Precise Control of Frozen Region During Cryosurgery Utilizing Peltier Effect

2007 ◽  
Author(s):  
Hiroki Takeda ◽  
Shigenao Maruyama ◽  
Setsuya Aiba ◽  
Atsuki Komiya
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heating Rate ◽  
Heat Production ◽  
Animal Experiment ◽  
Peltier Effect ◽  
Cooling Performance ◽  
Precise Control ◽  
Diseased Part ◽  
Peltier Module

In cryosurgery, it is necessary to control heat transfer precisely and actively in order to necrotize diseased part effectively and to avoid freezing healthy tissues. In order to control heat transfer, the cryoprobe utilizing peltier module was developed. This cryoprobe makes it possible to control cooling and heating rate actively and precisely due to peltier effect. Therefore, it is convenient to control the size of cell-destroyed area. In order to confirm cooling performance of the cryoprobe, gelatin cooling experiment and animal experiment was conducted. From the results, it can be said that this cryoprobe has enough cooling performance to destroy undesirable cell and it can control cooling and heating rate actively. Numerical simulation which considers biological heat production, freezing of tissue and peltier effect at same time was developed in order to evaluate frozen region or necrotized area, which are difficult to be measured.

Experimental and Numerical Evaluation of Small-Scale Cryosurgery Using Ultrafine Cryoprobe

2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Junnosuke Okajima ◽  
Atsuki Komiya ◽  
Shigenao Maruyama
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Transfer Coefficient ◽  
Temperature Distribution ◽  
Surface Temperature ◽  
Numerical Evaluation ◽  
Small Scale ◽  
Outer Diameter ◽  
Cooling Performance ◽  
The Heat Transfer Coefficient

The objective of this work is to experimentally and numerically evaluate small-scale cryosurgery using an ultrafine cryoprobe. The outer diameter (OD) of the cryoprobe was 550 μm. The cooling performance of the cryoprobe was tested with a freezing experiment using hydrogel at 37 °C. As a result of 1 min of cooling, the surface temperature of the cryoprobe reached −35 °C and the radius of the frozen region was 2 mm. To evaluate the temperature distribution, a numerical simulation was conducted. The temperature distribution in the frozen region and the heat transfer coefficient was discussed.

scholarly journals Thermal Design and Cooling Performance Evaluation of Electronic Equipment Containing Power Electronic Devices

2021 ◽  
Vol 39 (2) ◽  
pp. 451-459
Author(s):  
Zhengde Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Source ◽  
Electronic Devices ◽  
Thermal Design ◽  
Electronic Equipment ◽  
Source Analysis ◽  
Power Electronic ◽  
Cooling Performance ◽  
Scheme Design

In electronic equipment, thermal failure and thermal degradation are two increasingly prominent problems of the devices, with the deepening integration and growing power density. Currently, there are relatively few reports on the heat transfer mechanism, heat source analysis, and numerical simulation of electronic equipment containing power electronic devices (PEDs). Therefore, this paper carries out thermal design and evaluates the cooling performance of PED-containing electronic equipment. Firstly, the basic flow was given for the thermal design of PED-containing electronic equipment; the heat transfer mode of PEDs and the equipment were detailed, so was the principle of thermal design; the cooling principles were introduced for ventilation cooling, heat pipe cooling, and closed loop cooling. Then, numerical simulation was carried out on the solid and liquid state heat transfer of PEDs and the equipment under different cooling modes. Based on an engineering example, the cooling scheme was finalized through heat source analysis on the proposed electronic equipment. The experimental results rove the effectiveness of numerical simulation and electronic equipment cooling scheme. The results provide a reference for the cooling scheme design for other fields of thermal design.

Numerical Simulation of a Coke Oven

2012 ◽  
Vol 479-481 ◽  
pp. 586-589
Author(s):  
Dan Dan Hao ◽  
Wen Sheng Liu ◽  
Le Ping Dang ◽  
Hong Yuan Wei
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Temperature Distribution ◽  
Heating Rate ◽  
Wall Temperature ◽  
Coke Oven ◽  
Furnace Wall ◽  
Important Approach ◽  
Simulation Results ◽  
Char Structure

At present, the CFD numerical simulation, combined with an experiments involving heat transfer has become an important approach to studying coal carbonization. The aim of this paper is to illustrate how a standard CFD package may be modified so it can be used to simulate temperature distribution, coking time and carbonization processes that occur in coke oven charge. Content of volatile matters and moisture have important influence on heating rate during carbonization. Further, heating rate have effects on char structure an inner coking condition, as well as the carbonization time. In addition, furnace wall temperature have important effects on carbonization, because they can change the coking time. Our simulation results for the coke oven model are in agreement with experimental and virtual data.

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