| 摘要 |
An adsorber unit has an outer shell, a plurality of internal tubes extending through the shell for carrying heat transfer fluid, each tube having outwardly projecting fins along its entire length, and a solid adsorbent material in the shell surrounding the tubes such that the fins project into the adsorbent material, the fins being of a material (e.g., metal) of higher thermal conductivity than the adsorbent material. Metal wool loosely packed inside the tubes, or internal radial fins swaged into the tubes, increase internal surface area thereby enhancing convective heat transfer. Metal wool loosely packed between the external fins, or fine wire metal coils lightly squeezed between the external fins, further increase external surface area of the heat exchanger in contact with the adsorbent thereby enhancing contact heat transfer. Performance is enhanced because the external fins and wool or wire coils transport heat more efficiently to all regions of the adsorbent, and permit less non-adsorbent heat exchanger material (e.g., metal) to be used for a given amount of adsorbent. Two or more such units are used in an adsorption heat pump. This design utilizes existing components (e.g., shell-&-tube heat exchanger, internally and externally finned tubing, and metal wool or wire coils) in a novel manner heretofore untried. In one exemplary embodiment, automobile air conditioning, exhaust heat is used to power such an air conditioner. The significant additional power used by the mechanical compressor of an automobile (12%-17% during commuting for subcompact to midsize cars) can be nearly eliminated by powering the air conditioner with otherwise wasted exhaust heat. The adsorbent is heated and cooled by light oil (called Heat Transfer Fluid, HTF) which in turn is heated and cooled by exhaust and fresh air. Such indirect heating and cooling achieves the required efficiency, and allows using phase change material (e.g., wax) to store and therefore fully utilize exhaust heat. A refrigerant reservoir is included which provides immediate cooling after start-up of a cold engine, while the exhaust system and heat pump are still heating up in order to start pumping refrigerant. Eliminating the mechanical compressor increases fuel mileage by 14-18% for midsize, compact, MS and subcompact cars, or 4.6-6.0% annually, given a four-month cooling season.
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