A defrosting time prediction control method for a refrigeration machine

Abstract

The application discloses a kind of defrosting time prediction control methods of refrigerating machine, it is related to refrigerating machine defrosting technical field, and gathers night running stage environment humidity, environment temperature and evaporation temperature variation value constructs continuous change trajectory and identifies humidity sudden rise section, forms time mark;Based on the mark extraction evaporation temperature variation slope and segmented contrast determine humid cold coupling propulsion interval;Accordingly, the delay observation section is demarcated, and the frost change rhythm is characterized;Further define frozen sudden advance risk interval and move forward defrosting trigger time;Finally, pre-defrosting is executed, and heat recovery is completed, and the operation rhythm is restored.The application is aimed at the operation process of refrigerating machine, by humidity sudden rise section identification and delay observation mechanism, to avoid defrosting misjudgment, improve heat exchange stability and guarantee refrigerating capacity continuous output;At the same time, through frozen sudden advance risk interval determination and pre-defrosting control, load smooth transition is realized, compressor fluctuation is reduced, and energy consumption change is slowed down.

Description

Technical Field

[0001] This invention relates to the field of defrosting technology for refrigeration machines, and more specifically to a method for predicting and controlling the timing of defrosting in refrigeration machines. Background Technology

[0002] A refrigeration unit is a thermodynamic device that uses a compressor to drive the refrigerant to circulate between an evaporator, condenser, and throttling components, absorbing heat from a low-temperature environment and releasing it to the outside. Its core mechanism is based on phase change heat transfer and pressure energy conversion. It is used in industrial cooling, cold chain storage, and air conditioning systems to maintain a stable low-temperature state in a target space. Refrigeration unit defrosting timing prediction refers to continuously tracking the evaporator surface temperature change trajectory, heat exchange efficiency decay trend, and airflow resistance changes during equipment operation. This involves constructing a time-related expression of frost evolution, identifying the defrosting trigger point before the frost layer severely obstructs the heat exchange channels, and pre-regulating the compressor's operating rhythm and defrosting cycle accordingly. This embeds the defrosting process into the overall operating sequence, thereby reducing energy consumption fluctuations, avoiding sudden drops in heat exchange efficiency, and maintaining long-term stable system operation.

[0003] The existing technology has the following shortcomings:

[0004] During nighttime operation, when ambient humidity suddenly increases, the moisture content of the frost layer on the evaporator surface rises accordingly, altering its microstructure and pore distribution. This causes the frost growth rate to slow down temporarily. If the predictive control logic judges the current operating state solely based on changes in the growth rate, it may misinterpret this phase as frost entering a stable range, thus delaying defrosting. When the ambient temperature subsequently drops sharply, the evaporation temperature decreases further, and the unfrozen moisture inside the frost layer rapidly solidifies, forming a denser ice layer. This causes the frost thickness to exceed the critical threshold in a very short time, leading to a significant decrease in heat exchange capacity and insufficient cooling output. This forces the compressor to maintain high load operation for an extended period, causing a surge in current and ultimately resulting in a sharp increase in energy consumption and significantly exacerbating equipment operational risks.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a defrosting timing prediction and control method for a refrigeration unit. During the operation of the refrigeration unit, a mechanism for identifying and delaying observation of sudden humidity rises is used to avoid false defrosting judgments, improve heat exchange stability, and ensure continuous output of cooling capacity. At the same time, by determining the risk range of freezing surges and implementing pre-defrosting control, a smooth load transition is achieved, compressor fluctuations are reduced, and energy consumption changes are mitigated, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for predicting and controlling the defrosting timing of a refrigeration unit, comprising the following steps:

[0008] The system collects data on changes in ambient humidity, ambient temperature, and evaporation temperature during the nighttime operation phase. It constructs a corresponding continuous change trajectory in chronological order and identifies humidity surge segments based on the ambient humidity change data, marking the corresponding time intervals to form time markers for humidity surge segments.

[0009] Based on the time marker of the humidity surge period, the slope of the evaporation temperature change in the corresponding time interval is extracted and segmented. The evaporation temperature change trend in the corresponding time interval is synchronously compared with the evaporation temperature change trend of the adjacent time intervals to determine the humidity-cold coupling advancement interval.

[0010] Based on the wet and cold coupling propulsion interval, a delayed observation section is defined. Within the delayed observation section, the original defrosting delay judgment state is maintained. At the same time, the change rhythm of frost amount is continuously characterized by combining the change values ​​of evaporation temperature and ambient temperature, so as to avoid misjudgment based on the stage changes of frost growth rate.

[0011] Based on the delayed observation period, and combined with the rhythm of frost changes and the downward range of ambient temperature changes, the operating status is judged in intervals to define the freezing breakthrough risk interval, and the defrosting trigger time is moved forward according to the freezing breakthrough risk interval.

[0012] For the risk range of sudden freezing, a pre-defrosting control operation is performed within the corresponding time range, and the heat recovery process is completed under the constraints of changes in evaporation temperature and ambient temperature. Then, the original operating rhythm is restored to reduce compressor load fluctuations and energy consumption fluctuations.

[0013] Preferably, the formation of the time marker for the sudden increase in humidity includes the following steps:

[0014] Collect values ​​of changes in ambient humidity, ambient temperature, and evaporation temperature during the nighttime operation phase, arrange them point by point in chronological order and synchronize them to construct a continuous change trajectory.

