KR102056326B1 - Method of determine fouling of heat exchanger - Google Patents

Abstract

In a method performed by any processor and for determining fouling of a heat exchanger, the method comprises the following step of: calculating a plurality of the number of transfer units and usefulness with respect to a fluid passing through the heat exchanger from data regarding the temperature and the flow rate of the heat exchanger during a measurement time interval; calculating the slope value of the usefulness with respect to the number of transfer units using the plurality of the number of transfer units and the usefulness; calculating a first average usefulness value of the measurement time interval by applying the slope value; and determining fouling by comparing the first average usefulness value with a second average usefulness value calculated for a previous reference time interval for the heat exchanger.

Description

Method of determine fouling of heat exchanger

The present invention relates to a method for determining the pollution level of a heat exchanger, and more particularly, to determining the pollution level of a heat exchanger using a fluid temperature at an inlet and an outlet of a heat exchanger.

Heat exchangers are devices used for the purpose of exchanging heat between two fluid media with different temperatures and are used in many industrial processes and heating and cooling systems. In normal heat exchanger operation, the surface can be contaminated by impurities contained in the fluid, the formation of rust, or the reaction between the fluid and the wall material, resulting in a significant increase in thermal resistance. This is called fouling. Increased contamination can reduce heat exchange performance and shorten the life of the equipment. Therefore, it is necessary to decontaminate the heat exchanger at the appropriate time.

Decontamination periodically without checking for contamination can reduce unnecessary costs and shorten equipment life. Recently, the energy-saving oil permeation pump control method for controlling the heating and cooling water supply according to the change of heat consumption is becoming common, and it may be difficult to predict the pollution degree only by measuring the pressure loss of the heat exchanger.

Republic of Korea Patent Registration Publication No. 10-0905123 (Published: January 27, 2005) Republic of Korea Patent Registration Publication No. 10-1700538 (Registration Date: January 20, 2017)

In one embodiment, a method for determining a pollution level of a heat exchanger includes calculating a plurality of transfer unit numbers and usefulness of a fluid passing through an inside of the heat exchanger from data on a temperature and a flow rate of the heat exchanger during a measurement time interval. Calculating a slope value of the usefulness with respect to the number of transfer units using the plurality of transfer units and the usefulness; calculating a first average usefulness value of the measurement time interval by applying the slope value And comparing the first average usefulness value with a second average usefulness value calculated for a previous reference time interval for the heat exchanger to determine the fouling.

According to an embodiment, the calculating of the number of transfer units and the usefulness may include calculating an algebraic average temperature difference and a constant pressure specific heat using a property database according to temperature, and calculating a heat exchange amount and a maximum heat exchange amount using the constant pressure specific heat. And calculating the usefulness as the ratio of the heat exchange amount to the maximum heat exchange amount, and calculating the number of transfer units using the ratio of the heat exchange amount to the logarithmic mean temperature difference.

The temperature of the heat exchanger may be an inlet and outlet temperature on the heat source side and an inlet and outlet temperature on the load side of the heat exchanger.

According to another embodiment, the usefulness and the number of delivery units calculated during the predetermined period are calculated as temperature and flow rate values measured at at least one time point in the period, and the slope value of the usefulness is the number of delivery units-useful. It may be calculated using the usefulness and the number of transfer units at the at least one time point mapped in the degree coordinate system.

The method may further include storing the usefulness calculated by the temperature and the flow rate value measured at the first time point and the number of delivery units in a database, and the usefulness at the plurality of time points including the first time point stored in the database. And a gradient value of the usefulness using the number of transfer units.

According to the heat exchanger contamination degree determination method according to an embodiment, the flow rate value may be estimated by using an inverter using a situation recognition algorithm.

According to another exemplary embodiment, the method may further include determining the pollution degree in real time, and outputting an alarm when the pollution degree determined in real time is less than a preset threshold pollution degree value.

