• Title, Summary, Keyword: HVAC element

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Dynamic Analysis of HVAC Case for Passenger Car (승용차용 HVAC Case의 동특성 해석)

  • Yook, Ji-Yong;Cha, Yong-Kil;Lim, Jung-Su;Kim, Kwang-Il;Kang, Sung-Ho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.1
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    • pp.101-108
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    • 2009
  • This paper presents dynamic analysis of HVAC(heating ventilation & air conditioning) heater case which consists of heater and evaporator unit for passenger car. To analyze the dynamic characteristics of HVAC heater case, finite element model which consists of shell elements is constructed for modal analysis and experimental modal analysis has been conducted. Finite element analysis results are compared with experimental results to evaluate of validity of finite element model. After identifying mode shape and natural frequency of HVAC heater case, local stiffness of HVAC case is evaluated through point mobility using finite element analysis and experiment.

Dynamic Analysis of HVAC Case for Passenger Car (승용차용 HVAC Case의 동특성 해석)

  • Yook, Ji-Yong;Cha, Yong-Kil;Lim, Jung-Su;Kim, Kwang-Il;Kim, Sung-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.378-384
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    • 2008
  • This Paper presents dynamic analysis of HVAC(Heating Ventilation & Air Condition) Heater Case which consists of heater and evaporator unit for passenger car. To analyze the dynamic characteristics of HVAC Heater Case. finite element model which consists of shell elements is constructed for modal analysis and experimental Modal analysis has been conducted. Finite element analysis results are compared with experimental results to evaluate of validity of finite element model After identifying node shape and natural frequency of HVAC Heater Case, local stiffness of HVAC Case is evaluated through point mobility using finite element analysis and experiment.

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Development of Cabin Noise Prediction Program Induced by HVAC System (공조시스템 유기 격실 소음 예측 프로그램 개발)

  • Kim, Byung-Hee;Kwon, Jong-Hyun;Cho, Dae-Seung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.554-558
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    • 2004
  • In this paper, we introduce noise prediction program of HVAC system to assist low-noisy design of ship's cabin. The developed program calculates sound power levels at HVAC components considering primary and secondary noise generated by fan and duct element, duct element noise attenuation, and duct break-in noise based on the authentic empirical method suggested by NEBB and acoustic power balancing method. Sound pressure level at cabin with or without ceiling system is evaluated by the diffuse-field theory considering diffuser and duct break-out sound powers. Moreover, the program provides intuitive pre- and post-processors using modem GUI functions to help efficient modeling and evaluation of cabin and HVAC component noise. To validate the accuracy and convenience of the program, noise prediction for a HVAC system is demonstrated.

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Development of Integrated HVAC Noise Analysis Program for Ships (선박용 통합 HVAC 소음해석 프로그램 개발)

  • Han, Ju-Bum;Hong, Suk-Yoon;Song, Jee-Hun;Kim, Nho-Seong;Chun, Seung-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.588-593
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    • 2011
  • The Main design parameters of ship HVAC systems are pressure drop and noise analysis of ducts. The Noise prediction for HVAC(Heating, Ventilating and Air Conditioning) systems are normally performed by empirical method suggested by NEBB(National Environmental Balancing Bureau, 1994), but NEBB's method is not suitable for the ship HVAC systems. In this paper, numerical analysis methods are used to develop a noise prediction method for the ship HVAC systems, especially for large ducts. To develop regression formula of attenuation of sound pressure level in large duct, Boundary Element Method(BEM) is used. Using dynamic loss coefficient which is suggested by ASHRAE fitting data base and numerical methods of HVAC noise analysis, integrated HVAC noise analysis of Program is developed. The developed program can present pressure drop and noise analysis of the ship HVAC systems. To verify the accuracy and convenience of the developed program, prediction of HVAC system for Semi-Submersible Drilling RIG is carried out and the results are compared with measurement of noise level during sea trial.

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A Study on the Effective Operation of HVAC Systems on Manufacturing Plants by EnergyPlus and PSO Algorithm (EnergyPlus와 PSO알고리즘을 이용한 제조플랜트 냉난방/공조시스템의 최적 운영에 관한 연구)

  • Lee, Eon;Jeong, Jin Woo;Zhao, Wen Bin;Noh, Sang Do
    • Korean Journal of Computational Design and Engineering
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    • v.18 no.2
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    • pp.120-128
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    • 2013
  • Recently, the importance of the HVAC system (Heating, Ventilating and Air Conditioning System) is growing because comfortable working environment has emerged as important element for enhancing work efficiency. HVAC system is a general term of a system that collectively creates desired temperature and state through heating and air conditioning. HVAC system consists of many objects, so it requires a lot of constraints for its effective operation. Thus, specific strategy is needed for an optimal operation of HVAC System for plant. In this paper, manufacturing plants which have HVAC systems has been modeled and the objective function and constraints for an effective operation have been defined. And new strategy for an effective operation of HVAC system with energy simulations has been proposed.

