The invention relates to a vapour absorption refrigeration system including a condenser for condensing a refrigerant. A metal hydride chamber is connected to an outlet of the condenser. The metal hydride chamber provides a passage for a carrier gas to enter an evaporator. A metal hydride in the metal hydride chamber performs either adsorption of the carrier gas or desorption of the carrier gas based on temperature of the metal hydride, to control the flowing mass of the carrier gas in the vapour absorption refrigeration system.