Course work

by discipline: Operation of network infrastructure facilities

Subject: "Upgrading Your Desktop Cooling System"

Completed by a student of group D-KS-31

V. N. Reshetnikov _______________

(full name, student signature)

"__" ____________ 201___

Supervisor __________________

Otkidach Natalya Viktorovna

(full name, signature of the manager)

Coursework protected

with a rating of ____________________

Date of defense "___" ________ 201__

Yaroslavl 2017

Introduction
Purpose of the course project
Objectives of the course project
1. Analytical collection on the topic “Cooling system personal computer»
1.1. Air cooling system
1.1.1. Passive
1.1.2. Active
1.2. Liquid cooling system
1.3. Freon installations
1.4. Waterchillers
1.5. Open evaporation systems
1.6. Cascade cooling systems
1.7. Systems with Peltier elements
2. Modernization of the cooling system
2.1. Installing a fullcover water block on the motherboard
2.2. Installing a fullcover water block on the processor
2.3. Installing a fullcover water block on a video card
2.4. Radiator/pump/reservoir installation
3. Full side SVO
4. Switching on and working
5. Expenses
Conclusion
List of used literature
Appendix A. Air circulation diagram in the PC system unit
Appendix B. Water circulation diagram in the water circulation system of the PC
Appendix B. PC liquid cooling system diagram

Introduction

One of the important areas in the operation of a personal computer is its cooling system. The system is responsible for maintaining the optimal temperature for the operation of all components. Sometimes, due to heavy load or modernization of the computer itself, standard cooling is not enough to cool the components to the required temperature; for this, install additional cooling or it is being modernized.

When assembling powerful personal computers, many coolers are used for active cooling or additional copper radiators are installed for passive cooling, in some cases this is not enough, for these cases there is a liquid cooling system that uses water, nitrogen or dry ice as a coolant.

Relevance of the course project

This course work is relevant, since the problem of cooling a computer itself becomes more and more urgent as its performance increases, because greater performance means the consumption of high power, which naturally leads to an increase in the temperature of its components. The main energy consumers, and therefore heat sources, in a computer are the central processor, graphics processor and power supply. It is they who require their own cooling systems.

Purpose of the course project

The ultimate goal of this work is to research and install additional water cooling for a desktop computer to release the accumulated heat and prevent overheating of components such as the CPU, Video Card and Motherboard.

Objectives of the course project

1.Give general concept O various systems cooling.

2.Describe the basic principles of their work.

3.Install a water cooling system on your desktop computer.

Analytical collection on the topic “Cooling system of a personal computer”

A computer cooling system is a set of means for removing heat from computer components that heat up during operation.

The heat can ultimately be recovered:

· To the atmosphere (radiator cooling systems):

1. Passive cooling (heat is removed from the radiator by heat radiation and natural convection)

2. Active cooling (heat is removed from the radiator by radiation [radiation] of heat and forced convection [blowing by fans])

· Together with coolant (liquid cooling systems)

Due to the phase transition of the coolant (open evaporation system)

Based on the method of removing heat from heating elements, cooling systems are divided into:

Air (aerogenous) cooling systems

· Liquid cooling systems

· Freon installation

· Open evaporation systems

There are also combined cooling systems that combine elements of various types of systems:

· Waterchiller

· Systems using Peltier elements

Air cooling systems

Passive

Passive systems were the first cooling devices in the evolution of computer refrigeration. They got their name due to the lack of moving mechanisms and power sources.

A conventional radiator (Fig. 1) is the most common passive cooling system, operating on the principles of heat exchange with the surrounding air and natural convection of air flows (hot air rises, cold air falls). The efficiency of a radiator depends on two factors: surface area and material of manufacture.

Rice. 1. Radiator

The larger the surface area of ​​the radiator fins, the greater the amount of heat it can dissipate into the environment. But the temperatures of the components grew, and so did the radiator, threatening to fill the entire internal volume. system unit and turn your computer into a heater. It was at that moment that radiators with wave-shaped fins, multi-tiered fins, needle radiators, etc. began to appear.

