University System of Maryland

Heat Transfer Technologies, Inc.

The United States Environmental Production Agency

K Reinhard Radermacher

Yunho Hwang

Jiazhen Ling

Yiming Wu

Ichiro Takeuchi

Chunsheng Wang

Jan Muehlbauer

Ye Tao

Vikrant C Aute

William Leslie Kopko

Jun Cui

Yoram Leon Shabtay

Manfred R Wuttig

Suxin Qian

James M Tancabel

Kwangil Kim

Jurgen Pannock

Joseph Patrick Baker

Daniel Fernandes Bacellar

Zhenyuan Mei

Nicholas W Mattise

Daniel Alejandro Dalgo Reyes

Yilin Du

Rohit Dhumane

Jelena Srebric

A heat exchanger has first and second manifold portions and an array of substantially-parallel heat-transfer tubes extending between the first and second manifold portions. Each heat-transfer tube has an outer surface and an inner surface defining a conduit. In a cross-sectional view, the outer surface of each heat-transfer tube can form a first shape that is non-circular, and the inner surface of heat-transfer tube can form a second shape different than the first shape. Alternatively or additionally, at least one of the first shape and the second shape lacks reflectional symmetry in the cross-sectional view. Methods for fabricating such heat exchangers are also provided.

Cross-flow heat exchanger systems and methods for fabrication thereof

An electrochemical module (EM) transfers a fluid across a membrane thereof using oxygen as a carrier gas. The EM has an anion exchange membrane (AEM) disposed between a first and second electrodes, each of which includes a catalyst. At an inlet side, the catalyst facilitates reaction of the fluid with carrier gas, such that an anion is formed. The anion is transported across the AEM in the presence of an electric field applied to the electrodes. At an outlet side, the catalyst facilitates dissociation of the anion back to the fluid and carrier gas. In some embodiments, the fluid comprises carbon dioxide, and the transporting by the EM is part of a heating/cooling cycle or a power generation cycle, or is used to capture carbon dioxide for storage or regeneration of stale air. In some embodiments, the fluid comprises water vapor, and the transporting by the EM dehumidifies air.

Systems, devices, and methods employing electrochemical processing with oxygen as carrier gas

Hydrofluoroolefin (HFO) fluid can be transported through an electrochemical device, which has a proton exchange membrane (PEM) disposed between a pair of gas-permeable electrodes that include respective catalysts. At an inlet side, the catalyst facilitates reaction of HFO with hydrogen carrier gas. The resulting cation is transported across PEM in the presence of an electric field applied to the electrodes. At an outlet side, the catalyst of the opposing electrode facilitates dissociation of the cation back into HFO and hydrogen. In some embodiments, the transported HFO has a higher pressure than that before the electrochemical device. In some embodiments, the electrochemical device can be operated in reverse to expand HFO fluid and/or to recapture power. The electrochemical device can thus be used as a compressor or expander for vapor-phase HFO or as a pump or expander for liquid-phase HFO, for example, in power generation or heating/cooling cycles.

Systems, devices, and methods employing electrochemical processing of hydrofluoroolefins

A system for heating/cooling includes a plurality of thermoelastic modules. Each of the modules includes one or more structures formed of shape memory alloy, which converts from austenite to martensite upon application of a first stress and release latent heat from the conversion. During a first part of a heating/cooling cycle, a first module is stressed to cause conversion. The latent heat released from the first module is rejected to a heat sink while a second unstressed module absorbs heat from a heat source. During a second part of the heating/cooling cycle, the first and second modules are connected together to transfer heat therebetween for heat recovery. The cycle can be repeated indefinitely with the first and second modules alternating roles. Structures of the thermoelastic cooling material and specific applications thereof are also disclosed.

Solid-state heating or cooling systems, devices, and methods

A cooling system based on thermoelastic effect is provided. The system comprises a heat sink, a refrigerated space and a regenerator coupled to the refrigerated space and to the heat sink to pump heat from the refrigerated space to the heat sink. The regenerator comprises solid thermoelastic refrigerant materials capable of absorbing or releasing heat.

Thermoelastic cooling

Despite otherwise uncomfortable conditions in a surrounding environment, a customizable microenvironment can be created around a user to maintain a comfortable temperature and/or humidity level using a comfort unit. For example, the environment may be an office building where conditions are out of the comfortable range to save on energy or for other reasons, a factory/shop environment that is poorly conditioned, or an outdoor location with little to no conditioning. A sensing unit can monitor biometric and environmental data and can determine a comfort level of the user. The comfort unit can then dynamically respond to the determined comfort level and adjust the microenvironment to improve the user's comfort level. The comfort unit can follow the user as the user moves within the macro-environment, or can otherwise move within the macro-environment to achieve certain functions, such as recharging or spatial shifting of thermal load within the overall macro-environment.

Comfort units and systems, methods, and devices for use thereof

A refrigeration system for providing cooling to two or more compartments utilizing respective first and second evaporators. During the initial operation of a cooling cycle, the refrigerant is utilized for cooling the compartment (such as a fresh food compartment) which is to be maintained at a higher temperature as compared with another compartment (such as a freezer compartment). Cooling can thus be achieved by operating a fan in the fresh food compartment, even where the refrigeration system has not yet reached steady state after the compressor initially begins operating. After cooling has been achieved in the fresh food compartment, the refrigerant in the system has reached a state suitable for cooling of the freezer compartment, and the fan for the freezer evaporator is turned on while the fan for the fresh food compartment is turned off. As a result, a relatively simply refrigeration system is provided which is more efficient than conventional arrangements, particularly single-stage refrigeration systems. A defrosting cycle can also be accomplished with the fresh food fan operating, and with the freezer evaporator fan and compressor off. As the refrigerant evaporates in the fresh food evaporator during defrosting, a thermosiphon effect results in an exchange of refrigerant between the evaporators such that defrosting is accomplished without requiring a defrost heater.

Tandem refrigeration system

Growing community of inventors

Silver Spring, MD, United States of America

K Reinhard Radermacher