1 is a flowchart illustrating a cleaning cycle by analyzing a contamination level according to an exemplary embodiment.
2 illustrates a transfer unit number-utility coordinate system to which a transfer unit number and a usefulness value are mapped to at least one time point, according to an exemplary embodiment.
Figure 3 shows a heat exchanger having a temperature sensor at the inlet and outlet according to one embodiment.
4 illustrates a flow chart for calculating the number of delivery units and the usefulness value according to an exemplary embodiment.
FIG. 5 illustrates a flow chart for calculating a contamination level using calculated transfer unit numbers and usefulness according to one embodiment. FIG.
6 is a flowchart illustrating information processing of temperature data, according to an exemplary embodiment.
7 is a flowchart illustrating information processing of heat exchange information according to an exemplary embodiment.
8 illustrates calculating the degree of contamination by calculating an average usefulness value between an initial season and a season to be calculated, according to an embodiment.

Specific structural or functional descriptions of the embodiments are disclosed for purposes of illustration only, and may be practiced in various forms. Accordingly, the embodiments are not limited to the specific disclosure, and the scope of the present specification includes changes, equivalents, or substitutes included in the technical idea.

Terms such as first or second may be used to describe various components, but such terms should be interpreted only for the purpose of distinguishing one component from another. For example, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

When a component is referred to as being "connected" to another component, it should be understood that there may be a direct connection or connection to that other component, but there may be other components in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise" or "have" are intended to designate that the described feature, number, step, operation, component, part, or combination thereof exists, but includes one or more other features or numbers, It should be understood that it does not exclude in advance the possibility of the presence or addition of steps, actions, components, parts or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined herein. Do not. Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 is a flowchart illustrating a cleaning cycle by analyzing a contamination level according to an exemplary embodiment.

According to an embodiment, the method 100 of determining a pollution level of a heat exchanger may include collecting temperature data and flow rate data of the heat exchanger and processing the information (110, 120). Computing (130), thereby analyzing (140) the degree of contamination of the data collection period. In addition, the analysis may further include a step 160 of comparing the analyzed pollution degree with a predetermined threshold contamination level value 150 to indicate whether the contamination is deposited in the heat exchanger and needs cleaning.

The information processing step 110 regarding the temperature data may calculate data about the temperature by using the temperature flowing into and out of the heat exchanger. The temperature may be a temperature value obtained by measuring the temperature of the fluid flowing in and out of the heat source corresponding to the high temperature side of the heat exchanger and the portion related to the load corresponding to the low temperature side. By using the temperature, the logarithmic mean temperature difference (LMTD), and the specific specific heat according to the temperature can be obtained, which will be described later in detail with reference to FIG. 6.

In step 120 of collecting the flow rate data, the flow rate may be measured through a flow meter, and the flow rate may be estimated using a situational recognition algorithm. The process of collecting the temperature and flow rate data may include the method of directly measuring the temperature and the flow rate, but the present invention is not limited thereto, and the temperature and flow rate data may be collected as an estimated value using other data values. For example, the flow rate may be estimated using axial power data generated by an inverter installed at a portion where the fluid is input to the heat exchanger. The heat capacity and heat amount may be calculated using the flow rate data, which will be described later in detail with reference to FIG. 7.

The processing of heat exchange information 130 may include calculating heat exchange information using data on temperature and flow rate. The heat exchange information may include a number of heat transfer unit (NTU). And heat exchanger effectiveness.

Analyzing the pollution degree step 140 calculates the slope value of the usefulness for the delivery unit number using the transfer unit number and the usefulness, and applies the slope value to the average usefulness value for the period to be measured. Computing may be included. Pollution can be determined by comparing the average usefulness value calculated during initial operation of a heat exchanger having a relatively low pollution level with the average usefulness value during the period to be measured.

