An improved root-finding procedure for use in calculating transient heat flow through multilayered slabs

Hittle, Douglas C.; Bishop, Richard W.

doi:10.1016/s0017-9310(83)80089-1

Cited by 52 publications

(22 citation statements)

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“…This process is not always robust and can result in errors if all the roots are not found. Improved root finding methods have been developed [19,20] but difficulties remain if the time step size is small or the construction has high thermal mass.…”

Section: Response Factor Methodsmentioning

confidence: 99%

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A numerical implementation of the Dynamic Thermal Network method for long time series simulation of conduction in multi-dimensional non-homogeneous solids

Rees

Fan

2013

International Journal of Heat and Mass Transfer

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Article:Rees, SJ orcid.org/0000-0003- 4869-1632 andFan, D (2013) A numerical implementation of the Dynamic Thermal Network method for long time series simulation of conduction in multi-dimensional non-homogeneous solids. ReuseUnless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request.A numerical implementation of the Dynamic Thermal Network method for long time series simulation of conduction in multi-dimensional non-homogeneous solids AbstractThe Dynamic Thermal Network (DTN) approach to the modelling of transient conduction was conceived by Claesson (1999Claesson ( , 2003 as an extension of the network representation of steady-state conduction processes. The method is well suited to the simulation of building fabric components such as framed walls and thermally massive structures such as basements but can also be applied to the long timescale simulation of other conduction problems. The theoretical basis of the method and its discretized form is outlined in this paper and a new numerical procedure for the calculation of the necessary weighting factor data is presented. Such data has previously been generated for three-dimensional bodies by a heuristic process of blending analytical solutions and numerical data. The numerical approach reported here has the advantage of accommodating parametric representations of multi-dimensional geometries and allows the data to be produced in an automated fashion and so more easily incorporated into simulation tools. Enhancements to the data reduction procedure and a generalised approach to representing complex boundary conditions are also presented. The numerical procedure has been validated by a series of comparisons with analytical conduction heat transfer solutions and discretization errors were found to be acceptably small. Compared to numerical methods, calculations using the DTN method were found to be up to four orders of magnitude quicker but with comparable accuracy.

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Section: Response Factor Methodsmentioning

confidence: 99%

“…Consequently, it is often accurate to start the summation of the transmittive weighting factor and temperature products starting at index ρ = 1 in Eqs. (19) and (20). This may simplify the simulation procedure and avoid iteration in many cases.…”

Section: Discretizationmentioning

confidence: 99%

A numerical implementation of the Dynamic Thermal Network method for long time series simulation of conduction in multi-dimensional non-homogeneous solids

Rees

Fan

2013

International Journal of Heat and Mass Transfer

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“…These poles have been calculated using the Hittle method (see [22]) and characterize completely the dynamic thermal response of the element. The greater the k the biggest the α k becomes.…”

Section: Appendix a Successive Transition Statementioning

confidence: 99%

Discrete event heat transfer simulation of a room

Francés

Escrivà

Ojer

2014

International Journal of Thermal Sciences

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The paper presents a new proposal of a discrete event simulation (DEVS) model for heat transfer in an enclosure. To our knowledge this is the first proposal in this direction, therefore the model is not comprehensive (has no windows, no ground coupling,etcetera). It is a first step of DEVS into the heat transfer in buildings. The model presented is just one possible implementation for a single thermal zone, although it has been designed to be used in multi-zone models. Common methods like CTF (conduction transfer functions) or RTF (response transfer functions) cannot be used. Instead it employs the successive transition state formulation for the 1D conduction heat transfer through multi-layered walls. An example test room has been calculated and the results compared with software that uses well known methods (CTF,RTF). Finally the DEVS model has been tested with a random convective internal-load signal.Keywords: Successive state transition method, Building energy simulation, Discrete event simulation, DevsNumber of boundary conduction elements of the i-zone, equal as well to the number of its boundary surfaces

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“…Subbarao (1985), Barakat (1987) and Taylor (1988) present various methods to overcome some of the problems, such as instability, with models obtained from direct application of least-squares regression to time series of measured conditions and responses. Armstrong (2000) formulated a constrained search for CRTF model coefficients based on a CTF property demonstrated by Hittle (1983) and applied the method to training and testing time-series data sets ranging from several days to several months duration.…”

Section: Inverse Modelsmentioning

confidence: 99%

Cost-Effective Integration of Efficient Low-Lift Base Load Cooling Equipment

Jiang¹,

Winiarski²,

Katipamula³

et al. 2008

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Executive SummaryThe long-term goal of Department of Energy's (DOE's) Commercial Buildings Integration program is to develop cost-effective technologies and building practices that will enable the design and construction of net Zero Energy Buildings -commercial buildings that produce as much energy as they use on an annual basis -by 2025. 1 To support this long-term goal, DOE further called foras part of its FY07 Statement of Needs -the development by 2010 of "five cost-effective design technology option sets using highly efficient component technologies, integrated controls, improved construction practices, streamlined commissioning, maintenance and operating procedures that will make new and existing commercial buildings durable, healthy and safe for occupants." 2 In response, Pacific Northwest National Laboratory (PNNL) proposed and DOE funded a scoping study investigation of one such technology option set (TOS), low-lift cooling that offers potentially exemplary heating, ventilation and air conditioning (HVAC) energy performance relative to American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) Standard 90.1-2004. The primary purpose of the scoping study was to estimate the national technical energy savings potential of this TOS.The TOS PNNL evaluated consists of:1. Peak-load shifting by means of active or passive thermal energy storage (TES) 3 . 2. Dedicated outdoor air supply with enthalpy heat recovery from exhaust air. 3. Radiant heating and cooling panels or floor system. 4. Low-lift vapor compression cooling equipment. 5. Advanced controls at the HVAC equipment and HVAC system (supervisory) levels.The application of the TOS was simulated in three medium-sized office building prototypes (baseline, mid-performance and high-performance, which are defined later in the report) in five climate zones around the U.S. Results from our analysis indicate that the technical HVAC energy savings potential of the TOS ranges from 60% to 74% for temperate to hot and humid climates, and 30% to 70% in milder climates. The savings are calculated as a difference between the annual energy use (chiller, fans and pumps) for a building with a conventional HVAC system and the annual energy use for the same building with equipment and controls of the TOS. Because of the nature of this scoping study, a number of assumptions had to be made. These assumptions are listed in the individual sections of the report, where appropriate, and collected for convenient reference in Appendix C.The national technical energy savings potential (cooling, fans and pumps) from the TOS were then estimated by scaling the savings from the prototype building. In this report active denotes peak-shifting by means of a discrete TES such as a stratified water tank; passive refers to pre-cooling of the intrinsic mass (building fabric and contents) by forced air or hydronic radiant cooling using a chiller and/or air-, water-, or refrigerant-side free cooling.iv commercial building stock and the full TOS may be applicable to a frac...

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An improved root-finding procedure for use in calculating transient heat flow through multilayered slabs

Cited by 52 publications

References 0 publications

A numerical implementation of the Dynamic Thermal Network method for long time series simulation of conduction in multi-dimensional non-homogeneous solids

A numerical implementation of the Dynamic Thermal Network method for long time series simulation of conduction in multi-dimensional non-homogeneous solids

Discrete event heat transfer simulation of a room

Cost-Effective Integration of Efficient Low-Lift Base Load Cooling Equipment

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