Novel electrothermodynamic power generation
Novel electrothermodynamic power generation
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新型电热发电
DOI：
10.1002/aenm.201401942
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发表时间：
2015
影响因子：
27.8
通讯作者：
K.b a
中科院分区：
文献类型：
--
作者：
Kim;Y.a ; Kim;J.a; Yamanaka;S.a; Nakajima;A.a; Ogawa;T.a; Serizawa;T.a; Tanaka;H.a ; Baba;M.b; Fukuda;T.c; Yoshii;K.c; Takeda;M.b; Yamada;N.b; Nakayama;T.b; Niihara;K.b a
电热力循环由电位移环D与电场E环(D-E环)来描述。在图1a中，理论奥尔森循环的示意图显示为ABCD。循环开始于没有电场(A点)的低温(Tlow)。当施加电场(E1)时，状态移动到B点(路径AB)，对应于在Tlow获得的材料的磁滞回线部分(见图S1b，辅助信息)，表示电位移增加。温度增加到THIGH值(路径BC)。然后，电位移对应于在大腿(点C)处获得的另一个磁滞回线。除去外部电场，状态沿大腿处的磁滞回线移动到点D(路径CD)。最后，温度降低到Tlow，状态移动到点A(路径DA)。产生的回路面积被认为是能量密度(ND，D-E回路的面积)；功率密度(PD，=NDF)也是从该面积计算的。[7-14]就我们所知，由于很难找到能够同时提供交替热量和电场的合适的能源，没有一种应用能够满足真正的能量盈亏平衡。[7-14]在本研究中，提出了一种新的基于时间温度变化的电热力循环，以从汽车尾气热中获得实际的净能量。对另一种典型的热电转换循环Stirling循环进行了改进，该循环具有比Olsen循环更高的电势。采用了最具代表性的热释电材料PZT(C-6，居里温度：305℃)。在对排气温度波动成像的基础上，将温度变化视为简单的伪正弦波。根据温度变化对材料施加外加电场(请参阅支持信息中的详细信息)。通过二极管和开关的感应，重新设计了通用的Sawyer-Tower(ST)电路(称为DSW电路，请参见图S2B，支持信息)，以评估D-E环路并同时获取净能量。在图1a中，显示了我们的周期(ABC 1D)的示意图。AB路径与Olsen循环相同。然后将材料隔离，并在将温度提高到大腿的同时保持电位移D恒定。根据电热力学方程[15，16]d D/dt=ε·dE/dt+p·dT/dt，电压增加到E2值(路径BC 1)，其中D、E、T、ε、t和p分别是电场、电场、温度、介电常数、时间和热释电系数(请参阅支持信息中的详细信息)。然后，材料被重新连接到电路，并且状态移动到点D(路径C1d)。最后，温度降回Tlow，D-E回路闭合。三角形面积BC 1C是与外部施加相同E的奥尔森循环相比的额外势能。在图1b中，奥尔森循环的循环(ABCD)存在多少余热，以及我们如何将其用作可再生能源？这些问题已经在汽车应用中得到了探索。在这里，我们提出了一种基于时间温度变化(dT/dt)、热释电效应而不是空间温度梯度(dT/dx)和塞贝克效应的新型电热循环。在操纵面分析和真实发动机测功机实验中，都成功地产生了实际能量。主要的生成来源是晶体结构变化和与…相对应的偶极变化现象的组合
The electrothermodynamic cycle is described by the loop of the electric displacement, D, versus the electric field, E (D–E loop). In Figure 1a, a schematic of the theoretical Olsen cycle is presented as ABCD. The cycle begins at a low temperature (Tlow) with no electric field (point A). When the electric field (E1) is applied, the state moves to point B (path AB), corresponding to the hysteresis loop section of the material obtained at Tlow (see Figure S1b, Supporting Information), denoting an increase in electric displacement. The temperature is increased to the value Thigh (path BC). Then, electric displacement corresponds to another hysteresis loop, obtained at Thigh (point C). Removing the external electric field, the state moves to point D along the hysteresis loop at Thigh (path CD). Finally, the temperature is decreased to Tlow, and the state moves to point A (path DA). The produced loop area is considered as an energy density (ND, the area of the D–E loop); the power density (PD,= NDf) is also evaluated from the area.[7–14] To the best of our knowledge, there is no application that satisfies a true energy breakeven because of the difficulties associated with finding a suitable energy source that can simultaneously give alternative heat and an electric field.[7–14] In this study, a novel electrothermodynamic cycle is presented based on temporal temperature variation to obtain practical net energy from exhaust heat of automobile. Another representative heat electric conversion cycle, the Stirling cycle, is modified, and this cycle has a higher potential than the Olsen cycle.[6, 7] The most representative pyro and piezoelectric material, PZT (C-6, Curie temperature TC: 305 C), is employed. The temperature variation is considered as a simple pseudo-sinusoidal wave based on the imaging of the temperature fluctuation of the exhaust gas. An external electric field is applied to the material corresponding to the temperature variation (see details in the Supporting Information). The general Sawyer-Tower (ST) circuit is redesigned by inductions of a Diode and a SWitch (named as DSW circuit, see Figure S2b, Supporting Information) to evaluate the D–E loop and simultaneously harvest the net energy. In Figure 1 a, a schematic of our cycle (ABC 1D) is shown. The AB path is the same as the Olsen cycle. The material is then isolated and the electric displacement D is kept constant while the temperature is increased to Thigh. The voltage is increased to the E2 value (path BC 1) based on the electrothermodynamic equation:[15, 16] d D/d t= ε· d E/d t+ p· d T/d t, where D, E, T, ε, t, and p are the electric displacement, electric field, temperature, dielectric permittivity, time, and pyroelectric coefficient, respectively (see details in the Supporting Information). Then, the material is reconnected to the circuit, and the state moves to point D (path C1d). Finally, temperature is decreased back to Tlow, and the D–E loop is closed. The triangular area BC 1C is the additional potential compared to the Olsen cycle with the same externally applied E. In Figure 1 b, loops of Olsen cycle (ABCD)How much wasted heat exists, and how can we utilize it as renewable energy? These questions have been explored in automobile applications. Here, we present an innovative electrothermodynamic cycle based on temporal temperature variations (d T/d t); the pyroelectric effect, instead of spatial temperature gradient (d T/d x); and the Seebeck effect. Practical energy is successfully generated in both an Operando analysis and real engine dynamometer experiments. The main generating origin is revealed as a combination of a crystal structure change and a dipole change phenomenon that corresponds to the …