KR20220041690A - Air heat pump with machine-learned data set and its control methods - Google Patents

Abstract

The present invention is an air source heat pump with a machine-learned data set and a control method thereof and more specifically, to a heat pump in which cooling and heating temperatures are controlled as a result of machine learning based on prepared data sets in a management server or a cloud on the Internet such as temperature and pressure offered according to purposes of installation, and a control method thereof. The air source heat pump comprises: a water pipe passing through an indoor heat exchanger based on environmental management data and control algorithms already collected and analyzed in the management server or cloud, that is, a machine-learned management dataset; a temperature sensor provided at an outlet side of the water pipe to sense leaving water temperature of water flowing through the water pipe; and a control unit operating the compressor at a preset starting frequency during start-up operation and controlling the frequency of the compressor based on a target pressure of a refrigerant cycle after the start-up operation. The control unit determines a target pressure based on a set temperature difference, a difference between an input set temperature and the leaving water temperature sensed by the temperature sensor as a result of machine learning and uses the same.

Description

Air heat pump with machine-learned data set and its control methods

The present invention relates to an air heat pump, that is, an air heat exchanger system, and more particularly, in the case of a facility cultivation greenhouse, when heating variably by season, such as spring, summer, autumn and winter, temperature hunting is prevented. It relates to an air-heated district heating system having a function and a method for controlling the supply temperature of indoor air using the same.

The present invention also relates to an air-heated heat pump capable of minimizing repetitive on-off operation of a compressor through appropriate change of a target pressure of a refrigerant cycle, and a method for controlling the same.

A conventional air heat pump heating/cooling system is a system including a compressor for compressing a refrigerant, an indoor heat exchanger, an expansion valve for expanding the refrigerant, and a heat storage tank for cold and hot water in an outdoor heat exchanger. In addition to this, it is configured to suck air from the outside using an air conditioner on the outside and supply it to the inside by making air suitable for heating and cooling. In summer, the cold water supplied by the cooling and heating load pump cools and dehumidifies the air ventilated from the outside by the cold/hot water heat exchanger to reduce humidity.

However, in the case of conventional greenhouses, the humidity load is much higher than that of a general air-conditioning space, so a lot of dehumidification is required. However, when a large amount of dehumidification is performed, the temperature of the air supplied into the greenhouse is excessively lowered by lowering the temperature as well as the moisture in the cold and hot water heat exchanger. In this way, when air with an excessively lower temperature than the average temperature inside the greenhouse is supplied to the greenhouse, undesirable results such as poor growth of cultivated crops and poor ignition are caused. However, when the temperature difference between ventilation and supply air is reduced in order to prevent the growth and ignition failure of these crops, a very large amount of air must be circulated to handle the cooling load of the greenhouse, so the fan of the air conditioner increases and the fan power increases. In addition, if the number of air rotations is too high, the amount of air bypassed by the cold/hot water heat exchanger increases, which reduces the time for dew to form on the coil, which is disadvantageous in many ways, such as not performing adequate dehumidification.

In addition, when the indoor heat exchanger exchanges heat with indoor air, the indoor air may be heated or cooled through heat exchange with a refrigerant. When the indoor heat exchanger operates as an evaporator, the indoor air passing through the indoor heat exchanger may be cooled by heat exchange with the refrigerant. In contrast, when the indoor heat exchanger operates as a condenser, the indoor air passing through the indoor heat exchanger may be heated by heat exchange with the refrigerant.

In addition, when the indoor heat exchanger and room-temperature water supplied from a water supply source exchange heat, the room-temperature water may be heated or cooled through heat exchange with a refrigerant. In addition, when the indoor heat exchanger operates as an evaporator, room temperature water passing through the indoor heat exchanger may be cooled by heat exchange with the refrigerant. In contrast, when the indoor heat exchanger operates as a condenser, room temperature water passing through the indoor heat exchanger may be heated by heat exchange with the refrigerant.

In addition, the compressor may be formed as a frequency variable compressor, that is, an inverter compressor. However, the frequency of the compressor may be controlled based on a temperature set by the user. For example, a target pressure of a cycle, a high pressure in the case of heating, and a low pressure in the case of cooling may be determined according to the set temperature.

As a heat pump control method as described above, which has already been disclosed in Korean Patent Application Laid-Open No. 10-2007-0031655, the compressor is controlled by calculating a target pressure according to changes in indoor and outdoor temperature. That is, the conventional heat pump does not consider whether the current pressure state of the cycle is high pressure or low pressure, but only calculates and sets the target pressure. Accordingly, the target pressure according to the indoor and outdoor temperature change may be provided in the form of a table. At this time, the target pressure described in the table should be an optimal value determined through an experiment under specific conditions, but the target pressure set in the table cannot achieve optimal efficiency depending on the environment in which the heat pump is installed and the number of times the heat pump is driven. A value may be set, so that a large difference may occur between the target pressure set in the table and the actual pressure depending on the installation environment of the heat pump, or if there is a large difference between the target pressure and the actual pressure of the cycle, the compressor may be relatively Since it can be operated at a high frequency, in such a case, as the room temperature exceeds the set temperature, the compressor is stopped, and as the room temperature falls below the set temperature again, the compressor may be started unintentionally. That is, according to the conventional control method of the heat pump, the current pressure of the refrigerant cycle is not properly taken into account, so that there is a problem in that a lot of on-off of the compressor occurs.

In addition, when the compressor is turned on/off frequently, power consumption is large, and the temperature of the air discharged into the indoor space changes rapidly, that is, the 'hunting of the supply temperature' of the indoor air frequently occurs. There is this.

Here, 'hunting of supply temperature' refers to a systematic phenomenon in which the supply temperature value is not stable at the set value and continuously fluctuates up and down.

An object of the present invention is to provide an air-heated heat pump capable of preventing frequent on-off operation of a compressor by setting an appropriate target pressure in consideration of the current pressure of a refrigerant cycle, and a control method therefor .

Another object of the present invention is to control the supply temperature hunting phenomenon, which makes it difficult to control the heating temperature.

