KR20160104249A - Aeration tank efficiency measuring device and power control system using the same - Google Patents

Abstract

According to the present invention, an aeration tank efficiency measuring device comprises: a vacuum pump transferring off-gas of an aeration tank collected in a gas collecting device to the inside thereof; a sensor module measuring oxygen concentration, carbon dioxide concentration, temperature, humidity, and pressure of ambient air and off-gas transferred by the vacuum pump; a control unit collecting and storing data measured by the sensor module; a calculation unit calculating oxygen delivery efficiency of the aeration tank based on stored data in the control unit; and a display unit outputting a value of oxygen delivery efficiency calculated by the calculation unit.

Description

TECHNICAL FIELD [0001] The present invention relates to an aeration tank efficiency measuring apparatus and a power control system using the same. [0002] Aeration tank efficiency measuring apparatus,

The present invention relates to an apparatus for measuring an aeration tank efficiency and a power control system using the same, and more particularly, to an apparatus for measuring an aeration tank efficiency and a power control system through measurement of oxygen delivery efficiency.

Sewage treatment plants are known to consume a large amount of electricity, and power consumption differs depending on the treatment process and treatment capacity of each treatment plant, and the characteristics of the influent and aeration equipment. In the United States, about 45 to 75% of the total power consumption of sewage treatment plants is used for the operation of aeration equipment. Therefore, the economical and efficient operation of the aeration tank is directly linked to the reduction of the maintenance cost of the treatment plant, which depends on how effectively the oxygen is delivered to the sewage. The oxygen transmission rate depends on the type of the diffuser, the diffuser method, the installation depth of diffuser, the mounting arrangement of the diffuser, and the installation density.

In the past, the method of measuring the oxygen transfer efficiency of sewage has not been introduced. Therefore, in some sewage treatment plants, there is no accurate diagnosis or economic analysis of the existing facility for operation of the aeration tank, Existing aeration machine equipment was often replaced without an accurate assessment, resulting in large economic losses.

These problems have been recognized by many sewage terminal treatment plants, and it is recognized that enormous power is consumed due to the inefficient operation of the treatment process operation and the mechanical facility. However, since there is no clear efficiency measurement and diagnosis evaluation method, In fact.

At the end of the 1960s, to solve these problems, some scholars and engineers used the non-steady state method, which is a measurement method for the performance of the aeration tank operation condition and aeration equipment, Technologies such as Tracer Measurement of Oxygen Transfer Method have been developed. However, the proposed techniques are difficult to measure and costly and ineffective.

In the early 1980s, Offgas Analyzer technology was developed by Lloyd Ewing and David Redmon and is currently underway in the United States. The by-product gas analysis technique measures the difference in the mole ratio of oxygen that does not cause a chemical reaction between the amount of air supplied from the aeration unit in the aeration tank and the amount of air remaining. One of the most important indicators for evaluating the ability to transfer oxygen to sewage using aeration equipment is to remove pollutants from sewage by using an Oxygen Transfer Efficiency (OTE) It is possible to know how effectively the amount of oxygen supplied to the microorganisms in the aeration tank is supplied, and also to diagnose and evaluate whether it is operating unreasonably.

Therefore, data measured and analyzed by this method can be applied to aeration equipment manufacturers and drivers, which can fundamentally save energy consumption for the entire plant if accurate oxygen transfer data is used to improve the energy efficiency of the aeration equipment.

In the United States, development and marketability of aeration equipment has been rapidly changing, while data on oxygen transfer from a real-scale sewage treatment plant have been extremely limited up to 20 years ago, and understanding and performance of existing aeration equipment Before it was revealed on the side, various new facilities were introduced. On the other hand, there is little data on the oxygen transfer due to the lack of development of a simple and accurate technique for measuring the oxygen transfer efficiency to the aeration tank. In order to recognize the importance of data on aeration facilities and equipment, designers and operators of sewage treatment plants in the US Environmental Protection Agency (EPA) and the Society of Civil Engineers (ASCE) established the Design Manual on Fine Pore Aeration) was issued to many engineers in the United States.

Most of the data on oxygen transfer are made using by-product gas analysis techniques. By-product gas analysis technology has been approved by the US Environmental Protection Agency as well as the American Society of Civil Engineers as a standard measurement technology for oxygen transfer. Today, it is a part of diagnosis and evaluation for efficient operation of sewage treatment plant, It is widely commercialized as a retrofit for processing.

In addition, it is used as an indispensable technology for future design for expansion of existing processing facilities and advanced design process for the removal of nitrogen and phosphorus. This is effective in the operation of existing aeration facilities and the research and development of aeration equipment It is widely used.

