KR101918490B1 - A fouling monitoring apparatus for heat exchangers - Google Patents

Abstract

In a shell-and-tube heat exchanger used for recovering waste heat by heat exchange of hot wastewater with clear water, the present invention comprises: a light source for generating light to be irradiated inside a heat exchanger tube to monitor fouling occurring in a tube; an EX filter for filtering light of a first wavelength range from the light emitted from the light source; a light emitter for guiding the light emitted from the EX filter into the tube of the heat exchanger; a light projecting unit which forms a window for allowing the light emitted from a light control unit to pass through the heat exchanger tube; a light receiving unit for receiving and guiding fluorescence reflected inside the heat exchanger tube through the light projecting unit; an EM filter for filtering the light of a predetermined second wavelength region from the fluorescence guided by the light receiving unit; and a detector for detecting the fluorescence at a rear end of the EM filter. Thus, the apparatus can monitor a fouling state within the heat exchanger tube through intensity of the fluorescence received at the detector.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fouling monitoring apparatus for a heat exchanger,

The present invention relates to a fouling monitoring apparatus for a heat exchanger, and more particularly to a device for monitoring the degree of fouling in a tube in a shell and tube heat exchanger.

The heat exchanger is a device for transferring the heat of the high temperature fluid to the low temperature fluid by utilizing the phenomenon of heat transfer between the two fluids having different temperatures. Heat exchangers are widely used throughout the industry, such as for cooling and heating fluids as part of a production line, or as part of a cooling / heating system.

As a kind of heat exchanger, a shell-and-tube heat exchanger is a device for exchanging heat between two fluids while allowing one fluid to flow through a plurality of tubes and another fluid to flow into a large shell surrounding these tubes. In a shell-and-tube heat exchanger, undesirable substances accumulate over time on the surface of the tube that forms the heat transfer surface between two fluids, which is called fouling.

It is known that fouling is caused by such factors as the substance contained in the fluid reacts with other components, or crystallization occurs by changing the dissolution conditions according to the temperature change in the heat exchanger. The substances causing fouling include inorganic salts (e.g., calcium sulfate, barium sulfate, calcium carbonate, and magnesium carbonate), inorganic phosphates, silicates and silicates, corrosion products, particle deposits (e.g., sand) And biomineralized compounds consisting of organic deposits (e.g., bacteria, algae, proteins, mussel larvae and mussels), polymers, oils, resins and the above- ).

Fouling decreases the thermal conductivity of the tube surface, which is the heat transfer surface, and increases the frictional force against the fluid flow, thereby reducing the efficiency of the heat exchanger. Therefore, in order to maintain the performance of the heat exchanger, a cleaning process for removing the fouling should be periodically performed.

As a cleaning method for removing the fouling, there are a mechanical method of removing the fouling of the surface of the tube by a physical force and a chemical method of removing by using a reaction with a chemical substance. The cleaning process of the heat exchanger requires a lot of time and cost, and it is preferable to minimize the cleaning process because it causes a lot of waste when the flow of the whole process is stopped.

The present invention provides a method of monitoring the progress of the fouling of the heat exchanger so that the user can grasp the proper cleaning time. As a conventional fouling monitoring method, a method of measuring a change in pressure drop of a heat exchanger according to the progress of fouling or a change in heat transfer coefficient is used. These methods provide a way to indirectly confirm the fouling state, but there is a merit that the operation of the heat exchanger is not interrupted. However, there is a problem that there is a large error in the measurement result due to the turbulent flow or the flow rate of the fluid in the heat exchanger have. As another method, there is a method of directly measuring the thickness of the heat exchanger by checking the tube, but there is a problem that the operation of the heat exchanger must be stopped.

It is an object of the present invention to provide a new method of folling monitoring that is different from the conventional folling monitoring method in recovering the waste heat by heat exchange the high-temperature wastewater with fresh water.