The supply temperature hunting phenomenon refers to a phenomenon in which the heating temperature does not maintain the set temperature and frequently rises and falls above the set temperature. Although it is set as the basic opening rate, if there is a sharp decrease in heating demand such as spring, autumn, and summer or the amount of heating water fluctuates, and the amount of heating water is small, the temperature rises rapidly due to heat exchange.

As such, when the heating temperature is excessively increased, the temperature control valve automatically lowers the opening rate to lower the supply flow rate of medium hot water, thereby lowering the heat exchange rate of the heating water, and accordingly, the heating temperature is lowered again.

When the heating temperature falls, the temperature control valve automatically increases the opening rate to increase the supply flow rate of medium hot water, thereby increasing the heat exchange rate of the heating water, and thus the heating temperature rises again. As these mechanical operations are repeated, the heating temperature changes rapidly, so that the heating of the supply facilities is not performed smoothly. In order to control this temperature hunting phenomenon, a differential pressure valve is installed across the heating water supply pipe and the heating water return pipe, but the differential pressure valve can be controlled only when severe pressure fluctuations occur. Since this phenomenon occurs, it is virtually impossible to solve the supply temperature hunting phenomenon with the differential pressure valve alone.

In addition, as described above, the present invention provides an air-heated heat pump capable of preventing frequent on-off operation of a compressor and a hunting phenomenon in which the water outlet temperature or the temperature of the indoor discharge air changes rapidly, and a control method therefor, thereby providing usability and stability of the heat pump Its purpose is to provide a method that can simultaneously improve the power consumption and reduce power consumption.

The present invention provides an air heat pump including a compressor, an indoor heat exchanger, an expansion valve and an outdoor heat exchanger, and a water pipe passing through the indoor heat exchanger; a temperature sensor provided at the outlet side of the water pipe to sense the water outlet temperature of the water flowing through the water pipe; and a control unit for operating the compressor at a preset starting frequency during the starting operation and controlling the frequency of the compressor based on the target pressure of the refrigerant cycle after the starting operation, wherein the control unit includes the input set temperature and the temperature sensor It provides a control unit of the air heat pump, characterized in that for determining the target pressure based on a set temperature difference that is a difference between the detected water outlet temperature.

When it is determined that the set temperature difference is less than a preset first value in the middle of the starting operation, the control unit changes the target pressure to a current high pressure or a current low pressure of the refrigerant cycle based on an operation mode, and starts the starting operation in advance. It can be stopped before the end of the operating time, and the frequency of the compressor can be controlled for a preset normal operating time based on the changed target pressure.

Accordingly, when the set temperature difference is equal to or greater than the first value after the normal operation time has elapsed, the control unit sets the target pressure to a pressure determined according to the set temperature to control the frequency of the compressor, and after the normal operation time elapses, the When it is determined that the set temperature difference is less than the first value, the target pressure is changed back to the current high pressure or the current low pressure of the refrigerant cycle based on the operation mode.

In addition, the control unit, after changing the target pressure back to the current high pressure or the current low pressure of the refrigerant cycle, corrects the changed target pressure based on the set temperature difference and the set temperature difference change rate according to time, and a normal operation time based on the corrected target pressure while controlling the compressor.

In addition, if it is determined that the set temperature difference is less than or equal to a preset second value after the normal operation time has elapsed, the control unit may correct the target pressure based on the set temperature difference and the set temperature difference change rate according to time, but the set temperature difference exceeds the second value If it is determined that the target pressure is set, the frequency of the compressor may be controlled by setting the target pressure to a pressure determined according to a set temperature. Meanwhile, the second value is preferably larger than the first value.

In addition, the present invention is a starting operation step in which the compressor is operated at a preset starting frequency; a normal operation start step of controlling the compressor for a preset normal operation time based on the target pressure of the refrigerant cycle; and a normal operation repeating step in which the target pressure is reset based on a set temperature difference that is a difference between the input set temperature and the water outlet temperature sensed by the temperature sensor, and the compressor is controlled during the normal operation time based on the set target pressure; An object of the present invention is to provide a method for controlling an air-heated heat pump comprising a.

The above-described starting operation step may include a first starting operation step in which the compressor is operated at the starting frequency for a first time and a starting operation end determination step of determining whether the set temperature difference is less than a preset first value. .

And, the normal operation start step is a first target pressure change step of changing the target pressure to the current high pressure or the current low pressure of the refrigerant cycle based on the operation mode when the set temperature difference is determined to be less than the first value in the starting operation end determination step may include

In addition, the starting operation step may further include a second starting operation step in which the compressor is operated at the starting frequency for a second time when the set temperature difference is determined to be equal to or greater than the first value in the starting operation end determination step.

*

And, the normal operation starting step can be solved by further including a first target pressure determining step in which the target pressure is set to a pressure determined according to a set temperature after the second starting operation step.

The normal operation repeating step may include: a first determination step of determining whether the set temperature difference is less than a preset first value; and a second target pressure changing step of changing the target pressure to the current high pressure or the current low pressure of the refrigerant cycle based on the operation mode when it is determined in the first determination step that the set temperature difference is less than the first value, After the second target pressure changing step, the target pressure correction step of correcting the changed target pressure based on the set temperature difference and the set temperature difference change rate according to time and controlling the compressor during the normal operation time based on the corrected target pressure. can

The normal operation repeating step may further include a second determination step of determining whether the set temperature difference exceeds a preset second value greater than the first value after the target pressure correction step.

In addition, when it is determined that the set temperature difference is equal to or less than the second value in the second determination step, the process may return to the target pressure correction step.

In addition, in the normal operation repetition step, when it is determined that the set temperature difference is equal to or greater than the first value in the first determination step or it is determined that the set temperature difference exceeds the second value in the second determination step, the target pressure is set to the set temperature The method may further include a second target pressure determining step of setting a pressure determined according to the .

Accordingly, in the first target pressure determination step and the second target pressure determination step, the target pressure may be set based on a preset first table that matches the pressure corresponding to each set temperature. In the target pressure correction step, the target pressure is It may be set based on a preset second table in which the set temperature difference and the correction value corresponding to the set temperature difference change rate are matched.

