Abstract:

Given the situation of the lockdown produced in several countries as a result of the COVID-19 pandemic, it was necessary to modify the way of teaching at the universities. To facilitate learning to students, new work tools have been developed in recent months allowing students to work more autonomously. The objective of this paper is to present the tools used during the lockdown in the teaching of Thermal Engineering of the Degree in Industrial Engineering of the University of Almería (Spain). At first it was necessary to move immediately from face-to-face teaching to online courses. For this, the use of the Black Board virtual teaching platform already used in the subject during the previous 10 years was promoted.

To the tools available in the virtual course in previous courses (theory topics, relationships of solved problems, technical guides of organisms, regulations, links to websites of industrial companies) three new tools were added in the course 2020-21. First, the classes were held by videoconferences, which were recorded on the virtual platform so that students could see them at any time. Secondly, spreadsheets were generated for each of the practical classes with Microsoft Excel, in which all the calculations were carried out in an automated way. In the first two spreadsheets, the design calculations of a multi-tubular heat exchanger and the design of the insulation thickness on the building walls were implemented. In both cases, the spreadsheets included an automated calculation process using the tool SOLVER. The third spreadsheet included the design of an air conditioning system, includeing the automated drawing of the different processes that the air followed in a psychrometric chart. The fourth sheet designed the equipment of a compression refrigeration system including an automatic diagram of the cooling cycle in a pressure-enthalpy chart. Finally, a spreadsheet was generated to simulate the behavior of a real refrigeration equipment using a capillary tube and a thermostatic expansion valve.

To analyze the effect of the use of spreadsheets on student learning, two tests of self-evaluation were included as the third learning tool in the Virtual Classroom. In these tests the students had to solve problems similar to those developed in the spreadsheets. At the end of each of the two blocks of knowledge of the subject, the students took written tests remotely, in which both theoretical knowledge and problem solving were evaluated.

The grades obtained by the students in the problem-solving tests AP were 25% higher than the grades obtained in the written exams AE (AP=1.25· AE with R2=0.80). On the other hand, an improvement in the grades of the practice reports AR with respect to the exams was observed. Thus, in the 2019-20 academic year with face-to-face classes, the score of the reports was 43% higher than that of the exams (AR=1.43· AE with R2= 0.84), increasing this value to 77% in the 2020-21 academic year with online classes and with the use of spreadsheets (AR=1.77· AE with R2=0.79). Statistical analysis of the variance of grades showed no statistically significant differences for students reports in the two courses (8.06±0.97 in 2020-21 and 8.25±1.27 in 2019-20). However, the grade obtained in the exams was statistically significantly lower in the course with online teaching, 4.04±1.77 in 2020-21 compared to the previous course 2019-20 with face-to-face teaching (average grade of students of 5.38±1.69).

Keywords:

Higher education, Covid, evaluation, engineering, digital resources.