The role of secondary refrigerants is expected to grow as the focus on the reduction of greenhouse gas emissions increases. The effectiveness of secondary refrigerants can be improved when phase changing media are introduced in place of single phase media. Operating at temperatures below the freezing point of water, ice slurry facilitates several efficiency improvements such as reductions in pumping energy consumption as well as lowering the required temperature difference in heat exchangers due to the beneficial thermo-physical properties of ice slurry. Research has shown that ice slurry can be engineered to have ideal ice particle characteristics so that it can be easily stored in tanks without agglomeration and then be extractable for pumping at very high ice fraction without plugging. In addition ice slurry can be used in many direct contact food and medical protective cooling applications. This paper provides an overview of the latest developments in ice slurry technology.

Cold intravenous fluids rapidly induce hypothermia in swine with intact circulation. A two-phase (liquid plus ice) saline slurry cools more rapidly than an equal volume of cold saline at 0 degrees C. Ice-slurry could be a significant improvement over other cooling methods when rate of cooling and limited infusion volumes are important to the clinician.

This paper is concerned with the benefits of using phase-change slurries as enhanced heat-transfer/storage working fluids in solar energy and waste heat utilization systems. Literature is cited to show that a slurry containing a phase-change material as the dispersed phase promises to have much higher heat-transfer coefficients than conventional single-phase working fluids. Because of the latent heat, the phase-change slurry also requires lower pumping rates and smaller storage tanks than single-phase fluids for the same energy content. These benefits are documented by comparisons of temperature drops, pumping rates, pumping powers, and the sizes of storage tanks for a generic energy collection system operating with and without a slurry.

laparoscopically exposed; thermocouple probes were placed throughout the kidney and the hilum was clamped. MPS was delivered through a modified 5-mm laparoscopic suction/irrigation cannula. Cortical and core body temperatures were measured. RESULTSIn the ex vivo study, the mean ( SD ) initial temperature was 37.1 (0.4) ° C; the mean time to reach 15 ° C was 10.3 (2.6) min and the mean nadir temperature was 13.0 (1.5) ° C. In vivo , the MPS was delivered with no technical difficulty; the mean renal unit starting temperature and core body temperature were 37.2 ° C and 37.0 ° C, respectively. The mean (range) time to reach 15 ° C was 16.5 (5.5-28.6) min. The mean nadir core body temperature was 34.0 ° C. CONCLUSIONThis initial study showed efficient and rapid induction of renal hypothermia using MPS delivered through 5-mm laparoscopic ports, with no technical difficulty. These exploratory pilot findings support further, larger scale, histopathological and renal functional investigations of topical ice slurries as a means of providing renal hypothermia in laparoscopic procedures.