INDUSTRIAL HEAT RECOVERY THE GREENEST, OPTIMAL AND SUSTAINABLE ENERGY BOIXAC had the honor of being invited and participate in the podcast Con G de Geo, which aims to bring engineering closer analyzing concepts such as sustainability, through renewable energies, energy optimization and the efficient use of our resources. You can read the trasncription of our contribution below and we encourage you to listen to us through the following link. “In December 2019, the European Green Deal was approved, which aims to achieve climate neutrality by 2050. To do this, a scale was made with the different actions to be carried out and, one of the steps on which we will stop and we will analyze if we have done our job is in 2030. In addition to aspects such as recovering biodiversity, improving animal welfare or promoting sustainable forest management, there are three aspects that directly influence the field of energy: – Establish a minimum share of renewable energies of 40%. – Improve energy efficiency by 36-39%. – Reduce greenhouse gas emissions by 55%. All these aspects are important to find a solution to the climate emergency but, at BOIXAC, we understand that if the world population continues to increase, for example, only in Spain an increase of 2% in the next 15 years is prevented, beyond the use of renewable energies, sustainability goes through the change in consumption habits and the optimization of our resources. In this sense, considering that the Spanish industry consumes about 31% of total energy, its modernization and optimization is one of the keys to our future. When we go along the highway, as far as the eye can see, we see factories that need energy for their processes, for instance to heat wastewater and facilitate the biological digestion of sludge, dry cement for its correct conservation, increase CO2 in greenhouses to increase the rate of photosynthesis, cool foods such as chocolate for modeling, etc. All processes that need to heat or cool require energy, and energy maintains a balance. In fact, heat is the transfer of energy from an area of high temperature to another area of lower temperature. If, for example, we look at what happens in our homes when we turn on the air conditioning, we will see this balance. While the indoor unit blows out cool air, the outdoor unit blows out excess heat. Starting from this energy balance, we see that a certain renewal of the indoor air is needed to maintain its quality. For this renewal we take the outside air and cool or heat it depending on each need. At the same time that we introduce the new air, we must expel the excess air from the interior so that the new one can fit and this is where we come in with heat recovery. If we make a leap from our homes to the industry and imagine, for example, that the outside air is at 20ºC and we want to heat it so that it reaches 80ºC inside, for example, in a dryer where we need to extract moisture . Here we apparently need equipment that is capable of increasing the air temperature by 60ºC, from 20 to 80ºC. However, there is another option that is smarter, cheaper and more sustainable. When we take this air from the outside at 20ºC and we want to heat it to introduce it into a room, the same flow of air that was inside at 80ºC will be expelled. By means of a heat recovery system we make these two air flows cross each other without mixing through a system known as cross flows. We do not mix these flows in order to maintain the quality of the previously filtered air, but we do extract the heat from the outgoing air flow and transfer it to the incoming air flow. With this system we achieve two objectives; 1. The cold air that we are introducing will rise in temperature, so that the equipment we use to heat it, often boilers, will be able to work more relaxed, consuming less energy and, therefore, saving and being more sustainable. 2. The hot air that we are expelling will significantly lower its temperature, resembling the ambient temperature and, therefore, we will be even more sustainable. The technology of heat recovery units may change depending on the application and the manufacturer, but, as we have seen, it is based on perfecting the filters to offer correct air quality, and the fans to obtain air circulation. the lower electricity consumption and the energy recuperators that are the heart that allow the magic of heat exchange. Here you can add other added values such as control or isolation. In our particular case, from BOIXAC, we specialize in industrial heat exchangers and, just as it is important to work to improve ventilation and filtering techniques, exchangers also progress to offer solutions resistant to corrosive environments, high pressures and temperatures. up to 950ºC, with flattened tubes to reduce pressure losses and compact constructions that currently reach efficiency levels of over 80%. In the industrial field, applications have many singularities such as fluids, viscosities, pressures, temperatures, materials, fouling coefficients, etc. That is why each project is studied in detail to optimize its construction and thus achieve the objectives of energy efficiency, sustainability and savings necessary for industrial progress.”
