<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>The installation of a heat storage tank is a very cost-effective way to improve the performance and flexibility of a CHP plant. Such a heat storage tank usually accumulates heat by thermal stratification. This phenomenon is caused by the thermal buoyancy because of the difference in temperature between cold and hot water. The heat storage tank may have three operating modes, i. e. charge, discharge and storage in a CHP plant. When CHP units, which charge the heat storage tank, operate at full load, usually only two operation modes occur in the tank, i.e. charge and discharge.</p><p>The paper presents numerical simulation of heat storage tank operation modes in a CHP plant using <italic>PHOENICS</italic> - a multi-purpose computation fluid dynamics (CFD) software. Two-dimensional and three-dimensional transient models were created and solved numerically. Three domain grids were tested. Several charging and discharging processes with different flow rates were simulated. The influence of flow rate on the degree of thermal stratification during charging and discharging processes is analyzed. The computation possibilities and limitations of the numerical experiments are pointed out. Special attention is given to the validation of the numerical solutions. The validation of simulated results is made by comparison with the real data from the heat storage installed in the Hvide Sande CHP plant.</p></abstract>

The installation of a heat storage tank is a very cost-effective way to improve the performance and flexibility of a CHP plant. Such a heat storage tank usually accumulates heat by thermal stratification. This phenomenon is caused by the thermal buoyancy because of the difference in temperature between cold and hot water. The heat storage tank may have three operating modes, i. e. charge, discharge and storage in a CHP plant. When CHP units, which charge the heat storage tank, operate at full load, usually only two operation modes occur in the tank, i.e. charge and discharge.The paper presents numerical simulation of heat storage tank operation modes in a CHP plant using PHOENICS - a multi-purpose computation fluid dynamics (CFD) software. Two-dimensional and three-dimensional transient models were created and solved numerically. Three domain grids were tested. Several charging and discharging processes with different flow rates were simulated. The influence of flow rate on the degree of thermal stratification during charging and discharging processes is analyzed. The computation possibilities and limitations of the numerical experiments are pointed out. Special attention is given to the validation of the numerical solutions. The validation of simulated results is made by comparison with the real data from the heat storage installed in the Hvide Sande CHP plant.

Research of Operation Modes of Heat Storage Tank in CHP Plant Using Numerical Simulation

Department of Building Energetics, Vilnius Gediminas Technical University

Environmental and Climate Technologies

The installation of a heat storage tank is a very cost-effective way to improve the performance and flexibility of a CHP plant. Such a heat storage tank...

Research of Operation Modes of Heat Storage Tank in CHP Plant Using Numerical Simulation

Published Online: Jan 13, 2012

Page range: 91 - 99

DOI: https://doi.org/10.2478/v10145-011-0013-3

Keywords
CHP, heat storage tank, numerical simulation, thermal stratification

This content is open access.

Research of Operation Modes of Heat Storage Tank in CHP Plant Using Numerical Simulation

Published Online: Jan 13, 2012

Page range: 91 - 99

DOI: https://doi.org/10.2478/v10145-011-0013-3

KeywordsCHP, heat storage tank, numerical simulation, thermal stratification

This content is open access.

Keywords
CHP, heat storage tank, numerical simulation, thermal stratification