질량유량 기반의 스프링클러헤드 수별 급수관 구경 선정방법에 관한 연구

남준석(Jun Seok Nam) 안전문화포럼 2023 안전문화연구 Vol.- No.25

본 연구의 목적은 소방배관을 설계하는 방법은 수리계산방식과 규약배관방식이 있고 현장에서는 ‘스프링클러설비의 화재안전성능기준’ [별표 1]에 따른 규약배관방식을 선호하고 있다. 규약배관방식의 급수관 구경별 헤드수에 대한 근거와 물리적 의미에 대해서는 언급되지 않고 있고 사용할 수 있는 관의 종류도 늘어났다. 관의 종류별로 [별표 1]에 따른 헤드수를 계산하여도 적합한지에 대한 규명이 없어 각국의 규정 비교와 이에 대한 유체역학적 계산을 통해 그 근거를 마련하고자 하였다. 연구의 방법은 미국, 영국, 한국의 관련 기준 분석을 통해 ‘스프링클러설비의 화재안전성능기준’ [별표 1]의 근거를 확인하였다. 관에 흐르는 유속을 근거로 질량유량 기반의 헤드와 관의 헤드수를 계산하여 비교하였다. 관의 종류로는 일반적으로 가장 많이 사용되는 KS D 3507을 기준으로 하였고 KS D 5301과 3595 관을 상대적으로 비교하여 헤드수가 적합한지를 확인하였다. 또한, 가지배관의 유속한계(6 ㎧)와 기타배관의 유속한계(10㎧)를 기준으로 가지배관의 한계가 어디까지인지 확인하기 위해 25A(25 Su), 32A(30 Su), 40A(40 Su), 50A(50 Su)로 가지배관 수를 늘려가며 변화여부를 확인하였다. 본 연구를 통해 스프링클러헤드 수별 급수관 구경 산정방법의 근거는 NFPA 13에 있음을 확인하였다. 관 유속을 근거로 질량유량 기반의 헤드수를 헤드와 관에 대해 비교하여 헤드수를 계산하였다. KS D 3507을 [별표 1]의 산정기준으로 하여 KS D 5301과 3595관을 관조도를 고려하여 상대적으로 비교한 결과 충분히 사용할 수 있음을 확인하였다. 또한, 가지배관의 수를 늘려가며 확인한 결과 가지배관은 40A까지 사용하는 것이 적합한 것으로 판단되었고 가지배관의 호칭이 늘어남에 따른 변화는 없는 것으로 확인하였다. 기준 비교와 질량유량 기반의 헤드수 비교를 통해 ‘스프링클러설비의 화재안전성능기준’ [별표 1] 근거를 확인하였고 KS D 3507, 5301, 3595 모두 적용이 가능함을 확인하였다. KS D 3595의 경우 65A에 대응하는 호칭으로 60 Su와 75 Su가 있어 이에 대한 설계의 유연성을 가질 수 있다고 판단되었다. The purpose of this study is that there are two methods for designing firefighting piping: the hydraulic calculation method and the conventional piping method. In the field, the conventional piping method according to the ‘Fire Safety Performance Standards for Sprinkler Equipment’ [Appendix 1] is preferred. There is no mention of the basis and physical meaning of the number of heads for each water supply pipe diameter in the conventional piping method, and the types of pipes that can be used have also increased. Since there was no confirmation as to whether it was appropriate to calculate the number of heads according to [Appendix 1] for each type of pipe, an attempt was made to establish a basis through comparison of regulations in each country and hydrodynamic calculations. The research method was to confirm the basis of the ‘Fire Safety Performance Standards for Sprinkler Equipment’ [Appendix 1] through analysis of relevant standards in the US, UK, and Korea. Based on the flow rate in the pipe, the mass flow rate-based head and the number of pipe heads were calculated and compared. As for the type of pipe, KS D 3507, which is the most commonly used, was used as a standard, and KS D 5301 and 3595 pipes were compared to determine whether the number of heads was appropriate. In addition, in order to check the limits of branch piping based on the flow speed limit of branch piping (6 ㎧) and the flow speed limit of other piping (10 ㎧), 25A (25 Su), 32A (30 Su), 40A (40 Su), we checked for changes by increasing the number of branch pipes to 50A (50 Su). Through this study, it was confirmed that the basis for the method for calculating water supply pipe diameter by number of sprinkler heads is in NFPA 13. Based on the pipe flow rate, the number of heads was calculated by comparing the head number based on mass flow rate for the head and pipe. Using KS D 3507 as the calculation standard in [Appendix 1], it was confirmed that KS D 5301 and 3595 pipes can be sufficiently used as a result of comparative comparison considering the degree of irradiation. In addition, as a result of increasing the number of branch pipes, it was determined that it was appropriate to use branch pipes up to 40A, and it was confirmed that there was no change as the number of branch pipes increased. Through comparison of the standards and the number of heads based on mass flow rate, the basis of ‘Fire Safety Performance Standards for Sprinkler Equipment’ [Appendix 1] was confirmed, and it was confirmed that all KS D 3507, 5301, and 3595 are applicable. In the case of KS D 3595, there are 60 Su and 75 Su as names corresponding to 65A, so it was judged that flexibility in design could be achieved.

