Controllability of cross-flow two-phase heat exchangers
نویسنده
چکیده
The analysis of controllability of a heat exchanger operating under two-phase conditions is performed. An evaporator operating in a vapor compression system is chosen for the analysis. A moving-boundary model is used to simulate the dynamic behavior of the evaporator. First, the controllability of the linearized model is verified. Then, it is shown that the nonlinear model can be classified as a control-affine system with drift. Short-term local controllability of the nonlinear model is shown using Lie algebras. A linear quadratic (LQ) controller is developed for the linearized system and numerical simulations are provided that show a strong coupling between the variables of the model. ! 2007 Elsevier Ltd. All rights reserved.
منابع مشابه
Hydraulic Network Modeling to Analyze Stream Flow Effectiveness on Heat Transfer Performance of Shell and Tube Heat Exchangers
In this article, stream flow effectivness is based on hydraulic network studied in the shell-side of a shell and tube heat exchange as a case study. For an appropriate heat exchangers rating design to meet a specified duty, it's better to consider each stream flow separately. Using the hydraulic network principals, a set of the correlations for calculating different stream flow rates in the cro...
متن کاملInvestigation on Turbulent Nanofluid Flow in Helical Tube in Tube Heat Exchangers
In this study, the thermal characteristics of turbulent nanofluid flow in a helical tube in the tube heat exchanger (HTTHE) were assessed numerically through computational fluid dynamics (CFD) simulation. The findings of both the turbulent models: realizable k-epsion (k-ε) and re-normalisation group (RNG) k-epsilon were compared. The temperature distribution contours show that realizable and RN...
متن کاملInvestigating the effect of magnetic field on the forced convection of cross-corrugated triangular channels
Cross-corrugated triangular channels increase heat transfer in heat exchangers. The mixing effect increases the heat transfer coefficient at the surfaces. In this study, the fluid flow and heat transfer in a triangular corrugated channel are modeled under two constant heat fluxes and different Reynolds numbers. In order to validate, k-ω turbulence model is used. Also, the effect of magnetic fie...
متن کاملDrag coefficient and strouhal number analysis of cylindrical tube in two phase flow
In many industrial equipment such as boilers and heat exchangers, the cylindrical tubes are exposed to the gas- liquid two phase flow. For any immersed body in flow field vortex shedding is created with a frequency that may be constant or variable, according to conditions such as flow rates, geometry of body, and etc. The failure will happen in the equipment, when this frequency is close to...
متن کاملEffectiveness-ntu Computation with a Mathematical Model for Cross-flow Heat Exchangers
Due to the wide range of design possibilities, simple manufactured, low maintenance and low cost, cross-flow heat exchangers are extensively used in the petroleum, petrochemical, air conditioning, food storage, and others industries. In this paper a mathematical model for cross-flow heat exchangers with complex flow arrangements for determining ε-NTU relations is presented. The model is based o...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2007