[0015] Based on the continuous change trajectory, the environmental humidity change values ​​at adjacent time points are compared point by point to extract the time range of continuous increase and expansion of the increase rate, forming a humidity surge segment with a start time point and an end time point.

[0016] By combining the time range corresponding to the sudden increase in humidity, the changes in ambient temperature and evaporation temperature within the corresponding time interval are extracted from the continuous change trajectory, and then combined point by point to form a multi-dimensional data set. At the same time, interval marking is completed to distinguish different time intervals.

[0017] Based on the interval markers, the start and end times of the humidity surge segment and the process of environmental humidity change are integrated and expressed, and a correlation is established with the corresponding position of the continuous change trajectory to form a time marker for the humidity surge segment.

[0018] Preferred methods for creating a sudden increase in humidity include:

[0019] During the point-by-point comparison of environmental humidity changes at adjacent time points, the time range of continuous increase and expanding increase rate is obtained by recording the change difference point by point and arranging them in chronological order. The position where the increase relationship is interrupted is taken as the end boundary, and the position where the continuous increase begins is taken as the starting time point, thus forming the humidity surge segment.

[0020] Preferably, the determination of the wet-cold coupling propulsion range includes the following steps:

[0021] Extract the evaporation temperature change values ​​within the time interval corresponding to the time marker of the humidity surge, compare the change difference between adjacent time points point by point, and combine the collection time interval to form an evaporation temperature change slope sequence.

[0022] The evaporation temperature change slope sequence is compared point by point along the time sequence, and segments with the same direction of change and continuously progressive change amplitude are divided. The start time point and end time point are recorded to form the segmented arrangement result.

[0023] The time intervals adjacent to the sudden increase in humidity were identified and the corresponding evaporation temperature change values ​​were extracted. A evaporation temperature change slope sequence was formed point by point to construct a control sequence.

[0024] The evaporation temperature change slope at the corresponding position of the segmented arrangement result is compared point by point with that of the adjacent time interval, and the time range with continuous and consistent change direction is extracted to form the wet and cold coupled advancement interval.

[0025] Preferred methods for generating segmented arrangement results include:

[0026] During the point-by-point comparison of the evaporation temperature change slope sequence, the time range in which the change direction is consistent and the change amplitude continuously increases is formed by continuously recording the change difference between adjacent time points. The position where the change direction reverses is taken as the end time point of the segment, and the starting position of continuous increase is taken as the starting time point of the segment, so as to form the segmented arrangement result.

[0027] Preferably, the delineation of the delayed observation section and the characterization of the frost amount change rhythm include the following steps:

[0028] The start and end times of the wet-cold coupling propulsion interval are obtained, and extended along the time sequence to form a continuous time range. The points are then compared point by point with the direction of change of evaporation temperature values ​​to determine the delayed observation section.

[0029] Within the delayed observation period, the changes in evaporation temperature and ambient temperature at each time point are processed point by point to form a continuously arranged sequence of change data, while maintaining the original defrosting delay judgment state.

[0030] Based on the changing data sequence, the magnitude and direction of change at adjacent time points are continuously recorded and a change trajectory is constructed. The rhythm of frost change is characterized by the correspondence between the change values ​​of evaporation temperature and the change values ​​of ambient temperature.

[0031] Preferably, during the formation of the change data sequence, the change values ​​of evaporation temperature and the change values ​​of ambient temperature at adjacent time points are bound point by point, the change amplitude and change direction are continuously recorded in chronological order, and the change trajectory is formed by continuous connection to characterize the change rhythm of frost amount.

[0032] Preferably, the definition of the freeze-prone risk zone and the adjustment of the defrost trigger time include the following steps:

[0033] Construct a rhythm sequence of frost amount change within the delayed observation section, compare the evaporation temperature change values ​​at adjacent time points point by point and record the change amplitude and direction, divide the rhythm slowdown section and the rhythm acceleration section, and form a rhythm section.

[0034] Extract the environmental temperature change values ​​within the delayed observation section and form a continuous recording sequence. Mark the time range of continuous decrease and accumulation of change difference and obtain the downward amplitude. Combine the rhythm section to complete the time alignment.

[0035] Based on the correspondence between rhythm segments and downward exploration magnitude, the slowdown rhythm segment and the segment where the environmental temperature change value continues to decrease are jointly identified and extended to form the freezing breakthrough risk range.

[0036] Compare the starting time of the freeze advance risk zone with the original defrost trigger time, move the defrost trigger time forward in chronological order, and establish a correlation with the freeze advance risk zone.

[0037] Preferred methods for forming a freeze-up risk zone include:

[0038] The slowdown zone is formed by comparing the changes in evaporation temperature at adjacent time points. The time range in which the magnitude of change continuously decreases and the direction of change remains consistent is defined as the slowdown zone. This zone is then matched with the zone in which the change in ambient temperature continues to decrease to form the risk zone of sudden freezing.

[0039] Preferably, the pre-defrosting control operation and heat recovery process includes the following steps:

[0040] Set the defrosting trigger time after the shift as the start node, continuously record the change value of evaporation temperature and the change value of ambient temperature and compare them point by point, mark the continuous change time period and align it with the freezing rush risk zone in time.

[0041] Record the direction and magnitude of the evaporation temperature change in chronological order and the corresponding change in ambient temperature to form a continuous change record to constrain the heat recovery process and complete the heat recovery.

[0042] Referring to the end time of the freezing risk zone, the changes in evaporation temperature and ambient temperature at subsequent time points are compared point by point, and the operating rhythm is restored along the time series to reduce compressor load fluctuations and energy consumption fluctuations.