초음속 유동에 대한 핀틀형 수소인젝터의 질량유량 예측

이재현,배규한,문석수 한국자동차공학회 2024 한국 자동차공학회논문집 Vol.32 No.6

Hydrogen engines with low-pressure direct injection are in the spotlight as a sustainable energy system. The direct-injection system with a low-pressure fuel supply has adopted pintle-type hydrogen injectors to guarantee sufficient flow rates. Predicting the mass flow rate of the pintle-type injector precisely is essential; however, no concrete prediction models have been suggested so far. Thus, this study introduced a methodology to predict the mass flow rate of supersonic flow from pintle-type hydrogen injectors based on the compressible flow theories of convergent-divergent nozzles. The prediction accuracy of the methodology is examined by comparing the prediction results with experimental results under various injection and ambient pressure conditions with various gases (nitrogen and helium). The results confirmed the methodology’s prediction accuracy over 92 %, which would predict hydrogen mass flow rates from the results of surrogate gases and in various injection and ambient conditions.

Immersed Solid Method 를 이용한 외접형 기어 펌프의 수치해석

윤용한(Yong Han Yoon),박병호(Byung Ho Park),한용운(Yong Oun Han),홍병주(Byeong Joo Hong),심재술(Jaesool Shim) 대한기계학회 2014 大韓機械學會論文集B Vol.38 No.1

본 연구는 고속 회전형(~10,000 rpm) 기어펌프의 질량유량과 효율을 예측하기 위해서 2 차원 immersed solid method(ISM)를 이용한 수치해석을 수행하였다. 기어펌프와 하우징의 순환유동을 고려하기 위하여 유체 유동을 난류 유동으로 가정하였고, 기어 펌프의 입 출구의 일정 압력 조건하에 기어펌프의 회전 속도를 부가하였다. 기어펌프의 다양한 회전 속도 및 기어 끝 단과 하우징 사의의 서로 다른 간극에 대한 질량유량 및 효율을 검토하였다. 해석 결과로서, 회전 속도가 증가할수록 평균 질량유량 및 효율은 증가하였고, 기어펌프와 하우징의 간격이 증가할수록 평균 질량유량 및 효율은 감소하였다. 간격이 없는 조건하의 6,000 rpm, 8,000 rpm, 10,000 rpm 회전속도에의 효율은 각각 85.11 %, 90.94 %, 93.62 % 를 얻었고, 간격이 0 m, 0.00001 m, 0.00003 m 에 대해서 효율은 각각 93.62 %, 93.29 %, 92.74 % 를 얻었다. In this study, an ISM (immersed solid method) was used for investigating the mass flow rate and efficiency of an involute-gear pump featuring very high rotational speed. For considering circulation flow at the gear pump and housing, fluid flow was assumed as turbulent, and the rotational speed of the gear pump increased under the condition of constant pressure at both the inlet and outlet. The efficiency and mass flow rate of the gear pump were studied by varying its rotational speed and the clearance between the gear tip and the housing. In the simulation results, as the rotational speed were increased, the average mass flow rate and efficiency increased. Furthermore, as the clearance between the gear tip and the housing was increased, the average mass flow rate and efficiency decreased. The efficiency was 85.11, 90.94, and 93.62 at rotational speeds of 6,000 rpm, 8,000 rpm, and 10,000 rpm, respectively, under the condition that there was no clearance. In addition, the efficiency was 93.62, 93.29, and 92.74 at clearances of 0 m, 0.00001 m, and 0.00003 m respectively.