The first time and the second time as described above are preferably determined by selecting a simple moving average of past data, exponential smoothing for seasonal trend analysis, or machine learning.

According to the present invention, it is possible to provide an air-heated heat pump capable of preventing frequent on-off operation of a compressor by setting a target pressure in consideration of the current pressure of a refrigerant cycle, and a method for controlling the same.

In addition, according to the present invention, it is possible to provide an air-heated heat pump capable of reducing power consumption by preventing frequent on-off operation of the compressor, and a method for controlling the same.

In addition, the present invention can provide an air-heated heat pump capable of preventing a hunting phenomenon in which the temperature of the discharge water or the temperature of the indoor discharge air rapidly changes by preventing the repetitive on-off operation of the compressor, and a method for controlling the same.

1 is a view showing a conventional method for controlling an air-heated heat pump.
2 is a view showing an air heat heat pump according to an embodiment of the present invention.
3 is a view showing a connection relationship of main components included in the air heat heat pump according to the embodiment of the present invention.
4 is an azure machine learning studio for time-series data analysis machine learning of an auto-regressive integrated moving average (ARIMA) method for predicting a target water outlet temperature of an air heat pump according to an embodiment of the present invention; It is a flow chart of the procedure.
5 is a simple moving average and seasonality in order to estimate the target water temperature for 2019 and 2020 based on the monthly water temperature past data secured by the applicants from 2014 to 2018 as an embodiment of the present invention; It is a graph of the results of an exponential smoothing model including ETS (exponential smoothing) prediction technique and machine-learning time series analysis.
6 is a flowchart illustrating a control method of an air-heated heat pump according to an embodiment of the present invention.

Hereinafter, an air conditioner and a control method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

The accompanying drawings show exemplary forms of the present invention, which are only provided to explain the present invention in detail, and are not intended to limit the technical scope of the present invention.

In addition, regardless of the reference numerals, the same or corresponding components are given the same reference numbers and redundant description thereof will be omitted, and for convenience of description, the size and shape of each component shown may be exaggerated or reduced. there is.

2 is a view showing an air heat heat pump according to an embodiment of the present invention.

Hereinafter, for convenience, the description is limited to the case where the refrigerant exchanges heat with room temperature water in the indoor heat exchanger, but it is obvious that the same principle can be applied to the case where the refrigerant and the indoor air exchange heat in the indoor heat exchanger.

Referring to FIG. 2 , the heat pump 10 according to the embodiment of the present invention includes a compressor 100 , an indoor heat exchanger 200 , a water pipe 250 connected to the indoor heat exchanger 200 , and an expansion valve 300 . ), and an outdoor heat exchanger 400 . And in the illustrated embodiment, "I" may represent an indoor unit and "O" may represent an outdoor unit. In FIG. 2 , the expansion valve 300 is illustrated as being provided in the indoor unit I, but the expansion valve 300 may also be provided in the outdoor unit O. As shown in FIG.

The compressor 100 is configured to compress the refrigerant. That is, the compressor 100 may be formed to pressurize a low-temperature and low-pressure refrigerant into a high-temperature and high-pressure refrigerant. One or more compressors 100 may be provided in the heat pump 10 .

When a plurality of the compressors 100 are provided in the heat pump 10, the plurality of compressors may be provided in series or in parallel along the flow direction of the refrigerant, and may have a variable frequency. That is, the compressor 100 may be an inverter compressor. The indoor heat exchanger 200 may be formed to exchange heat between the refrigerant and the indoor air. That is, in the indoor heat exchanger 200 , the refrigerant and the indoor air may exchange heat with each other. For example, the indoor heat exchanger 200 may perform a function of an evaporator in a cooling mode of the heat pump 10 and a function of a condenser in a heating mode.

The expansion valve 300 may be formed to depressurize the refrigerant. For example, the expansion valve 300 may be provided between the indoor heat exchanger 200 and the outdoor heat exchanger 400 .

The expansion valve 300 may be formed to expand the refrigerant that has passed through a heat exchanger operating as a condenser among the indoor heat exchanger 200 and the outdoor heat exchanger 400 . That is, the expansion valve 300 may be formed to expand the refrigerant that has passed through the heat exchanger operating as the condenser and guide it toward the heat exchanger operating as the evaporator.

The outdoor heat exchanger 400 may be formed to exchange heat with the refrigerant and outdoor air. That is, in the outdoor heat exchanger 400 , the refrigerant and outdoor air may exchange heat with each other. For example, the outdoor heat exchanger 400 may perform a function of a condenser in a cooling mode of the heat pump 10 and a function of an evaporator in a heating mode.

In the water pipe 250 , room temperature water supplied from a water supply source may flow in one direction. Water flowing through the water pipe 250 may exchange heat with the refrigerant in the indoor heat exchanger 200 .

The outdoor heat exchanger 400 may be formed to exchange heat with external air or with cooling water. When the outdoor heat exchanger 400 is formed to exchange heat with external air, an outdoor fan (not shown) may be provided at one side of the outdoor heat exchanger 400 .

The heat pump 10 may include an accumulator 500 that separates the refrigerant flowing into the compressor 100 into a gaseous refrigerant and a liquid refrigerant and supplies only the gaseous refrigerant to the compressor 100 .

The accumulator 500 may be provided in front of the compressor 100 . The accumulator 500 is formed to separate only the gaseous refrigerant from the abnormal refrigerant that is evaporated in the indoor heat exchanger 200 or the outdoor heat exchanger 400 and is directed to the compressor 100 to guide it to the compressor 100 .

The heat pump 10 may include a flow path switching valve 600 for switching the circulation direction of the refrigerant when the cooling mode and the heating mode are switched. The flow path switching valve 600 may be formed as a four-way valve. For example, the flow path switching valve 600 may be configured to guide the refrigerant discharged from the compressor 100 to the outdoor unit in the cooling mode, and guide the refrigerant discharged from the compressor 100 to the indoor unit in the heating mode.