[0043] The technical effects and advantages provided by the present invention in the above technical solution are as follows:

[0044] This invention identifies the wet-cold coupling advancement interval by introducing a time marker for the humidity surge period and combining it with a segmented comparison relationship of the evaporation temperature change trend. Based on this, a delayed observation period is set to continuously characterize the frost amount change rhythm, so that the defrosting determination no longer depends on a single growth rate change. This allows for accurate differentiation between a phased slowdown and a true stable state during operation, avoiding delays in the defrosting trigger time, ensuring the stability of the heat exchange process during continuous operation, and maintaining the continuity of cooling capacity output.

[0045] This invention defines the risk range of freezing surge and adjusts the defrost trigger time in advance. It performs pre-defrost control operation before the freezing surge occurs, and completes heat recovery under the constraints of changes in evaporation temperature and ambient temperature. This ensures that temperature changes during operation remain continuous, thereby reducing load fluctuations of the compressor during operation, slowing down the magnitude of current changes, and keeping the overall energy consumption stable over time. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0047] Figure 1 This is a flowchart of the method of the present invention.

[0048] Figure 2 This is a flowchart illustrating the determination of the wet-cold coupling propulsion range in this invention.

[0049] Figure 3 This is a flowchart illustrating the delineation of the delayed observation section and the characterization of the frost amount change rhythm in this invention.

[0050] Figure 4 This is a flowchart illustrating the definition of the freeze-prone risk zone and the adjustment of the defrost trigger time in this invention. Detailed Implementation

[0051] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art.

[0052] This invention provides, for example Figures 1 to 4 The method for predictive control of defrosting timing in a refrigeration unit, as shown, includes the following steps:

[0053] Step 1: Collect the environmental humidity change value, environmental temperature change value, and evaporation temperature change value during the nighttime operation phase, construct the corresponding continuous change trajectory in chronological order, and identify the humidity surge segment based on the environmental humidity change value, and mark the corresponding time interval to form the humidity surge segment time identifier.

[0054] Based on the numerical changes in ambient humidity, we identify periods of sudden humidity increases and mark the corresponding time intervals to form time markers for these periods. The specific steps are as follows:

[0055] During the nighttime operation of the evaporator, a fixed time interval is set to collect data. The changes in ambient humidity, ambient temperature, and evaporation temperature are recorded at each collection time. A corresponding time stamp is added to each set of data so that each time point corresponds to a complete set of changes in ambient humidity, ambient temperature, and evaporation temperature.

[0056] The fixed time sampling interval is determined based on the sampling cycles of the ambient humidity sensor, ambient temperature sensor, and evaporation temperature sensor, as well as the temperature change response time during the nighttime operation of the refrigeration unit, so that adjacent sampling points can reflect the sudden increase in humidity and the trend of evaporation temperature change.

[0057] Subsequently, all the collected data were arranged point by point in chronological order, and the data at each moment were connected in sequence to form a continuous data sequence. The time intervals in this continuous data sequence were kept consistent and there was no interruption in the recording. During the arrangement process, the values ​​of changes in ambient humidity, ambient temperature, and evaporation temperature were synchronized and aligned so that the three types of changes at the same time point formed a corresponding relationship.

[0058] Based on this, the changes in ambient humidity, ambient temperature, and evaporation temperature are unfolded point by point along the time axis, forming a continuous change trajectory covering the entire nighttime operation phase. This continuous change trajectory can fully reflect the continuous evolution of the three types of change values ​​over time and provide a continuous and uninterrupted data foundation for subsequent segment identification.

[0059] Given that a continuous change trajectory has been formed, the point-by-point changes in the environmental humidity value in the time series are analyzed. The difference between two adjacent time points is used as the criterion. The environmental humidity value at each time point is compared with the environmental humidity value at the previous time point. When multiple consecutive time points show an increasing value and the rate of increase continues to expand, the continuous time range is recorded as a candidate segment, and the starting time point of the candidate segment is marked.

[0060] After the candidate segment is formed, the environmental humidity change values ​​are compared point by point along the time direction. When the increasing relationship between adjacent time points is interrupted, or the difference between two or more consecutive change differences is no longer greater than the preset increase judgment threshold, the corresponding time point is taken as the end boundary of the candidate segment, thus obtaining a humidity surge segment with a clear start time point and end time point.

[0061] During this process, all time segments that meet the above conditions are recorded one by one, and segments with fewer than the preset minimum number of continuous points are excluded. The preset minimum number of continuous points is determined based on the collection time interval, the stabilization time of the humidity sensor, and the statistical results of humidity changes during the nighttime operation phase, so as to ensure that the identified humidity surge segments have continuity and integrity in the time dimension.

[0062] After determining the start and end times of the humidity surge, the ambient temperature and evaporation temperature changes within the corresponding time intervals are extracted from the continuous change trajectory based on this time range. The ambient humidity, ambient temperature, and evaporation temperature changes within the time intervals are then combined point by point to form a multidimensional data set covering the entire humidity surge.

[0063] In forming this multidimensional dataset, the changes in environmental humidity, environmental temperature, and evaporation temperature at each time point are bound in a unified order. This creates a set of combined data containing all three types of changes at each time point. These combined data are then arranged chronologically to construct a continuous data segment that perfectly corresponds to the humidity surge. This continuous data segment is then marked with intervals within the overall continuous change trajectory, allowing for direct location of this time range in subsequent processing. These interval markings distinguish the humidity surge segment from other time segments, creating a clear boundary for this segment within the entire time series.

