What is the principle of extinguishing and what is the principle of air conditioner defrosting

First, the basic principle of fire extinguishing.

From the basic conditions that must be met for combustion, it can be known that fire extinguishing is the process of destroying the combustion conditions and stopping the combustion reaction. Its basic principles are summarized in the following four areas: cooling, asphyxiation, isolation and chemical inhibition.

1. Cooling fire extinguishing: For general combustibles, one of the conditions for continuous combustion is that they reach their respective ignition temperature under the action of flame or heat. Therefore, in the case of general combustible fires, the combustion reaction is stopped by cooling the combustible materials below their ignition point or flash point.

The fire extinguishing mechanism of water is mainly cooling.

2. Suffocation fire extinguishing: The combustion of all kinds of combustibles must be carried out above its minimum oxygen concentration, otherwise the combustion cannot be continued. Therefore, by reducing the oxygen concentration around the combustibles, it can play a role in extinguishing the fire.

The fire extinguishing mechanism of carbon dioxide, nitrogen, water vapor, etc., which is commonly used, is mainly asphyxiation.

3. Isolation and fire extinguishing: Isolate the combustible material from the ignition source or oxygen, and the combustion reaction will be automatically stopped. In the event of a fire, close the relevant valves and cut off the passage of combustible gases and liquids flowing to the fire area; Opening the relevant valves to allow the liquid combustibles in the already burning container or the container threatened by fire to be channeled through the pipeline to a safe area are all measures to isolate and extinguish the fire.

4. Chemical inhibition fire extinguishing: It is the use of fire extinguishing agent to react with the intermediate free radicals of the chain reaction, so that the chain reaction of combustion is interrupted and the combustion cannot be continued. The main fire extinguishing mechanism of commonly used dry powder fire extinguishing agents and halide fire extinguishing agents is chemical inhibition.

Isolate combustibles from oxygen.

Isolate combustibles.

Lowers the ignition point of combustibles.

So many copy parties!

Air conditioner defrost is mainly for "heat pump air conditioner", and of course, there is defrosting in cold storage.

In terms of the air conditioner model, as long as it is the prefix of kfr, the main thing is this "R", which means the heat pump type, which is often said to be the cold and warm dual-purpose type, of course, there is also electric auxiliary heating, but the electric auxiliary heating type does not need to be defrosted, which can be understood literally.

The so-called heat pump of heat pump air conditioner mainly refers to the outdoor unit of the air conditioner"Solenoid four-way valve"Institution. This thing is used to switch between cooling and heating.

How to understand its principle, first of all, we must know that it is installed in the **: it is installed in the compressor and condenser (or called the evaporator, because as long as it moves, the condenser also becomes an evaporator).

In summer, the solenoid coil is not energized, the four-way valve slider does not move, and the coil fin of the outdoor unit plays the role of dissipating the high-temperature and high-pressure refrigerant gas discharged by the compressor, and then enters the evaporator after throttling and decompression through the throttle valve (capillary tube is also a kind of throttle expansion device), and the refrigerant boils and absorbs heat in the evaporator (the boiling temperature of the refrigerant is far lower than the air temperature) to complete the refrigeration.

In winter, the solenoid coil is energized, the four-way valve acts, and the evaporator and condenser are switched, as mentioned above, the compressor discharges the refrigerant gas at high temperature and high pressure, and through the switching of the four-way valve, the indoor becomes this heat dissipation device, that is, the heating device, and the outdoor part also becomes heat absorption, because the ambient temperature is still higher than the boiling temperature of the refrigerant in the outdoor coil, because the heat absorption is less, and the air contains moisture, so ice or frost will be formed on the surface.

Let's explain defrosting again.

The above mentioned how the heat pump machine completes the two principles of refrigeration and heating, which is easy to explain.

Due to the frosting of the outdoor coil unit, the heat absorption effect will be poor, and the heating effect will also decline (according to the law of conservation of energy, how much you can suck and how much you can discharge, it can be understood in this way, hehe), so you have to defrost, the principle is simple, isn't there an electromagnetic four-way raft, we disconnect the electricity of the electromagnetic coil, it won't switch, no?! Therefore, according to this mode, the indoor machine will stop blowing (if the wind blows, it will be cold air, which is called anti-blowing cold air effect), the coil is not electrified, and the high-temperature and high-pressure refrigerant gas discharged by the compressor passes through the outdoor coil first, of course, it also plays a role in defrosting. Understood.

