Countercurrent exchange

About: Countercurrent exchange is a research topic. Over the lifetime, 2255 publications have been published within this topic receiving 28687 citations. The topic is also known as: Countercurrent exchange.

Heat exchanger for air conditioner

Abstract: The utility model discloses a heat exchanger for air conditioners, which comprises hydrophilic aluminum foil, a size U-shaped tube, a sheet metal end plate and various pipeline connecting pieces. An inlet tube set is divided into two ways which are respectively connected with inlets of an upper countercurrent segment and a lower countercurrent segment on an air-out side, and a collecting tube set is connected with outlets of the upper countercurrent segment and the lower countercurrent segment on a windward side; the collecting tube set is connected with an inlet of an over-cooling segment; an outlet of the over-cooling segment is connected with an outlet tube set; the collecting tube set and the over-cooling segment are arranged in the middle part of the windward side; an inlet of the lower countercurrent segment is arranged at the bottom of the heat exchanger for air conditioners. The utility model has the refrigeration high efficiency and the heating high capability of a split type heat pump air conditioner, and simultaneously solves the problem of heating defrosting under a low temperature work condition. The utility model has the advantages of simple structure and strong batch production capability, and does not need to reform the existing equipment and mould greatly.

Pulsed plate column for mass transfer/heat exchange

Abstract: Countercurrent mass transfer is effected in column between liquid and gas streams, the column having a number of sieve trays and having pulsed feed.

Countercurrent gas liquid flow in a PWR hot leg during reflux condensation

Abstract: The loss-of-RHR (residual heat removal systems) during mid-loop operation is one of the relatively high-risk events in pressurized water reactors. In order to increase reliability of transient analyses, the code scaling, applicability, and uncertainty methodology has been applied to evaluate the loss-of-RHR event, and a PIRT (phenomena identification and ranking table) for the event was developed. Based on the PIRT, important thermal-hydraulic behaviors during a loss-of-RHR event have been evaluated, and major results are summarized in this report. Reflux condensation by a steam generator is expected to be one of substitute methods of RHR cooling. In that case, countercurrent gas-liquid flow in the hot leg, which consists of horizontal, elbow and inclined sections, affects the reactor cooling system pressure and coolant level in the core. In order to evaluate flow patterns and CCFL (countercurrent flow limitation) characteristics in the hot leg, therefore, air-water experiments using small-scale models were carried out, and numerical simulations were conducted using a two-fluid model in FLUENT6.3.26. The calculated flow patterns and CCFL characteristics agreed well with the data. Flow patterns in the hot leg, which were split by the CCFL curve, were stratified flow without CCFL and wavy mist flow under CCFL conditions. Keyword: loss-of-RHR; reflux condensation; countercurrent flow; PWR hot leg