Using Condensate Water to Reduce Heat for Finned-Tube Condenser of Air Conditioning System

The mostly air condition are use vapor compression refrigeration system in which R-22 refrigerant is used as a working substance.Now a day the mostly air condition are use vapor compression refrigeration system in which R-22 refrigerant is used as a working substance. From the results of study, it found that the quantity of water vapor or moisture in the air is condensed with in the fan coil unit while through out the evaporator. The fluid after condense is called condensed water. By this process, the quantity of condensed water is increases when the air condition is used in the long time. To increase the utility, the condensed water is recovered for the heart reduction in the finned-tube condenser. The experiment is consist of two conditions by using the air and condensed water to heart reduction. But in case of condensed water, the pressure operation is controlled at 280 and 260 Psig respectively. The results of experiment shown the refrigeration effect, coefficient of performance (C.O.P) and energy efficiency ratio (EER) is 39,675 Btu/hr, 3.01 and 10.3 Btu/hr.Watt respectively with the air is used. At the pressure operation 280 Psig, refrigeration effect, (C.O.P) and (EER) is 44,212 Btu/hr, 3.38 and 11.5 Btu/hr.Watt respectively and 49,856 Btu/hr, 3.99 and 13.6 Btu/hr.Watt at pressure operation 260 Psig. Furthermore, the capacity of condenser is increases to 11.43% and 25.6% and also the refrigerant efficient is increases to 12.43% and 32.43% at the pressure operation 280 and 260 Psig. Thus, the parameter of the energy efficiency ratio depends on the capacity of condenser, working substance temperature (pressure operation) and air surrounding temperature

Finned-Tube Condenser Cleaner Machine

this research is to design the finned-tube condenser unit cleaner machine for increasing the heart reduction efficiency.Now a day the mostly air condition are use the air for reducing the temperature at the condenser unit. Moreover, many dusts are adhering in area of fin coil. From this reason, the heart reduction efficiency is decreased and increasing the energy consumption. Thus, the aim of this research is to design the finned-tube condenser unit cleaner machine for increasing the heart reduction efficiency. From the results of experiment, it found that the finned-tube condenser cleaner machine is desirable when comparing with the performance before used. By the original performance, the refrigeration effect, coefficient of performance (C.O.P) and energy efficiency ratio (EER) is 34,179 Btu/hr, 2.62 and 8.9 Btu/hr.Watt. On the other hand, the refrigeration effect, (C.O.P) and (EER) is 39,766 Btu/hr, 3.12 and 10.7 Btu/hr.Watt respectively when the condenser unit cleaner machine is used. Based on this condition, the value of the refrigeration effect and (EER) are increase to 16.35% and 19.19% respectively. Thus, the heart reduction in condensing unit can be aided the performance and prolong the life time of air condition by depending on the cleaning of condensing unit

A Modeling of Heat Transfer in Cooling Coil using Finite Element Method

รายงานวิจัย--มหาวิทยาลัยเทคโนโลยีราชมงคลพระนคร,2548In general for the refrigeration, the cooling coil is almost used to be the device to decrease the temperature. Thus, in order to design heat exchange, we should study the heat transfer into the cooling coil. This research proposes the numerical using finite element method for calculating the temperature at any position of the cooling point for considering to porous media. After that, to create an algebraic equation fmite element for writing the program to search the solution by estimating the temperature. The research demonstrates that the changing of temperature will be decreased to saturated condition, that is the temperature around the region of the cooling coil model edge will be decreased. The longer time, the lower temperature around each position will decrease respectively until the temperature at each position inside the model are the same as region of the cooling coil model edge. Therefore, this search result can be the basic for the comparison with the similar problem of otherRajamangala Unuversity of Technology Phra Nakh

Effects of dental monomeric resins on functions of odontoblasts <italic>in vitro</italic>.

Methacrylate-based dental resins polymerize incompletely, due in part to inhibitory effects of oxygen. Diffusion of residual monomeric resins through dentin to reach dental pulp, increased prevalence of dental pulp reactions of resin cavities with 0.5 mm or less dentin thickness and cytotoxicity of resins raised concerns of biocompatibility of resins with odontoblasts, the cells which secrete dentin. The toxic and subtoxic effects of four methacrylate-based resins on the functions of mouse odontoblast-like cells, MDPC.23, were studied. First, cytotoxicity of resins to MDPC.23 cells was assessed by measuring four metabolic functions of NMPC.23 cells. The results showed that the TC50 values measured by mitochondrial activity at 24-h exposure were as follows: HEMA, 8420 +/- 1974 muM; TENDENCY, 1252 +/- 145 muM; bisGMA, 52 +/- 14 muM; and UDMA 56 +/- 17 muM; Increased exposure time to the resins promoted toxicity of the resins. The rank of sensitivity of end-point measurements was as follows: mitochondrial activity (least) in vivo toxicity of resins. Third, mode of cell death of NMPC.23 (apoptosis or necrosis) caused by the resins was determined by flow cytometry and the TUNEL assay. The findings showed that MDPC.23 did not exhibit apoptosis, suggesting that necrosis may be the primary mode of cell death by resins. Fourth, effects of sublethal doses of resins on expression of three odontoblastic genes in NMPC.23 were investigated. Western analysis showed that the resins increased dentin sialoprotein expression. Nontoxic or slightly toxic concentrations of resins upregulated osteopontin and osteocalcin expression. Higher toxic concentrations interfered with osteopontin and osteocalcin expression, as seen in Northern analysis. Altered phenotypes of odontoblasts by resins suggests a role of resins in dentin mineralization.Ph.D.DentistryHealth and Environmental SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/132869/2/9990968.pd

