During operation, a car engine produces 4,000 controlled explosions every minute inside its cylinders as spark plugs ignite fuel and air to produce the energy to propel the vehicle. This creates a lot of heat that can destroy an engine in a matter of minutes unless the cooling system is efficient enough to control it.
The coolant in a typical automobile’s radiator continuously passes through the engine block, where it absorbs the generated heat. To keep the temperature of the coolant at an optimal level, the cooling system is pressurized. When the pressure reaches an unsafe level, the cap is designed to release pressure to prevent hoses or other parts from bursting. In the past, this would have released the pressurized coolant into the street, but now there’s a system in place to capture this excess pressure and temporarily store it in a reserve tank until the engine has cooled down again.
Similarly, industrial plants and equipment need to keep their water at a certain level to continue operating efficiently. The cooling systems that cool down the machines or other components do so by using pumps to circulate the water through a series of tubes, fans, and a radiator. This keeps the water at a level that’s just above its boiling point, so it can be cooled down by evaporation as it flows through the system.
If a system is left idle, the cooling fluid can start to boil and corrode the pipes and other components. To avoid this, a cooling system must be properly maintained, which includes draining the chiller and reservoir, shutting off the system’s fans, and opening building air intake vents to allow make-up water into the system. It is also important to close all automated chemical feed and shutdown devices.
Idle systems with no water circulation provide ideal conditions for problem-causing microbiological growth to cause corrosion and fouling concerns. These can result in high head pressures, high electricity costs, and problems when the system is restarted. The best solution is to use an off line cooling system that uses glycol or another non-toxic fluid to cool the equipment and return it to its original state.
MIT researchers have developed an off line cooling system that combines radiative and evaporative cooling into a single device that could be used to extend the safe storage life of food in regions with limited resources for refrigeration and cooling. The prototype resembles existing solar panels, but instead of producing electricity, it provides cooling by evaporating and reflecting a fraction of the sunlight that passes through it. It can add up to 19 degrees Fahrenheit (7 Celsius) of cooling to a refrigerated container, enough to double the storage time of some foods. Adding a layer of insulation can increase the effect by an additional 40 degrees. The technology is still in the early stages of development, but it has significant potential to reduce food losses due to spoilage in areas where it’s most needed.