Enhancing the Energy Efficiency of Domestic Dryer by Drying Process Optimization

Abstract

The domestic tumble dryers are becoming indispensable household appliances and responsible for up to 10% of the total residential energy use in developed countries. However, their energy efficiency is low. In this paper, the development of a multi-sensor computer-controlled prototype platform for fabric drying is described for improving the efficiency of dryers. The prototype platform enables the real-time control and recording of key drying parameters including heater power, air flow velocity, rotating speed of drying drum and drying cycle time. These parameters are automatically adjusted according to the exhaust air humidity instead of the temperature which is used traditionally. Additionally, a new drying model of dividing the drying process into 4 stages based on the humidity of the exhaust air has been investigated in order to further increase the energy saving. The performance of this staged drying model is experimentally evaluated in respect to energy consumption, drying time, and the smoothness of fabric after drying. The results clearly indicate that the staged controlling of heating power input not only decreases energy consumption by 21.5% but also improves the fabric smoothness by 0.9 grade compared to using a single heating power input for the whole drying process. The research outcome can enable the design and production of new dryers that are more energy efficient and lead to dried clothes that require less ironing, which in turn further reduces energy consumption.

Influence of load mass and drum speed on fabric motion and performance of a heat pump tumble dryer

“…widely in the open literature. Many researchers have demonstrated positive effects of increasing drying air temperature and flow rate on the tumble dryer performance [14][15][16][17][18][19][20][21].…”

Dimensional change of wool fabrics in the process of a tumble-drying cycle

“…19 In this stage, the main removed water was moisture from inside the fibers, and the bonding force of water to the fiber was stronger so that the higher temperature is required to remove the moisture from inside the fibers. 18,20 Figure 4 also shows that the untreated wool fabric dried slightly quicker than the Chlorine-Hercosett-finished wool fabric when the moisture content was more than 25%.…”

“…19 The moisture could migrate from the inside of the wool fabric to the fabric surface and compensate for the evaporation of free water on the fabric surface. 18 In the third stage, the moisture on the surface of the material decreased and some of the energy input was used to further increase the temperature of the drum and the fabric. 19 In this stage, the main removed water was moisture from inside the fibers, and the bonding force of water to the fiber was stronger so that the higher temperature is required to remove the moisture from inside the fibers.…”

“…Although the temperature in this stage was lower, the moisture content of both untreated and shrinkresist-finished wool fabrics decreased steadily. An explanation for this is that "free water" on the surface of fabric has a weak binding force between water and fabric, resulting in easier migration and evaporation in the first stage even at a lower temperature 18. At the second stage, evaporation of the moisture from the fabrics primarily took place.…”

The influence of mechanical action on felting shrinkage of wool fabric in the tumble dryer

“…The tumble dryer used in the study was a modified domestic thermoelectric air-vented dryer (GDZ10-977, Haier Co. Ltd, China) with adjustable parameters. 13,14 The drum radius of the tumble dryer was around 32.5 cm. At different drum rotation speeds, fabric movements varied.…”