the auxiliary heating electric valve opens the electric heating wire (power ≤500W) and continues to heat for 30 seconds to 1 minute until the temperature sensor detects T≥5℃.

[0068] When the ice layer detection sensor detects that the fin temperature remains at 0°C for more than 5 minutes (or the weight sensor reading increases sharply), the system enters the defrosting stage: the controller controls the refrigerant electric valve to switch the refrigerant flow direction between the two fin layers, so that the high-temperature refrigerant flows first through the ice layer fins; at the same time, the auxiliary heating electric valve opens the electric heating wire to assist in heating, and the water generated by melting the ice is discharged through the guide channel until the temperature sensor detects that the fin temperature is ≥5°C for 30 seconds, at which point the defrosting action stops.

[0069] Compared to conventional electric heating and hot gas bypass defrosting solutions, this system's defrosting device requires no additional high-energy-consuming components. During the prevention and monitoring phases, it prioritizes intervention using the system's own refrigerant flow regulation and compressor exhaust waste heat, only activating low-power auxiliary heating (≤500W) when necessary. Furthermore, the refrigerant piping employs a multi-branch design, shutting down only a single local branch during defrosting, significantly impacting refrigerant flow in other areas and avoiding substantial fluctuations in system energy efficiency. In actual operation, this reduces defrosting energy consumption, improves the heat pump system's heating efficiency ratio, and lowers equipment operating costs. Simultaneously, the controller uses multi-dimensional sensors to capture the state of the finned heat exchanger gaps in real time. All defrosting actions are performed locally on the problem area (e.g., adjusting only the refrigerant flow in the easily frosted fin layer, or shutting down only a single refrigerant branch), without affecting the overall heating output of the heat pump system. For example, in a residential air conditioning scenario, the defrosting process will not cause significant heating interruptions or a sudden drop in outlet air temperature, avoiding indoor temperature fluctuations caused by conventional defrosting solutions and optimizing the user experience.

[0070] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A defrosting method for a heat pump system, characterized in that, Includes the following steps: The temperature and humidity values ​​at the gap between the two finned heat exchangers of the heat pump system are monitored in real time. When the temperature value is not higher than the first preset temperature threshold and the humidity value is not lower than the first preset humidity threshold, it is determined that the anti-frost condition is met. In response to meeting the anti-frost condition, the temperature at the gap is increased by adjusting the electric valve of the refrigerant pipeline, and the humidity at the gap is adjusted by adjusting the electric valve of the airflow regulating device. Monitor the frost thickness on the finned heat exchanger. When the frost thickness reaches a first preset thickness threshold or the pressure difference on both sides of the gap exceeds a set threshold, it is determined that the defrosting condition is met. In response to meeting the defrosting condition, short-term interruption of cooling or low-power heating is started to defrost. The system monitors whether an ice layer forms on the finned heat exchanger. When the formation of the ice layer is confirmed, it is determined that the ice-melting condition is met. In response to meeting the ice-melting condition, the refrigerant flow direction is switched and heating is applied for strong removal.

2. The method according to claim 1, characterized in that, The first preset temperature threshold is the dew point temperature dynamically calculated based on environmental parameters plus a preset safety margin value. The step of increasing the temperature at the gap by adjusting the electric valve of the refrigerant pipeline and adjusting the humidity at the gap by adjusting the electric valve of the airflow regulating device includes: The electric valve controlling the refrigerant pipeline opens the bypass branch, adjusts the refrigerant distribution flowing through the finned heat exchanger to raise the temperature at the gap above the first preset temperature threshold, and the electric valve of the airflow regulating device controls the airflow regulating device to operate, so that the air flows at the gap to reduce the humidity at the gap below the first preset humidity threshold.

3. The method according to claim 1, characterized in that, The method of initiating a short-term interruption of cooling or low-power heating to defrost includes: briefly interrupting the flow of refrigerant to the area corresponding to the gap based on a preset time, and using the waste heat of the heat pump system for defrosting, and / or controlling the heating electric valve to start the auxiliary heating device for defrosting, until the temperature sensor detects that the fin temperature has reached the preset temperature and then stops.

4. The method according to claim 1, characterized in that, The method of powerfully removing the ice by switching the refrigerant flow direction and supplementing it with heating includes: switching the refrigerant flow direction through the fins of the ice layer so that the high-temperature refrigerant flows through the ice layer, and simultaneously starting the auxiliary heating device until the fin temperature rises to the preset temperature and the preset temperature state is maintained for a preset time and then stops.

5. The method according to claim 1 or 4, characterized in that, The monitoring of whether an ice layer forms on the finned heat exchanger includes: monitoring the weight change of the fins using a weight sensor, or monitoring the duration of the temperature at the gap remaining at 0°C using a temperature sensor; when the weight increases beyond a preset threshold or the duration of the temperature remaining at 0°C exceeds a preset time threshold, it is confirmed that an ice layer has formed.

6. A defrosting device for a heat pump system, characterized in that, include: Temperature sensors, humidity sensors, frost detection sensors, ice detection sensors, auxiliary heating devices, refrigerant piping, airflow regulating devices, and controllers are all installed at the gap between the two finned heat exchangers connected in the heat pump system. Among them: The auxiliary heating device is equipped with a heating electric valve; The refrigerant pipeline is equipped with an electric valve that can adjust the flow rate; The airflow regulating device is equipped with an electric valve that can adjust the flow rate; The controller is electrically connected to the temperature sensor, humidity sensor, frost detection sensor, ice detection sensor, auxiliary heating device, electric valve of refrigerant pipeline, and electric valve of airflow regulating device, and is used to execute the defrosting method of the heat pump system according to any one of claims 1-5.

7. The apparatus according to claim 6, characterized in that, The frost layer detection sensor is an infrared frost layer sensor or a differential pressure sensor.

8. The apparatus according to claim 6, characterized in that, The ice layer detection sensor is either a weight sensor or a temperature sensor.

9. The method according to claim 1, characterized in that, The airflow regulating device is a guide vane or a miniature fan.

10. A heat pump system, characterized in that, It includes at least two layers of spliced ​​finned heat exchangers, with gaps formed between the spliced ​​finned heat exchangers, and a defrosting device as described in any one of claims 6-9.

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