수직 액막형 흡수기의 흡수성능 변화에 미치는 냉각수 유량의 영향

김정국,조금남 대한설비공학회 2006 설비공학 논문집 Vol.18 No.5

The present study predicted the effect of the flow rate of coolant on the absorption performance of a vertical falling film type absorber. Heat and mass transfer performances were numerically investigated. The exit temperatures of solution and coolant were decreased as the flow rate of the coolant was increased at the film Reynolds number of 100. The absorption mass flux was increased and then decreased as the distance from the inlet of the absorber was increased. The distance showing the maximum absorption mass flux was ranged from 0.3 to 0.5m. The heat flux and the absorption mass flux were increased and then slowly decreased as the flow rate of the coolant was increased. The maximum values were obtained at the flow rate of coolant of 2.0L/min.

미소 유량 센서에 관한 실험적 연구

김태훈(Tae Hoon Kim),김성진(Sung Jin Kim) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4

In the present paper, a micro flow sensor, which can be used at bio-delivery systems and micro heat pumps, is developed. For this, the micro flow sensor is integrated on a quartz wafer (SiO₂) and is manufactured by simple and convenient microfabrication processes. The micro flow sensor aims for measuring mass flow rates in the low range of about 0~20 SCCM. The micro flow sensor is composed of temperature sensors, a heater, and a flow microchannel. The temperature sensors and the heater are manufactured by the sputtering processes in this study. In the microfabrication processes, stainless steel masks with different patterns are used to deposit alumel and chromel for temperature sensors and nichrome for the heater on the quartz wafer. The microchannel is made of Polydimethylsiloxane(PDMS) easily. A deposited quartz wafer is bonded to the PDMS microchannel by using the air plasma. Finally, we confirmed the good operation of the present micro flow sensor by measuring flow rate.

공기와 물의 이상 자연순환 유동의 1차원 해석

박래준(Rae-Joon Park),하광순(Kwang-Soon Ha),김재철(Jae-Cheol Kim),홍성완(Seong-Wan Hong),김상백(Sang-Baik Kim) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

Air-water two phase natural circulation flow in the T-HERMES (Thermo-Hydraulic Evaluation of Reactor cooling Mechanism by External Self-induced flow)-1D experiment has been evaluated to verify and evaluate the experimental results by using the RELAP5/MOD3 computer code. The RELAP5 results have shown that an increase in the coolant inlet area leads to an increase in the water circulation mass flow rate. However, the water outlet area does not effective on the water circulation mass flow rate. As the coolant outlet moves to a lower position, the water circulation mass flow rate decreases. The water level is not effective on the water circulation mass flow rate. As the height increases in the air injection part, the void fraction increases. However, the void fraction in the upper part of the air injector maintains a constant value. An increase in the air injection mass flow rate leads to an increase in the local void fraction, but it is not effective on the local pressure.

코일 형상에 따른 모세관내 냉매유량 특성

박차식(Chasik Park),강훈(Hoon Kang),정태훈(Taehun Jung),김용찬(Yongchan Kim) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

Air-conditioners use a spirally coiled capillary tube as an expansion device to enhance compactness of the unit. However, most empirical correlations in open literature were developed for straight capillary tubes without considering coiled effects on the mass flow rate. The objectives of this study are to investigate the flow characteristics of coiled capillary tubes and to develop a generalized correlation for mass flow rate through coiled capillary tubes. The mass flow rates through the coiled capillary tubes and straight capillary tubes were measured by varying operating conditions and tube geometry. The condensing temperatures varied at 40.5, 47.5, and 54.5℃, and subcoolings altered at 3.5, 6.5, and 11.5℃. The mass flow rates of the coiled capillary tubes decreased by 5 to 16% compared with those of the straight capillary tubes at the same operating conditions. An empirical correlation was developed by introducing non-dimensional parameters for operating conditions and coiled geometry based on the present data and the open literature database for R22.

