Contact Information
University: University of Texas at Dallas
Team Members (with year of graduation): Francis Mangona, Ian Derx, Zachary Koesters, Carlos Ho Graduating May 2013
Faculty Advisers:Yaoyu Li
Email Address:yxl115230@utdallas.edu;
We are a senior design project team at the University of Texas at Dallas (UT Dallas) looking to design and implement a controls and data acquisition setup for a newly proposed Heating, Ventilation, and Air Conditioning (HVAC) system. To design and test controls for a residential cooling system, we will require a hardware to control the components of our system. National Instrument’s provides us with the necessary tools to fully realize the potential of our HVAC design.
National Instruments is regarded as a leading provider in integrated hardware and software solutions platform that allows for innovative product development in industry, research, and academia. We believe that your products allow for sophisticated data acquisition, testing, and control. As such, your products are best suited for the needs of our project.
The Challenge
Our project is tasked to create a new, fully configurable HVAC system at our lab on campus. We hope to integrate Labview’s capability in order to control and test our design and benchmark its performance against a cooling system model in Dymola. This setup will remain as an ongoing project for future project teams at UT Dallas to continually improve and innovate. The HVAC hardware is being supplied to us by Lennox International and consists of the following:
- ● A two stage compressor
- ● Nine modulating dampers
- ● A variable speed fan controlled by a pulse width modulating (PWM) signal
We will also be gathering data from:
- Nine differential/gage pressure sensors
- Ten thermistor probes
Categorizing this into inputs and outputs, this is:
- 29 analog inputs
- 20 from thermistors
- 9 from pressure transducers
- 22 digital outputs
- 18 for dampers (3-wire motor)
- 9 for clockwise motion
- 9 for counter-clockwise motion
- 3 for equipment
- Compressor power
- Compressor stage 1
- Compressor stage 2
- 1 for variable fan speed control via PWM
The Solution
We aim to develop a control system that will provide a more efficient and cost-effective cooling solution compared to the current industry standards. Using National Instrument’s cDAQ, we can implement an intelligent control system to test various control algorithms. This will allows us to effectively satisfy the cooling demands of the user while minimizing the cycling of cooling system. In order to do this, we have divided the output of the system into 4 zones that are controlled by modulating dampers. Depending on the immediate demands of the individual zones, the compressor can cycle between two stages of cooling. The performance of the system will be determined by requirements set by the user across the zones as well as the environmental parameters seen by the control algorithm. To control the hardware being supplied, a National Instruments cDAQ will be necessary.
Products
To control components and gather data, we will require a mix of analog/digital inputs and outputs. We also need the capability to produce a PWM signal to control the fan speed. To do this, we have determined the following components will best suit our needs:
- cDAQ-9178 (781156-01), Qty: 1
- NI 9205 (779519-01), Qty: 1
- Used to measure output from pressure transducers and thermistors
- NI 9401 (779351-01), Qty: 4
- Used to generate PWM signal and control transistor/relay circuits that supply current to 24V components
- NI 9924 (781922-01), Qty: 4
- For NI 9403 to allow spring terminal connectivity
- PS-17 (781095-01), Qty: 1
- Used to power 24V components of the system
Conclusion
This project aims to reduce costs to the consumer by lowering energy bills through more efficient control. It will also lower maintenance costs by reducing the strain on cycling of the components when they are not in demand. Those who gain the most benefits, however, are the future industry leaders that push the standards for more efficient and effective designs. We hope to gain real-world experience by developing a National Instruments lab for innovating, controlling, and experimenting with HVAC solutions.