According to an embodiment, the pollution degree is determined in real time, and determining whether the pollution degree determined in real time is less than a predetermined threshold contamination level value 150, and outputting an alarm if the value is less than a threshold contamination level value 160. It may include. In order to determine the degree of contamination in real time, the temperature, flow rate data, and heat exchange data may be accumulated in real time to continuously update the average utility value. Therefore, the contamination value processed in real time may indicate whether the heat exchanger needs cleaning.

As a method of informing cleaning time of a conventional heat exchanger, there have been a conventional method of periodically removing contamination and a pressure loss measuring method of confirming a change in fluid resistance of the heat exchanger. Decontamination periodically without checking for contamination can reduce unnecessary costs and shorten equipment life. In addition, since the temperature and the flow rate of the fluid to be changed according to the use environment are not taken into consideration, it may be unnecessarily cleaned or a high degree of contamination may occur. The energy-saving oil permeation pump control method that controls the cooling and heating water supply according to the change of heat consumption is a method of determining the cleaning time by measuring the pressure loss of the heat exchanger quantitatively.

2 illustrates a transfer unit number-utility coordinate system 200 to which a transfer unit number and a usefulness value are mapped at a plurality of time points, according to an exemplary embodiment.

, 출구의 온도는

이고, 부하(저온)측 입구의 온도는

, 출구의 온도가

일 때, 열교환량(Q)은 질량유량(m)과 정압비열(

), 온도차(

)의 관계식인 수학식1로 표현될 수 있다.The heat exchanger may generally perform counter flow heat exchange to transfer heat from the heat source (high temperature) side to the load (low temperature) side. The temperature at the inlet of the heat source (high temperature)

, The temperature of the outlet

The temperature at the load (low temperature) side inlet is

, The temperature of the outlet

Where heat exchange amount (Q) is the mass flow rate (m) and

), Temperature difference (

It can be expressed by Equation 1, which is a relation of.

로 정의할 수 있다. 상기 수학식1에서 온도변화를 제외한 질량유량과 정압비열 곱의 항을 열용량(

) 이라 한다. 열교환기 입출구 온도를 알고 있는 경우, 열 교환량(Q)과 총괄열전달계수(U)의 관계는 수학식2로 표현할 수 있다.In an insulated structure without heat loss, energy exchange takes place without any energy lost on the heat exchanger's load and on the heat source side,

Can be defined as In Equation 1, the term of the mass flow rate and the static pressure specific heat product except for the temperature change is calculated as

) When the heat exchanger inlet / outlet temperature is known, the relationship between the heat exchange amount Q and the overall heat transfer coefficient U can be expressed by Equation 2.

The LMTD of Equation 2 is a logarithmic mean temperature difference, and the logarithmic mean temperature difference may be obtained through Equation 3 using the inlet and outlet temperatures of the heat exchanger.

)에 반비례한다 (수학식4). 상기 최소열용량은 열원측 열용량과 부하측 열용량 중 작은 값일 수 있다. 열교환기의 유체의 특성이 크게 변하지 않으면, 상기 열용량과 총괄연전달계수는 큰 변화가 없고, 따라서 전달단위수에는 전열면적이 큰 영향을 미치게 된다.The transmission unit number (NTU), which is the x-axis value of the coordinate system 200, is proportional to the overall heat transfer coefficient (U) and the plate heat exchanger heat transfer area (A), and the minimum heat capacity (

Inversely proportional to Equation (4). The minimum heat capacity may be a smaller value of the heat source side heat capacity and the load side heat capacity. If the characteristics of the fluid of the heat exchanger do not change significantly, the heat capacity and the overall transfer coefficient do not change significantly, and thus the heat transfer area has a large influence on the transfer unit number.

