A web-accessible heat exchanger experiment

− We have developed a remotely controlled heat exchanger experiment as part of the I-Lab project at MIT. It has been used on the Internet by students in a variety of chemical engineering courses, and the response of students to the online experiment has been assessed. The hardware consists of a general service unit, custom designed and fabricated for us (HT30XC, Armfield, Ltd., England), on which is mounted a heat exchanger (flat plate, shell and tube, or double pipe). Cold water flows through the exchanger in single pass, whereas hot water is recycled to a heated reservoir. Both fluid flowrates, their direction (cocurrent or countercurrent), and the inlet hot temperature are monitored and are under the control of the students. All other inlet and outlet temperatures are monitored. Monitoring and control is carried out with a computer/web server using LabVIEW 6.1 software (National Instruments, USA). Data is published to web-accessible LabVIEW graphical user interfaces (GUI) or via a Data Socket Server (National Instruments) to a Java2 GUI. A database (Microsoft SQL) is used for registering, authentication, and scheduling (ASP.NET) and for collaboration management software (Java2), which provides for chat capabilities and ability to pass local control between team members who are collaborating on carrying out the experiment from their own computers in different locations. The experiment has been used successfully in various ways in courses. Student response has been favorable in general, and students appreciate the ability to take data from real equipment, especially in engineering science courses that otherwise contain no laboratory component. Student response improves with increasing sophistication of the GUI and is very high when everything works as intended. Conversely, student response can be very negative when problems in control or operation of the website occur. These findings suggest that webaccessible, remotely controlled laboratory experiments can be valuable in a variety of settings and that the value of the experience, as perceived by the students, depends strongly upon the quality, richness, and reliability of the website and GUI and, in the case of complex experiments, on the ability of the students to gain control of the independent variables at their disposal. Index Terms − web, heat exchange, experiment, accessibility