Analysis of the thermodynamic performance limits of the organic Rankine cycle in low and medium temperature heat source applications

Thermodynamic analysis of working fluids: What is the highest performance of the sub- and trans-critical organic Rankine cycles?

“…In addition, operation condition parameters are also considered as optimization parameters: (Tevap, Tsph) of the sub-critical cases, and (Tevap, psu) of the trans-critical cases. In previous works [21,22], we found that pc is always at the upper optimization bound in subcritical cycles. In the present work, pc is fixed at the upper bound to speed up convergence.…”

“…Thus, it is expected that different optimal working fluid property and operation condition parameters would be identified for different Thf,ex. In previous works [21,22],…”

“…Rather than comparing between predefined working fluid candidates, the thermodynamic performance limits analysis aims to identify the highest possible performance of ORC in specific scenarios, and the optimal working fluid property and system parameters, and thus to reveal how these parameters affect system J o u r n a l P r e -p r o o f performance. In a following work, the framework was applied to geothermal and internal combustion engine (ICE) waste heat applications [22]. Property and system parameters were optimized simultaneously.…”

“…NPO shouldn't be compared between the different Thf,ex cases, because they represent different applications. This work uses 0.5 kg•s -1 and 1.2 kJ•kg -1 •K -1 , as of the ICE[8,22], in both cases. Using different heat source data only multiplies the obtained NPO by a constant factor, and has absolutely no effect on the obtained optimal property and system parameters or on the ηth and VPO results, which are the focus of the present work.…”

Analysis on the change factors of organic matter in sludge heat treatment process

“…Therefore, when scholars study the process of physical hydrothermal treatment, organic matter is the main influencing factor. However, the organic components contained in sludge in different regions are significantly different, as shown in Table 1 below: [7][8][9] Table 1 Organic composition analysis According to the types of organic components known in the above table, the specific content inside the sludge is measured and analyzed. There are two common methods:…”