| As people’s living standard is enhanced, the comfort of life requirement also becomes much higher. What’s more, as the more frequent use of air conditioning appliances, the energy consumption of power grid becomes more and more big, so is the peak to valley difference of power grid. In order to alleviate the pressure of the grid electricity, static ice-making cold energy storage system, which has some advantages like temperature stability, easy to control, high energy storage density, hermal design flexibility and low relative humidity, emerges at the historic moment. But at the same time, it also has some inevitable defects. So in order to change this, dynamic ice storage technology has gradually become the object of scholars to research both at home and abroad in recent years.Dynamic ice storage medium—ice slurry, which is also called binary ice, is the mixture of water and ice particles with diameters less than lmm. It is a new kind of good performance of cold transport and storage medium, which can be widely applied in life and large centralized cooling, food storage, fire rescue, medical and health care. At present, there are many methods of making ice slurry, for example, the super-cooling method, the scraping method, the direct contact method and so on. Among all those methods, the vacuum spray method has the advantages that many other methods do not have. But the research about it has not been very perfect. So this study mainly investigates the vacuum method of making ice slurry. And it is a kind of effective method. According to the relationship of the boiling point of water and pressure, when pressure decreases, the boiling point also decreases. As reducing pressure to make water reach the triple point, it is atomized through the tiny nozzle which increases the surface area of water. When the water falls down through the vacuum room, the surface of the water drop will evaporate while the temperature of the inside drops. And it even may get a certain degree of supercooling which ultimately will be destroyed, and most of the remaining water will turn into ice at the bottom of the vacuum room. In order to study the performance of the vacuum method of making ice slurry theoretical analysis, parts simulation and design, and the analysis of the parameters of system energy efficiency combining with the existing experimental results, have been carried out.Firstly, in order to analyze the influence of the control parameters on the vacuum spray process, and explore its effect on the ice crystal formation, the main factors effecting the atomizing performance of the nozzle were studied, and the reference evidence for the selection of pressure swirl atomizer were summed up.Secondly, this paper gives a further study on the process of freezing by vacuum evaporation. A physical model was developed to theoretically study the vacuum cooling of liquid in insulated and stable system. And the evolution of the water drop temperature along with the position was derived.Thirdly, based on the established experimental system of vacuum method, a continuous dynamic ice slurry production system by vacuum water spray method was designed.Finally, Based on existing formula for cold exergy and exergy loss, exergy analysis was performed for a laboratory-scale vacuum evaporation system to produce ice slurry.All the mentioned studies can provide the guidance on the optimization and operation efficiency basis of design and operation for the vacuum spray ice slurry making system. |
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