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운전인자 조절에 따른 박막강하형 농축기 처리수 효율 비교
박진석(Jinseok Park),정진도(Jindo Chung) 한국환경에너지공학회 2023 한국열환경공학회 학술대회지 Vol.2023 No.2
In a thin film falling concentrator, the product evaporates as it descends by creating a constant thin film from the top to the bottom inside the heating tube through the distributor, and the heated vapor condenses on the outside of the heating tube. An appropriate distributor must be applied according to the physical properties of the product. There are three types of distributors: perforated plate type, nozzle type, and tube type. Among these, the perforated plate type is widely adopted. Broadly speaking, the structure of the concentrator consists of a heating tube that performs heat exchange and a separator that separates the evaporated gas. Thin-film fall concentrators are the most widely used equipment at present because the product thickness is thin, so thermal efficiency is high, and the residence time is short, so there is no thermal denaturation of the product. Based on the T-N data of the analyzed facility treated water, we compared the wastewater properties according to the manipulation of several operating factors and how to supplement the facility. We will focus on comparing changes in the T-N removal efficiency of treated water and facility supplementation methods due to changes in the process, and conduct comparative studies on the sulfuric acid input amount and operation method that are expected to have an impact.
복합발전 증기온도 상향운전으로 에너지 효율 향상에 대한 연구
장재열(Jae-yel Jang),정진도(Jindo Chung) 한국환경에너지공학회 2023 한국열환경공학회 학술대회지 Vol.2023 No.2
Climate change, a basic plan is being established to abolish coal power generation and expand nuclear power plants and renewable energy in order to reduce carbon neutrality and greenhouse gases. It is difficult to further expand the proportion of spent nuclear fuel in nuclear power plants under the current supply conditions. In order to minimize job problems caused by the abolition of coal power generation, combined cycle using LNG power generation is expected to increase for the time being. In this paper, through analysis of operating conditions of combined cycle power plants, review of allowable temperature conditions for heat recovery boiler materials, improvement and tuning of control logic within the control system, and improvement of emergency stop conditions, HRSG (heat recovery steam generator) steam temperature increase operation is carried out, theoretical basis for improving energy efficiency of combined cycle power plants is presented, major factors are derived through various tests, and improvement results and effects are discussed.
유기성 폐수처리를 위한 역삼투막의 바이오파울링 세정에 관한 연구
김홍구(Heunggu Kim),정진도(Jindo Chung) 한국환경에너지공학회 2023 한국열환경공학회 학술대회지 Vol.2023 No.2
Reverse Osmosis(RO) membrane is used throughout the world for organic wastewater such as reuse of treated sewage water and industrial wastewater and it has gained wide popularity due to its efficient energy consumption and the safe operating process. However, biological fouling, which is the most problematic for membrane operation, is an inevitable process that cannot be avoided and can only be managed. The control of biological fouling on such RO membranes is restricted, since oxidising biocides like chlorine degrade the membrane material, thereby increasing salt passage and reducing membrane life. Therefore, this study investigated the use of a non-oxidizing biocide, namely 2,2-dibromo-3-propionamide (DBNPA), in CIP processes to control and reduce biological fouling of TFC PA membranes. During the inhibition of biofilm formation and removal of biological fouling on the RO membranes by CIP applying DBNPA, no significant changes occurred in RO feedwater pressure, permeate flux, and salt removal rate. CIP of DBNPA reduced the amount of biofouling, regardless of DBNPA concentration strategy used. However, within the scope of this study, biological fouling was best controlled with a DBNPA circulation for 30 minutes of 200 ppm twice daily.
시험소간 성능 검증을 위한 벽면 속도 보상 10회선 초음파 유량계 개발
박정규(Jungkyu Park),정진도(Jindo Chung) 한국환경에너지공학회 2023 한국열환경공학회 학술대회지 Vol.2023 No.2
Most wet- type multi-path ultrasonic flowmeters have their measurement accuracy rate to be deteriorated as the flow rate is decreased. Curve-fitting on the characteristics of ultrasonic flowmeters is essential to improve their measurement accuracy rate. This hinders their use as transfer standards in inter-laboratory comparisons for water flow metrology. A breakthrough to enhance the measurement accuracy rate of ultrasonic flowmeters is needed. This study suggests that the concept of near-wall flow velocity should enhance the characteristics of ultrasonic flowmeters. As a result, the repeatability can be improved as low as 土0. 02% which should be suitable to be used as transfer standards. Two main points of using the near-wall flow velocity for ultrasonic flowmeters are emphasized. One is a formula to describe the near-wall flow velocity as a function of both Reynolds number and surface roughness. The other one is the results of comparison calibrations between two national metrology institutes, which can support measurement equivalence. In particular, the number of equivalence is less than one (¦E_n¦ ≤ 1), and the inconclusiveness parameter is less than two (u_comp/u_base≤ 2) if the near- wall flow velocity is applied for ultrasonic flowmeters. This implies that the ultrasonic flowmeters could be used as transfer standards for the forthcoming inter-laboratory comparisons.
바이오매스 연료 투입을 위한 Ejector 성능 특성 연구
권안규 ( Ankyu Kwon ),정진도 ( Jindo Chung ) 한국폐기물자원순환학회 2023 한국폐기물자원순환학회지 Vol.40 No.4
Renewable energy is becoming a competitive resource in numerous countries, leading to continuous expansion in electricity generation. Burning biomass in Circulating Fluidized Bed Combustion (CFBC) systems presents a method for reducing CO<sub>2</sub> emissions and necessitates further technological advancements. After a comprehensive computational analysis of the ejector, parameters were established in which the air blower flowrate is 2.4 kg/s, the fuel input is between 8.3 to 10 tons per hour, and the fuel is stably injected at 180 mm of ejector nozzle diameter (Dnoz) and 300 mm of throat diameter (Dth). Additionally, we analyzed the benefits of using domestic, unused forest biomass fuel - a form of carbonneutral energy. The results show that it is possible to secure 11.2 million tons of Renewable Energy Certificates (RECs) per year as a Renewable Portfolio Standard (RPS) mandatory supplier without relying on imported wood pellets, thus reducing greenhouse gas CO<sub>2</sub> emissions by 120,000 tons annually.
바이오매스 연료 투입 비율에 따른 순환유동층 보일러의 성능 특성 연구
권안규 ( Ankyu Kwon ),정진도 ( Jindo Chung ) 한국폐기물자원순환학회 2023 한국폐기물자원순환학회지 Vol.40 No.1
In this study, biomass fuel was injected into a domestic 200 MW fluidized bed boiler to study the characteristics of the boiler’s flow state and performance changes. As the biomass mixing ratio increased, the temperature of the upper part of the boiler increased and combustibility increased. As the amount of biomass increased, the amount of fuel (coal) relatively decreased, and the temperature of the cyclone outlet decreased; it was confirmed that the combustibility increased. As the amount of the circulation flow substance of small particulate matter (ash) increased to the upper part, the upper pressure determines that heat transfer due to the conduction of the water wall tube increased and combustibility improved. It was determined that the heat absorption amount of the rear heat transfer part to the heat exchanger increased and the heat distribution due to the amount of exhaust gas increased.