China
Africa
Explore chapters and articles related to this topic
Typical Pre-Commissioining and Start-Up Procedures
Published in Maija Virta, HVAC Commissioning Guidebook, 2021
An expansion valve (Fig. 7.33. and 7.37.) is a component in refrigeration systems that controls the amount of refrigerant flow into the evaporator, thereby controlling the superheating at the outlet of the evaporator. The thermostatic expansion valve can be selected when the following are known: Refrigerant;Evaporator capacity;Evaporating pressure;Condensing pressure;Sub-cooling;Pressure drop across valve;Internal or external pressure equalization.
Review of solar assisted HVAC systems; Its performance analysis using CO2 as a refrigerant
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2019
Olusola Bamisile, Oluseyi Olagoke, Mustafa Dagbasi, Ferdinand Dika, Bonaking Okwesi
A water-cooled condenser is selected considering the design of the system. An expansion valve is used to regulate the flow of the refrigerant and make the drop of the pressure of the refrigerant from the condensing pressure to the evaporation pressure. The solar thermal collector is chosen based on the 30-kW capacity of the design to give additional heat input to the system so that it will reduce the electricity consumption of the compressor. A collector with evacuated tubes will be used for this design. Energy Equation Solver (EES) is used to analyze the systems’ performance with and without solar assistance. Coefficient of performance (COP) is calculated using the equations given below:
Dynamic model-based feature extraction for fault detection and diagnosis of a supermarket refrigeration system†
Published in Science and Technology for the Built Environment, 2023
Jian Sun, Teja Kuruganti, Brian Fricke, Yanfei Li, Shenglan Xuan, Wenhua Li
As a flow control device, expansion valve regulates the refrigerant flow through opening, closing or partially obstructing the orifice to control the amount of refrigerant flow into evaporator and eventually control the evaporator outlet superheat temperature. The refrigerant mass flow rate across the expansion valve can be calculated with a semi-thermodynamic model and is used to match with the refrigerant mass flow rate prediction from the compressor model to converge the system simulation.