) 대비 현재 열교환량(Q)의 비율로 수학식 5로 표시될 수 있으며, 열교환기에 실제 전달된 열전달률을 나타낸 것일 수 있다. 최대열교환량은 최소열용량으로 구할 수 있는데, 상기 최소열용량은 열원(고온)측 열용량과 부하(저온)측 열용량 중 작은 값일 수 있다.The usefulness of the y-axis value of the coordinate system 200 is the maximum heat exchange amount (

) May be represented by Equation 5 as a ratio of the current heat exchange amount (Q), and may represent the heat transfer rate actually transferred to the heat exchanger. The maximum heat exchange amount may be obtained by a minimum heat capacity, which may be a smaller value of a heat source (high temperature) side heat capacity and a load (low temperature) side heat capacity.

), 일반적인 유용도(

)는 수학식6과 같은 관계를 가지고 있다.According to the graph 210 illustrated in FIG. 2, the number of transfer units and the usefulness have a constant relationship, and the maximum usefulness (

), General usefulness (

) Has the same relationship as in equation (6).

W in Equation 6 is a ratio of general usefulness to maximum usefulness, and a method of obtaining w using collected temperature data and flow rate data will be described later.

The transfer unit number and the usefulness of the heat exchanger in the transfer unit number-utility coordinate system 200 of FIG. 2 may be represented by a graph 210 using Equation 6, and the initial heat exchanger without contamination has a high usefulness. Operation may be performed in the section 220. As the pollution degree increases, the overall heat transfer coefficient U decreases, and according to Equation 6, the transfer unit number also decreases. Therefore, if the pollution degree is increased, the usefulness may be operated in a section 230 lower than the initial stage. As the graph 210 increases, the heat transfer performance decreases as the pollution level increases and the number of transfer units decreases, thereby decreasing the usefulness of the heat exchanger, and may be operated on the left side of the graph 210.

As shown in FIG. 2, at least one mapping data mapped in the transfer unit number-availability coordinate system may be obtained through temperature and flow rate data of a heat exchanger measured at an arbitrary time point in real time. However, the present invention is not limited thereto, and may be obtained through continuously measured temperature and flow rate data.

According to one embodiment, the usefulness and the number of delivery units calculated for any period are calculated from the temperature and flow rate values measured at at least one time point in the period, and the slope value of the usefulness is the number of delivery unit-utility coordinate system. It may be calculated using the availability and the number of transfer units mapped at a plurality of time points.

According to another exemplary embodiment, the method may further include storing the usefulness calculated by the temperature and the flow rate value measured at the first time point and the number of transfer units in a database, and the usefulness at the plurality of time points stored in the database. And a gradient value of the usefulness using the number of transfer units. The usefulness and the number of delivery units may be calculated at a plurality of time points during the period, and as the collected data increases, the slope value of the usefulness may be more accurately calculated.

According to the above embodiment, the slope value of the usefulness may be calculated by performing a linear regression analysis on the discontinuously mapped data. The usefulness value according to the number of transfer units is changed to a certain pattern. Through linear regression analysis, the relationship between the number of transfer units and the usability is close to a straight line, and the slope value of the usefulness can be calculated from the slope value of the straight line. have.

For example, when the pollution level is determined for each branch, the temperature of the inlet / outlet fluid of the heat exchanger may be periodically measured in the first branch, and the flow rate may be estimated. Calculate and store the number of transfer units and the usefulness in the database based on the temperature and flow rate data collected at each periodic time point, and the slope value of the usefulness using the transfer number and usefulness accumulated in the database during the first quarter. Can be calculated.

3 shows a heat exchanger having a temperature sensor at the inlet and outlet according to one embodiment.

을 측정하기 위한 온도센서(310), 열원측(고온)의 출구온도

를 측정하기 위한 온도센서(320), 부하측(저온)의 입구온도

을 측정하기 위한 온도센서 (311), 부하측(저온)의 출구온도

를 측정하기 위한 온도센서(321), 열교환열량(Q)를 계산 하기 위한 유량(m)을 추정하는 인버터(330)로 구성될 수 있다.According to one embodiment, the heat exchanger 300 is the inlet temperature of the heat source side (high temperature)

Temperature sensor 310 for measuring the temperature of the outlet of the heat source side (high temperature)

Temperature sensor 320 for measuring the temperature, inlet temperature of the load side (low temperature)

Temperature sensor 311 for measuring temperature, outlet temperature of the load side (low temperature)

It may be composed of a temperature sensor 321 for measuring the, the inverter 330 for estimating the flow rate (m) for calculating the heat exchange heat (Q).