[0064] After marking the intervals of the humidity surge, the time information and corresponding data characteristics of the interval are integrated and processed. The start time, end time, and overall change process of the environmental humidity value within the interval are uniformly expressed, and the expression result is recorded as the time identifier of the humidity surge interval.

[0065] During the recording process, the time markers of the humidity surge segment are associated with the corresponding time positions in the continuous change trajectory. This allows subsequent processing to directly locate the specific time interval in the continuous change trajectory using the time markers. At the same time, the time markers retain the correspondence between the changes in ambient temperature and evaporation temperature within that segment. This ensures that the time markers of the humidity surge segment not only contain time range information but also the multidimensional change characteristics corresponding to that time range. This allows for the direct retrieval of the complete time interval and its corresponding data content when conducting further analysis based on the time markers.

[0066] Step 2: Based on the time marker of the humidity surge period, extract the slope of the evaporation temperature change within the corresponding time interval and arrange them in segments. Then, compare the evaporation temperature change trend within this time interval with the evaporation temperature change trend of its adjacent time intervals to determine the humidity-cold coupling advancement interval.

[0067] The trend of evaporation temperature change within the time interval corresponding to the period of sudden increase in humidity is compared synchronously with the trend of evaporation temperature change in the adjacent time intervals before and after it to determine the humidity-cold coupling advancement interval. The specific steps are as follows:

[0068] Based on the established time markers for the sudden increase in humidity, the corresponding time intervals in the continuous change trajectory are precisely located. Each time point within the time interval is unfolded one by one, and the corresponding evaporation temperature change values ​​are extracted in chronological order.

[0069] During the extraction process, the evaporation temperature change value at each time point is compared with the evaporation temperature change value at the previous time point, and the difference in change between adjacent time points is recorded. Simultaneously, combined with a fixed collection time interval between two time points, this difference in change is expressed in correspondence with the time interval, thus forming an evaporation temperature change slope expression result consistent with the time sequence at each time point. In this process, all time points within the time interval corresponding to the entire humidity surge period are processed one by one, so that each time point corresponds to a clear evaporation temperature change slope. These evaporation temperature change slopes are then connected sequentially according to time sequence to form a complete and continuous evaporation temperature change slope sequence.

[0070] When forming this sequence, the evaporation temperature change slope at each time point is sequentially correlated with the evaporation temperature change slope at the adjacent time points before and after, so that the entire evaporation temperature change slope sequence remains continuous in the time dimension, thus fully expressing the dynamic evolution process of evaporation temperature change within the time marker of the humidity surge period.

[0071] After the evaporation temperature change slope sequence has been formed, the sequence is scanned point by point along the time sequence. The evaporation temperature change slope at each time point is compared with the evaporation temperature change slope at the previous time point to determine whether the change direction between adjacent time points is consistent, and the progression of the change amplitude between consecutive time points is recorded.

[0072] When the slope of the evaporation temperature change at multiple consecutive time points remains in the same direction and the magnitude of the change is continuously progressive between adjacent time points, this continuous time range is defined as the starting range of the same segment, and the tracking continues along the time direction starting from this starting time point.

[0073] When the direction of the evaporation temperature change slope reverses or the change amplitude is interrupted between adjacent time points at subsequent time points, this time point is taken as the end boundary of the current segment, and the start and end time points of the segment are recorded, thus forming a complete evaporation temperature change slope segment. Then, the above process is repeated, using the end time point as the new starting reference point, to divide the entire evaporation temperature change slope sequence into segments, so that all time points are included in different segments, and that each segment is connected end to end in time sequence without overlapping areas.

[0074] After completing the segmentation of the entire system, the segments are arranged in chronological order, and the time range corresponding to each segment is recorded. This results in a segmented arrangement with clear boundaries, where the slope of the evaporation temperature change is within the time marker of the humidity surge zone.

[0075] After segmenting the evaporation temperature change slope, taking the time interval corresponding to the humidity surge segment as the center, select a continuous time interval immediately before the start time of the time interval and a continuous time interval immediately after the end time of the time interval, ensuring that the length of these two time intervals matches the humidity surge segment time interval, thus forming adjacent time intervals before and after. Subsequently, extract the corresponding evaporation temperature change values ​​from these three time intervals, and form an evaporation temperature change slope sequence point by point in the same way as the humidity surge segment time interval, so that both the adjacent time intervals before and after form an evaporation temperature change slope sequence consistent with the time order.

[0076] Based on this, the slope of evaporation temperature change in each segment within the time marker of the humidity surge section is compared point by point with the slope of evaporation temperature change at the corresponding time position in the preceding and following time intervals. The continuous change of the evaporation temperature change trend between the three time intervals is observed in chronological order. When a segment within the time marker of the humidity surge section maintains a continuous connection with the preceding and following time intervals in the direction of change, and continues in the same direction of change in the following time intervals, the time range corresponding to that segment is determined as the wet-cold coupling advancement interval, and this time range is marked so that the wet-cold coupling advancement interval has a clear start and end position in the entire time series, and forms a continuous correlation with the humidity surge section time marker and the preceding and following adjacent time intervals, thereby providing a clear time interval basis for subsequent steps.

[0077] Step 3: Delineate the observation period based on the wet-cold coupling propulsion interval. Maintain the original defrosting delay judgment state within the observation period. At the same time, combine the evaporation temperature change value and the ambient temperature change value to continuously characterize the frost amount change rhythm, so as to avoid misjudgment based on the stage changes of the frost growth rate.

