A method of heat transfer in an embedded structure of a heat regenerator, that is based on: a plurality of segments formed from a porous regenerative material, where the segments are hydraulically separated, and where a temperature gradient through a particularly hydraulically separated segment is smaller than the temperature gradient established along the embedded structure of the heat regenerator; a structure for flow of the primary (first) fluid that flows forward and backward through each of the hydraulically separated segments, consisting of porous regenerative material, with the flow forward and backward in a direction that is approximately perpendicular to a direction of the temperature gradient, which is established along the embedded structure of the heat regenerator; a structure for flow of secondary (second) fluid that flows uni-directionally in a hydraulic circuit, which connects heat source and heat sink with primary hot and cold heat exchanger (PT and PH), a primary hot heat exchanger, which is hydraulically connected with a first side of hydraulically separated segments, the hydraulically separated segments formed from the porous regenerative material; a primary cold heat exchanger, which is hydraulically connected with a second side of hydraulically separated segments, the hydraulically separated segments formed from the porous regenerative material; a second hot heat exchanger that represents the connection with a heat sink; a second cold heat exchanger that represents the connection with a heat source; the primary (first) fluid that flows forward and backward in parallel through each of the hydraulically separated segments consisting of porous regenerative material and whereas the primary (first) fluid releases or absorbs the heat from porous regenerative material; the primary (first) fluid that transfers heat from the in-parallel hydraulically separated segments of porous regenerative material to the primary hot heat exchanger; the primary (first) fluid that transfers heat from the primary cold heat exchanger to the in-parallel hydraulically separated segments of porous regenerative material; a secondary (second) fluid that flows uni-directionally in a hydraulic circuit, which connects heat source and heat sink with primary hot and cold heat exchanger (PT and PH). a plurality of segments formed from a porous regenerative material, where the segments are hydraulically separated, and where a temperature gradient through a particularly hydraulically separated segment is smaller than the temperature gradient established along the embedded structure of the heat regenerator; a structure for flow of the primary (first) fluid that flows forward and backward through each of the hydraulically separated segments, consisting of porous regenerative material, with the flow forward and backward in a direction that is approximately perpendicular to a direction of the temperature gradient, which is established along the embedded structure of the heat regenerator; a structure for flow of secondary (second) fluid that flows uni-directionally in a hydraulic circuit, which connects heat source and heat sink with primary hot and cold heat exchanger (PT and PH), a primary hot heat exchanger, which is hydraulically connected with a first side of hydraulically separated segments, the hydraulically separated segments formed from the porous regenerative material; a primary cold heat exchanger, which is hydraulically connected with a second side of hydraulically separated segments, the hydraulically separated segments formed from the porous regenerative material; a second hot heat exchanger that represents the connection with a heat sink; a second cold heat exchanger that represents the connection with a heat source; the primary (first) fluid that flows forward and backward in parallel through each of the hydraulically separated segments consisting of porous regenerative material and whereas the primary (first) fluid releases or absorbs the heat from porous regenerative material; the primary (first) fluid that transfers heat from the in-parallel hydraulically separated segments of porous regenerative material to the primary hot heat exchanger; the primary (first) fluid that transfers heat from the primary cold heat exchanger to the in-parallel hydraulically separated segments of porous regenerative material; a secondary (second) fluid that flows uni-directionally in a hydraulic circuit, which connects heat source and heat sink with primary hot and cold heat exchanger (PT and PH).