4 illustrates a flow chart of calculating the number of delivery units and the usefulness value according to an exemplary embodiment.

(406)와

(407)를 계산할 수 있다. 열교환기의 부하 및 열원 측의 유체 종류를 알고 있으므로, 상기

(406)는 상기 유체의 온도에 따른 물성 데이터베이스로 구할 수 있다. 상기

(407)의 계산방법은 부하 및 열원의 입출구 온도로 계산될 수 있으며, 구체적으로는 선술하였던 수학식3을 통해 구할 수 있다. 상기 계산된

(406),

(407), 및 VST 인버터(402)에 의해 추정된 유량값(404)를 통해 Q,

,

(408)을 계산할 수 있다. Q,

,

(408)를 계산하는 방법은 도2에서 선술하였으므로, 자세한 설명은 생략하도록 한다. 계산된 Q,

,

(508) 및

(507)로

(510),

(511),

(509)를 구할 수 있다.According to one embodiment, the temperature 403 collected through the temperature sensor 401, and according to the temperature using the physical property database 405 of the fluid

406 and

407 can be calculated. Since we know the load of the heat exchanger and the fluid type on the heat source side,

406 can be obtained from a physical property database according to the temperature of the fluid. remind

The calculation method of 407 may be calculated by the inlet and outlet temperatures of the load and the heat source, and specifically, may be obtained through Equation 3 described above. Calculated above

(406),

407, and through the flow rate value 404 estimated by the VST inverter 402, Q,

,

408 can be calculated. Q,

,

Since the method of calculating 408 has been described with reference to FIG. 2, detailed description thereof will be omitted. Calculated Q,

,

508 and

To 507

(510),

(511),

509 can be obtained.

The calculating of the number of transfer units and the usefulness may be performed at any first point in time during which a pollution degree is to be measured, and according to an embodiment, the number of transfer units and usefulness of a plurality of points including the calculated first point in time Can be stored in a database.

FIG. 5 illustrates a flow chart for calculating a contamination level using calculated delivery number and usefulness according to one embodiment. FIG.

As described above with reference to FIG. 4, the number of transfer units and the usefulness may be calculated 510 in real time at a first time point, and the number of transfer units and the usefulness at a plurality of time points including the first time point may be stored in a database. (520).

Number of Transfer Units-Using a plurality of transfer unit numbers mapped to a usefulness coordinate system and data on the usefulness, a slope value w of the number of transfer units may be calculated (530). The method of calculating the slope is not limited to the linear regression analysis alone, and any method of calculating a slope value of a plurality of data mapped in the coordinate system may be used. For example, the gradient of the usefulness may be obtained by recording the number of transfer units and the usefulness value in a database in a minute unit in real time and averaging the slope values of the straight lines connecting two successive time points.

이라고 할 때, 초기 1년간 열교환기 유용도 평균값 (

)은 수학식7을 통해 얻을 수 있다(540). 사용 후 오염도가 증가 되어 열전달 성능이 감소 된 이후 열교환기의 총괄열전달계수가

인 경우, 열교환기 유용도 평균값(

)도 수학식7을 통해 얻을 수 있다(550). 수학식7의 적분 구간의 시작점인 a는 측정기간 최소 전달단위수이고 종결점인 b 는 측정기간 전달단위수의 최대값이다. 상기 전달단위수는 전열면적에 따라 달라질 수 있고, 전열면적은 유량값에 따라 달라질 수 있다.For example, the overall heat transfer coefficient of an uncontaminated heat exchanger is

, The average heat exchanger useful value for the first year (

) Can be obtained through Equation 7 (540). The overall heat transfer coefficient of the heat exchanger after reducing the heat transfer performance due to the increased pollution after use

, The heat exchanger availability average value (

) Can also be obtained through Equation 7 (550). A, the starting point of the integration section of Equation 7, is the minimum number of transmission units in the measurement period, and b, the ending point, is the maximum value of the number of transmission units in the measurement period. The transfer unit number may vary depending on the heat transfer area, and the heat transfer area may vary depending on the flow rate value.