The frequency of the above-described compressor 100 may be controlled based on a set temperature input by a user. For example, when a set temperature is input, a target pressure of a refrigerant cycle corresponding to the set temperature may be determined, and the frequency of the compressor 100 may be controlled based on the target pressure.

The target pressure corresponding to the set temperature may be determined based on a simple moving average of past data, seasonal trend analysis, or machine learning, and may be prepared in advance in the form of a table, that is, as a data set. And it is preferable to store the past data in the management server and the cloud.

In addition, when the temperature of the room temperature water flowing through the water pipe 250 is higher than the set temperature, the operation of the compressor 100 may be stopped. And, when the temperature of the room temperature water drops to a certain level or more, the operation of the compressor 100 may be resumed. That is, when the target pressure corresponding to the set temperature provided in the table cannot reflect the installation environment or the age of use of the heat pump 10 , a problem in which the compressor 100 is frequently turned on and off may occur.

An object of the present invention is to solve the frequent on-off problem of the compressor 100 and to provide a heat pump 10 capable of continuously driving the compressor 100 while maintaining the temperature of room temperature water close to a set temperature.

The air heat heat pump 10 according to the embodiment of the present invention includes a temperature sensor 710 for detecting the outlet temperature of room temperature water, a first pressure sensor 720 for detecting a low pressure of a refrigerant cycle, and a first pressure sensor for detecting a high pressure of the refrigerant cycle. 2 may include a pressure sensor 730 .

The temperature sensor 710 may be provided at the outlet side of the water pipe 250 . That is, the temperature sensor 710 may be disposed on the water pipe 250 to sense the outlet temperature, which is the temperature after the room temperature water has passed through the indoor heat exchanger 200 .

The first pressure sensor 720 may be provided on the inlet side of the compressor 100 to sense the low pressure of the refrigerant cycle. In addition, the second pressure sensor 730 is preferably provided at the outlet side of the compressor 100 to sense the high pressure of the refrigerant cycle.

The air heat pump 10 according to the embodiment of the present invention may further include a control unit C to be described later for controlling the above-described compressor 100 .

Hereinafter, the control of the compressor 100 based on the set temperature and the water outlet temperature will be described with further reference to other drawings.

3 is a view showing a connection relationship of main components included in the air heat heat pump according to the embodiment of the present invention.

2 and 3 together, the controller C may control the compressor 100 and the expansion valve 300 described above. And the control unit (C) may be electrically connected to the command input unit 800, the temperature sensor 710, the first pressure sensor 720 and the second pressure sensor 730 to which a control command is input by the user. there is.

In addition, the control unit (C) stores the fixed value of the target pressure corresponding to the set temperature as a data set in the form of a table, and a correction value of the target pressure according to the set temperature difference, which is the difference between the set temperature and the water outlet temperature. It can be electrically connected to machine learning (M) to store in the form of a table.

In addition, the machine learning (M) is preferably used as an execution space of the Azure machine learning studio according to the present invention as well as storing past data as a past data management server or a cloud server.

To explain this in more detail, the data set of the fixed value of the target pressure corresponding to the set temperature is indicated as the first data set, and the data of the correction value of the target pressure according to the set temperature difference, which is the difference between the set temperature and the actual water outlet temperature The set is defined as the second dataset.

In the first data set, a set temperature and a fixed target pressure corresponding thereto may be provided in a 1:1 correspondence.

Also, in the second data set, a correction value of the target pressure according to the change rate of the set temperature and the set temperature difference may be provided.

Here, a method of setting the target water outlet temperature and pressure by the machine learning data set executed in the machine learning (M) that constitutes the feature of the present invention will be described in detail.

In the present invention, time series pattern analysis is preferable because actual information from the past can be used to set the target water outlet temperature and pressure, and the pattern of such information will continue in the future. In particular, since four distinct seasons exist in Korea, in order to adopt such a time series pattern analysis, the concepts of words such as "trend" and "seasonality" that have been used so far must be defined more specifically.

- trend

When data increases or decreases over the long term, a trend exists. The trend is not necessarily linear. However, when a trend changes from an increase to a decrease from time to time, it can be said that the trend has "changed direction". That is, there is a trend in the set temperature data of the present invention.

- seasonality

A pattern of seasonality appears when the same factors that occur in a specific season at a specific time of year or season influence the time series. Seasonality comes in the form of a frequency, the frequency of which is always constant and known. The water outlet temperature according to the present invention exhibits seasonality, which is due to fluctuations in outdoor temperature.

- cycle

A cycle appears when it increases or decreases in a form that is not a fixed frequency. Usually these fluctuations are caused by economic conditions and are often related to the “business cycle”. Usually, the duration of these fluctuations is at least 2 years.

It is not possible to confuse periodic patterns with seasonal patterns. That is, fluctuations that do not appear at a constant frequency are periodic. If the frequency does not change and is associated with some time of the year, then the fluctuation is seasonal. In general, the average length of the periods is longer than the length of the seasonal pattern, and the size of the period tends to be more volatile than the size of the seasonal pattern.

Many time series have trend, seasonality, and cycle. It is preferable to choose a technique.

Accordingly, in the present invention, as an embodiment, statistical prediction is performed by simple moving average, exponential smoothing model including seasonality, ETS (exponential smoothing) prediction technique, and machine learning (machine learning) time series analysis, and statistical prediction as described above Let's compare the mean absolute error (MAE) for the accuracy of each.

However, for this, the concepts of AE and MAE must first be accurately explained.

AE (absolute error) is the difference between the actual value and the predicted (measured) value.

Δx = xi-x

xi - measured value / x - actual value

Mean Absolute Error is the average of all absolute errors. Its formula is as follows.

n = number of errors

∑ = symbol for sum

|xi-x| = absolute error

As the first prediction technique, the simple moving average method is executed with the past data collected so far, and the average is determined to what extent, that is, n. In the above simple moving average method, tomorrow's figure is the average of the last few days, and the formula is as follows.

