An Investigation of a Residential Solar System Coupled to a Radiant Panel Ceiling

1988 ◽  
Vol 110 (3) ◽  
pp. 172-179 ◽  
Author(s):  
Z. Zhang ◽  
M. Pate ◽  
R. Nelson
Keyword(s):  
Heat Exchanger ◽  
Solar System ◽  
Flat Plate ◽  
Storage Tank ◽  
Heating System ◽  
Hot Water ◽  
Radiant Heating ◽  
Solar Collectors ◽  
Water Storage Tank ◽  
Radiant Panel

An experimental study of a solar-radiant heating system was performed at Iowa State University’s Energy Research House (ERH). The ERH was constructed with copper tubes embedded in the plaster ceilings, thus providing a unqiue radiant heating system. In addition, 24 water-glycol, flat-plate solar collectors were mounted on the south side of the residence. The present study uses the solar collectors to heat a storage tank via a submerged copper tube coil. Hot water from the storage tank is then circulated through a heat exchanger, which heats the water flowing through the radiant ceiling. This paper contains a description of the solar-radiant system and an interpretation of the data that were measured during a series of transient experiments. In addition, the performance of the flat-plate solar collectors and the water storage tank were evaluated. The characteristics of a solar-to-radiant heat exchanger were also investigated. The thermal behavior of the radiant ceiling and the room enclosures were observed, and the heat transfer from the ceiling by radiation and convection was estimated. The overall heating system was also evaluated using the thermal performances of the individual components. The results of this study verify that it is feasible to use a solar system coupled to a low-temperature radiant-panel heating system for space heating. A sample performance evaluation is also presented.

Design, Implementation, and Evaluation of Thermal Performance of a Thermosiphon Flat-Plate Solar Collector for Water Heating in Ecuadorian Coastal Region

2017 ◽  
Author(s):  
Carola Sánchez ◽  
José Macías ◽  
Jonathan León ◽  
Geancarlos Zamora ◽  
Guillermo Soriano
Keyword(s):  
Flat Plate ◽  
Thermal Performance ◽  
Solar Collector ◽  
Storage Tank ◽  
Hot Water ◽  
Attractive Alternative ◽  
Local Market ◽  
Water Heating ◽  
Water Storage Tank ◽  
Flat Plate Solar Collector

Passive solar water heating (SWH) is a convenient method to meet domestic hot water requirements in rural areas, where electricity may not be available or fuel supply might be limited due to difficult access. In this work, a low-cost thermosiphon flat-plate solar collector alternative is presented. The design was purposely limited to materials and recyclable products widely available in the local market, such as Tetra Pak, plastic bottles, and polypropylene (PP) fittings and pipes. Since PP is a thermoplastic polymer, a poor heat conductor, it was necessary to ensure a suitable system isolation to obtain an optimum thermal performance, comparable to commercial solar collectors. The design was built and tested in Guayaquil, Ecuadorian coastal city. Six inexpensive temperature sensors were placed at the entrance and exit of the collector, on the flat-plate and inside the hot water storage tank. Data was recorded using an Arduino single-board computer and later analyzed with the data gathered via weather station. The implementation costs of the system are approximately US$300, the overall performance during January 2017 fluctuated between 54% and 23%, and the storage tank temperature range varied from to 46°C to 33°C. Due to its reliability and affordable cost, the SWH system is an attractive alternative to an Ecuadorian commercial solar flat plate collector, which price is set between US$600 and US$700, it has an efficiency around 60%, and the average annual storage tank temperature is 62°C.

scholarly journals Modelling and testing a passive night-sky radiation system

2017 ◽  
Vol 28 (1) ◽  
pp. 76 ◽  
Author(s):  
G.D. Joubert ◽  
R.T. Dobson
Keyword(s):  
Storage Tank ◽  
Cold Water ◽  
Water Storage ◽  
Heating System ◽  
Hot Water ◽  
Theoretical Simulation ◽  
Water Storage Tank ◽  
Heating And Cooling ◽  
Night Sky ◽  
Radiation Cooling