Conventional measuring devices using byproduct gas analysis technology are composed of sensors and indicators for measuring the oxygen transfer efficiency. Through the manual valve operation, the measured values of the by-product gas and the atmospheric gas are written by hand to calculate the mole fraction of oxygen And it was difficult to calculate the oxygen efficiency value by calculating the oxygen transfer efficiency using only the mole fraction of oxygen except carbon dioxide and humidity.

Korean Patent Registration No. 10-0193784 (Feb. 4, 1999) Korean Patent Registration No. 10-0913728 (Aug. 18, 2009) Korean Patent Registration No. 10-0913726 (Aug. 18, 2009)

It is an object of the present invention to provide an aeration tank efficiency measuring apparatus capable of measuring oxygen delivery efficiency more accurately and conveniently and using the same to control the blower, And to increase the power use efficiency.

In order to accomplish the above object, an apparatus for measuring an aeration tank efficiency according to the present invention comprises a vacuum pump for transferring off-gas of an aeration tank collected in a gas collecting apparatus to the inside, a by- a sensor module for measuring oxygen concentration, carbon dioxide concentration, temperature, humidity and pressure of ambient air, a control section for collecting and storing the measured data in the sensor module, calculating the oxygen transfer efficiency of the aeration tank based on the data stored in the control section And a display unit for outputting an oxygen delivery efficiency value calculated by the operation unit.

The sensor module may include a first module for measuring oxygen, carbon dioxide, temperature, humidity and pressure of the by-product gas and a second module for measuring oxygen, carbon dioxide, temperature, humidity and pressure of the atmospheric gas.

The apparatus for measuring an aeration tank efficiency according to an embodiment of the present invention may further include a flow meter for measuring a flow rate of by-product gas.

In the aeration tank efficiency measuring apparatus according to an embodiment of the present invention, the gas collecting apparatus may include a floating hood, and may further include a transfer tube connected to the floating hood to transfer the by-product gas.

The aeration tank efficiency measuring apparatus according to the present invention has the effect of increasing the power use efficiency of the sewage treatment plant by evaluating the efficiency of the aeration tank more accurately and easily.

Further, the apparatus for measuring an aeration tank efficiency according to the present invention has an effect of measuring the efficiency of the aeration tank more conveniently by increasing portability and mobility.

1 is a conceptual diagram illustrating an aeration tank equipped with an aeration tank efficiency measuring apparatus according to an embodiment of the present invention.
2 is a side view of the aeration tank efficiency measuring apparatus according to the embodiment of the present invention installed in the aeration tank.
3 is a transmission plan view of the aeration tank efficiency measuring apparatus shown in Fig.
4 is a conceptual diagram of an aeration tank efficiency measuring apparatus according to an embodiment of the present invention.
5 is a graph showing changes in the oxygen transmission rate and the optimum operating range of the blower according to the blowing amount.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having ", and the like, specify that the presence of stated features, integers, steps, operations, elements, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless expressly defined herein Do not.

Hereinafter, an aeration tank efficiency measuring system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram showing an apparatus 100 for measuring an aeration tank efficiency according to an embodiment of the present invention and an aeration tank 200 using the same. The aeration tank 200 of the sewage treatment plant includes an air blower 110 for supplying oxygen or air and an air diffuser 120 for introducing oxygen or air supplied from the blower 110 into the wastewater in an aeration state.

Further, the apparatus 100 for measuring an aeration tank efficiency according to the embodiment of the present invention includes a gas collecting apparatus 10, a transfer tube 20, and a case 30.

The gas collecting apparatus 10 is installed at one or more measuring points in the aeration tank 200 to maintain the floating state and collect the by-product gas. As shown in the figure, a plurality of measuring apparatuses 100 can be used for measuring the efficiency of the aeration tank 200. In this case, the aeration tank 200 is divided into a plurality of regions, and a plurality of gas collecting apparatuses 10 As shown in Fig.

The case 30 of the measuring apparatus 100 accommodates a vacuum pump, a sensor module, a control unit, a calculating unit and a display unit to be described later. The measuring apparatus 100 includes a sensor module housed in the case 30, a control unit, And calculates and outputs the oxygen transmission efficiency of the aeration tank 200.

2 is a side view of an apparatus 100 for measuring aeration efficiency according to an embodiment of the present invention. As shown in the figure, in the present embodiment, the gas collecting apparatus 10 is constituted by a floating hood, and the conveying tube 20 is connected to a gas collecting apparatus 10 constituted by a floating hood, 100).

