Development of an experimental unit and methodology for ground-based experimental testing of two-phase thermoregulation systems for spacecrafts

This article presents a detailed description of an experimental setup for testing two-phase thermal control systems of spacecraft. The setup is a climatic chamber for simulating real operating conditions of elements in the subzero temperature range and includes three circuits: a coolant pumping circuit corresponding in parameters to the thermal control system under study, a cooling system circuit, and a thermal load simulator circuit. Electric heating elements are used as a thermal load simulator. Transparent inserts provide the ability to visually monitor the structure of a two-phase flow during boiling and estimate the volume content of the vapor phase. A testing methodology was developed for the installation under consideration, including a testing algorithm and a description of the software and hardware testing tools. The software and hardware testing tools include electronic measuring tools for the main parameters of the operating modes of the two-phase thermal control system and an automated testing process control system. The developed automated testing process control system provides the ability to monitor a wide range of thermal and physical parameters of the coolant at various points in the circuit. The control system is based on the use of programmable logic controllers. To automate the operation of the installation, the OWEN PLC200 controller is used in the stand - a monoblock controller with discrete and analog inputs/outputs, designed to control and manage the operating modes of small systems. The software part of the algorithm is based on the CODESYS environment. The results obtained in the work can be used in planning and implementing programs for ground-based experimental testing of two-phase thermal control systems, in developing test stands for conducting research on spacecraft systems.