Performance test methodology for the LCCP determination of supermarket and other integrated systems

Abstract

A new flexible supermarket R-744 refrigeration unit has been implemented in the laboratories at NTNU/SINTEF. The unit is fully equipped with real display cabinets for both medium and low temperature, as well as seven large volume counter flow glycol heat exchangers to simulate the entire load of a supermarket. The entire range of alternative system architectures can be experimentally investigated, from a simple booster system, parallel compression towards ejector supported parallel compression. Various air conditioning (AC) loads can also be handled, to demonstrate the performance and potential of integrated R-744 systems. Life Cycle Climate Performance (LCCP) tools are commonly applied to compare different system architectures. These tools are very detailed, accounting for most of the Greenhouse Gas (GHG) releases from CO2 emissions due to energy usage (indirect) and CO2 equivalent emissions from other operations (direct CO2equ) from “cradle” (refrigerant and product manufacturing), through use, to “grave” (recycling and disposal) for a product. The results of LCCP investigations are mainly dependent on the energy usage, i.e. the energy demand for different load conditions at various ambient conditions, often expressed as the Seasonal Energy Efficiency Rating (SEER) of the refrigeration unit. Several options are proposed in the literature for the determination of the LCCP in systems such as mobile air conditioning (MAC), heat pumps or refrigeration systems, but there is no approach for integrated units, i.e. equipment that meet simultaneously more than one load. This paper addresses this issue and suggests a possible way to deal with these cases.