It is another object of the present invention to provide a monitoring apparatus capable of checking the fouling state without interrupting the operation of the heat exchanger.

It is another object of the present invention to provide a monitoring device capable of distinguishing the generated fouling material in a heat exchanger tube.

In order to achieve the above object, the present invention provides a fouling monitoring apparatus for monitoring the fouling state of the inner surface of a tube through which waste water flows in a shell-and-tube heat exchanger for recovering heat from hot wastewater, A first sensor module for monitoring the fouling state using the intensity of fluorescence emitted directly from the material, and a second sensor module for monitoring the fouling state using the intensity of fluorescence emitted from the fluorescent material layer applied on the inner surface of the heat exchanger tube A control unit for controlling the first sensor module and the second sensor module, and a control unit for receiving a command for controlling the device from a user and receiving a command for controlling the fouling received from the first sensor module and the second sensor module, Wherein the first sensor module comprises: a first light source; and a second light source, A first EX filter for filtering the emitted light with light of a predetermined first wavelength range and providing the filtered light to the inside of the tube of the heat exchanger, A first light path portion for guiding the first fluorescent light to be emitted to a first detector for detecting the first fluorescent light, a first light path portion for filtering the first fluorescent light at a front end portion of the first detector by light of a predetermined second wavelength region, The second sensor module includes a second light source, a second EX filter for filtering the light emitted from the second light source into light of a predetermined third wavelength range and providing the light, A second detector for guiding light into the tube of the heat exchanger and detecting a second fluorescence emitted from the fluorescent material layer as a fouling is formed on the surface of the fluorescent material layer applied on the inner surface of the tube of the heat exchanger Guide The second comprises a light path portion, and the filter 2EM provided to filter the second fluorescence at a predetermined second wavelength range of the light 4 in the front end portion of the second detector.

In addition, the first sensor module monitors the fouling state by the biofouling material NADH, and the first wavelength range may be 340 nm and the second wavelength range may be 460 nm.

The first light path portion may include a first light projecting portion that forms a window for transmitting light into the heat exchanger tube, a first light projecting portion for guiding the light emitted from the first EX filter to the first light projecting portion, And a first light receiving portion for guiding the first fluorescent light received through the first light transmitting portion to the first electromagnetic filter, and the second light transmitting portion includes a second light transmitting portion for transmitting light to the inside of the heat exchanger tube, And a second light receiving unit for guiding the second fluorescent light received through the second light emitting unit to the second electromagnetic wave filter.

The first light control section, the first light receiving section, the second light control section, and the second light receiving section extend from the tube of the heat exchanger to the outside of the shell of the heat exchanger, and the first light source, the first detector, The light source and the second detector may be installed outside the heat exchanger shell.

According to another aspect of the present invention, there is provided a fouling monitoring apparatus including a light source for generating light to be irradiated inside a heat exchanger tube for monitoring fouling occurring in a tube of a shell-and-tube heat exchanger, An EX filter for filtering light in the first wavelength range from the light emitted from the light source; a light control unit for guiding the light emitted from the EX filter into the tube of the heat exchanger; A light receiving unit for receiving and guiding fluorescence emitted from the inside of the heat exchanger tube through the light transmitting unit, and a light receiving unit for emitting light in a predetermined second wavelength range from the fluorescence guided by the light receiving unit, And a detector for detecting fluorescence at a rear end of the EM filter, wherein the intensity of the fluorescence received by the detector is represented by The fouling condition inside the heat exchanger tube is monitored.

Further, the light control unit and the light receiving unit extend outside the shell of the heat exchanger, and the light source and the detector are installed outside the shell of the heat exchanger.

Further, a fluorescent material layer may be applied to the surface of the transparent portion.

The fouling monitoring apparatus according to the present invention is characterized in that, in a heat exchanger for recovering waste heat by heat exchange of high-temperature wastewater with clear water, unlike the conventional fouling monitoring apparatus, the fouling monitoring apparatus uses the fluorescence characteristic of the fouling material, And a new fouling monitoring method using the intensity of fluorescence emitted from the light source.