In addition, the concept of the exponential smoothing model is that a certain percentage of tomorrow's values is today's value, and the 'constant percentage' is the sum of today's forecast values. There is a task to find the α that best reproduces the current data, such as n of the average method or the weight of the weighted moving average method. Its formula is as follows:

Calculation of the exponential smoothing method in this embodiment is Microsoft Excel's FORECAST.ETS. By using the SEASONALITY function, the seasonality value used as an option in the FORECAST.ETS function was calculated. That is, the classification of the above function is 'time series to be predicted, existing value range, existing time series range, [seasonality], [missing data processing], [duplicate time series processing])', and the explanations for each of the above arguments are as follows.

- Time series to predict

The reference time series value to predict. This value can be a date, time, or number. If the target date is earlier than the last value of the existing time series range, the #NUM! returns an error

- Existing value range

It is the range of values previously input to calculate the value of the reference time series to be predicted.

- Existing time series range

This is the previously entered time series range. For the time series range, the variance must be greater than zero. That is, if all input time series values are the same, the FORECAST.ETS function returns #NUM! returns an error

- Seasonality [optional argument]

When analyzing with exponential smoothing algorithm, it is decided with how many cycles to predict the data.

ㅇ Default is 1 or blank

ㅇ When the seasonality factor is greater than 2: Predict the data in the corresponding period

ㅇ When the seasonality factor is 0: Linear prediction assuming there is no period

ㅇ If the seasonality factor is 1 or blank: Excel automatically predicts the seasonality

- Processing of missing data [optional argument]

It determines how to handle missing data in the existing time series range.

ㅇ Default is 1 or blank

ㅇ When the missing data processing argument is 1 or empty: Missing data is calculated as the average value of surrounding data

ㅇ When the missing data processing factor is 0: Calculated by considering missing data as 0

- Duplicate time series processing [optional argument]

If there is missing time series data, it is necessary to decide how to calculate the missing value from values located in the same period.

ㅇ Default is 1 or blank

ㅇ 1 or blank: AVERAGE (reflected as average)

ㅇ 2: CㅇUNT (counts and reflects only non-blank numbers)

ㅇ 3: C0UNTA (counts and reflects the number of all non-blank values)

ㅇ 4: MAX (only the maximum value is reflected)

ㅇ 5: MEDIAN (reflected as an intermediate value)

ㅇ 6: MIN (only the minimum value is reflected)

ㅇ 7: SUM (reflects the total)

And, in the machine learning embodiment of the present invention, Azure Machine Learning Studio was used as time series data analysis machine learning of ARIMA (auto-regressive integrated moving average) method. However, we Azure Machine Learning Studio is a data science technology that predicts future behavior, results, and trends using existing data on a computer. It helps build smarter apps and devices.

The azure machine learning can be used for all kinds of machine learning from traditional machine learning to deep learning, supervised learning and autonomous learning, and can be used in Python or Azure Machine Learning Studio used in this example because you can build, train, and track machine learning and deep learning models in the Azure Machine Learning workspace, whether you are writing R code or working with no-code or low-code options in the studio. is Azure Machine Learning's web portal to low-code and no-code options for model training, deployment, and asset management. The Azure Machine Learning Studio features integration with Azure Machine Learning Development Kit (SDK) for a seamless experience. And if you have a suitable model, you can easily use that model in a web service, IoT device, or Power BI.

You can then manage your deployed models using Azure Machine Learning Development Tools (SDK) for Python, Azure Machine Learning Studio, or machine learning command-line interface (CLI), making those models available and mass-produced. It can return predictions on data in real-time or asynchronously, and use advanced machine learning pipelines to collaborate at each stage, from data preparation to model training, evaluation, and deployment. There is something different about the method.

The Azure Machine Learning workspace is the primary resource in the cloud used to experiment, train, and deploy machine learning models, connecting Azure subscriptions and resource groups to easy-to-use entities in the service. An Enterprise version workspace is created through the Azure portal, which is a web-based console for managing the Azure resources. In case of machine learning work with Azure Machine Learning Studio, first, the machine learning web service is created, managed, and monitored. The above procedures are managed by the Azure Machine Learning Web Service Management Portal, and monitored and verified on the Azure Portal.

First, a new work area must be created in the Azure portal, and information as shown in Table 1 below must be provided to the new work area.

The operation procedure in Azure Machine Learning Studio for machine learning according to the present invention will be sequentially described as follows using the flowchart of FIG. 5 .

(P100) Select Dataset and upload ShipLog.csv file. After selecting a module from the left panel, drag and drop it on the center panel (palette) to use the module.

(P200) Drag and drop the module to execute the R script as well.

(P210) Import Data Input past data.

(P300) Add the Select Columns in Dataset module.

(P400) Edit Metadata module is added. Specifies the name of the new column name.

Some of the data is also fetched and used through a URL. You can have it as a Dataset and use it right away.

(P410) Add the Datasets module of the text.preprocessing.zip file.

(P500) Execute R Script Add R script module.

(P600) Add Split Data module. It is desirable to set the split ratio to 7:3.

(P700, P701) Add Feature Hashing module.

(P800, P801) Select Columns in Dataset. Select a column in the dataset.

(P900) Add the most important Train Model module. And select the model to be trained on the left. Here, Multiclass Decision Forest (①) is selected.

(PA00) Add the Score Model module. The remaining data of Split Data is connected to the 2nd input of Score Model.

(PB00) Add the Evauate Model module. Then the completed palette will appear.

Then, finally, run Run, and when it is completed, click Evaluate Model > Evaluation Results > Visualize. As a result, the evaluation results learned with Multi-class Decision Fores (①) are displayed.

The evaluation table for the results of estimating the target water temperature for 2019 and 2020 based on the monthly water temperature data secured by the applicants from 2014 to 2018 is as follows.

MAE is the mean absolute error, which is the average of all absolute errors.

5 is a graph showing the estimation results for each of the above examples.

However, first, looking at the MAE values in Table 2 above, the simple moving average is 11.43% and the exponential smoothing method is 8.80%, but the result of machine learning by the ARIMA method time series data analysis method according to the present invention is 8.43%, each 0.36%P. , about 3.%P is excellent.

In addition, as shown in FIG. 5 , it can be visually determined that the trend of the machine-learned prediction result according to the present invention is relatively superior to that of the other two methods.

