Evaluation of high performance evacuated tubular collectors in a residential heating and cooling system: Colorado State University Solar House I. Report for October 1, 1976--September 30, 1977

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.

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Colorado State University Program for developing, testing, evaluating and optimizing solar heating and cooling systems. Project status report, October--November 1993

10.2172/10116120 ◽

1993 ◽

Author(s):

Keyword(s):

Solar Heating ◽

Status Report ◽

State University ◽

Cooling Systems ◽

Colorado State University ◽

Heating And Cooling

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Colorado State University Program for developing, testing, evaluating, and optimizing solar heating and cooling systems. Project status report, June 1994--July 1994

10.2172/95522 ◽

1995 ◽

Author(s):

Keyword(s):

Solar Heating ◽

Status Report ◽

State University ◽

Cooling Systems ◽

Colorado State University ◽

Heating And Cooling

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An Analytic Model of Stratification for Liquid-Based Solar Systems

Journal of Solar Energy Engineering ◽

10.1115/1.3268075 ◽

1986 ◽

Vol 108 (2) ◽

pp. 105-110 ◽

Cited By ~ 5

Author(s):

K. DenBraven

Keyword(s):

Temperature Distribution ◽

Storage Temperature ◽

Direct Calculation ◽

Hot Water ◽

Forced Flow ◽

State University ◽

Colorado State University ◽

Liquid Storage ◽

System Data ◽

Solar House

Accurate modelling of solar air or liquid heating, cooling, or domestic hot water systems with storage generally requires an accounting of the stratification within such storage. Overall system performance may be significantly affected by the storage temperature distribution. Most current stratification models utilize a finite difference scheme for solution to the general equations. An analytic method to determine the temperature distribution has been derived for liquid storage within a solar system. In liquid storage, it is assumed incoming fluid enters at the location with the temperature closest to its own. Hence, the solution requires the possibility of a region within storage where there is no forced flow. In addition, ther may be collector loop flow, load loop flow, or both concurrently. Each of these cases has different boundary conditions, and each must be solved separately. Comparisons of the resulting calculations with system data for the Colorado State University Solar House I show good agreement. This suggests that inclusion of an analytic stratification model within a system simulation may be useful by allowing direct calculation of temperatures in stratified storage.

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