AC-2359 (RP-66-OS) — Simulation and Verification of a Direct Expansion Refrigeration System

This paper reports on a portion of the research sponsored by the ASHRAE Task Group on Energy Requirements (RP-66-0S), designed to field verify calculation methodologies for determining the energy requirements of buildings based on studies at The Ohio State University. Other sub-systems and the total sYptems are described in companion papers.

The purpose of this study is to computer simulate the refrigeration subsystem (of a building’s environmental control system) by modeling the system components and controls. Manufacturers performance data and the algorithms recommended in Ref 1 were used where possible. The simulation is carried out on an hour-by-hour steady-state basis. Field measurements made to verify the simulated results are collected on an hourly average basis. The preliminary results for this system were presented previously in Ref 6.

The input to the simulution program was the measured load on the cooling coil and the measured fresh air dry-bulb temperature to which the controls respond. The primary output of the program is the energy consumed by the refrigeration system.