)은 최대 유용도 값(

)에서 기울기 값(w)을 곱한 것일 수 있다. 초기 평균 유용도 값을 계산한 것과 같은 방법으로 오염도를 측정하고자 하는 기간의 평균 유용도 값(

)을 계산할 수 있다(550). 예시적으로 초기 평균 유용도 값은 세정 후 오염이 없는 상태에서 1년 동안 측정하여 계산한 유용도 값일 수 있고, 측정하고자 하는 기간의 평균 유용도 값은 그 이후 1년 동안 측정하여 계산한 유용도 값일 수 있다.Average utility value (

) Is the maximum usability value (

) May be multiplied by the slope value (w). The average usefulness value of the time period for which you want to measure contamination (the same way you calculated the initial average usefulness value)

May be calculated (550). For example, the initial average usefulness value may be a usefulness value measured for one year in the absence of contamination after cleaning, and the average usefulness value of a period to be measured is a usefulness measured for one year thereafter. Can be a value.

,

을 이용하여 상기 열교환기의 오염도를 구할 수 있다(560). 오염도는 초기 오염되지 않은 열교환기의 평균 유용도(

)에 대한 측정하는 구간에서의 유용도 값의 차이(

-

)의 비율일 수 있다.Calculated through Equation 7

,

The degree of contamination of the heat exchanger can be obtained using 560. Pollution degree is the average usefulness of the initial uncontaminated heat exchanger (

Difference in the usefulness value over the interval you're measuring (

-

It can be a ratio of).

가 오염 정도가 적어 도2의 220과 같은 분포를 보인다면, 기울기 값이 작아지고, 따라서

는 작은 값을 갖게 된다.

가 작은 값을 가지게 되므로, 오염도는 1에 가까운 값을 가질 수 있다. 이에 반해,

가 오염 정도가 커 도2의 210과 같은 분포를 보이게 된다면, 기울기 값이 커지고, 따라서

도 큰 값을 갖게 된다.

가 큰 값을 가지게 되므로, 오염도는 오염 정도가 작을 때보다 작은 값을 가질 수 있다.As an example,

If the contamination level is small and shows the same distribution as 220 in FIG. 2, the slope value becomes small, and thus

Has a small value.

Since H has a small value, the pollution degree may have a value close to one. In contrast,

If the pollution degree is large and shows the same distribution as 210 in FIG. 2, the slope value becomes large, and thus

Also has a large value.

Since has a large value, the pollution degree may have a smaller value than when the degree of contamination is small.

6 is a flowchart illustrating information processing of temperature data, according to an exemplary embodiment.

,

,

,

)를 수집할 수 있고, 대수평균 온도차(620)를 상기 데이터를 이용하여 계산할 수 있다.According to one embodiment, the data 610, the temperature of the fluid at the inlet and outlet of the heat exchanger

,

,

,

) And a logarithmic mean temperature difference 620 can be calculated using the data.

,

, 650)을 구할 수 있다.According to one embodiment, to calculate the specific heat of the property according to the temperature, an average value 630 of the inlet and outlet temperatures of the heat exchanger may be used. When the average of the inlet and outlet temperatures of the heat exchanger is calculated, the physical specific heat according to the temperature is obtained using the database 640 in which the physical specific heat according to the temperature is mapped.

,

, 650).

