A heat exchanger cleaning system comprises: a target rotating body which rotates around a rotation axis; a first inlet through which first gas on the target rotating body is introduced; and a first soot blower located in the inner space of the first inlet and including a first injection port through which a first substance is injected and a second injection port through which a second substance is injected, wherein a first distance of the first injection port from the rotation axis is substantially the same as a second distance of the second injection port from the rotation axis. A heat exchanger cleaning method using the heat exchanger cleaning system comprises: a step for positioning the first soot blower; a step for spraying the first substance and the second substance at the same time; and a step for removing foreign substances.

A dedicated outdoor air system and method that is capable of operating over a broader spectrum of conditions. The HVAC system of the present invention utilizes a heating means positioned within the return air passageway in order to optimize the regeneration of the desiccant wheel and energy recovery device. By positioning a heating means upstream of the regeneration side of the desiccant wheel, the system is capable of providing supply air having low dew points to the enclosed space while still providing improved energy efficiency over conventional HVAC systems.

The leakage reduction system includes a heat exchanger, a duct arrangement and a separation arrangement. The heat exchanger includes a rotor assembly rotatably mounted along a rotor post. The heat exchanger further includes a second inlet plenum, whereat the duct arrangement is configured. Further, the separation arrangement is incorporated at the duct arrangement dividing thereto into primary and secondary inlets. Through the primary inlet, a flue gas enriched with Oxygen is carried, and through the secondary inlet a recycled flue gas flow is allowed to be carried, keeping the Oxygen enriched recycled flue gas flow substantially away from turnover towards the flue gas flow to avoid turnover towards a flue gas flow, reducing leakage thereof.

Disclosed herein is a heat exchanger for transferring heat between a first gas flow and a second gas flow, the heat exchanger comprising at least two sectors; a first sector that is operative to receive a combustion air stream; and a second sector that is opposed to the first sector and that is operative to receive either a reducer gas stream or an oxidizer gas stream, and a pressurized layer disposed between the first sector and the second sector; where the pressurized layer is at a higher pressure than combustion air stream, the reducer gas stream and the oxidizer gas stream.

A support structure for a rotary regenerative heat exchanger includes an upper section, a lower section, and a plurality of support members. The upper section includes an upper ring having a first exterior surface, an upper hub and at least three upper spokes each extending between and secured at respective ends thereof to the upper ring and the upper hub. Each of the plurality of support members are fixedly secured, directly or indirectly, to the upper ring and the lower section. An annular space is between the upper ring and the lower ring, which is configured to receive compartments of a rotor assembly. The upper hub, the upper spokes and the support members cooperate to provide rigidity to the support structure by cooperating to support and transmit the weight of the upper spokes, the upper ring and the upper hub to the lower section.

A heat regenerating material particle of an embodiment contains a heat regenerating substance having a maximum value of specific heat at a temperature of 20 K or less is 0.3 J/cm.sup.3.Math.K or more, and one metal element selected from the group consisting of calcium (Ca), magnesium (Mg), beryllium (Be), strontium (Sr), aluminum (Al), iron (Fe), copper (Cu), nickel (Ni), and cobalt (Co). The heat regenerating material particle includes a first region and a second region, the second region is closer to an outer edge of the heat regenerating material particle than the first region, and the second region has a higher concentration of the metal element than the first region.

A dedicated outdoor air system and method that is capable of operating over a broader spectrum of conditions. The HVAC system of the present invention utilizes a heating means positioned within the return air passageway in order to optimize the regeneration of the desiccant wheel and energy recovery device. By positioning a heating means upstream of the regeneration side of the desiccant wheel, the system is capable of providing supply air having low dew points to the enclosed space while still providing improved energy efficiency over conventional HVAC systems.

A support structure for a rotary regenerative heat exchanger includes an upper section, a lower section, and a plurality of support members. The upper section includes an upper ring having a first exterior surface, an upper hub and at least three upper spokes each extending between and secured at respective ends thereof to the upper ring and the upper hub. Each of the plurality of support members are fixedly secured, directly or indirectly, to the upper ring and the lower section. An annular space is between the upper ring and the lower ring, which is configured to receive compartments of a rotor assembly. The upper hub, the upper spokes and the support members cooperate to provide rigidity to the support structure by cooperating to support and transmit the weight of the upper spokes, the upper ring and the upper hub to the lower section.

A heat exchanger for heat exchange between fluid streams incorporates rotary features to control the passage of the streams.

A two-stage heat regenerating cryogenic refrigerator may include: a vacuum vessel; a first and second cylinder in the vessel; the second cylinder coaxially connected to the first cylinder; a 1.sup.st regenerator in the first cylinder and accommodating heat regenerating material (HRM) 1; and a second regenerator in the 2.sup.nd cylinder accommodating HRM 2, HRM 2 including HRM particles, each HRM particle including a metal element and a heat regenerating substance including an oxide or oxysulfide and having a maximum specific heat at ≤20 K of ≥0.3 J/cm.sup.3.Math.K; each HRM particle including a 1.sup.st and 2.sup.nd region, the 2.sup.nd region being closer to each HRM particle's outer edge than the 1.sup.st, and the 2.sup.nd region having a higher metal element concentration than the 1.sup.st, the 1.sup.st and 2.sup.nd region containing the heat regenerating substance.