[0078] Based on the wet-cold coupling propulsion interval, a delayed observation section is defined. Within the delayed observation section, the defrosting delay judgment result formed before entering the delayed observation section remains unchanged, and the defrosting trigger time is not updated separately based on the frost amount change rhythm. The specific steps are as follows:

[0079] Based on the established wet-cold coupling propagation interval, the start and end times of this time interval in the continuously changing trajectory are extracted. Using the end time as the new time reference starting point, a fixed number of consecutive acquisition time points are sequentially extended forward along the time sequence. These consecutive time points are then included in the observation range to form the initial extended time period. The fixed number is determined based on the refrigeration unit's acquisition time interval, historical defrosting response time, and the duration of evaporation temperature changes during nighttime operation. When invoked, it is represented by the number of consecutive acquisition time points, used to limit the maximum extension range of the delayed observation segment.

[0080] During the extension process, the trend of the evaporation temperature change value in the wet-cold coupling propulsion interval at the end stage is used as a reference. The evaporation temperature change value at each time point during the extension process is compared point by point. When the extended time point still continues the change direction in the wet-cold coupling propulsion interval, the time point is included in the observation range. When the evaporation temperature change value changes direction at a certain time point, the time point is used as the end boundary of the delayed observation section, thus obtaining a complete time interval that starts from the end time point of the wet-cold coupling propulsion interval and extends continuously thereafter.

[0081] Once the time interval is determined, all time points within the interval are recorded uniformly, and the interval is associated with the wet-cold coupling propulsion interval. This allows the time interval to be located through the wet-cold coupling propulsion interval, thereby forming a delayed observation segment. This delayed observation segment is ensured to be immediately adjacent to the wet-cold coupling propulsion interval in time and to cover the continuous transition phases during the change process.

[0082] After the start and end times of the delayed observation period are clearly defined, the original defrosting delay judgment state is maintained unchanged within the delayed observation period. That is, the current defrosting triggering conditions are not adjusted within this time interval. At the same time, each time point in the delayed observation period is processed point by point. The evaporation temperature change value and the ambient temperature change value of each time point are extracted synchronously, and a point-by-point correspondence is established according to the time sequence, so that each time point forms a combination of data containing the evaporation temperature change value and the ambient temperature change value.

[0083] During this process, the evaporation temperature change value at the current time point is compared with the evaporation temperature change value at the previous time point point, and combined with the ambient temperature change value at the current time point, the continuity of the evaporation temperature change is recorded, so that the temperature change process within the delayed observation section forms a complete time series record; at the same time, the above point-by-point processing process is continuously repeated throughout the entire delayed observation section, so that all time points within the section form a continuously arranged change data sequence, thereby constructing a complete and continuous joint change record of evaporation temperature change value and ambient temperature change value while maintaining the original defrosting delay judgment state.

[0084] Given a continuously changing data sequence within the extended observation period, the evaporation temperature change value at each time point is linked to the corresponding ambient temperature change value. The relationship between adjacent time points is then analyzed point by point along the time sequence. By recording the magnitude, direction, and duration of the continuous change in the evaporation temperature change values ​​between adjacent time points, and synchronously mapping these characteristics to the corresponding ambient temperature change values, each time point generates a record reflecting the correlation between temperature change and environmental conditions. Based on this, all time points within the entire extended observation period are connected sequentially, forming a continuous change trajectory covering the entire extended observation period. This continuous change trajectory serves as the basis for expressing the rhythm of frost amount changes.

[0085] When observing the continuous change trajectory segment by segment, the time periods in which the change in evaporation temperature slows down between consecutive time points are recorded in relation to the time periods in which the change in ambient temperature continues to decrease or maintain its original state. The process of this change is then tracked at subsequent time points to form a complete record of the change process in the time series.

[0086] By using the above method, the rhythm of frost amount change within the delayed observation section is represented in the form of a continuous change trajectory, and the change rhythm is continuously tracked throughout the entire delayed observation section, thereby avoiding misjudgment of the operating status due to changes in the frost growth rate in a short period of time.

[0087] Step four: Based on the delayed observation period, and combined with the rhythm of frost changes and the downward range of ambient temperature changes, the operating status is judged in intervals to define the freezing breakthrough risk interval, and the defrosting trigger time is moved forward according to the freezing breakthrough risk interval.

[0088] The operating status is analyzed to define the risk range of freezing sudden advance, and the defrost trigger time is adjusted forward according to the risk range of freezing sudden advance. The specific steps are as follows:

[0089] Within the time frame from the start to the end of the extended observation period, the established frost amount change rhythm trajectory is unfolded point by point in chronological order. The evaporation temperature change value at each time point is compared with the evaporation temperature change value at the previous time point. The amplitude, direction, and duration of the change in the same direction between consecutive time points are recorded. These records are then arranged in chronological order to form a frost amount change rhythm sequence covering the entire extended observation period.

[0090] In the rhythmic sequence of frost amount changes, the time range in which the direction of change remains consistent and the magnitude of change gradually decreases between consecutive time points is marked as the rhythm slowing segment, and the time range in which the direction of change remains consistent and the magnitude of change gradually increases between consecutive time points is marked as the rhythm accelerating segment. The rhythm boundary point is formed at the time point where the direction of change reverses, so that the rhythmic change of frost amount within the delayed observation segment is divided into multiple consecutive rhythmic segments.

