scholarly journals Comparative investigation of performance of gas dryer and two other types of domestic clothes dryers

Author(s):  
Xiao-Mei Huang ◽  
Lian-Sen Xiong ◽  
Yan-Wen Zheng ◽  
Hui-Qing Liu ◽  
Yi-Zhen Xu ◽  
...  

Abstract The moisture extraction rate (MER) and energy efficiency of domestic gas clothes dryers, heat-pump clothes dryers and electric clothes dryers were assessed. The assessment was performed with regard to five indices: the MER, specific MER, specific thermal energy consumption for dehumidification (mSPC), energy efficiency (ηt) and primary energy efficiency (η1). The effects of the dry mass of clothes (mBD) and the ambient temperature on the performance of the clothes dryers were evaluated. The experiments were divided into two parts. In the first part, the ambient temperature was 20°C, and mBD was set as 1.5, 2.5, 3.5, 4.5 and 6 kg. In the second part, mBD was 3.5 kg, and the performance of the dryers was tested at ambient temperatures of 5, 7.5, 10, 12.5, 15 and 20°C. The experimental results indicated that the gas dryer had the highest MER the heat-pump dryer had the best performance with regard to energy conservation and all three types of dryers had a higher MER and energy efficiency when the ambient temperature increased. The performance of the gas dryer was lower than that of heat-pump dryer when the temperature was 20°C. But when the temperature was < 9.5°C, the primary energy efficiency of the gas dryer was higher than that of the heat-pump dryer.

2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt

Industrial heat pumps are heat-recovery systems that allow the temperature ofwaste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses ofintegrating backpressure turbine ofa power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency ofthe primary fuel is calculated for different operating range ofthe heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperaturedifference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit.


Author(s):  
Viral K. Patel ◽  
Kyle R. Gluesenkamp

This paper provides an overview of a thermoelectric heat pump clothes dryer which was developed with the aim of reducing the significant primary energy consumption attributed to residential electric clothes drying in the United States (623 TBtu/yr). The use of thermoelectric modules in place of the conventional electric resistance heater resulted in a 40% reduction in the energy consumption of the system, compared to the minimum energy efficiency standard. This was achieved for the first time for a standard test load of 8.45 lb, using a clothes dryer prototype with a thermoelectric heat pump module as the sole heating mechanism. The current experimental prototype was developed after extensive modeling, system design and control optimization, and experimental system-level evaluation of control parameters. The demonstration of improved energy consumption has laid the foundation for future development of this technology.


Author(s):  
Maurizio Sasso ◽  
Raffaello Possidente ◽  
Carlo Roselli ◽  
Sibilio Sergio

The cogeneration, or the combined production of electric (and/or mechanical) and thermal energy, is a well established technology, which has important environmental benefits and it has been noted by the European Community as one of the first elements to save primary energy, to avoid network losses and to reduce the greenhouse gas emissions. In particular, the study will be focused on the micro-cogeneration process with micro-combined heat and power system, or MCHP (electric power output ≤ 15 kW), which represents a valid and interesting application of this technology applicable, above all, to residential and light commercial users. This paper presents the Energy, Economic and Environmental (3-E) analysis of a natural gas-fired MCHP in combination with an electric heat pump (EHP). The 3-E analysis of the MCHP/EHP begins with the results of a detailed experimental activity developed in a test facility [1] for a wide range of conditions. Two operating conditions were simulated: a heating mode with co-production of electric and thermal energy, and a cooling mode with co-production of electric, thermal and cooling energy (tri-generation). The annual operating performance, also based on the typical features of the Italian market, is also discussed with a simplified approach.


Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3125 ◽  
Author(s):  
Yuan ◽  
Lin ◽  
Mao ◽  
Li ◽  
Yang ◽  
...  

This study presents the development and evaluation of a novel partially open-loop heat pump dryer with a unit-room (HPDU). The unit-room was designed to enable the ambient air to be mixed with the return air, thereby reducing the influence of the ambient air on the system performance, while maintaining a high system thermal efficiency. A modelling system for the HPDU was developed and validated based on a real-scale experimental study. By using the modelling system, the system characteristics under different ambient conditions and bypass factors were analyzed. The energy benefit of the proposed HPDU was quantified through a comparative study with a closed-loop heat pump dryer (CHPD). It is evident that a maximal specific moisture extraction rate (SMER) and a minimal total energy consumption (TEC) existed when changing the bypass factor of the HPDU under certain ambient temperatures. Compared to the CHPD, the coefficient of performance (COP) of the HPDU increased by up to 39.56%, presenting a significant energy benefit for the application of HPDU.