When the heat pump type air conditioner heats up in winter, the heat exchanger in the outdoor part is the low temperature part of the system. Frost forms on the coils when the surface temperature of the heat exchanger coil reaches 0 or lower in the outdoor section. And over time, the frost will become thicker and thicker, or even freeze completely, which is not good for the equipment itself and the heating cycle.

When the outdoor heat exchanger coil freezes, it is difficult to melt even if the ambient air temperature rises, unless there is a prolonged shutdown. Therefore, if there is frost on the heat exchanger of the outdoor unit, it must be defrosted in order for the air conditioner to work properly. The defrosting method is generally the reverse circulation hot gas defrosting method

When the heat exchanger in the outdoor part is lower than a certain set temperature value, the defrost temperature controller will act and automatically cut off the power supply of the electromagnetic four-way reversing valve, so that the original heating cycle becomes a cooling cycle. In this way, the outdoor heat exchanger changes from an evaporator during heating to a condenser for refrigeration. The hot refrigerant discharged from the compressor flows into the outdoor heat exchanger coil, where the frost that forms on it quickly melts.

When the outdoor unit of the heat pump air conditioner is defrosted in winter, in order to prevent the indoor unit from being blown out by cold air and affecting the room temperature, it is also necessary to set the cold air temperature switch. This switch automatically shuts down the indoor fan of the air conditioner when the temperature of the indoor heat exchanger drops to a certain value. When the defrosting is complete, the system resumes heating operation.

When the coil temperature of the indoor heat exchanger rises to a certain value, the indoor fan supply circuit is turned on, and the fan starts to run to supply air.

What does air conditioning defrost mean Overview: Air conditioning defrost is a function of air conditioning, this function is based on the principle of defrosting in its making: when certain conditions are reached (each air conditioner has been set: such as the fin temperature is lower than the ambient temperature.

When the heating mode of the air conditioner is running, when the outdoor environment reaches certain conditions, the heat exchanger of the outdoor unit will gradually frost, and the heat exchange capacity of the outdoor unit will decrease; As a result, the evaporation ability of the liquid refrigerant becomes weaker, and the evaporation pressure and temperature are reduced.

When it is low to a certain extent, the indoor and outdoor fans of the air conditioner stop running, and the four-way reversing valve reverses to the operation path of refrigeration to achieve the purpose of defrosting.

It is heated directly, not by far-infrared to heat the ice.

If you heat it directly, you won't be afraid that the temperature will rise, or it will turn into water and flow down after heating -- in fact, there is a drain pipe leading to the outside of the refrigerator in the refrigerator, and there is a water tray under the drain pipe.

The frost-free refrigerator is not a real frost-free refrigerator, it is nothing more than the use of a finned evaporator, the evaporator is hidden, and the cold air is sent to various parts through the fan through each air duct to achieve the purpose of cooling, it should be noted that each frost-free refrigerator has a mechanical or electronic defrosting system, when the compressor works for a period of time (about 8-12 hours) the surface of the fin evaporator will also frost, if the defrosting is not carried out, the frost will become thicker and thicker, and the fin evaporator will be full and the air duct will be blocked, As a result, the cold air can not be circulated, and the refrigeration effect is reduced. The middle part of the fin evaporator is equipped with an electric heating wire and a bimetallic temperature control and a temperature fuse, and the evaporator is heated by the electric heating wire to a certain temperature during defrosting, and the bimetal temperature control is disconnected after the defrosting is over, and the refrigeration is resumed.

The law of the immortality of matter, also known as the "law of conservation of mass", can be summarized as: "Although matter can change, it cannot be destroyed or created out of thin air." ”

1) A brief explanation of the law of conservation of mass.

One of the fundamental laws of nature. In any system of matter that is isolated from its surroundings (an isolated system), its total mass remains the same regardless of the changes or processes that occur. In the 18th century, after the French chemist Lavoisier experimentally overturned the phlogiston theory, this law was recognized.

Since the beginning of the 20th century, it has been found that the mass of high-speed moving objects changes with its velocity, and it has been found that the physical object and the field can be converted into each other, so the mass of the field should be considered according to the mass-energy relationship. The development of the concept of mass has led to a new development of the principle of conservation of mass, and the two laws of conservation of mass and energy have been merged into one conservation law through the mass-energy relationship, that is, the law of conservation of mass and energy.

The law of conservation of mass was put to the last test at the end of the 19th century, when precision measurement technology was already highly developed. The results show that there is no change in mass (even the tiniest of them) in any chemical reaction. For example, if sugar is dissolved in water, the mass of the solution will be strictly equal to the sum of the mass of the sugar and the mass of the water.

Experiments have shown that the mass of the object is invariant. No matter how it is divided or dissolved, the quality remains the same. The mass also remains the same in any chemical reaction.