In addition, the foul monitoring apparatus according to the present invention includes a first sensor module for monitoring bio-fouling and a second sensor module for monitoring the entire fouling including bio-fouling, So that the user can select an appropriate cleaning method.

Also, the foul monitoring apparatus according to the present invention provides a convenience of monitoring the foul state without interrupting the operation of the heat exchanger.

Further, the foul monitoring apparatus according to the present invention extends outside the shell of the heat exchanger so that a light source (LED lamp) sensitive to heat and a detector can be installed outside the heat exchanger.

1 is a block diagram showing the configuration of a foul monitoring apparatus according to a preferred embodiment of the present invention;
2 is a view showing an installation state of a foul monitoring apparatus according to a preferred embodiment of the present invention.
3 is a photograph showing the bottom surface of the transparent portion of the first sensor module and the second sensor module of the foul monitoring apparatus according to the preferred embodiment of the present invention
FIG. 4 is a graph showing intensity of fluorescence received by a detector according to the degree of contamination of a light-transmitting portion in a first sensor module of a foul monitoring apparatus according to a preferred embodiment of the present invention. FIG.
5 is a graph showing the intensity of fluorescence received by a detector according to the degree of contamination of a fluorescent material layer applied to a transparent portion in a second sensor module of a foul monitoring device according to a preferred embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below may be modified in various ways by those skilled in the art. The embodiments described below are not intended to limit the invention to the embodiments. It is to be understood that the invention includes various modifications, alternatives, and equivalents within the scope of the following claims, as well as the following embodiments.

It is to be understood that the expressions " comprising, " " comprising, " " having ", and the like, which may be used hereinbelow,

The term " first ... " "," Second ... Quot ;, " first ", " second ", etc. should not be construed as limiting the order or significance of the elements, unless explicitly stated.

It is to be understood that the expressions " coupled, " " connected ", and the like, which may be used herein, unless the context clearly dictates otherwise, do.

It is to be understood that the singular use of the terms below does not exclude a plurality of representations unless explicitly stated to the contrary.

Hereinafter, a foul monitoring apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the drawings.

The fouling monitoring apparatus according to the present invention is for monitoring the fouling state of the inner surface of the tube to which the wastewater is delivered in the shell-and-tube heat exchanger. The foul monitoring apparatus according to the present invention can be used in a shell-and-tube heat exchanger that recovers heat from hot wastewater on a production line such as dyeing wastewater.

Referring to FIG. 1, a foul monitoring apparatus 1 according to the present invention includes a first sensor module 10 and a second sensor module 20 for monitoring a fouling state in a heat exchanger tube, A controller 30 for controlling signals received from the sensor modules 10 and 20 and an interface 40 for receiving various commands for controlling the devices from the user.

The first sensor module 10 and the second sensor module 20 may be configured to measure a fouling state by different materials, respectively. For example, the first sensor module 10 monitors a biofouling state by microorganisms and the like, and the second sensor module 20 monitors not only biofouling but also fouling by an entire fouling material including an inorganic substance And may be configured to monitor the status. For this purpose, the sensor modules 10 and 20 are configured to irradiate light of a specific wavelength band to a heat exchanger tube and to measure intensity of light emitted therefrom.

First, the first sensor module 10 will be described. The first sensor module 10 includes a light source 11 that generates light to be irradiated to the heat exchanger tube, a detector 15 that detects fluorescence emitted from the fouling material in the heat exchanger, And a light passage portion 13 for guiding the light into the heat exchanger tube and guiding the fluorescence emitted from the fouling material to the detector 15 again.