The as-built and tested passive night-sky radiation cooling/heating system considered in this investigation consists of a radiation panel, a cold water storage tank, a hot water storage tank, a room and the interconnecting pipework. The stored cold water can be used to cool a room during the day, particularly in summer. A theoretical time-dependent thermal performance model was also developed and compared with the experimental results and it is shown that the theoretical simulation model captures the experimental system performance to within a reasonable degree of accuracy. A natural circulation experimental set-up was constructed and subsequently used to show that under local (Stellenbosch, South Africa) conditions the typical heat-removal rate from the water in the tank is 55 W/m2 of radiating panel during the night; during the day the water in the hot water-storage tank was heated from 24 °C to 62 °C at a rate of 96 W/m2. The system was also able to cool the room at a rate of 120 W/m3. The results thus confirmed that it is entirely plausible to design an entirely passive system, that is, without the use of any moving mechanical equipment such as pumps and active controls, for both room-cooling and water-heating. It is thus concluded that a passive night-sky radiation cooling/heating system is a viable energy-saving option and that the theoretical simulation, as presented, can be used with confidence as an energy-saving system design and evaluation tool. Keywords: passive cooling and heating, buoyancy-driven fluid flow, theoretical simulation, experimental verification Highlights:Passively driven renewable energy heating and cooling systems are considered.Time-dependent mathematical simulation model is presented.Experimental buoyancy-driven heating and cooling system built and tested.Experimental results demonstrate the applicability of the theoretical simulation model.Saving and evaluation design tool.

Generation of Electricity Utilizing Solar Hot Water Collectors and a Tesla Turbine

2009 ◽  
Author(s):  
Ryan Crowell
Keyword(s):  
Heat Exchanger ◽  
Flat Plate ◽  
Alternative Energy ◽  
Plate Heat Exchanger ◽  
Hot Water ◽  
Working Fluid ◽  
Solar Collectors ◽  
Gaseous State ◽  
Plate Heat ◽  
Ambient Temperatures

Threats of climate change and depleted petroleum supplies have prompted the need for eco-conscious alternative energy. This paper introduces a ground-breaking concept for harnessing the sun’s power that is significantly more efficient than existing systems. Solar collectors gather the electromagnetic radiation emitted by the sun and heat a propylene glycol to a high temperature that will then transfer the heat to a working fluid (Care30) through a plate heat exchanger. The Care30 then exits the heat exchanger in a gaseous state, and is passed through a Tesla turbine, which in turn rotates a shaft. The shaft is connected to a generator, which transforms the mechanical energy into electricity. The absorption efficiency of the solar collectors allows for mechanical loses while maintaining the overall efficiency at higher levels than any existing PV based system. Ambient temperatures drastically reduce the effectiveness of flat plate solar collectors, cooling the liquids inside before the heat can be efficiently consumed. In contrast, an evacuated tube collector maintains efficiency during such conditions. The collectors are insulated from ambient temperatures by the vacuum pressure inside the tube. A stainless steel flat plate heat exchanger is used to transfer the heat from the glycol/water solution to the refrigerant, which is sent to the turbine after it has been converted to its gaseous state. The solution also provides freeze protection in colder climates. A heat exchanger then cools the gas, returning it to its liquid state, which completes the cycle for the working fluid. The water used in the heat exchanger is then used as a supplementary heating source for the home, for domestic or radiant heating needs. As it is effective even in environments that compromise the functionality of existing PV systems, the proposed system responds effectively to the need for more efficient alternative energy sources.

Thermal stratification in a solar hot water storage tank with mantle heat exchanger

2021 ◽  
Author(s):  
Qiong Li ◽  
Xiaoqiao Huang ◽  
Yonghang Tai ◽  
Wenfeng Gao ◽  
Wenxian Lin ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Storage Tank ◽  
Thermal Stratification ◽  
Water Storage ◽  
Hot Water ◽  
Water Storage Tank

scholarly journals Thermal evaluation of an indirect air heating system using solar collectors

2021 ◽  
pp. 6-22
Author(s):  
Jeisell Marisol Cabrera-Chairez ◽  
Néstor Manuel Ortíz-Rodríguez ◽  
Rodrigo Cervando Villegas-Martínez ◽  
Juan Manuel García-González
Keyword(s):  
Fossil Fuels ◽  
Heating System ◽  
Hot Water ◽  
Water Tank ◽  
Solar Collectors ◽  
Water Storage Tank ◽  
Air Heating ◽  
Conventional Drying ◽  
Alternative Energies

