Solar Assisted Household Clothes Dryer

Author(s):  
Jeff Luttrell ◽  
Dereje Agonafer

Energy savings for domestic appliances have been an emphasis for several years. The efficiencies of several appliances have improved dramatically as a result of this attention. Refrigerator, water heater, and washing machine energy consumptions have been reduced. One appliance has not experienced significant improvement, the clothes dryer. Typical household clothes dryers use large amounts of electricity or natural gas to heat air that is circulated with the clothes. The energy to heat the air is a function of the amount of air and heat needed to remove moisture from the clothes. Using solar heat to augment or replace the other energy sources can provide significant energy savings. Conventional house construction includes features which collect and concentrate solar energy in the air occupying the attic space. Typical home design provides a roof which functions as a large area solar energy collector. Many roofing materials have solar absorption of 80% or more. Insulation of the roof decking is uncommon so that absorbed solar heat conducts through and heats the attic air. Through simple, low-cost ducting and minor modification of a clothes dryer air inlet, this energy resource becomes available for use. This study evaluates the potential energy savings of using solar-heated attic air as a clothes dryer air source. Considering house construction as well as seasonal and regional climate variations, attic air can augment and may fully replace utility energy as the heat source for drying air during daylight hours when solar energy is incident on the roof. The energy savings can be up to 3.5 kilowatt hours (or the heating equivalent for natural gas) for each dryer load.

2019 ◽  
Vol 276 ◽  
pp. 01031 ◽  
Author(s):  
Partogi H Simatupang ◽  
Petrus Lubalu ◽  
Herry L Sianturi ◽  
Wilhelmus Bunganaen

Kupang City in Timor Island of Indonesia, as a semiarid area, has abundant solar energy sources. Based on climatology data of Kupang City in 2013-2015, the minimum and maximum average temperatures in Kupang City range from 19.3-34.8oC. Besides, dry seasons last for about 8 months (April-November). This abundance of solar energy is a potential energy resource for the manufacturing of environmentally friendly ferrogeopolymer elements. Based on previous research, the production of geopolymer material can be done optimally with dry curing treatment at 60-80oC for less than 48 hours. Therefore, in this paper, a low-cost, energy efficient oven operated by a solar energy collector was developed. This paper describes a feasibility study of the use of solar energy for curing ferro-geopolymer elements. The ferro-geopolymer elements made were beams with length 600 mm, width 100 mm and height 100 mm. Wire meshes with 6x6mm of opening were used in 5 layers. The solar energy collector system used as an oven was a zinc coated drum which was painted black outwardly and was covered by a glass plate. Using this oven, it was possible to increase the ambient temperature by 1.62 to 2,37 times. Furthermore, this oven can also increase the flexure strength of ferrogeopolymer elements about ± 25.34%. This paper shows good potential use of solar energy in the manufacturing of ferro-geopolymer elements in the semiarid region.


Author(s):  
Stephan Mo¨ller ◽  
Dario Kaucic ◽  
Christian Sattler

Today’s production of renewable hydrogen using energy sources such as solar and wind is too expensive compared with conventional production, normally by an order of magnitude. The high costs are a major bottleneck for the launch of the hydrogen economy. This paper will present a bypass of this bottleneck, which is a compromise between the use of fossil and solar energy: the solar steam reforming of natural gas (NG). It comprises the production of hydrogen from NG and the use of solar energy as the renewable source at low cost. Using the solar reformer technology for generation of hydrogen, we expect fuel savings of up to 40% compared to a conventional plant. Therefore, the CO2 emissions can be reduced accordingly. Based on the experiences in DLR solar reformers, which were successfully demonstrated at a level of few hundred kW in previous EC co-funded projects (e.g. SOLASYS), industrial plant layouts were developed. For a 50 MWth solar reforming plant a cost study was prepared. Two process layouts were investigated and the hydrogen costs were calculated. Sensitivity analyses of different parameters such as the natural gas prize were conducted. The conceptual layout of a solar driven hydrogen production plant comprises the innovative solar reformer followed by a water gas shift reactor and gas separation units. For the separation of hydrogen and carbon dioxide a PSA unit and gas washing unit using methyldiethanolamine (MDEA) are considered. The remaining methane rich gas is recycled to the process. The results of this cost study show that hydrogen produced by solar reforming costs between 4.5 and 4.7ct€ / kWh (LHV of H2). Therefore it is only about 20% more expensive than conventionally produced hydrogen. Increasing the cost of methane (NG) will result in favorable conditions for the solar hydrogen.


2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.


2006 ◽  
Vol 90 (20) ◽  
pp. 3557-3567 ◽  
Author(s):  
U. Gangopadhyay ◽  
K.H. Kim ◽  
S.K. Dhungel ◽  
U. Manna ◽  
P.K. Basu ◽  
...  

Author(s):  
Cheng Tian ◽  
Chengcheng Li ◽  
Delun Chen ◽  
Yifan Li ◽  
LEI XING ◽  
...  

