U.S. patent application 20170314839 (applicant Enviro-Cool Commercial Ltd., Tonbridge, Great Britain):
"A refrigerator having a thermal store comprising a phase change material is disclosed. The refrigerator has a cooling chamber for containing an object to be cooled, and a vapor compression refrigeration system including a first evaporator for cooling the cooling chamber and a second evaporator for cooling the phase change material. A valve is provided to control the flow of refrigerant to the first and second evaporators depending on the cooling load on the refrigerator. When the refrigerator is subject to a relatively low cooling load, refrigerant flows to the second evaporator to cool the phase change material and, when the refrigerator is subject to a relatively high cooling load, refrigerant flows to the first evaporator such that increased cooling is provided to the cooling chamber by the first evaporator and the phase change material."