A power plant includes a solar receiver heating solid particles, a standpipe receiving solid particles from the solar receiver, a pressurized heat exchanger heating working fluid by heat transfer through direct contact with heated solid particles flowing out of the bottom of the standpipe, and a flow path for solid particles from the bottom of the standpipe into the pressurized heat exchanger that is sealed by a pressure P produced at the bottom of the standpipe by a column of heated solid particles of height H. The flow path may include a silo or surge tank comprising a pressure vessel connected to the bottom of the standpipe, and a non-mechanical valve. The power plant may further include a turbine driven by heated working fluid discharged from the pressurized heat exchanger, and a compressor driven by the turbine.
The United States Government may have certain rights to this invention pursuant to contract number DE-AC36-08GO28308 between the United States Department of Energy and Alliance For Sustainable Energy, LLC. This invention was developed under subcontract ZGJ-3-23315-01 between Alliance For Sustainable Energy, LLC. and Babcock & Wilcox Power Generation Group, Inc. under contract number DE-AC36-08GO28308.