为了开发高效的太阳能冷却技术,建立了一个由光伏(photovoltaic,PV)模块和基于范德华异质结构(van der Waals heterostructure,vdWH)的热离子制冷器(thermionic refrigerator,TIR)组成的新型耦合系统。在充分考虑内部和外部的不可逆因...为了开发高效的太阳能冷却技术,建立了一个由光伏(photovoltaic,PV)模块和基于范德华异质结构(van der Waals heterostructure,vdWH)的热离子制冷器(thermionic refrigerator,TIR)组成的新型耦合系统。在充分考虑内部和外部的不可逆因素的情况下,建立了耦合系统的理论模型,推导了关键性能指标的数学表达式。在此基础上,研究了耦合系统的一般性能特征,并确定了允许系统运行的电压区域。根据计算,最大制冷量和最大性能系数(coefficient of performance,COP)分别为75.88 W和0.49。此外,还进行了灵敏度分析,以得出关键参数对整体性能影响的规律和大小,包括太阳辐照度、有效肖特基势垒高度、层间热阻、外部热阻、热泄漏热阻和热库温度。所得结果可能有助于实际耦合系统的设计和运行。展开更多
In this paper, an irreversible thermionic refrigerator model based on van der Waals heterostructure with various irreversibilities is established by utilizing combination of non-equilibrium thermodynamics and finite t...In this paper, an irreversible thermionic refrigerator model based on van der Waals heterostructure with various irreversibilities is established by utilizing combination of non-equilibrium thermodynamics and finite time thermodynamics. The basic performance characteristics of the refrigerator are obtained. The effects of key factors, such as bias voltages, Schottky barrier heights and heat leakages, on the performance are studied. Results show that cooling rates and coefficients of performances(COPs) can attain the double maximum with proper modulation of barrier heights and bias voltages. Increasing cross-plane thermal resistance as well as decreasing electrode-reservoir thermal resistance and reservoir-reservoir thermal resistance can enhance the performance of the device. The optimal performance region is the interval between the maximum cooling rate point and the maximum COP point. By modulating the bias voltage, the working state of the device can fall into the optimal performance region. The optimal performance of the refrigerator when using single layer graphene and a few layers graphene as electrode material is also compared.展开更多
文摘为了开发高效的太阳能冷却技术,建立了一个由光伏(photovoltaic,PV)模块和基于范德华异质结构(van der Waals heterostructure,vdWH)的热离子制冷器(thermionic refrigerator,TIR)组成的新型耦合系统。在充分考虑内部和外部的不可逆因素的情况下,建立了耦合系统的理论模型,推导了关键性能指标的数学表达式。在此基础上,研究了耦合系统的一般性能特征,并确定了允许系统运行的电压区域。根据计算,最大制冷量和最大性能系数(coefficient of performance,COP)分别为75.88 W和0.49。此外,还进行了灵敏度分析,以得出关键参数对整体性能影响的规律和大小,包括太阳辐照度、有效肖特基势垒高度、层间热阻、外部热阻、热泄漏热阻和热库温度。所得结果可能有助于实际耦合系统的设计和运行。
基金supported by the National Natural Science Foundation of China (Grant Nos.51779262, 51576207, 51306206)the Hubei Province Natural Science Foundation of China (Grant No.2017CFB498)。
文摘In this paper, an irreversible thermionic refrigerator model based on van der Waals heterostructure with various irreversibilities is established by utilizing combination of non-equilibrium thermodynamics and finite time thermodynamics. The basic performance characteristics of the refrigerator are obtained. The effects of key factors, such as bias voltages, Schottky barrier heights and heat leakages, on the performance are studied. Results show that cooling rates and coefficients of performances(COPs) can attain the double maximum with proper modulation of barrier heights and bias voltages. Increasing cross-plane thermal resistance as well as decreasing electrode-reservoir thermal resistance and reservoir-reservoir thermal resistance can enhance the performance of the device. The optimal performance region is the interval between the maximum cooling rate point and the maximum COP point. By modulating the bias voltage, the working state of the device can fall into the optimal performance region. The optimal performance of the refrigerator when using single layer graphene and a few layers graphene as electrode material is also compared.
