3. The array structure with free-standing stencil cantilever was designed. The thermal isolation effect of array structure was theoretically analyzed, with the total thermal conductance of each pixel 1.73* 10'6 ( W/K ) .

The experimental results indicate that there are two factors that impact the total conductance of the system. The positive factor is the utilized area of condenser,while the negative one is the superheating of vapor in evaporator.

Numerical examples were given to show the effects of the temperature ratio of the two reservoirs, the total heat exchanger inventory and the temperature ratio between heat sink and surroundings on the optimal performance of the refrigerator.

When the pressure decreases to lower than 10~ -2 Pa, the influence of gas conductance can be neglected, the total thermal conductance decreases to the limit of radiative conductance, and the random vibration noise of the cantilever is reduced to a minimum.

However, metal wicks increase the heat leak from the evaporator to the compensation chamber, and hence reduce the overall thermal conductance.

Some of the remaining NCG will block part of the condenser and reduce the system overall thermal conductance.

The net effect is an increase of the loop operating temperature and a decrease of the overall thermal conductance.

The theory of finite time thermodynamics is applied to analyze the performance of irreversible air refrigeration cycles in this paper. For the fixed total heat exchanger inventory,the ratio of heat conductance of low-temperature side heat exchanger to that of high-temperature side heat exchanger is optimized for maximizing the cooling load and the coefficient of performance (COP) of the cycles. The influences of various parameters on the characteristic of the cycle are analyzed. The results obtained may provide...

The theory of finite time thermodynamics is applied to analyze the performance of irreversible air refrigeration cycles in this paper. For the fixed total heat exchanger inventory,the ratio of heat conductance of low-temperature side heat exchanger to that of high-temperature side heat exchanger is optimized for maximizing the cooling load and the coefficient of performance (COP) of the cycles. The influences of various parameters on the characteristic of the cycle are analyzed. The results obtained may provide guidance for the design of practice air refrigeration plants.

Some groundexperiments were carried out to study the operating principles,passive thermal control capability and the heattransfer characteristics of LHP.This paper presents some graphs of LHP's temperature distribution and variation with heat load for thermal analysis.The physical processes of LHP's heat transfer are described and explaned.Hysteresis of opertating temperature with heat load is shown and explained.The experiments also aimed at analyzing the law of the variation of LHP's conductance with heat...

Some groundexperiments were carried out to study the operating principles,passive thermal control capability and the heattransfer characteristics of LHP.This paper presents some graphs of LHP's temperature distribution and variation with heat load for thermal analysis.The physical processes of LHP's heat transfer are described and explaned.Hysteresis of opertating temperature with heat load is shown and explained.The experiments also aimed at analyzing the law of the variation of LHP's conductance with heat load.The experimental results indicate that there are two factors that impact the total conductance of the system.The positive factor is the utilized area of condenser,while the negative one is the superheating of vapor in evaporator.The influence of the relative orientation of evaporator and condenser on LHP's operation and its passive thermal control characteristics is discussed.The conclusion is drawn that gravitational force carries out negative effects on LHP's operating temperature,thermal control capability and its total conductance.

The performance of closed cycle helium turbine nuclear power plant for submarine propulsion is optimized in the viewpoint of finite time thermodynamics (FTT) or entropy generation minimization (EGM) in this paper. The power output, the power dinsity (ratio of power output to the maximum specific volume in the cycle) and the thermal efficiency of the cycle are derived. The model adopted is an irrevarsible regenerated closed Brayton cycle coupled to variable temperature heat reservoirs. In the analysis, the...

The performance of closed cycle helium turbine nuclear power plant for submarine propulsion is optimized in the viewpoint of finite time thermodynamics (FTT) or entropy generation minimization (EGM) in this paper. The power output, the power dinsity (ratio of power output to the maximum specific volume in the cycle) and the thermal efficiency of the cycle are derived. The model adopted is an irrevarsible regenerated closed Brayton cycle coupled to variable temperature heat reservoirs. In the analysis, the heat resistance losses in the hot side heat exchanger (intermediate heat exchanger) and cold side heat exchanger (precooler) and the recuperator, the irreversible compression and expansion losses in the compressor and turbine, the pressure drop losses at the heater, cooler and recuperator as well as in the piping, and the effect of the finite thermal capacity rate of the heat reservoirs are taken into account. The maximum power, the maximum power dinsity and the maximum efficiency are obtained by searching the optimum heat conductance distribution among the hot and cold side heat exchangers and the recuperator for the fixed total heat exchanger inventory with respect to the corresponding optimization objectives. The optimum results are compared with those reported in recent references for the conceptual design of a closed cycle helium turbine nuclear power plant for submarine propulsion. The numerical example shows that the method herein is valid and effective. The theory, the method and the results herein may provide guidance for the performance improvement and optimum design of real closed cycle helium turbine nuclear power plant.