The purposes of this research were to develop and to test performance of mini heat pump dryer for slice banana. Drying chamber of 0.48×0.47×0.39 m3 was designed and it could contain three trays. The three trays had dimension of 0.33×0.409 m2. A blower with 174.6 W motor of air condition was modify and could adjust flow rates of three levels for air cycle system in dryer. The air system had bypass air at evaporator. The refrigerant of R-134a and four main parts were used in the heat pump system. The four main parts were a 497 W hermetic compressor a 1800 W condenser an expansion valve and a 1300 W evaporator. Experiments for test performance of the mini heat pump dryer used close loop air system an evaporator bypass air of 60 % a temperature of 60 oC and various flow rates of 0.117 0.128 and 0.140 m3/s. Slide bananas of 400-500 g had an initial moisture content of 244-281 %dry basis and were dried until final moisture content lower than 6.24±0.007 %dry basis. It was found that the flow rates of 0.117 0.128 and 0.140 m3/s had coefficients of performance (COPh) of 3.32±0.066 3.88±0.031 and 4.24±0.08 respectively and had specific moisture extraction rates (SMER) of 184.5±11.85 186.2±8.17 and 200.1±21.34 g/kWh respectively. The flow rate at 0.140 m3/s was the best condition because it had high specific moisture extraction rate.

The objectives of this research were to construct a jar oven for the production of roasted chicken using heat from far-infrared radiation and to find the amount of electricity and specific energy consumption used in the production of roasted chicken. The physical properties in terms of color softness cooking yield and water holding capacity of roasted chicken were also investigated. By using far-infrared radiation at electrical power levels of 1000 1200 and 1400 watts to roast marinated chicken which had an initial mass of about 1650 grams until the mass of the roasted chicken had a lower than 1220 grams. From the experimental results it was found that the production of roasted chicken at far- infrared radiation with a high electrical power level requires significantly less electricity and specific energy consumption than that with low electrical power level (P≤0.05). Roasted chicken breasts with far-infrared radiation at 1400 watts had significantly higher lightness (L value) but lower redness (a value) and yellowness (b value) than those of 1000 watts (P≤0.05). However lightness (L value) yellowness (b value) and redness (a value) of the roasted chicken breast with far-infrared radiation at 1200 watts were not significantly different from those at 1000 and 1400 watts (P>0.05). The shear force and water holding capacity of roasted chicken were significantly increased when the electrical power levels of far-infrared radiation increased (P≤0.05). Moreover the electrical power levels of far-infrared radiation (1000 1200 and 1400 watts) did not significantly affect the cooking yield of roasted chicken (P>0.05).Sponso

This study investigates three different types of power plant include a trilateral cycle (TLC) subcritical organic Rankine cycle (ORC) and supercritical ORC power plant driven by geothermal heat source with mass flow rate 1 kg/s and temperature of 100๐C 110๐C and 120๐C. with 27 substances were examined as the working fluid of the power plant. While the net power output of 4.78 kW and 7.74 kW is obtained from the subcritical ORC with RC318 as its working fluid when the heat source temperature are at 100๐C and 110๐C respectively. Meanwhile the net power output of 11.85 kW is obtained from the subcritical ORC with R227ea as its working fluid when the heat source temperature is at 120๐C. The net power output of 5.64 kW and 9.16 kW are obtained from the supercritical ORC with R218 as its working fluid when the heat source temperature are at 100๐C and 110๐C respectively. Meanwhile the net power output of 12.88 kW is obtained from the supercritical ORC with R143a as its working fluid when the heat source temperature is at 120๐C. Furthermore the net power output of 7.96 kW 12.27 kW and 17.38 kW are obtained from the TLC plant with heptane as its working fluid when the heat source temperature are at 100๐C 110๐C and 120๐C respectively.

A closed wet cooling tower became popular for heat transfer process but the existing system was not sufficient for the heat transfer of the manufacturing line. This research aimed at investigating the heat transfer enhancement of the 200-ton closed cooling tower by installing spray nozzles to spray water to the condenser. The distance between the spray nozzles and the condenser were 20 30 40 50 and 60 centimeters. The mass flow rates of water spray were 8 10 12 and 14 liters per minute. The objectives of the study therefore were to study the heat transfer coefficient of cooling water and to evaluate the economic value of this improvement option’s investment costs. In this study the outlet temperature of the cooling tower was set to be less than 37°C the difference of inlet and outlet water temperature was 2.9°C and the overall heat transfer rate approximated 360 kW. The results of the study reported that the distance of the spray nozzles and the condenser was at 30 centimeters and the mass flow rate of water spray was 12 liters per minute. The rate of heat transfer was 362 kW. The efficiency of the cooling system was 0.8 which became suitable for real use. In addition to considering value investing the results showed that the payback period was 0.47 years and the net present value was 1693801 baht. The rate of return received from the project was 207% which was worth investing.

Sweet tamarind is a unique and economic plant of Phetchaboon province and it has already been geographical indication (GI) registered. One of its main problems is fungal degeneration which cannot be physically visible. This causes the consumer’s uncertainty on its quality especially sweet tamarind from small communities. This led to the study on the use of household heat to reduce fungal degeneration by steaming at 100oc for 50 60 70 and 80 minutes and drying in the hot air oven at 70 oc for 3 hours. Lt was found that increasing the heat resulted in darkening the sweet tamarind color and heightening up its moisture content (p≤0.05) Drying temperature at 60 70 and 80oc revealed the higher the heat the shorter the drying time and the sweet tamarind content was darker. In addition drying significantly decreased the moisture and preference score of sweet tamarind (p≤0.05). The storage of sweet tamarind in a significant increase in the moisture of the sweet tamarind shell (p≤0.05) and could preserve the tamarind for at least 12 weeks without the deterioration from the fungus.