Experimental analysis of a high temperature heat pump prototype with low global warming potential refrigerant R-1336mzz(Z) for heating production above 155 °C

There is an urgent need to reduce fossil fuel dependency on heating processes in many sectors, highlighting industries. Vapour compression heat pumps are the most promising technologies for decarbonisation in high temperature processes. However, a climate-friendly working fluid is required for a sustainable transition. This paper presents one of the first experimental assessments of a high temperature heat pump operating refrigerant with R-1336mzz(Z). This refrigerant is an alternative to R-245fa because it is the only high temperature fluid with low global warming and zero ozone depletion potential. Fifty-one steady-state experiments were performed in a scroll compressor prototype with a liquid-to-suction heat exchanger at production temperatures between 100 and 160 °C and waste heat temperatures between 80 and 118 °C. The main considerations for the experimental campaign have been discussed, such as the control of the operational temperatures, compressor operation and liquid-to-suction heat exchanger influence. The volumetric heating capacity varied between 9.2 and 12.3 kW, and the heating coefficient of performance resulted between 1.9 and 4.4. Considering the working fluid's negligible global warming potential and high system energy performance, all considered carbon emission factors make this solution more climate-friendly than a natural gas boiler.