Structure Design of Calorimeter of EAST-NBI System Using Thermal Inertia with Cooling Water

An enhanced circulating cooling water (CCW) machine is developed to simultaneously achieve high temperature stability and dynamic performance of CCW temperature control. Dynamic thermal filtering based on an auto-updatable thermal capacity medium is proposed to reduce the temperature fluctuation of the CCW. Agile thermal control is presented to realize a quick response and high resolution of temperature control, through thermal inertia minimization and bidirectional regulation of heating/cooling power. Experimental results indicate that a temperature stability of ±3 mK (peak to peak value) and a settling time of 128 s, corresponding to a 1 K step set value, are achieved. It can therefore be concluded that the developed machine can satisfy the challenging requirements of precision manufacturing.

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Numerical Simulation of Condensation Heat Transfer in Shell Side of Double Inlet Condenser

Volume 6A: Thermal-Hydraulics and Safety Analyses ◽

10.1115/icone26-81370 ◽

2018 ◽

Author(s):

Kai-yu Li ◽

Ruo-jun Xue ◽

Zhao-heng Liu ◽

Ji-lin Sun ◽

Le Liang

Keyword(s):

Heat Transfer ◽

Numerical Simulation ◽

Short Circuit ◽

Control Variable ◽

Cooling Water ◽

Axial Direction ◽

Structure Design ◽

Positive Pressure ◽

Shell Side ◽

Pressure Zone

The object of this research is a double inlet condenser, which is designed by optimizing and revamping the traditional surface-type condenser. In this paper, firstly, a mathematical model was established to describe the process of heat transfer in the condenser. Secondly, according to the structure and the operating parameters of double inlet condenser, a full three-dimensional numerical simulation was performed on the double inlet condenser by using Fluent software to obtain the spatial distribution of the important parameters in the shell side of the condenser. Finally, a series of numerical simulations were carried out by control variable method in order to study the effect of various factors, such as inlet water temperature, main and auxiliary steam flow and fouling thickness inside the pipe wall, on the flow and heat transfer in the double inlet condenser. The result is as follows. 1)There are the positive pressure zone and the negative pressure zone in the shell side of the condenser; 2) The pressure shows a mountain-type distribution along the axial direction of the cooling water pipe. 3) There is no obvious whirlpool zone and steam short circuit zone in the double inlet condenser, which shows that the structure design of the condenser is reasonable.

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Dynamic Modeling and Operation Characteristics Analysis of LiBr Absorption Heat Pump

E3S Web of Conferences ◽

10.1051/e3sconf/202125701022 ◽

2021 ◽

Vol 257 ◽

pp. 01022

Author(s):

Xianfa Hu ◽

Shuqing Zhang ◽

Zhen Peng ◽

Shaopu Tang ◽

Ning Liu

Keyword(s):

Heat Source ◽

Temperature Change ◽

Heat Pump ◽

Cooling Water ◽

Thermal Inertia ◽

Inlet Temperature ◽

Absorption Heat Pump ◽

Upper Limit ◽

Crystallization Risk ◽

Operation Characteristics

In order to fully exploit the dynamic operation characteristics of absorption heat pump, a dynamic simulation model of LiBr absorption heat pump considering mass transfer and distribution parameters is established. The thermal inertia characteristics of the system are studied, and the thermal performance and crystallization characteristics of the system are analyzed under the conditions of heat source temperature change, cooling water temperature change and refrigerant water temperature change. The results show that: the model can accurately simulate the steady-state and dynamic characteristics of the absorption heat pump; the thermal inertia of the unit is mainly related to the mass of the solution stored in the unit; the upper limit of the heat source inlet temperature is affected by the COP of the system and the crystallization risk, the decrease of the inlet temperature of cooling water can increase the COP of the system, and the lower limit is limited by the crystallization risk, and the cooling water inlet temperature is affected by the crystallization risk , and the lower limit of the inlet temperature of cooling water is limited by the crystallization characteristics. The upper limit of the inlet temperature of refrigerant water is not limited by the crystallization characteristics, but is mainly limited by the user’s energy demand. This provides a reference for the dynamic operation of absorption heat pump.

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CFD Analysis for Cooling Water Cavity of a Four-Cylinder Gasoline Engine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.940.184 ◽

2014 ◽

Vol 940 ◽

pp. 184-187

Author(s):

Xiao Xu Liu ◽

Min Chen

Keyword(s):

3D Model ◽

Gasoline Engine ◽

Cooling Water ◽

Calculation Model ◽

Structure Design ◽

Cfd Analysis ◽

Inlet Channel ◽

Set Up ◽

Water Speed ◽

Four Cylinders

s: The 3D model of cooling water cavity was set up, which was in a four cylinders gasoline engine, and the CFD analysis was done after setting the CFD calculation model and boundary conditions. The CFD analysis results shows that the structure design of engine’s cooling water cavity can meet the requirements basically, but there are some zone in which the water speed is lower than 0.5m/s, and there are some whirlpools in cylinder water jacket. In order to improve the cooling effect of the engine, the cooling water inlet channel and cylinder head should be improved.

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A SYSTEM FOR PROTECTING AN OIL DIFFUSION PUMP AGAINST FAILURE OF THE MECHANICAL FORE PUMP, COOLING WATER, OR ELECTRICITY

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068710 ◽

1970 ◽

Vol 28 ◽

pp. 344-345

Author(s):

W. C. Bigelow ◽

F. B. Drogosz ◽

S. Nitschke

Keyword(s):

High Vacuum ◽

Cooling Water ◽

Effective Protection ◽

Pump Line ◽

Diffusion Pump ◽

System Pressure ◽

Control Relay ◽

Vacuum Systems ◽

Vacuum Gage ◽

Pressure Switch

High vacuum systems with oil diffusion pumps usually have a pressure switch to protect against Insufficient cooling water; however, If left unattended for long periods of time, failure of the mechanical fore pump can occur with equally serious results. The device shown schematically in Fig. 1 has been found to give effective protection against both these failures, yet it is inexpensive and relatively simple to build and operate.With this system, pressure in the fore pump line is measured by thermocouple vacuum gage TVG (CVC G.TC-004) whose output is monitored by meter relay MRy (Weston 1092 Sensitrol) which is set to close if the pressure rises above about 0.2 torr. This energizes control relay CRy (Potter & Brumfield KA5Y 120VAC SPDT) cutting off power to solenoid-operated fore line valve Vf (Cenco 94280-4 Norm. Closed) which closes to prevent further leakage of air into the diffusion pump

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