Virtual Pressure Sensor for Electronic Expansion Valve Control in a Vapor Compression Refrigeration System

Abstract

Virtual sensor technology, which uses simulation models/algorithms to calculate a value to represent an unmeasured variable or replace a directly measured reading, has attracted many studies in the heating, ventilation, air conditioning and refrigeration (HVAC&R) industry. However, most virtual sensor technologies are developed for fault detection and diagnostics (FDD) purposes, which generally compare the virtual sensor values with actual measured values to detect if any fault occurred and identify the causes that led to the fault. It is rare to see studies focus on control performance of virtual sensors after substituting an actual sensor. This is particularly important for the system with no redundant sensor since a virtual sensor is the most effective way to operate the system in the desirable region when any sensor failure occurs. To address this gap, this paper develops a new virtual pressure sensor technology to substitute the actual pressure measurement for electronic expansion valve (EXV) control in a vapor compression refrigeration system by integrating compressor and valve characteristics. The control performance of this proposed virtual pressure sensor technology under various operating conditions is validated with experimental data. Closed loop EXV control simulations with the proposed virtual pressure sensor are conducted, and the results are analyzed.

Virtual Sensors for Estimating District Heating Energy Consumption under Sensor Absences in a Residential Building

“…Several studies focused on the application of virtual sensors in building energy systems have been conducted [4][5][6][7][8][9]. Qian et al [6] suggested virtual power consumption sensors for variable refrigerant flow (VRF) systems using a multiple linear regression model developed with laboratory datasets.…”

Heat Transfer, Refrigeration and Heat Pumps

“…In the next section, we provide a brief review of the seven published papers [1][2][3][4][5][6][7] and their potential scope of application.…”

“…The paper by Sun et al [1] describes the option of using a virtual sensor as a costeffective and convenient way of estimating the pressure to maintain electronic expansion valve (EXV) superheat control instead of using both temperature and pressure sensors, as in conventional HVAC systems. The paper concludes that the pressure sensor can be substituted with a virtual pressure sensor without compromising the system's operational needs while eliminating the need for a separate sensor.…”