Presented to graduate management as part of the academic activities required to obtain a master's degree
in the field of mechatronics
Abstract
As you know, the air conditioner is a high-consumption device and has a Freon refrigeration cycle. What drew the companies to the production of inverters was to solve the shortcoming of air conditioners in high energy consumption. To improve energy consumption in every part of the industry, one should pay attention to several parameters, it is better to review and improve all its parts in order to have an optimal cooling system. And in general, he used systems such as inverters, solar collectors, and various sensors. In solar collectors, part of the required power is actually supplied from solar energy, which is about 20-30%, and for further improvement, one should focus on sensors, including laser sensors, to achieve this. By using the infrared thermometer sensor, people can be identified and if they are not present, the system consumption can be reduced and finally turned off. With this method, about 10 to 20 percent of the energy consumption of these systems can be saved.
Key words: intelligence, infrared sensor, refrigeration, air conditioning
History of refrigeration and air conditioning system
The comfort and convenience of human life is one of the goals of human progress, and humans have always sought to invent and build devices to achieve this goal. One of the examples of the comfort of life is to provide the optimal temperature for the place of human life so that it is possible to live without hardship in the high summer and low winter temperatures. This requires the use of a cooling system in summers and heating in winters. Using the cooling system in summers, in addition to providing the comfort of life, also provides the possibility of healthy storage of perishable food. For this purpose, refrigeration systems have been developed and improved. These systems are used to provide human comfort and air conditioning. In fact, air conditioning can be called as a kind of air treatment for humans, that is, it is responsible for controlling temperature, humidity, cleanliness, and smell at the same time. The subject of refrigeration and air conditioning, which is a human need to preserve food and human comfort, has evolved over time and its beginnings date back centuries. Every aspect of the history of refrigeration is very interesting, the availability of refrigerant, prime mover and developments in compressors and methods of refrigeration are all part of this history[1]. In Europe, America and Iran, a number of ice houses were built to store ice. Materials such as sawdust or wood chips were used as insulation in these ice houses. Later, cork was used as insulation material. Literature shows that ice was always available to nobles and they could keep it. In India, the Mughal emperors were very fond of using ice during the harsh summers in Delhi and Agra.
In 1806, the ice trade began. The ice trade was considered a thriving business in North America. Ice was transported to the southern states of America in the compartment of trains insulated by cork insulation with a diameter of 30 cm. Ice trading was also popular in several other countries, including Britain, Russia, Canada, Norway and France. In these countries, ice was either transported from colder regions or harvested in winter and stored in ice houses to be used in summer. The ice trade reached its peak in 1872 when America alone exported 225,000 tons of ice to various countries including China and Australia. However, with the advent of artificial refrigeration, the ice trade gradually declined. 1-1-1 Artificial Refrigeration The history of artificial refrigeration began in 1755. The basis of the modern refrigeration system is the ability of liquids to absorb a large amount of heat (latent heat) as boiling and evaporation. William Cullen of the University of Edinburgh demonstrated this method in 1755 by placing water in thermal contact with ether under a receiver from a vacuum pump. Evaporation rate of ether is increased due to vacuum pump and water can freeze. This process includes two thermodynamic concepts, vapor pressure and latent heat. The liquid is in thermal equilibrium with its vapor, at a pressure called the saturation pressure, which depends on the temperature.For example, if the water pressure on the gas stove increases, the water will boil at a higher temperature. The second implication is that liquid vaporization requires a high latent heat during vaporization. If the latent heat is removed from the liquid, the liquid cools. As long as the vacuum pump maintains the pressure at saturation pressure, the desired ether temperature will remain constant. This requires the removal of all vapors formed due to evaporation. When a low temperature is desired, the saturation pressure must be lowered, which is done by the vacuum pump. A part of the modern refrigeration system in which cooling is done today is produced with this method, which is called the evaporator. In this cooling process, the vapors must be cycled depending on the liquid state, so that the cycle can be carried out continuously. The condensation process needs to dissipate heat to the surrounding environment, this can be done at ambient temperature by increasing the condensation pressure. The condensation process was discovered in the second half of the 18th century. Yu. F. Clute and J. Monge discovered liquid sulfuric acid (So2) in 1780, while van Marum and van Troostwyck discovered liquid ammonia in 1787. The important point is that the evaporated vapors can condense at higher temperatures than the surrounding environment. As a result, the compressor needs to stay at high pressure. Oliver Evans described a closed refrigeration cycle for the production of ice by ether under suction. Figure (1-1) shows the closed refrigeration cycle for the production of ice by ether under suction[1].
Figure (1-1) The closed refrigeration cycle for the production of ice by ether under suction
In the figure above, the cooling fluid (ether or other volatile liquid) in the evaporator (B) takes the heat from the surrounding water in the container (A), the pump (C) steams away from the equilibrium and compresses it to a higher pressure where you can Liquids in dense pipes D, giving heat to water in liquid vessel E. Condensed flows through the weight of the load valve H, which maintains the pressure difference between the condenser and the evaporator. A small pump at the top of the H is used to charge the device with refrigerant.
Alexander Twining patented an invention in 1850 that uses ether and ammonia (NH3) and carbon dioxide (CO2) for a vapor compression system. James Harrison was responsible for developing a practical vapor condensation refrigeration system in 1856. He built the vapor compression system using ether, alcohol and ammonia at that time. In 1864, Charles Tillier from France built a refrigeration system using dimethyl ether, whose normal boiling point was -23.6 degrees Celsius [2]. David Boyle built the first ammonia system in 1871 in San Francisco. Also, John Enritt built a similar system in 1876 in Buffalo, New York. Franz Willhanson in Germany in 1886 created a refrigeration system with carbon dioxide (CO2) and based on the vapor compression system. The carbon dioxide compressor required a pressure of about 80 atmospheres and as a result its construction was very heavy. Linde in 1882 and Love in 1887 attempted to build similar systems in the United States of America. The carbon dioxide system is a very safe system and was used for refrigeration on ships until the 1960s. Raoul Pictet built this cycle at the same time using sulfur dioxide (SO2) refrigerant, but the pressure was so high that air leaked into it. Palmer used ethyl chloride (C2H5Cl) in rotary compressors in 1890. To reduce the flammability of ethyl chloride, he mixed it with bromoethane (C2H5Br). Edmond Copeland and Harry Edwards used isobutane in small refrigerator freezers in 1920. They replaced the refrigerant with methyl chloride (CH3Cl) refrigerant in 1930[3].
The home refrigerator using natural ice (home icebox) was invented in 1803 and was used without much change for almost 150 years. Efforts to develop home refrigerators and freezers using mechanical systems began in 1887. Early mechanical home refrigerators and freezers were expensive, not automatic, and not very reliable. However, the development of domestic mechanical refrigerator freezers was large-scale, but the development of compressors was low. General Electric Company first introduced home refrigerators and freezers in 1911, home mechanical refrigerators were widely launched in the United States in 1918. In 1925, the United States produced about 25 million domestic refrigerators and freezers, of which only 75,000 were mechanical.