The light source 11 is a lamp that emits light in a wavelength range including visible light, ultraviolet light, and infrared light, and may be, for example, an LED (Light Emitting Diode) lamp. Other Xenon lamps, mercury lamps, and the like. An EX filter 12 is formed at the rear end of the light source 11 to filter only light of a predetermined wavelength range so as to be transmitted to the light passage portion 13. [ In the front end of the detector 15, an EM filter 14 that filters only light of a predetermined wavelength region from the fluorescent light to be emitted and transmits the light to the detector 15 is formed. The wavelength range of the EX filter 12 and the EM filter 14 may vary depending on the spectroscopic characteristics of the fouling material to be detected. That is, in consideration of the fluorescence characteristic of the fouling material to be monitored, the light of the wavelength region that changes the electronic arrangement of the fouling material from the ground state to the excited state The EX filter 12 is selected so that the EM filter 14 is selected so that only the wavelength region of the light radiated while returning from the excited state of the electromagnetic arrangement of the fouling material to the ground state is selected . For example, when the biofouling state is to be monitored, the EX filter 12 is selected so as to filter light in a wavelength range of 340 nm absorbed by the coenzyme (NADH) in the microorganism, and the light in the wavelength region of 460 nm emitted from the coenzyme is filtered The EM filter 14 is selected as much as possible.

The light passage portion 13 is provided with a light control portion 13a for guiding the light irradiated through the EX filter 12 to the heat exchanger tube and a light projecting portion 13b for projecting light into the heat exchanger tube, (13b), and a light receiving portion (13c) for receiving fluorescence emitted from the fouling material inside the heat exchanger tube and guiding the fluorescence to the EM filter (14).

2, the transparent portion 13b is provided on the tube 2a of the heat exchanger 2 so that light can be transmitted to the inside and the outside of the tube 2a. The transparent portion 13b may be made of a transparent material such as quartz, glass, pyrex, or acryl.

Further, the light control section 13a and the light receiving section 13c extend from the tube 2a to the outside of the heat exchanger shell 2b. The light source 11, the EX filter 12, the EM filter 14, the detector 15, etc. constituting the first sensor module 10 are connected to the outer case 50 formed outside the heat exchanger shell 2b Can be embedded. Such a configuration of the light path portion 13 enables the installation position of the outer case 50 to be changed and enables the light source 11 and the detector 15, which can be particularly sensitive to heat, to be disposed outside the heat exchanger, Thereby improving the stability of the device.

Next, the second sensor module 20 will be described. The second sensor module 20 is configured to monitor not only the biofouling but also the state of the entire fouling material including the organic material and the inorganic material. Like the first sensor module 10, the second sensor module 20 also includes a light source 21, an EX filter 22, a light path portion 23, an EM filter 24, a detector 25, and the like. The light path portion 23 includes a light control portion 23a, a light projecting portion 23b, and a light receiving portion 23c. Unlike the first sensor module 10, the fluorescent material layer 26 is applied to the surface of the transparent portion 23b. This is to make it possible to monitor the fouling by substances which do not have fluorescence properties. That is, even if there is no fluorescence property in the fouling material itself, the amount of fluorescence emitted from the fluorescent material layer 26 increases as the amount of fouling formed on the surface of the phosphor layer 26 increases, So that it can be monitored. The EX filter 22 selects an electromagnetic arrangement of the fluorescent material composing the fluorescent material layer 26 in accordance with a wavelength range that changes the excitation state in a ground state, The electron arrangement of the fluorescent material constituting the fluorescent material layer 26 is selected in accordance with the wavelength region of the light emitted while being returned from the excited state to the ground state. For example, the wavelength range of the EX filter 22 may be 410 nm, and the wavelength range of the EM filter 24 may be 520 nm. The wavelength range of the EX filter 22 and the EM filter 23 may vary depending on the material constituting the fluorescent material layer 26.

The light control section 23a and the light receiving section 23c extend from the tube 2a to the outside of the heat exchanger shell 2b like the first sensor module 10. The light source 21, the EX filter 22, the EM filter 24 and the detector 25 are connected to the light source 11 of the first sensor module 10, the EX filter 12, the EM filter 14, the detector 15 And the like are incorporated in the outer case 50.