인공신경망을 이용한 가변 기구 터보차저의 터빈 질량유량 모델링

박영섭(Yeongseop Park),오병걸(Byounggul Oh),이민광(Minkwang Lee),선우명호(Myoungho Sunwoo) 대한기계학회 2010 大韓機械學會論文集B Vol.34 No.8

이 논문에서는 인공신경망을 이용하여 가변 기구 터보차저(VGT)의 터빈 질량유량을 추정하는 모델을 제안하고자 한다. 터빈 질량유량을 추정하기 위한 모델의 입력변수는 VGT 베인 개도량, 엔진 회전속도, 배기매니폴드 압력, 배기매니폴드 온도, 터빈 출구 압력이 사용되었으며, 터빈 입구 유효 단면적을 추정하는 부분에 인공신경망을 적용하였다. 실험을 통하여 이 논문에서 제안한 모델의 터빈 질량유량 추정 성능을 검증하였으며, 터빈 맵을 이용하여 추정한 결과와 비교를 통하여 제안한 모델의 우수성을 확인하였다. In this paper, we propose a turbine mass flow rate model for a variable geometry turbocharger (VGT) using an artificial neural network (ANN). The model predicts the turbine mass flow rate using the VGT vane position, engine rotational speed, exhaust manifold pressure, exhaust manifold temperature, and turbine outlet pressure. The ANN is used for the estimation of the effective flow area. In order to validate the results estimated by the proposed model, we have compared estimation results with engine experimental results. The results, in addition, represent improved estimation accuracy when compared with the performance using the turbine map.

최적의 타공판을 통한 열풍건조로 성능향상 연구

서응수(Eung Soo Seo),김용식(Yongsik Kim),황중국(Joong Kook Hwang),채영석(Young Suck Chai),심재술(Jaesool Shim) 대한기계학회 2015 大韓機械學會論文集A Vol.39 No.9

염료감응형 태양전지용 플렉시블 필름에 도포된 코팅물질의 균질한 코팅은 제품의 성능과 내구성과 매우 밀접한 관계가 있고, 균질한 코팅은 열풍건조로 노즐에서의 균일한 온도분포와 질량유량에 의해 얻어질 수 있다. 본 연구에서 열풍건조로의 성능향상에 영향을 주는 다양한 인자들에 대한 수치해석을 수행함으로써 열풍건조로 출구의 균일한 온도분포와 질량유량을 얻고자 하였다. 수치해석 모델은 유동방정식과 에너지방정식으로 구성되었고, 수치해석을 모델의 검증을 위해 수치해석 결과값과 실험결과를 비교하였다. 연구결과로서 열풍건조로의 타공판이 균일한 온도분포 및 질량유량에 큰 영향을 미친다는 것을 알 수 있었다. The homogeneous coating of a flexible film that is applied to dye-sensitized solar cells is related to the performance and durability of the product. The applied coating is obtained from the uniform temperature distribution and the mass flow rate in the nozzle of the hot air dryer. In this study, we determine the uniform temperature distribution and mass flow rate of each nozzle by performing numerical simulations to understand how various factors affect the performance of the hot air dryer. The numerical model is composed of the momentum equation for flow motion and the energy equation for temperature. In addition, we compare the numerical results to the experimental results to validate the model. Based on the results, the round-hole plate inside the hot air dryer significantly affects the uniform temperature and the mass flow rate.

과산화수소/케로신 점화용 분사기 설계 및 분무특성에 관한 연구

김보연(Boyeon Kim),황오식(Ohsik Hwang),이양석(Yangsuk Lee),고영성(Youngseong Ko),김유(Yoo Kim),김선진(Sunjin Kim) 한국추진공학회 2009 한국추진공학회 학술대회논문집 Vol.2009 No.5

본 연구에서는 케로신/과산화수소 점화용 분사기의 설계/제작하여 분무특성에 관한 연구를 수행하고자 하였으며, 이에 앞서 촉매점화방식으로 적용할 때 가장 적합한 분사기를 설계하고자 하였다. 설계/제작된 분사기를 수류시험을 통해 질량 유량 및 분산각을 측정하였다. 그 결과 케로신의 목표 질량유량(12.88g/s)은 설계 차압과 같은 차압인 3 bar에서 측정되었으며, 이 때 분산각은 40˚임을 확인하였다. 또한 과산화수소의 목표 질량 유량(94.39g/s)은 설계 차압(3 bar) 보다 작은 1 bar에서 측정됨을 확인하였다. This study was performed to design of H2O2/Kerosene catalyst ignition injector and cold flow test to measure the mass flow rate and spray angle. Mass flow rate and spray angle were measured by designed injector through cold flow test. Result of test kerosene mass flow rate was measured 12.88 g/s and 40 deg of spray angle at pressure drop 3 bar as same as design point. And hydrogen peroxide was measured 94.39 g/s at pressure drop 1 bar smaller than design point.