Designing low-cost and efficient evaporation system to maximize solar energy utilization is of great importance for the emerging solar water purification technologies. Herein, we demonstrate a universal sandwich hydrogel by...


2020 ◽  
Vol 13 (1) ◽  
pp. 235
Author(s):  
Fernando Martín-Consuegra ◽  
Fernando de Frutos ◽  
Ignacio Oteiza ◽  
Carmen Alonso ◽  
Borja Frutos

This study quantified the improvement in energy efficiency following passive renovation of the thermal envelope in highly inefficient residential complexes on the outskirts of the city of Madrid. A case study was conducted of a single-family terrace housing, representative of the smallest size subsidized dwellings built in Spain for workers in the nineteen fifties and sixties. Two units of similar characteristics, one in its original state and the other renovated, were analyzed in detail against their urban setting with an experimental method proposed hereunder for simplified, minimal monitoring. The dwellings were compared on the grounds of indoor environment quality parameters recorded over a period covering both winter and summer months. That information was supplemented with an analysis of the energy consumption metered. The result was a low-cost, reasonably accurate measure of the improvements gained in the renovated unit. The monitoring output data were entered in a theoretical energy efficiency model for the entire neighborhood to obtain an estimate of the potential for energy savings if the entire urban complex were renovated.


2021 ◽  
Vol 13 (15) ◽  
pp. 8244
Author(s):  
Francesca Cirisano ◽  
Michele Ferrari

Highly hydrophobic and superhydrophobic materials obtained from recycled polymers represent an interesting challenge to recycle and reuse advanced performance materials after their first life. In this article, we present a simple and low-cost method to fabricate a superhydrophobic surface by employing polytetrafluoroethylene (PTFE) powder in polystyrene (PS) dispersion. With respect to the literature, the superhydrophobic surface (SHS) was prepared by utilizing a spray- coating technique at room temperature, a glass substrate without any further modification or thermal treatment, and which can be applied onto a large area and on to any type of material with some degree of fine control over the wettability properties. The prepared surface showed superhydrophobic behavior with a water contact angle (CA) of 170°; furthermore, the coating was characterized with different techniques, such as a 3D confocal profilometer, to measure the average roughness of the coating, and scanning electron microscopy (SEM) to characterize the surface morphology. In addition, the durability of SH coating was investigated by a long-water impact test (raining test), thermal treatment at high temperature, an abrasion test, and in acidic and alkaline environments. The present study may suggest an easy and scalable method to produce SHS PS/PTFE films that may find implementation in various fields.


2021 ◽  
Vol 18 (2) ◽  
pp. 323-338
Author(s):  
Xiong-Qi Pang ◽  
Zhuo-Heng Chen ◽  
Cheng-Zao Jia ◽  
En-Ze Wang ◽  
He-Sheng Shi ◽  
...  

AbstractNatural gas hydrate (NGH) has been widely considered as an alternative to conventional oil and gas resources in the future energy resource supply since Trofimuk’s first resource assessment in 1973. At least 29 global estimates have been published from various studies so far, among which 24 estimates are greater than the total conventional gas resources. If drawn in chronological order, the 29 historical resource estimates show a clear downward trend, reflecting the changes in our perception with respect to its resource potential with increasing our knowledge on the NGH with time. A time series of the 29 estimates was used to establish a statistical model for predict the future trend. The model produces an expected resource value of 41.46 × 1012 m3 at the year of 2050. The statistical trend projected future gas hydrate resource is only about 10% of total natural gas resource in conventional reservoir, consistent with estimates of global technically recoverable resources (TRR) in gas hydrate from Monte Carlo technique based on volumetric and material balance approaches. Considering the technical challenges and high cost in commercial production and the lack of competitive advantages compared with rapid growing unconventional and renewable resources, only those on the very top of the gas hydrate resource pyramid will be added to future energy supply. It is unlikely that the NGH will be the major energy source in the future.


Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 524
Author(s):  
Jihui Yuan ◽  
Kazuo Emura ◽  
Craig Farnham

The Typical meteorological year (TMY) database is often used to calculate air-conditioning loads, and it directly affects the building energy savings design. Among four kinds of TMY databases in China—including Chinese Typical Year Weather (CTYW), International Weather for Energy Calculations (IWEC), Solar Wind Energy Resource Assessment (SWERA) and Chinese Standard Weather Data (CSWD)—only CSWD is measures solar radiation, and it is most used in China. However, the solar radiation of CSWD is a measured daily value, and its hourly value is separated by models. It is found that the cloud ratio (diffuse solar radiation divided by global solar radiation) of CSWD is not realistic in months of May, June and July while compared to the other sets of TMY databases. In order to obtain a more accurate cloud ratio of CSWD for air-conditioning load calculation, this study aims to propose a method of refining the cloud ratio of CSWD in Shanghai, China, using observed solar radiation and the Perez model which is a separation model of high accuracy. In addition, the impact of cloud ratio on air-conditioning load has also been discussed in this paper. It is shown that the cloud ratio can yield a significant impact on the air conditioning load.


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