scholarly journals Heat flow metering in building practice - A critical field study for a large industrial building complex

2021 ◽  
Vol 2042 (1) ◽  
pp. 012085
Author(s):  
Karl Walther ◽  
Karsten Voss
Keyword(s):  
Heat Flow ◽  
Management Strategies ◽  
Industrial Building ◽  
Heat Flows ◽  
Heating And Cooling ◽  
Flow Metering ◽  
Flow Detection ◽  
Building Practice ◽  
Heat Meters ◽  
Industrial Demonstration

Abstract Increasingly complex concepts for the heating and cooling supply of buildings require both intelligent and transparent operational management strategies. One way of sequencing and coordinating different generator components is to include information about heat flows on the consumption side. In addition to heat meters, modern pumps also provide heat flow detection. The present study compares the heat flow detection via heat meters and pumps for multiple hydraulic circuits in the operating phase of a large industrial demonstration object. In particular, the influence of typical errors in the installation of the temperature measurement and their elimination are quantified.

Applications of thermoelectric modules on heat flow detection

2012 ◽  
Vol 51 (2) ◽  
pp. 345-350 ◽  
Author(s):  
Thananchai Leephakpreeda
Keyword(s):  
Heat Flow ◽  
Thermoelectric Modules ◽  
Flow Detection

scholarly journals A study of sensing heat flow through thermal walls by using thermoelectric module

2015 ◽  
Vol 19 (5) ◽  
pp. 1497-1505 ◽  
Author(s):  
Noppawit Sippawit ◽  
Thananchai Leephakpreeda
Keyword(s):  
Heat Transfer ◽  
Heat Flow ◽  
Thermoelectric Module ◽  
Plane Wall ◽  
Thermal Engineering ◽  
Transfer Coefficients ◽  
Thermoelectric Effects ◽  
Flow Through ◽  
Flow Detection ◽  
Engineering Practices

Demands on heat flow detection at a plane wall via a thermoelectric module have drawn researchers? attention to quantitative understanding in order to properly implement the thermoelectric module in thermal engineering practices. Basic mathematical models of both heat transfer through a plane wall and thermoelectric effects are numerically solved to represent genuine behaviors of heat flow detection by mounting a thermoelectric module at a plane wall. The heat transfer through the plane wall is expected to be detected. It is intriguing from simulation results that the heat rejected at the plane wall is identical to the heat absorbed by the thermoelectric module when the area of the plane wall is the same as that of the thermoelectric module. Furthermore, both the area sizes of the plane walls and the convective heat transfer coefficients at the wall influence amount of the heat absorbed by the thermoelectric module. Those observational data are modeled for development of sensing heat flow through a plane wall by a thermoelectric module in practical uses.

Conductive and convective heat flows of exercising humans in cold water

1989 ◽  
Vol 67 (6) ◽  
pp. 2473-2480 ◽  
Author(s):  
G. Ferretti ◽  
A. Veicsteinas ◽  
D. W. Rennie
Keyword(s):  
Heat Flow ◽  
Water Temperature ◽  
Convective Heat ◽  
Rectal Temperature ◽  
Cold Water ◽  
Subcutaneous Fat ◽  
Skin Surface ◽  
Heat Flows

The apparent conductance (Kss, in W.m-2.degrees C-1) of a given region of superficial shell (on the thigh, fat + skin) was determined on four nonsweating and nonshivering subjects, resting and exercising (200 W) in water [water temperature (Tw) 22-23 degrees C] Kss = Hss/(Tsf-Tsk) where Hss is the skin-to-water heat flow directly measured by heat flow transducers and Tsf and Tsk are the temperatures of the subcutaneous fat at a known depth below the skin surface and of the skin surface, respectively. The convective heat flow (qc) through the superficial shell was then estimated as qc = (Tsf - Tsk).(Kss - Kss,min), assuming that at rest Kss was minimal (Kss,min) and resting qc = 0. The duration of immersion was set to allow rectal temperature (Tre) to reach approximately 37 degrees C at the end of rest and approximately 38 degrees C at the end of exercise. Except at the highest Tw used, Kss at the start of exercise was always Kss,min and averaged 51 W.m-2.degrees C-1 (range 33-57 W.m-2.degrees C-1) across subjects, and qc was zero. At the end of exercise at the highest Tw used for each subject, Kss averaged 97 W.m-2.degrees C-1 (range 77-108 W.m-2.degrees C-1) and qc averaged 53% (range 48-61%) of Hss (mean Hss = 233 W.m-2).(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithm and Program for Simulating Heat Transfer in Cavities of Structural Members under Fire Conditions