In addition, as shown in the figure, the display unit 32 is provided on the upper part of the aeration tank efficiency measuring apparatus 100 so that the user can monitor the measurement result in real time.

The case 30 may be made of a rigid material that can protect the components stored therein. For example, the case 30 may be made of a SUS material. A plurality of wheels 34 are mounted on the lower portion of the case 30 and a handle 38 is mounted on the upper portion of the case 30 so that the user can easily move the measuring apparatus 100.

An opening 36 is formed in the side surface of the case 30 so that the transfer tube 20 can be inserted. The by-product gas collected in the gas collecting apparatus 10 flows into the case 30 of the measuring apparatus 100 through the transfer tube 20 inserted through the opening 36. [

3 is a transmission plan view of an aeration tank efficiency measuring apparatus 100 according to an embodiment of the present invention. A sensor module 40, a control unit 44, a vacuum pump 46, an operation unit (not shown), and a display unit 32 are disposed inside the case 30.

The vacuum pump 46 is disposed inside the case 30 and transfers the off-gas of the aeration tank 200 collected in the gas collecting apparatus 10 through the transfer tube 20 to the inside.

The sensor module 40 measures the components of the by-product gas and the atmospheric gas, and the temperature and the humidity. More specifically, the sensor module 40 includes a first module 41 and a second module 42. The first module 41 measures the oxygen, carbon dioxide, temperature, humidity and pressure of the by-product gas and transmits the result to the controller 44. The second module 42 measures oxygen, carbon dioxide, temperature, humidity And the pressure is measured and the result is sent to the control unit 44.

The control unit 44 collects and stores the data transmitted from the sensor module 40 and transmits the collected data to the operation unit (see FIG. 4). The operation unit calculates the oxygen transmission efficiency of the aeration tank 200, Lt; / RTI > Further, the operation unit controls the operation of the blower based on the measured value.

The display unit 32 outputs the calculated value of the oxygen transfer efficiency transmitted from the calculation unit in real time.

4 is a conceptual diagram of an aeration tank efficiency measuring apparatus 100 according to an embodiment of the present invention. Hereinafter, the operation of the measuring apparatus 100 according to the present embodiment will be described in detail with reference to FIG.

4, the apparatus 100 for measuring an aeration tank efficiency according to an embodiment of the present invention includes a vacuum pump 46, a sensor module 40, a control unit 44, an operation unit 52, and a display unit 32, . The control unit 44 and the operation unit 52 may be configured to perform the functions of both the control unit 44 and the operation unit 52. In this case, And the arithmetic unit 52 may be separated from each other by separate components, and the functions thereof may be performed.

Further, the measuring apparatus 100 according to the present embodiment includes a flow meter 54 for measuring a flow rate of the by-product gas and the air to be introduced.

The sensor module 40 measures the oxygen concentration, the carbon dioxide concentration, the temperature, the humidity and the pressure of the by-product gas and the atmospheric gas transferred by the vacuum pump 46. The sensor module 40 may be controlled to transmit the measurement results to the control unit 44 at intervals of about 5 to 10 seconds.

Specifically, the sensor module 40 includes a first module 41 for measuring oxygen, carbon dioxide, temperature, humidity and pressure of the by-product gas, a second module 41 for measuring oxygen, carbon dioxide, temperature, humidity, 42).

The first module 41 and the second module 42 include an oxygen sensor, a carbon dioxide sensor, a temperature and humidity sensor, and a pressure sensor, respectively, and are connected to the control unit 44 in a wired or wireless manner. The sensors of the first module 41 and the second module 42 may be installed on a printed circuit board (PCB) to measure the information of the by-product gas or air flowing in real time.

The oxygen sensor of the first module 41 measures oxygen remaining after being absorbed by the microorganisms in the aeration tank 200 while the oxygen supplied from the blower 110 provides an aerobic condition to the microorganisms and smooth microorganisms purify the wastewater. In addition, the carbon dioxide sensor measures the carbon dioxide that the microorganisms breathe and emits, and the temperature and humidity sensor measures the temperature, humidity and atmospheric pressure of the measuring point.

The measured value is transmitted to the controller 44 and stored, and the controller 44 transmits the measured value to the calculator 52 at intervals of 5 to 10 seconds.

The control unit 44 includes an MCU (not shown) for verifying an error of the data transmitted from the first module 41 and the second module 42 and transmitting the data to the operation unit 52 at regular intervals, And a memory unit (not shown) for storing the measured data and the data correction information transmitted from the operation unit 52. [ The controller 44 may further include a power terminal portion connected to the battery power source and a rectifier portion (not shown) for stably rectifying the current.

