System and method for auxiliary fluid circuit heating or cooling of a superheater during startup and shutdown operations

A method for at least one of pre-startup preparations and post-shutdown preparations of a solar operated power plant, the solar operated power plant comprising a solar receiver having a superheater section comprising a plurality of superheater panel arrangements, wherein each of the superheater panel arrangements comprises bottom and top headers disposed in a horizontal or sloped manner and connected by a number of vertically disposed heat absorbing tubes, the method comprising:

• circulating a working fluid flow in a first direction from an inlet of the superheater section to an outlet of the superheater section;
• and
• circulating in a second direction opposite to that of the first direction an auxiliary fluid flow of varying parameters, one parameter being temperature of the auxiliary fluid flow based on process variables of the superheater section, from the outlet of the superheater section to the inlet of the superheater section, the auxiliary fluid flow circulating:
• before circulating the working fluid flow, as the pre-startup preparation of the solar operated power plant during which the auxiliary fluid flow is of a temperature higher than a highest temperature of the headers to gradually heat the headers, and
• after cessation of the working fluid flow, as the post-shutdown preparation of the solar operated power plant during which the auxiliary fluid flow is of a temperature lower than a temperature of the headers to gradually cool the headers.