2011 ◽  
Vol 90-93 ◽  
pp. 3227-3233
Author(s):  
Yong Jun Liu ◽  
Dong Wang ◽  
Xing Tao Ma
Keyword(s):  
Heat Transfer ◽  
Heat Flow ◽  
Radiative Heat ◽  
Coefficient Matrix ◽  
System Of Equations ◽  
Structural Members ◽  
Finite Element Program ◽  
Heat Flows ◽  
Element Program ◽  
Fire Conditions

In this paper, an algorithm based on the network method suggested by Oppenheim for calculating the radiative heat flow in a cavity of structural members, say hollow core concrete slabs, exposed to fires is presented. It is assumed that the pressure in a cavity keeps atmospheric pressure through the whole cause of a fire, and the lost heat from the air due to expansion and immediate moving away from a cavity is neglected. The heat in a cavity is transfer via both heat conduction in air and thermal radiation among boundaries, and special regard is paid to modeling heat transfer by radiation. The effective radiative heat flow system of equations is derived and expressed in matrix form. The system of equations features a symmetric coefficient matrix, which can be stored in a one dimensional array, and can be solved using LDLT factorization. Node radiative thermal loads are calculated from effective radiative heat flows at edges of elements located on internal cavities. The nonlinear finite element program TFIELD written by first author has employed the new algorithm. Temperature distribution in two structural members with cavities are calculated using TFIELD, and numerical results demonstrate that the new algorithm is very effective and is useful for further study of structural behavior of structural members under fire conditions.

A heat flow profile across the Sverdrup Basin, Canadian Arctic Islands

Geophysics ◽  
1989 ◽  
Vol 54 (2) ◽  
pp. 171-180 ◽  
Author(s):  
F. W. Jones ◽  
J. A. Majorowicz ◽  
A. F. Embry
Keyword(s):  
Heat Flow ◽  
Canadian Arctic ◽  
Ground Surface ◽  
Geothermal Gradient ◽  
Flow Profile ◽  
Heat Flows ◽  
Boundary Temperature ◽  
Sverdrup Basin ◽  
Base Boundary ◽  
Rock Analysis

An average geothermal gradient of 25 ± 5 mK/m and an average heat flow of [Formula: see text] have been determined for 16 out of 20 analyzed wells along a profile across the Sverdrup Basin in the Canadian Arctic. These estimates, based on deep bottom‐hole temperature (BHT) data from exploration wells and the permafrost base boundary temperature, together with assumed heat conductivities from net rock analysis, are surprisingly low and disagree with previously published results based on shallow data. The differences may be due to the dramatic changes in boundary temperature conditions from moderate subsea conditions to ground‐surface low temperatures as a result of marine regression. Because of these effects, it appears that deep BHT temperature data are valuable in providing information about the deep heat flow. The heat flows thus determined indicate that the basin has approached thermal equilibrium.

scholarly journals Energy analysis, numerical simulations and intervention proposals for a NZEB industrial building: the “Loccioni Leaf Lab” case study

2021 ◽  
Vol 238 ◽  
pp. 06004
Author(s):  
Ettore Stamponi ◽  
Nicola Lattanzi ◽  
Francesco Giorgini ◽  
Fabio Serpilli ◽  
Sergio Montelpare ◽  
...  
Keyword(s):  
Smart Grid ◽  
High Performance ◽  
Energy Performance ◽  
Heat Pumps ◽  
Weather Data ◽  
Industrial Building ◽  
Dynamic Simulations ◽  
Heating And Cooling ◽  
Energy Consumptions

The object of this paper is the “Loccioni Leaf Lab”, an industrial nZEB connected to a thermal and electric smart grid. Having nZEB buildings connected to a smart grid offers the possibility of maximizing the benefits that can be obtained by optimal regulation of the grid itself, providing excellent economic and energy results. The case study, which hosts offices and workers operating on test benches, features high performance envelope, solar photovoltaic systems, groundwater heat pumps and a hightechnology control and monitoring system. In order to analyse HVAC-related energy consumptions, the building was modelled using DesignBuilder and EnergyPlus software. The annual dynamic simulations for the assessment of building thermal-energy performance were carried out using available monitored weather data (2019). The model was validated according to ASHRAE guidelines, comparing the outputs of the software with data collected and stored by Company internal database. In the validation process, mean indoor air temperatures of several zones and heating and cooling energy consumptions were considered as key outputs. The validated model has then been used to suggest optimization strategies and to analyse the results obtained with proposed interventions in terms of energy saving.

