Temperatures were measured every 0.1 s, and fan speed and heater outputs were adjusted every 0.5 s based on the measured temperature differential from the target temperature.
Utilizing finite element approximation a discretized input/output representation of the system is created with the inputs being powers of heaters and output the extruder temperature field.
The evolution of temperature and the heater thermal output were also reasonably well predicted by the model.
In addition, the thermal efficiency of system can be maximized by feed fluid heater pressure, while refrigeration output can be maximized by mass extraction ratio.
Based on the energy and exergy output rates, heater with double glass covers and fins (Type II) is more effective and the difference between the input and output air temperature is higher than of the others.
A feedback method was utilized to generate a time-dependent heat flux by controlling the output power of radiative heater.
The presently available equations for determination of heat outputs from these room heaters are valid for a certain height at a specific temperature range.
The increased power output of the replacement heater, which was needed to achieve the anticipated maximum operating temperature of 500 °C, resulted in the increased local temperature gradient and made the temperature ramp more erratic (Fig. 2).
A custom-made manifold was attached to the output ports of the heater to increase flow volume and to provide heat insulation.
The input light can be routed to any of the four output ports by different metal heater control.
An experimental investigation of the thermal performance of the air heater is performed, and the experimental results demonstrate the presented high-temperature solar air heater has excellent collecting performance and large output power, even in the winter.