The MCU verifies the reliability of the oxygen amount (concentration), the amount of carbon dioxide (concentration) in the by-product gas measured by the first module 41, the temperature and humidity of the measurement point, and the pressure data. That is, in order to improve linearity and accuracy of each sensor of the first module 41, it is collected and processed by the MCU built-in program of the control unit 44.

Hereinafter, a method of analyzing the oxygen transfer efficiency based on the real-time oxygen amount information, the carbon dioxide information, the temperature information, the humidity information, and the atmospheric pressure information measured by the sensor module 40 will be described in detail.

In the embodiment of the present invention, the oxygen transfer efficiency is a function of the relative oxygen fraction (Fraction of Oxygen) contained in the gas flowing into the aeration tank 200 from the air supplied from the blower 110 and the gas discharged into the atmosphere from the aeration tank 200, .

The calculation unit 52 measures the by-product gas emission amount and the oxygen fraction in the exhaust gas. Byproduct gas means a gas which is absorbed by the microorganisms of the mixed water (MLSS) in the sewage in the air supplied into the aeration tank 200 and flows out into the atmosphere.

The oxygen transfer efficiency is calculated by the gas phase mass balance of the oxygen by the inflow and outflow gas, and the oxygen transfer coefficient (KLaf) is calculated by measuring the molar fraction of oxygen in the outflow and inflow gas, ) Can be estimated. Based on this coefficient, the oxygen transfer efficiency (OTE) is calculated by introducing the concept of mole ratio to express the oxygen transfer efficiency as a fraction.

Hereinafter, the oxygen transmission rate measurement and the energy efficiency analysis method using the measurement apparatus 100 of the present invention will be described in detail.

In order to measure the oxygen transmission rate, the amount of air to be injected into the aeration pipe 120 for injecting oxygen or air into the aeration tank 200, that is, the operation data of the blower 110, is used.

The method of measuring the oxygen transfer efficiency can be roughly divided into a clean water test and a process water test. The test at Chungsu was developed by the American Society of Civil Engineers (ASCE) to test the performance of an aeration device under standard conditions using clean water as an approved test method. The results derived from this authorized testing method are used as a basis for manufacturers to provide information to the buyer about the performance of the device 120 and to select the distributor 120 for the designer Can be used.

When an aeration unit 120 for aeration is installed in the aeration tank 200, it is necessary to test whether it is operated in accordance with the originally planned one. Several universal or progressive methods can be used to test the aeration apparatus 120 apparatus during operation of the aeration tank 200, all of which are also referred to as respiring-system tests.

For reference, the standard elimination efficiency (SAE) is calculated using the standard oxygen delivery rate and the oxygen delivery rate per injected unit power in the operation unit 52 using the following equations. The following equations are programmed to be calculated when data is input through the program stored in the operation unit 52. [

SAE = SOTR / power input

Here, SAE is generally expressed in units of kg / kW-hr (lb / hp-hr). Therefore, it is based on the power consumption of the blower 110 for measuring the oxygen transmission rate.

It is preferable to use a three-phase CT type power meter developed by EcoSense to measure the power consumption of the blower 110 used at this time. The measured power is transmitted to the calculating unit 52 in a wireless communication manner, and oxygen transmission efficiency is analyzed using oxygen and carbon dioxide concentration of off-gas.

The field measurement data sheet includes the name of the measurement plant, the name of the instrument (120) measured, the depth of the installation (120), the atmospheric pressure, C *, MLSS concentration of the sewage, total dissolved solids, Should be displayed. In addition, the following parameters indicating a stable state should be supplied for the position of each measuring apparatus 100 analyzed.

That is, the measurement time and position, the mole fraction of carbon dioxide to the by-product gas, the absolute humidity of the by-product gas and the atmospheric air in the analysis circuit, and the output value from the oxygen sensor to the by- Output value used to measure the temperature and concentration of sewage, dissolved oxygen change (C * - C), flow rate used, and by - product gas flow rate. Parameters such as byproduct gas outflow, OTEf, SOTE and SOTEsp20 are calculated for each location of the byproduct gas measurement device 100 where the measurement takes place.

The values of OTE, OTEsp20, and SOTEpw can be calculated as follows, and the formulas of MRi and MRe are as follows.

Here, the mole fraction of oxygen in atmospheric air (Yi) and by-product gas (Offgas) (Ye) can be determined using the following equation.

The OTEf is calculated as follows.

OTEsp is calculated by the following equation.

Finally, SOTEpw is calculated using the following equation.