7 is a flowchart illustrating information processing of heat exchange information according to an embodiment.

According to one embodiment, the flow rate value may be estimated using an inverter using a situation recognition algorithm. The flow rate can be estimated by using the information of the controlled pump and the real-time information generated by the inverter to recognize and inform the oil quantity. When the load in the pipe is predicted to be reduced by using the axial power data generated by the inverter and the situational recognition algorithm, the pump speed is decreased. On the contrary, when the load in the pipe is expected to be increased, the pump speed is increased while the flow rate is increased. Can be estimated. The flow rate value may be estimated through an algorithm according to the embodiment, but is not limited thereto. For example, the data regarding the flow rate may be collected by a method including a method of measuring the flow rate through a flow sensor.

According to an embodiment, the heat exchange amount 701 may be calculated by estimating only the flow rate of any one of the heat source and the load of the heat exchanger. In an insulated heat exchanger without heat loss, the heat exchange amount of the heat source and the load may be the same. Therefore, the heat exchange amount of the other side can be known using the calculated heat exchange amount 701, and through this, the heat capacity 702 of the opposite side can be calculated.

When the heat capacity of the heat source and the load of the heat exchanger is calculated, the minimum heat capacity 703 may be obtained by comparing the two heat capacities, thereby obtaining the maximum heat quantity 704. Through the maximum heat quantity 704 and the logarithmic mean temperature difference 602 calculated in FIG. 6, the product of the total heat transfer coefficient and the heat transfer area (UA, 705) can be calculated, and the UA 705 is divided by the minimum heat capacity 703. The number of transfer units 706 can be calculated. The usefulness value 707 may be expressed as the ratio of the current calorie to the maximum calorie 704.

The calculation process may be calculated sequentially at the first time point of the period to be measured, and the final calculated number of transfer units and the usefulness may be stored 708 in the database. According to an embodiment, the data regarding the number of transfer units and the usefulness may be stored in the database by mapping the time and period when the data is calculated.

FIG. 8 illustrates that the pollution degree is calculated by calculating an average usefulness value of an initial season and a season to be measured.

First, an average usefulness value may be obtained in an initial season 810 compared to a season in which contamination is to be measured. The user sets a start date and an end date of the initial season 810, and collects temperature and flow data periodically or during a time period between the start date and the end date to calculate the number of delivery units and the usefulness. Can be. In order to calculate the average usefulness value, the minimum and maximum number of delivery units for the season are calculated (820), and the average usefulness value is calculated by integrating the usefulness between the maximum and minimum number of delivery units. 830 to store 840.

The average usefulness value in the season 850 to measure the pollution degree can be obtained by calculating the average usefulness value in the earlier season described above. The user may set a start date and an end date of the season 850, and measure the number of delivery units and the usefulness periodically during a period between the start date and the end date or at a time point satisfying any condition. In order to calculate the average usefulness value, the minimum number of delivery units and the maximum number of delivery units during the season are obtained (860), and the average usefulness value is calculated by integrating the usefulness between the maximum and minimum number of delivery units ( 870). Thereafter, the degree of contamination may be calculated 880 by comparing the average usefulness value 840 of the initial season, which has been calculated and stored, with the average usefulness value of the season to be measured.

The embodiments described above may be implemented as hardware components, software components, and / or combinations of hardware components and software components. For example, the devices, methods, and components described in the embodiments may include, for example, processors, controllers, arithmetic logic units (ALUs), digital signal processors, microcomputers, field programmable gates (FPGAs). It may be implemented using one or more general purpose or special purpose computers, such as an array, a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to the execution of the software. For the convenience of understanding, the processing apparatus may be described as one used, but those skilled in the art will appreciate that the processing apparatus includes a plurality of processing elements and / or a plurality of types of processing elements. It can be seen that it may include. For example, the processing device may include a plurality of processors or one processor and one controller. In addition, other processing configurations are possible, such as parallel processors.