One of the current problems is the use of energy obtained from fossil fuels, especially due to the emission of greenhouse gases. An option to replace fossil fuels is the use of alternative energies such as solar or wind energy. The objective of this work is to carry out a thermal and energy analysis of an indirect air heating system that receives energy through solar collectors that operate with water as the thermal fluid used in a food dehydration system, in order to know the efficiency of the system and therefore, make improvements to the circuit, in addition to the characterization of the water storage tank of the system, obtain the amount of energy that can be provided and the behavior of temperatures at different operating flows. According to the methodology, the temperature profile was obtained inside the hot water tank in two modes of operation (heating and energy extraction) reaching temperatures of 50 to 70 ° C, where the optimum temperature for drying is found and in turn reaching an efficiency 84%, compared to a conventional drying system that uses LP gas.

Domestic Hot Water Storage Tank: Design and Analysis for Improving Thermal Stratification

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Nathan Devore ◽  
Henry Yip ◽  
Jinny Rhee
Keyword(s):  
Heat Exchanger ◽  
Storage Tank ◽  
Thermal Stratification ◽  
Reverse Flow ◽  
Storage System ◽  
Water Storage ◽  
Hot Water ◽  
Inlet Temperature ◽  
Domestic Hot Water ◽  
Water Storage Tank

Experimental designs for a solar domestic hot water storage system were built in efforts to maximize thermal stratification within the tank. A stratified thermal store has been shown by prior literature to maximize temperature of the hot water drawn from the tank and simultaneously minimize collector inlet temperature required for effective heat transfer from the solar panels, thereby improving the annual performance of domestic solar hot water heating systems (DSHWH) by 30–60%. Our design incorporates partitions, thermal diodes, and a coiled heat exchanger enclosed in an annulus. The thermal diodes are passive devices that promote natural convection currents of hot water upward, while inhibiting reverse flow and mixing. Several variations of heat exchanger coils, diodes and partitions were simulated using ansys Computational Fluid Dynamics, and benchmarked using experimental data. The results revealed that the optimum design incorporated two partitions separated by a specific distance with four diodes for each partition. In addition, it was discovered that varying the length and diameter of the thermal diodes greatly affected the temperature distribution. The thermal diodes and partitions were used to maintain stratification for long periods of time by facilitating natural convective currents and taking advantage of the buoyancy effect. The results of the experiment and simulations proved that incorporating these elements into the design can greatly improve the thermal performance and temperature stratification of a domestic hot water storage tank.

Domestic Hot Water Storage Tank: Design and Analysis for Improving Thermal Stratification

2012 ◽  
Author(s):  
Nathan Devore ◽  
Henry Yip ◽  
Jinny Rhee
Keyword(s):  
Heat Exchanger ◽  
Storage Tank ◽  
Thermal Stratification ◽  
Reverse Flow ◽  
Storage System ◽  
Water Storage ◽  
Hot Water ◽  
Solar Panels ◽  
Domestic Hot Water ◽  
Water Storage Tank

Experimental designs for a solar domestic hot water storage system were built in efforts to maximize thermal stratification within the tank. A stratified thermal store has been shown by prior literature to maximize temperature of the hot water drawn from the tank while simultaneously increasing the temperature delta required for effective heat transfer from the solar panels, thereby improving the annual performance of domestic solar hot water heating systems (DSHWH) by 30%–60%. Our design incorporates partitions, thermal diodes, and a coiled heat exchanger enclosed in an annulus. The thermal diodes are passive devices that promote natural convection currents of hot water upwards, while inhibiting reverse flow and mixing. Several variations of heat exchanger coils, diodes and partitions were simulated using ANSYS Computational Fluid Dynamics, and benchmarked using experimental data. The results revealed that the optimum design incorporated two partitions separated by a specific distance with four diodes for each partition. In addition, it was discovered that varying the length and diameter of the thermal diodes greatly affected the temperature distribution. The thermal diodes and partitions were used to maintain stratification for long periods of time by facilitating natural convective currents and taking advantage of the buoyancy effect. The results of the experiment and simulations proved that incorporating these elements into the design can greatly improve the thermal performance and temperature stratification of a domestic hot water storage tank.

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