Engineers Studio #25 - Modeling Refrigerants in Simulink

Summary

In this educational video, Terry Dennery guides viewers through building a refrigeration model from scratch using Simulink and Simscape. He introduces essential components like reservoirs, sensors, and the significance of fluid properties. The tutorial covers setting up a basic model, selecting appropriate materials, and plotting thermodynamic cycles, laying the groundwork for understanding refrigeration systems and their components.

Takeaways

• 😀 The video is part of a series on refrigeration, aiming to provide an out-of-the-box experience by building a model from scratch in Simulink.
• 🛠️ The presenter introduces the Simscape Foundation Library and its two-phase fluid blocks, which will be used extensively alongside the Simscape Fluids library for more complex component models.
• 🔍 The importance of setting up the Simscape solver block and sensors for pressure, internal energy, and thermodynamic properties is emphasized for monitoring the fluid's state.
• 🔧 The presenter demonstrates how to create a creative subsystem to act as a probe for measuring fluid dynamics, highlighting the need for careful interfacing.
• 📏 Connectivity and physical domain considerations within Simulink are discussed, including the significance of units and physical signals in the model.
• 🔄 The PS to Simulink converter is introduced to handle the translation between physical signals and Simulink, with a focus on units such as megapascals for pressure.
• 🔢 The use of buses in Simulink for organizing and measuring multiple thermodynamic properties like temperature, enthalpy, and vapor quality is explained.
• 🌡️ The selection of fluid properties, such as critical pressures and internal energy ranges, is crucial for accurate modeling, with R1234YF being used as an example.
• 📈 The video illustrates how to use a thermodynamic chart to visualize the state of the fluid, including concepts like subcooling, superheating, and the vapor-liquid equilibrium.
• 🔄 The presenter outlines a strategy for developing a refrigeration cycle, including specifying pressures and enthalpies at different stages of the cycle.
• 🛠️ The video concludes with a preview of the next steps, which involve specifying devices such as evaporators and compressors in the refrigeration system.

Q & A

What is the main focus of the third video in the series on refrigeration?

The main focus of the third video is to provide an out-of-the-box experience by building a model from scratch using Simulink and Simscape Fluids.

What are the two libraries Terry Dennery mentions for building the refrigeration model?

Terry Dennery mentions using the Foundation Library and Simscape Fluids for building the refrigeration model.

What is the purpose of the 'f of x equals zero' block in Simscape Utilities?

The 'f of x equals zero' block serves as the base with the Simscape solver block, allowing users to set various important parameters that guide the calculation.

Why is it important to consider the condition of the fluid in the model?

The condition of the fluid is important because it helps in understanding the thermodynamic properties and the state of the fluid within the system, which is crucial for accurate modeling.

What are the different types of sensors Terry Dennery introduces to measure the fluid's condition?

Terry Dennery introduces pressure, internal energy, and thermodynamic property sensors, as well as a vapor quality sensor to measure the fluid's condition.

What is the significance of using a creative subsystem as a probe in Simscape?

The creative subsystem as a probe allows for the measurement of various fluid properties at a specific fluid node, providing a way to monitor and analyze the fluid's dynamic state.

Why are the arrows in the Simscape model shown as hollow?

The hollow arrows indicate that there is a physical signal being represented, which is part of the connectivity and physical domain environment within Simulink.

What is the purpose of the PS to Simulink converter block?

The PS to Simulink converter block is used to convert physical signals to Simulink-compatible signals, allowing users to specify the units of measurement, such as megapascals for pressure.

What does the term 'mux blocks' refer to in the context of the video?

Mux blocks, or multiplexer blocks, are used to combine multiple input signals into a single output signal, which is useful for considering multiple points in the fluid system.

What is the significance of the thermodynamic chart in the video?

The thermodynamic chart is used to visualize the state of the fluid in terms of pressure and enthalpy, helping to understand the fluid's behavior and its transitions between different states in the refrigeration cycle.

What are the key components Terry Dennery mentions for the next steps in the refrigeration system model?

The key components mentioned for the next steps are the evaporator, which takes the fluid from state four to state one, the compressor, which increases the pressure from state one to state two, and the condenser, which changes the fluid from a vaporized state to a liquid state.