3 is a photograph of the bottom surfaces of the transparent portions 13b and 23b of the first sensor module 10 and the second sensor module 20 of the foul monitoring device 1 according to the present invention. The bottom surface of the transparent portion 13b of the sensor module 10 is photographed and the bottom surface of the transparent portion 23b of the second sensor module 20 is photographed. It is confirmed that the fluorescent substance layer 26 is coated on the bottom surface of the transparent portion 23b of the second sensor module 20. [

The control unit 30 controls the operation of the sensor module 10 and receives the reflected optical signal sensed through the detectors 15 and 25 to monitor the fouling state. The controller 30 may be implemented by a PLC (Programmable Logic Controller) or the like.

The interface unit 40 may include an input unit for receiving various commands for controlling the apparatus from the user, a display unit for displaying the degree of fouling numerically or graphically and displaying the same to the user.

Next, the operation of the foul monitoring device 1 according to the present invention will be described. The fouling monitoring apparatus 1 according to the present invention is configured to monitor the fouling state by biofouling and the fouling state by the entire material including biofouling, respectively. The first sensor module 10 is a structure for monitoring biofouling. The first sensor module 10 can monitor the degree of biofouling by detecting the intensity of fluorescence emitted from the coenzyme using the fluorescence characteristic of the coenzyme. As described above, the EX filter 12 filters light in the 340 nm wavelength region, and the EM filter 14 filters the light in the 460 nm wavelength region. The light irradiated to the transparent portion 13b is emitted by a biofouling material deposited on the surface of the transparent portion 13b forming the inner surface of the heat exchanger tube 2a. The fluorescent light passes through the EM filter 14, and detected by the detector 15. The controller 30 monitors the fouling state based on the intensity of the fluorescent light sensed through the detector 15. Table 1 shows experimental results in which relative intensity of fluorescence detected according to the number of times of application is measured while repeatedly applying coenzyme NADH to the surface of the transparent portion 13b. As shown in the graph. The X-axis in FIG. 4 represents the number of times of application, and the Y-axis represents the intensity of fluorescence.

0 1 application 2 doses 3 doses 4 times application 5 doses 6 doses No. 7 application Apply 8 times Intensity
(mV) 20 20 40 30 40 50 60 60 60

It is confirmed that the intensity of fluorescence detected increases as the number of coenzyme application increases on the surface of the transparent portion 13b. Therefore, the biofouling state in the heat exchanger tube can be monitored using the intensity of fluorescence sensed through the first sensor module 10.

The second sensor module 20 can be used to monitor the fouling state of the entire substance including the biofouling. A fluorescent material layer 26 for emitting fluorescence in a predetermined wavelength region is coated on the bottom surface of the transparent portion 23b of the second sensor module 20. [ In the above-described embodiment, the EX filter 22 filters light in a wavelength region of 410 nm, and the EM filter 24 filters light in a wavelength region of 520 nm. The light irradiated to the transparent portion 23b is emitted by the fluorescent material layer 26. The fluorescent light is detected by the detector 25 via the EM filter 24 through the light receiving portion 23c. The controller 30 monitors the fouling state based on the intensity of fluorescence sensed through the detector 25. [Table 2] shows the relative intensity of fluorescence detected according to the number of times of application while repeatedly applying the calcium carbonate (CaCO ₃ ) solution, which is one of the inorganic fouling substances, to the surface of the fluorescent substance layer 26 FIG. 5 is a graph showing the result of the measurement. The X-axis in FIG. 5 represents the number of times of application, and the Y-axis represents the intensity of fluorescence.

