Performance Assessment of Direct Vapor Generation Solar Organic Rankine Cycle System Coupled with Heat Storage

Round 1

Reviewer 1 Report

This combination of solar ORC and phase change materials has some significance. However, the manuscript still has some problems which should be solved. Otherwise, it cannot be accepted. The major problem is about Fig.1. In Lines 167-168, as the author reported, I feel the system cannot work during charging. It seems that only one pump cannot work both in charging mode and discharging mode because it has different flow direction. The location of the pump also seems wrong and it cannot pressurize the liquid at the condenser outlet. The turbine also has a wrong direction and this is misleading for readers. Only when the problem is suitable solved, the further investigations on it will has some significance.

Author Response

"Please see the attachment." 

Author Response File: Author Response.pdf

Reviewer 2 Report

1. The paper discusses the thermodynamic performances of a simple organic Rankine system with a heat storage by a phase change material.

The considered cycle scheme (Figure 1) did not consider a recuperator (a regenerator), which could instead increase the cycle efficiency.

2. It seems unusual not to consider (for the detailed description of the PCM storage tank, given its geometry, see Figure 3) the radial variation of the temperature?

3. Did the authors consider the effect of the quality (on the density, for example) in the two-phase conditions of the heat storage material? 

4. Is the temperature in Figure 4 the mean temperature of the thermal energy storage material?

5. It is not clear to the reader how relations (12) are evaluated. The parameter "lambda" (the liquefaction heat) is not in Nomenclature.

Author Response

"Please see the attachment." 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The paper can be accepted as it is.