Modeling of Complex Hydronic Systems for Energy Efficient Operation

2009 ◽  
Author(s):  
Vikas Chandan ◽  
Gina Zak ◽  
Andrew Alleyne
Keyword(s):  
Energy Efficient ◽  
Management Strategies ◽  
Efficient Operation ◽  
Control Techniques ◽  
Heating And Cooling ◽  
Proposed Model ◽  
Model Complex ◽  
Advanced Control ◽  
Time Scale Decomposition ◽  
End Use

Energy requirements for heating and cooling of residential, commercial and industrial spaces constitute a major fraction of end use energy consumed. Centralized systems such as hydronic networks are becoming increasingly popular to meet those requirements. Energy efficient operation of such systems requires intelligent energy management strategies, which necessitates an understanding of the complex dynamical interactions among its components from a mathematical and physical perspective. In this work, concepts from linear graph theory are applied to model complex hydronic networks. Further, time-scale decomposition techniques have been employed to obtain a more succinct representation of the overall system dynamics. Lastly, the usefulness of the proposed model for energy efficient operation of the system through advanced control techniques has been discussed.

Cutaneous heat flow during heating and cooling in Alligator mississipiensis

1976 ◽  
Vol 230 (5) ◽  
pp. 1205-1210 ◽  
Author(s):  
EN Smith
Keyword(s):  
Heat Exchange ◽  
Heat Flow ◽  
American Alligator ◽  
Cooling Rates ◽  
Mean Values ◽  
In Vivo Measurement ◽  
Heating And Cooling ◽  
Cutaneous Perfusion ◽  
Alligator Mississipiensis

Direct in vivo measurement of heat flow across the skin of the American alligator (Alligator mississipiensis) showed increased heat flow during warming. Mean values at 25 degrees C during warming (15-35 degrees C) in air (airspeed 300 cm/s) were 17.9 +/- 92 SE cal/cm2 per h (mean alligator wt 3.27 kg). Cooling heat flow at the same temperature was 13.6 +/- 0.57 cal/cm2 per h. Subdermal heat flow was reduced during warming and was not significantly different from cutaneous heat flow during cooling. This indicated that the alligator was able to control its rate of heat exchange with the environment by altering cutaneous perfusion. Atropine, phenoxybenzamine, nitroglycerin, and Xylocaine did not affect cutaneous heat flow or heating and cooling rates. Atropine blocked bradycardia during cooling.

The basis for a room global temperature

1992 ◽  
Vol 339 (1653) ◽  
pp. 153-191 ◽  
Keyword(s):  
Heat Transfer ◽  
Limited Extent ◽  
Point Temperature ◽  
Heat Flows ◽  
Heating And Cooling ◽  
Radiant Exchange ◽  
Least Squares Fit ◽  
Radiant Temperature ◽  
Building Heat ◽  
Bounding Surfaces

The design of heating and cooling appliances in buildings in routine cases normally proceeds on the assumption of a room index temperature which combines the separate effects of air temperature and of the longwave radiant field m the enclosure. It is pointed out that the basis for the index in current use in the U.K. and elsewhere is flawed, and this article is concerned with the logic of setting up a valid in ex temperature in its place. The argument depends first on reducing the surface-to-surface radiant exchange between enclosure surfaces to an approximately equivalent surface-to-star point exchange, using a least-squares fit. The fit proves to be quite good. It is next established that to a limited extent the star point temperature - a fictitious construct - will do duty for the space-averaged observable radiant temperature in the room. Thirdly, since the index temperature is taken to drive the radiant and convective heat flows from the room as a whole to one of its bounding surfaces, the question is discussed as to how reliably these physically dissimilar mechanisms can be formally merged in this way. Finally, simple expressions are given for enclosure heat needs in relation to comfort temperature and similar quantities. The arguments present some innovative features in building heat transfer.

scholarly journals Exergy of heat flows in exchanger consisting f gravity heat pipes

2012 ◽  
Vol 51 (No. 3) ◽  
pp. 73-78
Author(s):  
D. Adamovský ◽  
P. Neuberger ◽  
D. Herák ◽  
R. Adamovský
Keyword(s):  
Heat Flow ◽  
Air Temperature ◽  
Thermal Efficiency ◽  
Heat Pipes ◽  
Exergy Efficiency ◽  
Heat Flows ◽  
Heat Processes ◽  
The Impact

The paper deals with the analysis of the impact of inlet air temperature on the exergy efficiency and exergy of the losing heat flow and determination of the relation between the exergy and thermal efficiency in an exchanger consisting of gravity heat pipes. The assessment of heat processes quality and transformation of energy in the exchanger are also dealt with.

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