Applied Basic Research On Gas-hydrate Cool Storage System

There are some shortcomings in the cool storage-release processes in the gas hydrate air conditioning system,they are low crystallize ratio and long time for cool storage,which makes it is difficult to apply to the real items.As energy is the key resources of every country,in China when it comes to the electricity using summit,the air-conditioning accounts for nearly 20%of the total electricity use,and most of the air conditioners are those not energy saving ones,which disobey the policy of valley-summit electricity price.So it's urgent to improve gas hydrate technology in both technical ways as well as marketing and popularized application.To tackle with the technical problems of the formation and decomposition of refrigerant gas hydrate cool storage,subject group clarify the nucleation and growth theory from microcosmic point of view that based on hydrate nucleation kinetics,a related equation of under-cooling,driving force and induction time will be established,and the Mpemba effect in hydrate formation will be investigated.Combined with the growth kinetics,crystal nucleation and the chemical equilibrium theory,we study the crystal promotion measures of gas hydrate effect on under-cooling and induction time,and a mathematical framework will be created which includes the coupling action of various factors.The heat and mass exchange model among gas-liquid and liquid-liquid interfaces is established which is based on the heat and mass transfer principle of multiphase mixture,dynamic numerical simulation will be conducted for the solidification/melting cycle of boundary layer,then inducting the porous materials to boundary layer,analyzing the strengthening mechanism of porous medium on the heat and mass transfer of gas hydrate to relieve heat and mass armor effect.Three dimensional turbulent thermal and mass resistance model for dual refrigerant gas hydrate cool storage system is set sup,a indirect-contact static cool storage air-conditioning device is used as the experimental platform,the influence mechanism of coupling factors of pressure and temperature on hydrate formation-decomposition will be explored to improve equipment performance of heat and mass exchange devices.Control strategy of pressure and temperature on gas hydrate storage cool process will also be founded.As a novel energy storage medium,the conclusions about refrigerant gas hydrate in this item will help a lot to make gas hydrate storage air-conditioning technology more and more practical.Take a energy-saving renovation program in a University as an example.The measures to use gas hydrate cool storage and heat pipe system can achieve about 20%less energy and the comprehensive COP reaches 4.5,the EPC model was also investigated and it proves that the policy and incentives are as important as the marketing on ESCO.And this kind of cool storage system like gas hydrates will be most suitable to all aspects and become popular when the summit-valley ratio of electricity reaches over 4:1.