The sum of the mass of the charcoal before combustion and the mass of oxygen consumed in the air during combustion is exactly equal to the mass of the substance produced after combustion.

The principle of electrostatic treasure is to use air ionization to generate a large number of positive and negative charges, and use a fan to blow out the positive and negative charges. A flow of positive and negative charges is formed to neutralize the charges on the surface of the object. When the surface of the object is negatively charged, it will attract the positive charge in the air flow, and when the surface of the object is positively charged, it will attract the negative charge in the current, so that the static electricity on the surface of the object is neutralized and the purpose of eliminating the static electricity is achieved.

The pain of discharging in the hand is due to high-voltage discharge, which produces instantaneous high voltage due to the sudden contact of the hand with other objects in a very small area. If you take out the key in your pocket, first hold the key in a large area (a bunch of keys themselves can't transmit much charge so there will be no electric shock at this time), and then use the tip of a key to contact the large conductor, at this time, the contact point of the discharge is not a point on the hand, but the tip of the key, so the hand will not feel pain.

Therefore, the principle of the electrostatic treasure is to first use the electrostatic treasure to transmit the static electricity directly to the electrostatic treasure, which will not produce a small area of the human body to directly discharge high voltage, and there is no pain, therefore, the bunch of keys can achieve the anti-static effect without spending money to buy the so-called electrostatic treasure.

I also bought one, I hung it on my bag, and it looked pretty good. It can also remove static electricity, and can be used as bag accessories, which is quite fun.

Method collapse (1).

The original formula is 2 50

The last digit of 2 50 is 4

In 2004 50 was divided by 7 by 4

Method (2) 2002+2) 50 is out.

The result was 2 out of 50

The answer is 4 hope group mold burning.

In addition to completing the forward and reverse switching of the main shaft, the friction clutch can also be used as a brake.

The friction plate clutch used in the CA6140 is a multi-plate friction clutch.

The working principle of the decarbonizer is that water is introduced from the upper part of the equipment, flows through the surface of the packing layer through the spray device, and the air enters from the lower tuyere and passes through the packing layer in reverse. The free carbon dioxide in the water quickly dissolves into the air and is expelled from the top.

In the water treatment process, it is generally set behind the hydrogen ion exchanger and reverse osmosis equipment, and under normal preparation, the residual carbon dioxide in the water does not exceed 5mg liters after degassing by the decarbonizer.

The principle is very simple, the specific gravity of the gas is lighter than H2O, and the CO2 in the water is taken away by the fan blower, resulting in a decrease in the CO2 content in the water, and the colleagues are also changing the pH value of the water!

The solubility of carbon dioxide gas in water is subject to Henry's law, which states that the solubility of a gas in solution at a certain temperature is directly proportional to the partial pressure of that gas on the liquid surface. Therefore, only the partial pressure of carbon dioxide in the gas in contact with water is reduced, and the free carbon dioxide dissolved in the water will be desorbed out of the water, so as to remove the free carbon dioxide in the water, and the decarbonizer is designed according to this principle!

The function of carbon dioxide remover in the ion exchange water treatment process is to remove carbon dioxide from water, reduce the load of anion exchange, and improve the economy of water treatment system and effluent quality. When the carbon dioxide content (alkalinity) in the inlet water is greater than 50mg 1, it is more economical and reasonable to set up a carbon dioxide remover in the one-stage double-bed desalination system. In the water treatment process, it is generally placed behind the hydrogen ion exchanger, as long as the appropriate one is selected, after the decarbonizer, the residual carbon dioxide in the water is 5mg l.

The water enters from the upper part of the decarburizer, is poured down by the water distribution equipment, passes through the packing layer, and enters the tank from the lower part. In the decarbonizer, due to the blocking effect of the filler, the water flowing down from above is dispersed into many small strands or droplets, and the air bulging in from the bottom has a very large contact area with the water, and the partial pressure of the carbon dioxide in the air is very low, so that the carbon dioxide desorbed from the water is quickly taken away. Water is decarbonized by blasting, which reduces the carbon dioxide content to less than 5 mg l.

In fact, the simple point is that the content of dissolved gas in the water is proportional to the partial pressure of the air content it is exposed to, which is similar to the working principle of the atmospheric deaerator in the power plant. Hope it helps

Oil and water are incompatible, and when the surfactant function of the detergent is exerted, the oil and water form an emulsion, which distributes the oil in the water to remove. The surfactant has a lipophilic group at one end and a hydrophilic group at the other end, so it is well soluble with oil and water.