This will be described again with reference to FIGS. 2 and 3 together. Originally, the air heat pump 10 is driven in the order of a starting operation, a normal operation, and a repeated normal operation. However, in the starting operation, the compressor 100 may be operated at a preset starting frequency.

However, the starting operation may refer to an operation in a preparation stage for operating the refrigerant cycle in a normal state. During normal operation and during repeated normal operation, the frequency of the compressor 100 may be controlled based on the target pressure. For example, as the target pressure increases, the frequency of the compressor 100 may increase. That is, the control unit C may operate the compressor 100 at a preset starting frequency during the starting operation. In addition, the control unit C may control the frequency of the compressor 100 based on the target pressure of the refrigerant cycle after the start-up operation. In this case, the target pressure may be determined based on a set temperature difference that is a difference between the set temperature and the water outlet temperature. More specifically, when the set temperature difference is less than a preset first value during the start-up operation, the target pressure may be changed to a current high pressure or a current low pressure of the refrigerant cycle. The first value may be 0. That is, when the set temperature difference is less than the first value, the outlet water temperature can be adjusted to the desired temperature even if the high or low pressure of the current refrigerant cycle is flexibly set as the target pressure regardless of the set temperature. In other words, when it is determined that the set temperature difference is less than the first value in the middle of the starting operation, the control unit C sets the target pressure based on the operation mode to the current high pressure or current of the refrigerant cycle, not the pressure determined according to the set temperature. It can be changed to low pressure. For example, in the heating mode, the target pressure may be changed to a current high pressure, and in the cooling mode, the target pressure may be changed to a current low pressure. In this case, the current low pressure and the current high pressure may be sensed by the first and second pressure sensors 720 and 730 described above.

Also, when it is determined that the set temperature difference is less than the first value during the starting operation, the control unit C may stop the starting operation before the end of the preset starting operation time. In addition, the control unit C may control the frequency of the compressor 100 for a preset normal operation time based on the changed target pressure.

Therefore, according to the present invention, it is possible to prevent an unnecessary increase in the frequency of the compressor 100 and, at the same time, reduce power consumption to a significant level by shortening the start-up operation time.

In addition, according to the present invention, frequent on-off problems of the compressor 100 caused by a sudden increase in the frequency of the compressor 100 can be prevented.

Meanwhile, the control unit C may compare the set temperature difference with the first value again after the normal operation time has elapsed. In this case, when it is determined that the set temperature difference is less than the first value, the controller C may change the target pressure back to the current high pressure or the current low pressure of the refrigerant cycle based on the operation mode. That is, if the controller C determines that the set temperature difference is less than the first value after the normal operation time has elapsed, the frequency of the compressor 100 may be controlled during the normal operation time based on the changed target pressure again. .

As described above, according to the present invention, the data set is basically provided in the form of a table in which the target pressure based on the machine-learned set temperature is set, and the target pressure of the refrigerant cycle can be actively adjusted according to the installation environment or service life of the heat pump 10 . there is. After the target pressure is changed again, the changed target pressure may be corrected by the controller C based on the set temperature difference and the set temperature difference change rate according to time. In addition, the compressor 100 may be controlled by the controller C during the normal operation time based on the corrected target pressure.

Here, the rate of change of the set temperature difference according to the time may mean a rate of change of the set temperature difference before and after the normal operation time.

In addition, if the set temperature difference is less than or equal to a preset second value greater than the first value after the normal operation time elapses again, the target pressure is corrected again based on the set temperature difference and the set temperature difference change rate according to time, and based on the corrected target pressure Thus, the compressor 100 can be controlled. In contrast, when the set temperature difference exceeds the second value, the target pressure is set to a pressure determined according to the set temperature, and the frequency of the compressor 100 is controlled by the controller C based on the set target pressure. This can be controlled to increase the target pressure based on the set temperature when the set temperature difference exceeds the second value to reduce the set temperature difference at a relatively high speed.

Hereinafter, a method of controlling an air-heated heat pump according to an embodiment of the present invention will be described in detail with reference to other drawings.

6 is a flowchart illustrating a method for controlling an air-heated heat pump according to an embodiment of the present invention.

Referring to FIG. 6 , in the control method of the heat pump according to the embodiment of the present invention, the starting operation step (S10) in which the circulation of the refrigerant through the refrigerant cycle starts, and the normal operation in which the refrigerant starts to circulate the refrigerant cycle in a normal state It may include a step (S20), and a normal operation repetition step (S30) in which the refrigerant circulation in a normal state is repeated.

In the starting operation step (S10), the compressor 100 is controlled to a preset starting frequency.

In the normal operation start step ( S20 ), the compressor may be controlled for a preset normal operation time based on the target pressure of the refrigerant cycle. It is preferable to set an appropriate time by machine learning the set normal operation time as well.

And in the normal operation repetition step (S30), the target pressure is reset based on the set temperature difference, which is the difference between the set temperature input by the user and the water outlet temperature sensed by the temperature sensor 710, and based on the set target pressure, the compressor ( 100) can be controlled during normal operation time. That is, it is preferable that the target pressure determined in the normal operation start step S20 is reset based on the set temperature difference in the normal operation repetition step S30 .

The starting operation step (S10) is a first starting operation step (S110) in which the compressor is operated at the starting frequency for a first time and a starting operation end determination step of determining whether the set temperature difference is less than a preset first value (A) (S120) may be included.

In the first starting operation step S110 , power is input to the heat pump 10 , and driving of the compressor 100 may be started. In the starting operation end determination step ( S120 ), whether the set temperature difference is less than a set first value (A) may be determined by the control unit (C).

The normal operation starting step S20 may include a first target pressure changing step 210 of changing the target pressure to the current high pressure or low pressure of the refrigerant cycle based on the operation mode.