Where OTEf is the oxygen transfer efficiency as a fraction of water at the site conditions and the temperature of the sewage, OTEsp is the oxygen transfer efficiency per mg / l under the standard conditions of 20 1 atm, SOTEpw is the effluent concentration at 0 mg / OTEsp20 C * 20), the offgas flux rate is the by-product gas release rate per area measured by the offgas flow meter, OTE is the captured by-product gas (Offgas) is the weighted average of OTE based on outflow rate.

The weighted average of SOTEpw is used to evaluate the by-product oxygen transfer efficiency in embodiments of the present invention.

The calculation unit 52 calculates the oxygen delivery efficiency of the aeration tank 200 based on the data stored in the control unit 44. The concentration of the oxygen supplied to the aeration tank 200 through the blower 110 and the remaining amount of the microbes are used for the biological reaction, Analyzing the oxygen transfer efficiency based on the real-time oxygen amount (concentration) information, the carbon dioxide information, the temperature information, the humidity information, and the atmospheric pressure information measured by the module 40. When the oxygen transmission efficiency is low, the operation unit 52 transmits a control command to increase the blowing amount and sends a control command to the blower 110 through the gateway to reduce the blowing amount when the oxygen transmission efficiency is sufficient. Control operation.

The wireless power measurement device used in measuring the power consumption of the blower 110 may be a three-phase CT type power meter developed by EcoSense. This is an uninterruptible type measuring instrument and can be installed on the blower 110 installed in the existing aeration tank in an uninterrupted manner. In the case of the blower 110 of the new aeration tank, a general wireless power device can be used.

Wireless power measuring device The measured power consumption of the blower 110 is transmitted to the calculating part 52 in a wireless communication manner and the oxygen transmission efficiency is analyzed using oxygen and carbon dioxide concentration of by-product gas (off-gas).

The information input to the arithmetic unit 52 is oxygen and carbon dioxide concentration, temperature, and humidity information for each spot measured by the sensor module 40. The information through the fan 110 is related to the power required for the fan 110, And effluent concentration (BOD), treatment flow rate, and the like.

The data output by the arithmetic unit 52 that processes such information is the flow rate of the blower 110, the blowing load, the measuring point, and the oxygen delivery efficiency (average) by time. Such output data can provide the acid efficiency, exchange cycle, sludge generation amount, and the like of the air diffuser 120.

FIG. 5 is a graph showing changes in oxygen transmission rate and optimum operating range of the blower according to the amount of air blown through by-product gas measurement according to an embodiment of the present invention. If the oxygen transfer efficiency is reflected in real time by using the measuring device according to the embodiment of the present invention, excessive power consumption can be prevented by controlling the amount of power of the blower operating at constant speed.

Hereinafter, a blower control method through a measuring apparatus will be described. First, the control unit 44 collects measured data from the sensor module 40, and transmits data to the operation unit 52 when there is no error in the measured value input from the sensor module in the MCU of the control unit 44.

Next, the data transmitted from the operation unit 52 is collected to calculate the oxygen transmission efficiency, and the operation unit 52 calculates real-time power consumption data of the blower transmitted through the wireless power measurement device for measuring the amount of power of the blower, Calculates the operating time of the blower according to the efficiency, and transmits the control command related to the blower operation to the blower to control the operation of the blower.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

100: aeration tank efficiency measuring device 200: aeration tank
10: gas collecting device 20: conveying tube
30: Case 110: Blower
120:

Claims (6)

A vacuum pump for transferring the off-gas of the aeration tank collected in the gas collecting device to the inside,
A sensor module for measuring by-product gas and ambient air oxygen concentration, carbon dioxide concentration, temperature, humidity and pressure transferred by the vacuum pump,
A controller for collecting and storing data measured by the sensor module,
An operation unit for calculating the oxygen delivery efficiency of the aeration tank based on the data stored in the control unit, and
And a display unit for outputting the oxygen transmission efficiency value calculated by the operation unit
And an aeration tank efficiency measuring device. The method according to claim 1,
The sensor module includes:
A first module for measuring oxygen, carbon dioxide, temperature, humidity and pressure of the by-product gas, and
Second module for measuring atmospheric oxygen, carbon dioxide, temperature, humidity and pressure
And an aeration tank efficiency measuring device. The method according to claim 1,
And a flow meter for measuring the flow rate of the by-product gas. The method according to claim 1,
Wherein the gas collecting device includes a floating hood. 5. The method of claim 4,
And a transfer tube connected to the floating hood for transferring the by-product gas. An aeration tank power control apparatus comprising an aeration tank efficiency measuring apparatus according to any one of claims 1 to 5.

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