การนำน้ำคอนเคนเซดมาระบายความร้อนให้กับแผงคอนเดนเซอร์ของระบบปรับอากาศ

รายงานวิจัย -- มหาวิทยาลัยเทคโนโลยีราชมงคลพระนคร, 2550Now a day the mostly air condition are use vapor compression refrigeration system in which R-22 refrigerant is used as a working substance. From the results of study, it found that the quantity of water vapor or moisture in the air is condensed with in the fan coil unit while through out the evaporator. The fluid after condense is called condensed water. By this process, the quantity of condensed water is increases when the air condition is used in the long time. To increase the utility, the condensed water is recovered for the heart reduction in the finned-tube condenser. The experiment is consist of two conditions by using the air and condensed water to heart reduction. But in case of condensed watcr, the pressure openation is controlled at 280 and 260 Psig respectively. The results of efficicncy ratio (EER) is 39,675 Btu/hr 3.01 and 10.3 Btu/hr, Watt respectively with the air is used, At the pressure operation 280 Psig, refrigeration effect, (C.O.P) and (EER) is 44,212 Btu/hr, 3.38 and 11.5 Btu/hr. Watt respectivecly and 49,856 Btu/hr, 3.99 and 13.6 Btu/hr Watt at pressure operation 260 Psig. Furthermore, the capacity of condenser is increases to 11.43% and 25.6% and also the refrigerant efficient is increases to 12.43 % and 32.43% at the pressure operation 280 and 260 Psig. Thus, the pararneter of energy efficiency ratio depends on the capacity of condenser, working substance temperature (pressure operation) and air surrounding tcmperature.Rajamangala University of Technology Phra Nakho

Finned-tube Condenser Cleaner Machine

รายงานวิจัย -- มหาวิทยาลัยเทคโนโลยีราชมงคลพระนคร, 2550Now a day the mostly air condition are use the air for reducing the temperature at the condenser unit. Moreover, many dusts are adhering in area of fin coil. From this reason, the heart reduction efficiency is decreased and increasing the energy consumption. Thus, the aim of this research is to design the finned-tube condenser unit cleaner machine for increasing the heart reduction efficiency. From the results of experiment, it found that the finned-tube condenser cleaner machine is desirable when comparing with the performance before used. By the original performance, the refrigeration effect, coefficient of performance (C.O.P) and energy efficiency ratio (EER) is 34,179 Btu/hr, 2.62 and 8.9 Btu/hr.Watt. On the other hand, the refrigeration effect, (C.O.P) and (EER) is 39,766 Btu/hr, 3.12 and 10.7 BtuIhr.Watt respectively when the condenser unit cleaner machine is used. Based on this condition, the value of the refrigeration effect and (EER) are increase to 16.35% and 19.19% respectively. Thus, the heart reduction in condensing unit can be aided the performance and prolong the life time of air condition by depending on the cleaning of condensing unit.Rajamangala University of Technology Phra Nakho

Comparison between the efficacy of self-prepared chlorhexidine varnishes and of EC 40®

It was reported that clinical application of chlorhexidine (CHX) varnish could reduce dental caries occurrence effectively.However, this form of CHX is not commercially available in Thailand. Our previous study showed that the released CHX from 20% and 40% self-prepared CHX varnishes were sufficient to inhibit the growth of Streptococcus mutans. This study aimed to compare the efficacy of the 20% and 40% self-prepared CHX varnishes to commercial CHX varnish EC 40®. The study included CHX release, antibacterial activity against S. mutans ATCC 25175, and the cytotoxic effect of CHX on fibroblasts. The results showed that the greatest amount of CHX was released by EC 40® followed by 40% and 20% selfpreparedCHX, which were 4,111.29 g, 2,408.7 g, and 1,136.4 g, respectively. EC 40® gave the strongest antibacterial activity; however, there was no statistical significant difference. The 20% self-prepared CHX gave the highest viability of fibroblasts. This study indicates that the self-prepared CHX should be considered to be used as antimicrobial agents for the prevention of dental caries