0 1 application 2 doses 3 doses 4 times application 5 doses 6 doses No. 7 application Apply 8 times No. 9 application Intensity (mV) 1880 2800 3100 3700 3900 4600 4500 4600 4800 4900

It is confirmed that the intensity of fluorescence detected increases as the application frequency of the calcium carbonate solution increases on the surface of the fluorescent material layer 26. Accordingly, the degree of fouling in the tube can be monitored using the intensity of fluorescence sensed through the second sensor module 20. [

The folling monitoring apparatus according to the present invention provides a new folling monitoring method using the fluorescence characteristic of a material, unlike the conventional folling monitoring apparatus.

In addition, the foul monitoring apparatus according to the present invention includes a first sensor module for monitoring bio-fouling and a second sensor module for monitoring the entire fouling including bio-fouling, So that the user can select an appropriate cleaning method. In other words, after the entire fouling state is determined through the second sensor module, it can be confirmed through the first sensor module whether or not it is caused by biofouling.

Also, the foul monitoring apparatus according to the present invention provides a convenience of monitoring the foul state without interrupting the operation of the heat exchanger.

1: foul monitoring device 2: heat exchanger
2a: tube 2b: shell
10: first sensor module 11: light source
12: EX filter 13: Light path portion
14: EM filter 15: detector
20: second sensor module 21: light source
22: EX filter 23: light path portion
24: EM filter 25: detector
30: control unit 40: interface unit
50: outer case

Claims (8)

An apparatus for monitoring a fouling condition of an inner surface of a tube through which wastewater flows in a shell-and-tube heat exchanger for recovering heat from hot wastewater,
A first sensor module for monitoring the fouling state using the intensity of fluorescence emitted directly from the fouling material, and a second sensor module for monitoring the fouling state by using the intensity of fluorescence emitted from the fluorescent material layer applied on the inner surface of the heat exchanger tube. A controller for controlling the first sensor module and the second sensor module, and a controller for receiving a command for controlling the apparatus from a user and receiving a command for controlling the apparatus from the first sensor module and the second sensor module, And an interface unit for displaying a foul state to a user,
The first sensor module includes a first light source, a first EX filter for filtering the light emitted from the first light source into light of a first wavelength range and providing the filtered light, A first light path portion for guiding the first fluorescence emitted from the fouling material to the inside of the tube and for guiding the first fluorescence to the first detector, And a first EM filter for filtering and providing light of a predetermined second wavelength range,
The second sensor module includes a second light source, a second EX filter for filtering the light emitted from the second light source with light of a predetermined third wavelength range and providing the light to the heat exchanger, Guiding the second fluorescent light emitted from the fluorescent substance layer to a second detector for detecting the second fluorescent light as the fouling is formed on the surface of the fluorescent substance layer applied on the inner surface of the tube of the heat exchanger, And a second EM filter for filtering the second fluorescent light at the front end of the second detector with light of a predetermined fourth wavelength range and providing the second fluorescent light. The method according to claim 1,
Wherein the first sensor module monitors the fouling state by the bio-fouling material, NADH. 3. The method of claim 2,
Wherein the first wavelength region is 340 nm and the second wavelength region is 460 nm. 3. The method of claim 2,
The first light path portion includes a first light projecting portion that forms a window through which light can be transmitted into the heat exchanger tube, a first light control portion that guides the light emitted from the first EX filter to the first light projecting portion, And a first light receiving portion for guiding the first fluorescence received through the one light transmitting portion to the first EM filter,
The second light path portion includes a second light projecting portion that forms a window through which light can be transmitted into the heat exchanger tube, a second light projecting portion that guides the light emitted from the second EX filter to the second light projecting portion, And a second light receiving portion for guiding a second fluorescent light received through the second light transmitting portion to the second electromagnetic filter. 5. The method of claim 4,
The first light receiving portion, the first light receiving portion, the second light control portion, and the second light receiving portion extend from the tube of the heat exchanger to the outside of the shell of the heat exchanger,
Wherein the first light source, the first detector, the second light source, and the second detector are installed outside the heat exchanger shell. delete delete delete

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