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.

This research is to study in heat transfer of hot water tank from an air conditioner which is a cylinder type and has a hot water pipe around the tank. It is used for finding a position and a pattern of distribution of the hot water pipe around the tank in the highest heat transfer condition. The study uses the cylinder of hot water tank filled 45 liters of 25 oC water. An experiment separates in 3 positions of pipe wrapping which are the bottom the center and the top of the tank. Then 80 oC of hot water run thought the hot water pipe which is wrapped around the tank for 120 minutes. The result of the experiment shows that tubing position that causes the highest heat transfer is at the bottom of tank. Pipe wrapping at the bottom of the tank has the heat transfer higher than the top of the tank at 30%. Furthermore this experiment studies in spacing of hot water pipe. There are 3 types for testing which are spacing hot water pipe as one time two times and three times of diameter of pipe. The result illustrates that spacing the hot water pipe can significantly increase the heat transfer. The heat transfer of spacing the hot water pipe in three times of diameter of pipe is higher 5.8 % than spacing in one times. In addition this research is to study in the effect of turbulent flow on the heat transfer by installing agitator in order to stir water in the tank. The result is that water stirring in the tank for increasing the heat transfer is not effective for investment because the energy using for stirring is higher than the enhanced heat transfer

Admittedly a disc brake plays an important role in the auto part industry since it concerns directly with safety. Therefore the wide range of disc brake has been designed in order to develop its heat ventilation. There are two physical kinds of brakes: front-vented disc brake and backvented disc brake. As a result such difference affects directly to the heat ventilation which is a vital factor of the brake’s capability. The project team recognizes its importance and tries to create the test to find out the temperature diffusion of the disc brake with the hope to evaluate the coefficient of the heat convection varied by the temperature changing in both kinds of brakes under the forced heat convection in the steady condition. However the steady heat conduction and radiation value will not be counted because it is insignificant. The JASO C406: 2000 Standard is adopted as a guideline in the test. The outcome coefficient of heat conduction will be used in the simulation via the Finite Element Method (FEM) in order to study the temperature diffusion and heat ventilation of both kinds of brakes at each temperature level. Consequently the experimental work reveals then the heat convection coefficients of both kinds are unidirectional. The heat convection coefficient of the front-vented disc brake is 4.40 % in average higher than that of the back-vented disc brake. From the simulation the front-vented disc brake can ventilate the heat better than the back-vented disc brake at 3.02 % in average. It can be summarized that the front-vented disc brake has more temperature difference than the backvented disc brake. Hence the front-vented disc brake likely gets more stress from the temperature than the back-vented disc brake and might be damaged during the operation more than the another type.

The aim of this study was to develop a three-dimensional transient condition model to predict the heat transfer rate of a heat pipe heat exchanger. This paper presents the details of the calculated domains which consist of the wall wick and vapor core. They were numerically simulated using the finite element method. The heat transfer rate values obtained from the model simulation can be used to design heat pipe heat exchangers. The values obtained from the model calculation were then compared with the results from experiments and the differences were 10.3% 10.4% and 6.7% for the working fluids of distilled water ethanol and R134a respectively. The working fluids of distilled water ethanol and R134a obtained heat transfer rates of 627.3 watts 522.8 watts and 836.4 watts from the experiments respectively.

The objective of this research is to study the implementing the agricultural residue to the design of outdoor paving block for lowering the building temperature. The base layer admixture (layer no.1) is selected from cement type1: quarry dust: rice husk: rice straw: water ratios equal to 1: 3: 0: 0: 0.3 1: 1: 0: 1: 0.5 1: 1. 0.25: 0.75: 0.5 1: 1: 0.5: 0.5: 0.5 1: 1: 0.75: 0.25: 0.5 and 1: 1: 1: 0: 0.5 by weight. The surface layer admixture (layer no.2) is white silica cement: yellow stone chip no.4: water equals to 1: 4: 0.3 by weight. The exterior floor-covering blocks were tested following density testing water absorption testing compressive testing and surface temperature testing compare with laterite sandstone paving concrete block marble and granite. Resulting the best ratio of cement type1: quarry dust: rice husk: rice straw: water is 1: 1: 0.75: 0.25: 0.5 that has properties at 28 days following 1939.43 kg/m of density 14.97 % of water absorption 284.69 ksc of compressive strength and lower than other paving blocks around 3 – 13 degrees Celsius of surface temperature