Not only do people need to stay cool, especially in summer record breaking heat wave. Many machines, including cell phones, data centers, cars, and airplanes, become less efficient and degrade faster with use. extremely hot. The machine also generates its own heat, which makes the surrounding temperature even higher.
we are engineering researchers who studies How machines manage heat and ways to efficiently recover and reuse wasted heat. Extreme heat can affect a machine in a number of ways.
No machine is perfectly efficient – all machines face some internal friction in their operation. This friction causes the machine to dissipate some heat, so the hotter it is outside, the hotter the machine will be.
cell phone and similar devices Lithium Ion Battery It will also stop working when operating in climates above 95 degrees Fahrenheit (35 degrees Celsius) to avoid overheating and stressing electronics.
With innovative cooling design phase change fluid Can help keep the machine cool, but the heat still ends up dissipating into the air in most cases. So the hotter the air, the harder it is to keep the machine cool enough to run efficiently.
Also, the closer the machines are, the more heat will be dissipated from the surrounding area.
deformation material
Higher temperatures due to weather or excess heat radiated by the machine can cause deformation of materials in the machine. To understand this, consider what temperature means at the molecular level.
exist molecular scale, temperature is a measure of the degree of molecular vibration. Therefore, the hotter it is, the greater the vibrations of the molecules that make up everything from the air to the ground to mechanical materials. When a metal is heated, the molecules in it vibrate faster and move farther apart. This causes the metal to expand.
As temperatures rise and molecules vibrate more, the average space between them increases, causing most materials to expand when heated. Roads are one place where this phenomenon can be seen – hot concrete expands, contracts, eventually rupture. This phenomenon can also occur mechanically, and thermal stress is only the beginning of the problem.
He Penglei/China News Agency
Travel Delays and Safety Risks
High temperatures can also change the way oil in a car’s engine behaves, leading to potential engine failure.For example, if a heat wave makes it 30 degrees Fahrenheit (16.7 degrees Celsius) above normal, the viscosity, or consistency, of a typical car engine oil changes three times.
Fluids such as engine oil become thinner when heated, so if the temperature is too high, the oil may not be thick enough to properly lubricate and protect engine parts from wear.
Additionally, hot weather can cause the air in your tires to expand and increase tire pressure, which can lead to tire wear. Increased risk of wear and slippage.
Airplanes are also not designed to take off in extreme temperatures. As it gets hotter outside, the air begins to expand and take up more space than before, making it thinner or less dense.this Air Density Decreased reduce the amount of weight the aircraft can support during flight, which could lead to serious travel delay or flight cancellations.
battery degradation
In general, electronics in devices such as cell phones, personal computers and data centers are composed of a variety of materials that respond differently to changes in temperature. These materials are all adjacent to each other in a small space.Therefore, different kinds of materials deform differently with increasing temperature, which may lead to premature wear and failure.
Lithium-ion batteries in automobiles and general electronics degrade faster at higher operating temperatures.This is due to the higher temperature Improve reaction speed Inside the battery, including the corrosion reactions that deplete the lithium in the battery. This process consumes its storage capacity.Recent studies have shown that electric vehicles May lose about 20% of range When exposed to sustained 90°F weather.
data centerBuildings are filled with servers storing data and need to dissipate a lot of heat to keep components cool. On hot days, the fans have to work harder to make sure the chips don’t overheat. In some cases, powerful fans are not enough to cool electronics.
To keep the center cool, dry air entering from the outside usually passes through the wet pad first. The water on the pad evaporates into the air and absorbs heat, cooling the air.This technique is called evaporative cooling and is usually a cost effective method Keep the chip at a reasonable operating temperature.
However, evaporative cooling may require lots of water. This problem is very problematic in water-scarce regions.Water for cooling can be added to the already dense resource footprint associated with data centers.
Jahi Chikwendiu/The Washington Post
The Air Conditioning Dilemma
When it’s getting hotter outside, air conditioners struggle to operate effectively — just when they’re needed most.On a hot day, the air conditioner compressor has to work harder send the heat out of the home external, which in turn increases power consumption disproportionately total electricity demand.
For example, in Texas, every 1.8°F (1°C) increase in temperature leads to an increase in Electricity demand about 4%.
High temperatures lead to a staggering 50% increase in summer electricity demand in hotter countries, posing a serious threat to power systems power shortage Or power outages, plus increased greenhouse gas emissions.
How to Prevent Heat Damage
Heat waves and rising temperatures around the globe pose major short- and long-term problems for humans and machines. Fortunately, there are steps you can take to minimize your losses.
First, make sure your machine is stored in an air-conditioned environment, well insulated space Or avoid direct sunlight.
Second, consider using energy-intensive appliances such as air conditioners, or charging electric vehicles during off-peak hours when fewer people use electricity. This helps avoid local power shortages.
heat reuse
Scientists and engineers are developing ways to use and recycle the vast amounts of heat emitted by machines.A simple example is utilizing waste heat from a data center heating water.
Waste heat can also drive other types of air conditioning systems such as absorption chillerwhich can actually use heat as an energy source to support the cooler through a series of chemical and heat transfer processes.
In either case, the energy needed to heat or cool something comes from heat that would otherwise be wasted.In fact, it is assumed that waste heat from power plants can support 27% of the electricity Residential Air Conditioning Demandwhich will reduce overall energy consumption and carbon emissions.
Extreme heat affects every aspect of modern life, and heat waves are not going away for years to come. However, we have the opportunity to take extreme heat and make it work for us.
Srinivas GarimelaProfessor of Mechanical Engineering, Georgia Institute of Technology and Matthew Hughespostdoctoral fellow, Massachusetts Institute of Technology (MIT)
This article is reproduced from dialogue Licensed under Creative Commons.read source article.
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