[0091] After the division is completed, the start time, end time, and cumulative change of the change amplitude within each rhythm segment are recorded. This allows the frost amount change rhythm to form a segmented expression with clear boundaries in the time dimension, providing a clear data structure for subsequent joint analysis with environmental temperature change values.

[0092] After the frost amount change rhythm section has been divided, the environmental temperature change values ​​within the delayed observation section are expanded point by point. The environmental temperature change value at each time point is compared with the environmental temperature change value at the previous time point, the change difference between adjacent time points is recorded, and these change differences are arranged in chronological order to form a continuous recording sequence of the environmental temperature change process.

[0093] In a continuous recording sequence, the time range in which the change in ambient temperature continuously decreases between consecutive time points and the magnitude of the decrease gradually expands at each time point is marked as a continuous temperature decline segment. The difference in change at each time point within this segment is accumulated and recorded to obtain the magnitude of the temperature decline within this segment. At the same time, the time points where the decrease in the ambient temperature change is interrupted or the downward trend stops are marked as boundaries, so that the continuous temperature decline segment has clear start and end time points.

[0094] After completing the division of all continuous temperature decline sections, the sections are arranged in chronological order, and each continuous temperature decline section is matched one by one with the frost amount change rhythm section within the same time range, so that each time section simultaneously contains the frost amount change rhythm characteristics and the decline range information of the ambient temperature change value.

[0095] After aligning the frost amount change rhythm segment with the continuous temperature decline segment in time, a joint analysis is performed on each corresponding time segment. The time range marked as the slowdown segment within the frost amount change rhythm segment is recorded in relation to the continuous decline in ambient temperature within the corresponding time segment, with the decline gradually accumulating. This is then marked as the initial risk segment in the time series. Subsequently, this initial risk segment is tracked chronologically. When the evaporation temperature change value shifts from a slowdown to an acceleration segment at subsequent time points, and the ambient temperature change value continues to decline continuously during this process, this entire continuous time range is marked as the freezing breakthrough risk zone.

[0096] During the labeling process, the start and end times of the freezing advance risk interval are recorded, and it is ensured that the interval is completely within the range of the delayed observation section. At the same time, the time correspondence between the interval and the frost amount change rhythm section and the temperature continuous decline section is maintained, so that the freezing advance risk interval forms a clear and continuous interval expression in the entire time series.

[0097] Once the freeze advance risk zone has been determined, the original defrost trigger time is compared one by one with the starting time of the freeze advance risk zone. When the original defrost trigger time is after the starting time of the freeze advance risk zone, the defrost trigger time is moved forward to a fixed time position before the starting time of the freeze advance risk zone. This fixed time position is determined by selecting several consecutive time points forward, so that the new defrost trigger time falls within the time range before the start of the freeze advance risk zone.

[0098] This fixed time position is not an absolutely constant time value, but is determined based on the relative time interval formed by continuous collection points in the time series. Specifically, it takes the starting time point of the freezing breakthrough risk interval as a reference benchmark, traces back several consecutive time points along the time axis, and uses the time range covered by these consecutive time points as candidate forward shift intervals. Within these candidate forward shift intervals, combined with the frost amount change rhythm and the downward process of the ambient temperature change value already formed in the delayed observation section, a time point that is both before the starting time point of the freezing breakthrough risk interval and in the transition stage before the frost amount change changes from slowing down to accelerating is selected as the fixed time position for frost triggering.

[0099] During the setting process, this time position usually corresponds to the time node when the change value of evaporation temperature has not yet entered the rapid change stage and the change value of ambient temperature has already shown a continuous downward trend. This time point can serve as a transition position before the start of the freezing breakthrough process, thereby ensuring that the defrosting trigger action is embedded in the operation process in advance, while not entering the defrosting stage too early and affecting normal refrigeration operation. Through this fixed time position determined by continuous time point backtracking, the new defrosting trigger time is stably placed within the time range before the start of the freezing breakthrough risk zone, and a continuous correlation is maintained with the frost amount change rhythm and ambient temperature change process in the time series.

[0100] After the forward adjustment is completed, the new defrost trigger time is associated with the freeze surge risk zone and recorded. This allows the specific time point of the defrost trigger time to be determined directly based on the location of the freeze surge risk zone during subsequent operation. This enables defrost scheduling to be completed before the freeze surge occurs, avoiding drastic changes in the operating status in a short period of time and maintaining the continuity and stability of the operation.

[0101] Step 5: For the risk range of freezing sudden advance, perform pre-defrosting control operation within the corresponding time range, and complete the heat recovery process under the constraints of changes in evaporation temperature and ambient temperature. Then restore the original operating rhythm to reduce compressor load fluctuations and energy consumption fluctuations.

[0102] For the risk zone of sudden freezing, pre-defrosting control operations are performed within the corresponding time interval, and the heat recovery process is completed under the constraints of changes in evaporation temperature and changes in ambient temperature. The specific steps are as follows:

[0103] Before the start time of the freezing advance risk zone, based on the defrost trigger time that has been moved forward, the time point corresponding to the trigger time is taken as the start node of the pre-defrost control operation. When the pre-defrost control operation is reached, it is immediately started, and subsequent consecutive time points are processed point by point from this time point. At each time point, the evaporation temperature change value and the ambient temperature change value are extracted synchronously and compared with the corresponding value of the previous time point point by point. The direction and magnitude of the change in evaporation temperature value between adjacent time points are recorded, and the change in ambient temperature value between adjacent time points is also recorded.

