Novel Cascade Refrigeration Cycle for Cold Supply Chain of COVID-19 Vaccines at Ultra-Low Temperature -80°C Using Ethane (R170) Based Hydrocarbon Pair

Several media report highlight on that the pharmaceutical companies require ultra-low temperatures -80°C to transport and store its COVID-19 vaccines. This research presents the thermodynamic analysis on cascade refrigeration system (CRS) with several refrigerant pairs which are R32/R170, R123/R170, R134a/R170, R404A/R170, R407c/R170, R410/R170, and the hydrocarbon (HC) refrigerant pair Propane/Ethane, namely R290/R170. Besides, the results of R22/R170 pair, which is not recommended to be used due to phase out of R22 as per Montréal Protocol, are included as base case to compare the novel hydrocarbon pairs in CRS and the old trend of refrigerant pairs. Thermodynamic properties of all these pairs were investigated and compared under different intermediate temperature used in CRS heat exchanger, which thermally connected both the Low and High temperature cycles (LTC) and (HTC). By applying the first law of thermodynamics, the coefficients of performance (COPs) and the specific power consumptions (SPC) in kW/TR are presented and compared. In addition, by applying the second law of thermodynamics the exergetic efficiencies were estimated. The results reveal the promising opportunity of using the HC pair (R290/R170). The minimum SPC in kW/TR is recorded for the pair R123/R170. One the other hand, the highest exegetic efficiency values are observed to be 40%, 38%, and 35% for the pairs R123/R170, R290/R170, and R134/R170, respectively. This research concludes that the HC pair (R290/R170) is highly recommended for CRS applications either to transport the COVID-19 or store it in cold storage rooms in hospitals and clinics. All precautionary measures should be carefully applied in design and operation of HC pair (R290/R170) due to its flammability hazard.

Cold supply chain inventory models for agricultural products with multi-stage stochastic deterioration rates

In India,majority of the families depend upon agricultural business.Also,40%of agricultural food and vegetables are rotted due to improper planning.It is predicted in 2023 that US$293.27 billions will be wastage of food.That’s why,the cost of these items are high in the retail market and farmers get least price for their produce.It is essential to avoid the loss by adopting cold supply chain and its impact will help to increase the GDP of country.Here,we proposed the supply chain model which includes one warehouse and multi-retailers.Cold storage facility is available at warehouse,transport facility and retailers.To support the proposed model,we have collected the numerical data of coriander(highly perishable)product from the market yard,Pune,India.The proposed model solved by using real world numerical case study.The life of this product is very less hence it needs to develop a cold supply chain for this item.Also,we solved multiple inventory differential equations by using boundary value problem.To solve the proposed models for single retailer and multiple retailers,we have developed a solution methodology based on evolutionary algorithm.We have observed that,optimum profit is highly sensitive to the warehouse demand and purchase cost.Hence it is essential to reduce the deteriorated items at storage point.The warehouse,retailer and customer demand significantly affect on the deteriorated items.In single and multiple retailer,for low warehouse and retailer demand,we get maximum profit.Thus,less number of deteriorated items of the supply chain will helps to the society,as well as country to increase the profit of the supply chain.