The first target pressure change step S210 may be performed when it is determined that the set temperature difference is less than the preset first value A in the start operation end determination step S120 . That is, when it is determined that the set temperature difference is less than the first value A in the start operation end determination step S120 , the target pressure is set based on the operation mode in the first target pressure change step S210 , the current of the refrigerant cycle. It can be changed to high pressure or current low pressure. For example, in the heating mode, the target pressure may be changed to the current high pressure of the refrigerant cycle, and in the cooling mode, the target pressure may be changed to the current low pressure of the refrigerant cycle. In addition, the current low pressure and high pressure of the refrigerant cycle may be detected by the first and second pressure sensors 720 and 730 .

Therefore, if the set temperature difference is less than the first value (A) after the first starting operation step (S110), the starting operation step (S10) is immediately terminated and the normal operation starting step (S20) proceeds, so unnecessary Power consumption can be prevented.

In addition, when the set temperature difference is less than the first value (A) after the first starting operation step (S110), the target pressure is not determined according to the set temperature, but the target temperature is determined or changed according to the current high or low pressure. It is possible to prevent the frequency increase of the compressor 100 and the repetitive on-off driving of the compressor 100 . On the other hand, the starting operation step (S10) may further include a second starting operation step (S130) after the starting operation end determination step (S120).

In the second starting operation step ( S130 ), the compressor 100 may be operated at the starting frequency for a second time. In this case, the second time period may be the same as the first time period. That is, in the starting operation step (S10), when the set temperature difference is determined to be equal to or greater than the first value (A) in the starting operation end determination step (S120), the compressor 100 is operated at the starting frequency for a second time. 2 may include a starting operation step (S130).

In addition, the normal operation starting step (S20) may further include a first target pressure determining step (S220) in which the target pressure is set to a pressure determined according to a set temperature after the second starting operation step (S130). there is. That is, in the first target pressure determination step ( S220 ), the target pressure of the refrigerant cycle may be determined based on a first table prepared to match the set temperature and the target pressure. The first table may be provided in advance in machine learning (M) to match the pressure corresponding to the set temperature.

The first table is preferably provided so that the higher the set temperature, the higher the target pressure. On the other hand, the above-described normal operation repetition step (S30) is a first determination step (S310) of determining whether the set temperature difference is less than the first value (A) and if the set temperature difference is less than the first value (A), the operation mode is A second target pressure change step ( S330 ) of changing the target pressure to the current high pressure or the current low pressure of the refrigerant cycle may be included based on the step S330 .

Therefore, even in the normal operation repetition step (S30), when the set temperature difference is less than the first value (A), the target pressure is not determined according to the set temperature, but the target temperature is determined or changed according to the current high or low pressure, so unnecessary It is possible to prevent the frequency increase of the compressor 100 and the repetitive on-off driving of the compressor 100 . The repeating normal operation step ( S30 ) may further include a target pressure correction step ( S330 ) after the second target pressure changing step ( S320 ).

In the second target pressure changing step S320 , the target pressure may be corrected based on the set temperature difference and the set temperature difference change rate over time in the target pressure correcting step S330 .

And, it is preferable that the compressor 100 is controlled during the normal operation time based on the corrected target pressure. The change rate of the set temperature difference according to the time may mean the rate of change of the set temperature difference before and after the normal operation time. It is desirable to determine the normal operation time by machine learning.

In the target pressure correction step (S330), it is preferable that the target pressure of the refrigerant cycle is corrected based on the second table in which correction values corresponding to the set temperature difference and the set temperature difference change rate are provided.

The second table may be prepared in advance in machine learning (M) to match the set temperature difference and the correction value corresponding to the set temperature difference change rate. That is, it is preferable that the target pressure changed to the current high pressure or the current low pressure in the second target pressure change step S320 is corrected again through the target pressure correction step S330 .

Therefore, according to the above method, it is possible to prevent hunting at the outlet temperature of the water that has exchanged heat with the refrigerant in the indoor heat exchanger.

The normal operation repetition step (S30) is a second determination step of determining whether a set temperature difference exceeds a preset second value (B) greater than the first value (A) after the target pressure correction step (S330) ( S340) may be further included.

If it is determined in the second determination step S340 that the set temperature difference is equal to or less than the second value B, the process may return to the target pressure correction step S330. That is, if it is determined in the second determination step (S340) that the set temperature difference is equal to or less than the second value (B), based on the target pressure set temperature difference and the set temperature difference change rate over time through the target pressure correction step (S330) can be corrected. And, based on the corrected target pressure, the frequency of the compressor 100 may be controlled during the normal operation time. Meanwhile, the normal operation repetition step S30 may further include a second target pressure determination step S350 in which the target pressure is set to a pressure determined according to a set temperature.

As described above, when it is determined that the set temperature difference is equal to or greater than the first value (A) in the first determination step (S310) or it is determined that the set temperature difference exceeds the second value (B) in the second determination step (S340) The second target pressure determination step S350 may be performed.

In the second target pressure determination step S350 , similarly to the first target pressure determination step S220 , the target pressure of the refrigerant cycle may be determined based on a first table prepared to match the set temperature and the target pressure.

Since the target pressure was changed to the current high pressure or the current low pressure through the second target pressure changing step S320 before the second determination step S340, the first value compared with the set temperature difference in the first determination step S310 ( It is preferable that the second value (B) compared with the set temperature difference in the second determination step (S340) is larger than A).

This is, after the target pressure is changed to the current high pressure or the current low pressure through the second target pressure change step (S320), the target pressure is finely corrected through the target pressure correction step (S330) as much as possible to control the hunting of the outlet temperature and the compressor. This is because it is desirable to prevent repeated driving stops. Nevertheless, when the set temperature difference is large enough to exceed the second value (B) in the second determination step ( S340 ), in order to relatively quickly reduce the set temperature difference, the second target pressure determination step ( S350 ) is set through the The target pressure may be determined based on the first table, that is, the data set in which the temperature and the target pressure are matched.

The method of controlling an air-heated heat pump according to an embodiment of the present invention may further include a step (S360) of determining whether a stop signal of the air-heated heat pump is input after the second target pressure determination step (S350). At this time, the normal operation repeating step (S30) may be repeatedly performed until a stop signal of the air heat pump is input.