2011 ◽  
Vol 347-353 ◽  
pp. 587-590
Author(s):  
Qing Hai Luo ◽  
Zheng Zuo

This paper analyzes the energy consumption of hot water supply in buildings and the insurmountable shortcoming of low energy efficiency of conventional water heaters, and investigates the progress and problems of developing heat pump water heaters. It is pointed out that developing of heat pump water heaters is one of the efficient approaches to improve the energy efficiency of hot water supply.


2018 ◽  
Vol 10 (9) ◽  
pp. 3216 ◽  
Author(s):  
Haolu Liu ◽  
Khurram Yousaf ◽  
Kunjie Chen ◽  
Rui Fan ◽  
Jiaxin Liu ◽  
...  

In this study, an experimental heat pump dryer was designed. The specific moisture extraction rate and moisture extraction rate were used as performance indicators to explore the influence of environmental factors and the style of the hot air cycle on heat pump drying. The average temperature and humidity in Nanjing’s summer, winter, and throughout the whole year were taken as the experimental ambient temperature and humidity. Garlic slices 3 mm thick, with an initial moisture content of 66.714% w.b., were dried until the end moisture content was 10% w.b. Experimental results and thermal analysis showed that the open and semi-open heat pump dryers were greatly affected by ambient temperature and humidity. The closed heat pump drying system was greatly affected by the bypass air rate.


2019 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Paolo Iora ◽  
Laura Tribioli

In this paper, a general quasi-steady backward-looking model for energy consumption estimation of electric vehicles is presented. The model is based on a literature review of existing approaches and was set up using publicly available data for Nissan Leaf. The model has been used to assess the effect of ambient temperature on energy consumption and range, considering various reference driving cycles. The results are supported and validated using data available from an experimental campaign where the Nissan Leaf was driven to depletion across a broad range of winter ambient temperatures. The effect of ambient temperature and the consequent accessories consumption due to cabin heating are shown to be remarkable. For instance, in case of Federal Urban Driving Schedule (FUDS), simplified FUDS (SFUDS), and New European Driving Cycle (NEDC) driving cycles, the range exceeds 150 km at 20 °C, while it reduces to about 85 km and 60 km at 0 °C and −15 °C, respectively. Finally, a sensitivity analysis is reported to assess the impact of the hypotheses in the battery model and of making different assumptions on the regenerative braking efficiency.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3179 ◽  
Author(s):  
Anti Hamburg ◽  
Targo Kalamees

The aim of the renovation of apartment buildings is to lower the energy consumption of those buildings, mainly the heating energy consumption. There are few analyses regarding those other energy consumptions which are also related to the primary energy need for calculating the energy efficiency class, including the primary energy need of calculated heating, domestic hot water (DHW), and household electricity. Indoor temperature is directly connected with heating energy consumption, but it is not known yet how much it will change after renovation. One of the research issues relates to the change of electricity and DHW usage after renovation and to the question of whether this change is related to the users’ behavior or to changes to technical solutions. Thirty-five renovated apartment buildings have been analyzed in this study, where the data of indoor temperature, airflow, and energy consumption for DHW with and without circulation and electricity use in apartments and common rooms has been measured. During research, it turned out that the usage of DHW without circulation and the usage of household electricity do not change after renovation. Yet there is a major increase in indoor temperature and DHW energy use in buildings that did not have circulation before the renovation. In addition, a small increase in the use of electricity in common areas was discovered. This study will offer changes in calculations for the energy efficiency number.


Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2123 ◽  
Author(s):  
Lamberto Tronchin ◽  
Kristian Fabbri ◽  
Chiara Bertolli

Indoor air quality (IAQ) of buildings is a problem that affects both comfort for occupants and the energy consumption of the structure. Controlled mechanical ventilation systems (CMVs) make it possible to control the air exchange rate. When using CMV systems, it is interesting to investigate the relationship between the useful thermal energy requirements for ventilation and the energy consumption of these systems. This paper addresses whether there is a correlation between these two parameters. The methodology used in this work involves the application of equations of technical Italian regulations UNI/TS 11300 applied to a case study. The case study is represented by a 54 m3 room, which is assumed to have three CMV systems installed (extraction, insertion, insertion and extraction) for twenty different devices available on the market. Afterwards, simulations of useful thermal energy requirements QH,ve and primary energy EP,V were performed according to the electrical power of each fan W and the ventilation flow. The results show that the two values are not linearly correlated: it is not possible to clearly associate the operating cost for CMV systems according to building requirements. The study also shows that CMV systems are particularly efficient for high-performance buildings, where there is no leakage that can be ascribed to windows infiltrations.


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