[0104] During the execution of the pre-defrosting control operation, time periods in which the evaporation temperature changes continuously rise between consecutive time points, or where the direction of change remains consistent and the magnitude of change does not exceed the preset recovery deviation threshold, are marked. These time periods are then aligned with the time range of the freezing advance risk zone, ensuring that the pre-defrosting control operation always covers the time range corresponding to the freezing advance risk zone. This allows the pre-defrosting control operation to be continuously executed within the freezing advance risk zone, creating a continuous change trajectory for the temperature change process in the time series.

[0105] During the continuous execution of the pre-defrosting control operation, the changes in evaporation temperature and ambient temperature are used as constraints to adjust the heat recovery process point by point. At each time point, the change in evaporation temperature at the current time point is compared with the change in evaporation temperature at the previous time point, and the heat recovery status at the current time point is adjusted in conjunction with the change in ambient temperature at the current time point. When the change in evaporation temperature gradually expands between consecutive time points and the change in ambient temperature continuously decreases at the corresponding time points, the current heat recovery process is maintained to ensure continuous heat recovery within that time period.

[0106] When the change in evaporation temperature reverses direction between consecutive time points, and the change in ambient temperature decreases or stops decreasing at the corresponding time point, the pace of the heat recovery process is adjusted so that the heat recovery process is always constrained by both the change in evaporation temperature and the change in ambient temperature throughout the entire freezing advance risk range.

[0107] In this process, the heat recovery status at each time point is linked to the corresponding changes in evaporation temperature and ambient temperature, and recorded in chronological order. This ensures that the entire heat recovery process forms a continuous record of changes in the time series, thereby completing the heat recovery process before the end of the freezing advance risk zone.

[0108] After the heat recovery process is completed and the end time of the freezing risk zone is reached, the current time point is taken as the operation state transition node. After this time point, the operation process is restored point by point. The operation rhythm before the freezing risk zone is used as a reference. The evaporation temperature change value and the ambient temperature change value at subsequent time points are extracted point by point and compared with the corresponding value at the end time of the freezing risk zone, so that the recovery process unfolds gradually in chronological order.

[0109] During the recovery process, the direction of change in evaporation temperature at each time point is correlated with the direction of change in ambient temperature, so that the operating rhythm gradually returns to the state of change before the risk zone of freezing in the time series, and the continuity of the change process is maintained between consecutive time points.

[0110] By performing pre-defrosting control operations and completing the heat recovery process in advance within the freezing risk range, the evaporation temperature change value remains continuously changing in subsequent time points, thereby reducing the fluctuation of compressor load between adjacent time points throughout the entire operation. At the same time, by synchronously adjusting the ambient temperature change value and the evaporation temperature change value, the energy consumption change remains continuously changing in the time series, thereby reducing compressor load fluctuation and energy consumption fluctuation.

[0111] By introducing a time marker for the humidity surge period and combining it with a segmented comparison relationship of the evaporation temperature change trend, the wet-cold coupling advancement interval is identified. Based on this, a delayed observation period is set to continuously characterize the frost amount change rhythm, so that the defrosting determination no longer depends on a single growth rate change. This allows for accurate differentiation between a phased slowdown and a true stable state during operation, avoiding delays in the defrosting trigger time, ensuring the stability of the heat exchange process during continuous operation, and maintaining the continuity of cooling capacity output.

[0112] By defining the risk range of freezing surge and adjusting the defrost trigger time in advance, the pre-defrost control operation is performed before the freezing surge occurs. At the same time, heat recovery is completed under the constraints of changes in evaporation temperature and ambient temperature, so that the temperature change during operation remains continuous. This reduces the load fluctuation of the compressor during operation, slows down the current change, and keeps the overall energy consumption stable over time.

[0113] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for predicting and controlling the defrosting timing of a refrigeration unit, characterized in that, Includes the following steps: Collect values ​​of ambient humidity, ambient temperature and evaporation temperature changes during the nighttime operation of the chiller. Identify humidity surge segments based on the ambient humidity change values ​​and mark the corresponding time intervals to form time markers for humidity surge segments. Based on the time marker of the humidity surge period, the slope of the evaporation temperature change in the corresponding time interval is extracted and segmented. The evaporation temperature change trend in the corresponding time interval is compared with the evaporation temperature change trend of the adjacent time intervals to determine the humidity-cold coupling advancement interval. Based on the wet and cold coupling propulsion interval, a delayed observation section is defined, and the original defrosting delay judgment state is maintained within the delayed observation section; Based on the delayed observation period, and combined with the rhythm of frost changes and the downward range of ambient temperature changes, the operating status is judged in intervals to define the freezing breakthrough risk interval, and the defrosting trigger time is moved forward according to the freezing breakthrough risk interval. For the risk range of freezing advance, pre-defrosting control operations are performed within the corresponding time range, and the heat recovery process is completed under the constraints of changes in evaporation temperature and changes in ambient temperature.

2. The defrosting timing prediction and control method for a refrigeration unit according to claim 1, characterized in that, The formation of time markers for sudden increases in humidity includes the following steps: Collect data on changes in ambient humidity, ambient temperature, and evaporation temperature during the nighttime operation phase to construct a continuous change trajectory. Based on the continuous change trajectory, the environmental humidity change values ​​at adjacent time points are compared point by point to extract the time range of continuous increase and expanding increase rate, forming the humidity surge segment. By combining the time range corresponding to the sudden increase in humidity, the changes in ambient temperature and evaporation temperature within the corresponding time interval are extracted from the continuous change trajectory, and then combined point by point to form a multi-dimensional data set, while completing the interval labeling. Based on the interval markers, the start and end times of the humidity surge segment and the process of environmental humidity change are integrated and expressed, and a correlation is established with the corresponding position of the continuous change trajectory to form a time marker for the humidity surge segment.