According to the present invention through the above process, frequent on-off operation of the compressor and hunting of the water outlet temperature or the indoor discharge air temperature can be prevented by setting the target pressure in consideration of the current pressure of the refrigerant cycle of the air heat pump. .

Also, according to the present invention, power consumption can be reduced by setting the target pressure in consideration of the current pressure state. In particular, since the current high pressure or the current low pressure is set as the target pressure based on the set temperature difference in the starting operation stage of the air heat pump, unnecessary starting operation time in the starting operation stage can be reduced.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration only, and various modifications, changes, and additions may be made by those skilled in the art within the spirit and scope of the present invention. Modifications and additions should be considered to fall within the scope of the following claims.

2 and 3,
100 Compressor 200 Indoor Heat Exchanger
250 Water pipe 300 Expansion valve
400 Outdoor Heat Exchanger 500 Accumulator
600 Euro changeover valve 710 Temperature sensor
720 first pressure sensor 730 second pressure sensor

Claims (15)

an air heat heat pump including a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger, the water pipe passing through the indoor heat exchanger;
a temperature sensor provided at the outlet side of the water pipe to sense the water outlet temperature of the water flowing through the water pipe; and
The compressor starts at a preset starting frequency and includes a control unit for controlling the frequency of the compressor based on the target pressure of the refrigerant cycle after the starting operation,
The controller determines the target pressure based on a set temperature difference that is a difference between the input set temperature and the water outlet temperature sensed by the temperature sensor, and determines that the set temperature difference is less than a preset first value during the starting operation when it is, the air heat pump, characterized in that the target pressure is changed to the current high pressure or the current low pressure of the refrigerant cycle based on the operation mode. The method of claim 1,
The control unit stops the starting operation before the end of the preset starting operation time, and controls the frequency of the compressor based on the changed target pressure during the preset normal operation time. 3. The method of claim 2,
When the set temperature difference is equal to or greater than the first value after the normal operation time has elapsed, the control unit sets the target pressure to a pressure determined according to the set temperature to control the frequency of the compressor. 4. The method of claim 3,
When it is determined that the set temperature difference is less than the first value after the normal operation time has elapsed, the control unit changes the target pressure back to the current high or low pressure of the refrigerant cycle based on the operation mode. 5. The method of claim 4,
The control unit, after changing the target pressure back to the current high or low pressure of the refrigerant cycle, corrects the changed target pressure based on the set temperature difference and the set temperature difference change rate according to time, and based on the corrected target pressure during normal operation time Air-heated heat pump, characterized in that for controlling the compressor. 6. The method of claim 5.
If it is determined that the set temperature difference is less than or equal to a preset second value after the normal operation time has elapsed, the control unit corrects the target pressure based on the set temperature difference and the set temperature difference change rate according to time, and the set temperature difference exceeds the second value when it is determined that the target pressure is set to a pressure determined according to a set temperature, the frequency of the compressor is controlled, and the second value is greater than the first value. a starting operation step in which the compressor is operated at a preset starting frequency;
a normal operation start step of controlling the compressor for a preset normal operation time based on the target pressure of the refrigerant cycle; and
The target pressure is reset based on the set temperature difference, which is the difference between the input set temperature and the water outlet temperature detected by the temperature sensor installed on the outlet side of the water pipe passing through the indoor heat exchanger, and the compressor operates based on the set target pressure. Including; a normal operation repetition step controlled during the normal operation time;
The starting operation step includes a first starting operation step in which the compressor is operated at a starting frequency for a first time and a starting operation end determination step of determining whether the set temperature difference is less than a predetermined first value, and the normal operation The starting step includes a first target pressure changing step of changing the target pressure to the current high or low pressure of the refrigerant cycle based on the operation mode when the set temperature difference is determined to be less than the first value in the starting operation end determination step, Control method of air heat pump. 8. The method of claim 7,
The starting operation step further includes a second starting operation step in which the compressor is operated at the starting frequency for a second time when the set temperature difference is determined to be equal to or greater than the first value in the starting operation end determination step, and the normal operation starting step includes: and a first target pressure determining step in which the target pressure is set to a pressure determined according to a set temperature after the second starting operation step. 8. The method of claim 7,
The normal operation repeating step may include: a first determination step of determining whether the set temperature difference is less than a preset first value; and
and a second target pressure changing step of changing the target pressure to the current high pressure or the current low pressure of the refrigerant cycle based on the operation mode if it is determined in the first determination step that the set temperature difference is less than the first value Control method of air heat pump. 10. The method of claim 9,
The normal operation repeating step is to correct the changed target pressure based on a set temperature difference and a set temperature difference change rate according to time after the second target pressure change step, and control the compressor for a normal operation time based on the corrected target pressure A control method of an air-heated heat pump, characterized in that it further comprises a target pressure correction step. 11. The method of claim 10,
The normal operation repetition step is after the target pressure correction step,
A second determination step of determining whether the set temperature difference exceeds a preset second value greater than the first value further includes a second determination step of determining whether the set temperature difference is equal to or less than the second value in the second determination step A control method of an air-heated heat pump, characterized in that returning to the target pressure correction step. 12. The method of claim 11,
The normal operation repetition step is,
When it is determined that the set temperature difference is equal to or greater than the first value in the first determination step or it is determined that the set temperature difference exceeds the second value in the second determination step, the target pressure is set to a pressure determined according to the set temperature The method of controlling an air-heated heat pump, characterized in that it further comprises a second target pressure determining step. 13. The method of claim 12,
In the first target pressure determining step and the second target pressure determining step, the target pressure is set based on a first table, which is a preset table-type data set in which the pressures corresponding to the respective set temperatures are matched. How to control the pump. 14. The method of claim 13,
In the target pressure correction step, the target pressure is set using a table-type data set determined by machine learning of past data that matches the set temperature difference and the correction value corresponding to the set temperature difference change rate as a second table. How to control the pump. 14. The method of claim 13,
After the second target pressure determination step, further comprising the step of determining whether a stop signal of the heat pump is input, characterized in that the normal operation repeat step is repeatedly performed until the stop signal of the heat pump is input A control method for an air-heated heat pump.

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