The software may include a computer program, code, instructions, or a combination of one or more of the above, and may configure the processing device to operate as desired, or process independently or collectively. You can command the device. Software and / or data may be any type of machine, component, physical device, virtual equipment, computer storage medium or device in order to be interpreted by or to provide instructions or data to the processing device. Or may be permanently or temporarily embodied in a signal wave to be transmitted. The software may be distributed over networked computer systems so that they may be stored or executed in a distributed manner. Software and data may be stored on one or more computer readable recording media.

The method according to the embodiment may be embodied in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the media may be those specially designed and constructed for the purposes of the embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Although the embodiments have been described with reference to the accompanying drawings, those skilled in the art may apply various technical modifications and variations based on the above. For example, the described techniques may be performed in a different order than the described method, and / or components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different form than the described method, or other components. Or, even if replaced or substituted by equivalents, an appropriate result can be achieved.

Claims (8)

In the method carried out by any processor, for determining the pollution degree of the heat exchanger,
The method is:
Calculating a plurality of transfer unit numbers and usefulness of the fluid passing through the heat exchanger from data regarding the temperature and flow rate of the heat exchanger during the measurement time interval;
Calculating a slope value of the usefulness with respect to the number of transfer units using the plurality of transfer units and the usability;
Calculating a first average usefulness value of the measurement time interval by applying the slope value; And
Determining the fouling by comparing the first average usefulness value with a second average usefulness value calculated for a previous reference time interval for the heat exchanger.
Including,
The step of calculating the number of transfer units and the usefulness,
Obtaining a logarithmic mean temperature difference and a static pressure specific heat using a property database according to temperature;
Calculating a heat exchange amount and a maximum heat exchange amount using the constant pressure specific heat, and obtaining the usefulness as a ratio of the heat exchange amount to the maximum heat exchange amount; And
Obtaining the number of transfer units using the ratio of the heat exchange amount to the logarithmic mean temperature difference
How to include. delete The method of claim 1,
The temperature of the heat exchanger,
And the inlet and outlet temperatures on the heat source side of the heat exchanger and the inlet and outlet temperatures on the load side. The method of claim 1,
The usefulness and the number of delivery units calculated during the period are calculated from temperature and flow rate values measured at at least one time point in the period,
And the slope value of the usefulness is calculated using the usefulness and the number of transfer units at the at least one time point mapped in the number of transfer units-use coordinate system. The method of claim 4, wherein
Storing the usefulness and the number of transfer units calculated in the temperature and flow rate values measured at the first time point in a database,
And calculating a slope value of the usefulness using the availability and the number of transfer units at the plurality of time points including the first time point stored in the database. The method of claim 1,
Flow rate data values are estimated using an inverter using a situational awareness algorithm. The method of claim 1,
Determine the pollution degree in real time,
And outputting an alarm when the pollution degree determined in real time is less than a predetermined threshold pollution degree value. In the processor for determining the contamination level of the heat exchanger during the measurement time interval,
The processor is:
Calculating a plurality of transfer unit numbers and usefulness of the fluid passing through the heat exchanger from data on the temperature and flow rate of the heat exchanger during the measurement time interval;
Calculating a slope value of the usefulness with respect to the number of transfer units using the plurality of transfer units and the usability;
Calculating a first average usefulness value of the measurement time interval by applying the slope value; And
Determining the fouling by comparing the first average utility value with a second average utility value calculated for a previous reference time interval for the heat exchanger
And then
The step of calculating the number of transfer units and the usefulness,
Obtaining a logarithmic mean temperature difference and a static pressure specific heat using a property database according to temperature;
Calculating a heat exchange amount and a maximum heat exchange amount using the constant pressure specific heat, and obtaining the usefulness as a ratio of the heat exchange amount to the maximum heat exchange amount; And
Obtaining the number of transfer units using the ratio of the heat exchange amount to the logarithmic mean temperature difference
Processor containing

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