3. The defrosting timing prediction and control method for a refrigeration unit according to claim 2, characterized in that, Methods for creating a sudden increase in humidity include: During the point-by-point comparison of environmental humidity changes at adjacent time points, the time range of continuous increase and expanding increase rate is obtained by recording the change difference point by point and arranging them in chronological order. The position where the increase relationship is interrupted is taken as the end boundary, and the position where the continuous increase begins is taken as the starting time point, forming a humidity surge segment.

4. The defrosting timing prediction and control method for a refrigeration unit according to claim 1, characterized in that, The determination of the wet-cold coupling propulsion range includes the following steps: Extract the evaporation temperature change values ​​within the time interval corresponding to the time marker of the humidity surge, compare the change difference between adjacent time points point by point, and combine the collection time interval to form an evaporation temperature change slope sequence. The evaporation temperature change slope sequence is compared point by point along the time sequence, and segments with the same direction of change and continuously progressive change amplitude are divided. The start time point and end time point are recorded to form the segmented arrangement result. Select the time intervals adjacent to the humidity surge period and extract the corresponding evaporation temperature change values ​​to form a sequence of evaporation temperature change slopes point by point. The evaporation temperature change slope at the corresponding position of the segmented arrangement result is compared point by point with that of the adjacent time interval, and the time range with continuous and consistent change direction is extracted to form the wet and cold coupled advancement interval.

5. The defrosting timing prediction and control method for a refrigeration unit according to claim 4, characterized in that, Methods for generating segmented arrangement results include: During the point-by-point comparison of the evaporation temperature change slope sequence, the time range in which the change direction is consistent and the change amplitude is continuously progressive is formed by continuously recording the change difference between adjacent time points. The position where the change direction reverses is taken as the end time point of the segment, and the starting position of continuous progression is taken as the starting time point of the segment, thus forming the segmented arrangement result.

6. The defrosting timing prediction and control method for a refrigeration unit according to claim 4, characterized in that, The delineation of the delayed observation zone and the characterization of the rhythm of frost amount changes include the following steps: The start and end times of the wet-cold coupling propulsion interval are obtained, and extended along the time sequence to form a continuous time range. The points are then compared point by point with the direction of change of evaporation temperature values ​​to determine the delayed observation section. Within the time-delayed observation period, the changes in evaporation temperature and ambient temperature at each time point are processed to form a continuously arranged sequence of change data. Based on the changing data sequence, the magnitude and direction of change at adjacent time points are continuously recorded and a change trajectory is constructed. The rhythm of frost change is characterized by the correspondence between the change values ​​of evaporation temperature and the change values ​​of ambient temperature.

7. The defrosting timing prediction and control method for a refrigeration unit according to claim 6, characterized in that, During the formation of the change data sequence, the change values ​​of evaporation temperature and the change values ​​of ambient temperature at adjacent time points are bound point by point. The magnitude and direction of change are continuously recorded in chronological order, and the change trajectory is formed by continuous connection to characterize the rhythm of frost amount change.

8. The defrosting timing prediction and control method for a refrigeration unit according to claim 6, characterized in that, The steps for defining the risk zone of freezing and adjusting the defrost trigger time include: The changes in evaporation temperature at adjacent time points are compared point by point, and the magnitude and direction of the changes are recorded. The rhythm is divided into slowing-down and accelerating sections, and rhythm sections are formed. Extract the environmental temperature change values ​​within the delayed observation section and form a continuous recording sequence. Mark the time range of continuous decrease and accumulation of change difference and obtain the downward amplitude. Combine the rhythm section to complete the time alignment. Based on the correspondence between rhythm segments and downward exploration magnitude, the slowdown rhythm segment and the segment where the environmental temperature change value continues to decrease are jointly identified and extended to form the freezing breakthrough risk range. Compare the starting time of the freeze advance risk zone with the original defrost trigger time, move the defrost trigger time forward in chronological order, and establish a correlation with the freeze advance risk zone.

9. The defrosting timing prediction and control method for a refrigeration unit according to claim 8, characterized in that, Methods for establishing a freeze risk zone include: The slowdown zone is formed by comparing the changes in evaporation temperature at adjacent time points. The time range in which the magnitude of change continuously decreases and the direction of change remains consistent is defined as the slowdown zone. This zone is then matched with the zone in which the change in ambient temperature continues to decrease to form the risk zone of sudden freezing.

10. The defrosting timing prediction and control method for a refrigeration unit according to claim 8, characterized in that, The pre-defrosting control operation and heat recovery process includes the following steps: Set the defrosting trigger time after the shift as the start node, continuously record the change value of evaporation temperature and the change value of ambient temperature and compare them point by point, mark the continuous change time period and align it with the freezing rush risk zone in time. Record the direction and magnitude of the evaporation temperature change in chronological order and the corresponding change in ambient temperature to form a continuous change record to constrain the heat recovery process and complete the heat recovery. By referring to the end time of the freezing risk zone, the changes in evaporation temperature and ambient temperature at subsequent time points are compared point by point to restore the operating rhythm of the refrigeration unit along the time series.

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