Noise Characteristics of the HVAC System of Korea High Speed Train (한국형 고속전철 공조시스템 소음에 관한 연구)

  • 하인수;박철희;이우식;한기흥
    • Proceedings of the KSR Conference
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    • pp.379-387
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    • 1998
  • HVAC systems are used to maintain comfort conditions in occupied spaces. Like rolling noise and aerodynamic noise, noise from the HVAC system of train increases interior noise level. For an appropriate interior noise level, it is necessary not to find noise sources and their propagation paths. Noise emission from the sources and propagation through the propagation paths should be regulated in order to reduce their effect to the interior noise level. In general, the main noise source in the HVAC system is blower which operates at high static pressure. This noise propagates through ducts which are directly connected to the residential area. Since the blower noise can be reduced only to some degree, it is necessary for the propagation paths to have enough noise attenuation. Acoustic properties of ducts are usually found by experimental methods but it is rather difficult and expensive to set up such test equipments. In this thesis, the design and the noise characteristics of TGV-K HVAC system are studied. Finite element method in accordance with experimental method is used to study the acoustic properties of TGV-K duct system.

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Computational Analysis on the Noise Characteristics of Ship Large Duct (선박용 대형 덕트의 소음 특성 전산해석 연구)

  • Song, Jee-Hun;Hong, Suk-Yoon;Lee, Yi-Soo;Kwon, Hyun-Wung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.6
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    • pp.751-758
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    • 2015
  • Noise prediction for HVAC(Heating, Ventilating and Air Conditioning) systems are normally performed by empirical method suggested by NEBB(National Environmental Balancing Bureau, 1994). However, the method is not suitable for large ducts in ships. In this paper, computational analysis methods are used to develop a noise prediction method for the large ducts in ships. To develop regression formula of attenuation of sound pressure level in large ducts, Boundary Element Method(BEM) is used. BEM and Computational Fluid Dynamics(CFD) are applied to the analysis of flow-induced noise in ducts with stiffeners inside. Loud noise above 100 dB can be generated in some cases. Breakout noises of large ducts are also analyzed by using BEM and Finite Element Method(FEM). The acoustic pressure level shows about 10-15dB difference between inside and outside of the duct. Utilizing the results of this study, it is expected that shipyard planners can predict noise of the HVAC system for ships.

Development of shipboard large-sized low-noise room unit with multiple outlets (다수의 출구를 가진 선박용 대형 저소음 룸유닛 개발)

  • Kim, Sang-Ryul;Kim, Hyun-Sil;Lee, Sung-Hyun;Park, Geun-Hyo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.600-605
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    • 2012
  • In this paper, the acoustic performance of a shipboard large-sized room unit is studied. The room unit is a kind of rectangular absorptive chamber with a partition whose surface absorptive material with fabric skin is attached to. The room unit has one inlet and three outlet. At the inlet, a plane damper is installed to control the flow rate. The acoustic performance of a prototype room unit is measured using a HVAC mock-up. It is shown that its insertion loss is comparable with that of a commercially-used room unit but the developed room unit generates flow noise higher than the other one. The major source of flow noise is analyzed by NADS-R, the noise analysis program for room unit. Cone-shaped dampers are proposed to be used as the damper of a room unit to reduce flow noise. It is shown that the cone-shaped damper decrease flow noise remarkably.

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Development of Shipboard Large-sized Low-noise Room Unit with Multiple Outlets (다수의 출구를 가진 선박용 대형 저소음 룸유닛 개발)

  • Kim, Sang-Ryul;Kim, Hyun-Sil;Lee, Sung-Hyun;Park, Keun-Hyo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.5
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    • pp.468-473
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    • 2012
  • In this paper, the acoustic performance of a shipboard large-sized room unit is studied. The room unit is a kind of rectangular absorptive chamber with a partition whose surface absorptive material with fabric skin is attached to. The room unit has one inlet and three outlets. At the inlet, a plane damper is installed to control the flow rate. The acoustic performance of a prototype room unit is measured using a HVAC mock-up. It is shown that its insertion loss is comparable with that of a commercially-used room unit but the developed room unit generates flow noise higher than the other one. The major source of flow noise is analyzed by NADS-R, the noise analysis program for room unit. Cone-shaped dampers are proposed to be used as the damper of a room unit to reduce flow noise. It is shown that the cone-shaped damper decrease flow noise remarkably.

A Study on Insertion Loss Estimation Formulas of Rectangular Silencers for Ships (선박용 사각 소음기의 삽입손실 추정식 연구)

  • Kim, Tae-Gyoung;Hong, Suk-Yoon;Song, Jee-Hun;Kwon, Hyun-Wung;Kong, Young-Mo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.7
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    • pp.820-826
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    • 2016
  • The acoustic performance estimation formulas for silencers are developed mainly by theoretical or empirical methods. However, the existing formulas are available only for a limited range of silencers. In this paper, the procedures for noise analysis of the silencers are established by comparing analytic results to experimental results. With the proven analysis procedures, impedances of the rectangular silencers for ships are adversely predicted from National Environmental Balancing Bureau (NEBB) data, and with the estimated impedances, insertion loss formulas for large silencers are developed using boundary element method (BEM). The developed formulas can be efficiently used for predicting acoustic performance of the silencers for ships.