The material used to manufacture the first radiators was easy-to-process, cheap and fairly thermally conductive aluminum. But during the “global warming of processors” it turned out that aluminum’s ability to dissipate heat was not enough. And then more expensive, but more thermally conductive copper was used. At first, only radiator cores with pressed aluminum fins were made from it, and then radiators began to be made entirely from copper.

When even all-copper radiators reached impressive sizes and weights, so-called heat sink pipes began to be used to remove hot components. They are a closed metal tube (copper is most often used as the tube materials) with evacuated air, inside which there is a certain amount of liquid and a capillary system. The liquid, evaporating at the hot end of the tube, instantly transfers heat, distributing it evenly along the entire length of the tube, and condenses at the cold end, returning to its original liquid state. The efficiency of heat pipes is many times higher than that of a metal rod of the same diameter, but they are not suitable for direct cooling. Heat pipes are used only to remove heat to a more spacious and cooler part of the computer case, where it is possible to install a massive radiator that dissipates the heat brought by the pipe. On latest models extreme motherboards Heat pipe radiators that cool the chipset are positioned to come into contact with air outside the computer case.

IN modern computers Due to the high heat generation of the components, cooling using passive systems alone is not possible. Therefore, passive cooling systems are constant companions of active systems and act as an autonomous cooler only in the least hot places.

Advantages: economy, reliable operation, safety, lack of noise

Disadvantages: low efficiency for modern equipment

Active

Air cooling (Fig. 2) is still the most popular way to deal with temperature excesses. The essence of this method comes down to organizing the correct air flow - hot air must be effectively removed outside the system unit. Typically, one or more fans are installed that circulate air flow from the front wall of the case to the back. An ill-designed air-cooling system can cause air stagnation or hot air migration from one component to another, which means the cooling system becomes a heating system.

Rice. 2. Air cooling your computer

The rule for air cooling efficiency is very simple: the more intense the air flow, the better the heat is removed from the heating components. To improve the quality of airflow, you can use one or more methods:

Increasing the number of fans;

Increasing the impeller rotation speed;

Installation of larger diameter fans;

Increasing the number of blades, as well as changing their shape (i.e. replacing existing fans with more “advanced” models);

Development of a more efficient scheme for the movement of air masses;

Removing obstacles in the air exhaust path.

Very often, fan efficiency is increased by adding a radiator (passive cooling system).

Advantages: low cost; ease of installation and maintenance

Disadvantages: the main source of noise in the computer; modest, in comparison with other active systems, efficiency indicators; little potential to cover ever-increasing cooling needs.

Liquid cooling systems

The next stage in the development of cooling systems was the use of liquid to “lower the temperature of hot spots” in the system unit. The liquid in such systems is most often distilled water with the addition of alcohol (to combat the formation of “green”) or antifreeze. In extreme cooling systems, water or antifreeze is replaced with liquid nitrogen. The liquid cooling system (Fig. 3) consists of three components - a heat exchanger, a radiator and a pump, connected by tubes into one closed circuit. The heat exchanger, also known as the water block, transfers heat from the heating element to the liquid flow, the pump circulates the flow, and the liquid is cooled in the radiator. Next, with other elements the whole process is repeated.

Rice. 3. Liquid cooling of the computer

There are also pumpless water cooling systems, the operation of which is based on the principle of evaporation.

The quality of the liquid system is determined by two key factors: the speed of liquid circulation and the cooling efficiency of the radiator (read - the size of the radiator).

Advantages of SVO: almost silent operation; high cooling efficiency, no heat transfer from one unit to another (as is the case with air cooling)

Disadvantages of SVO: high cost; installation complexity, big size systems, there is a high probability of damage to a number of key computer components due to depressurization of the system or failure of the pump.

Despite all the shortcomings of such systems, they are becoming increasingly widespread due to the permanent increase in cooling requirements for new computers.

Freon installations

A refrigeration unit (Fig. 4), the evaporator of which is installed directly on the component to be cooled. Such systems make it possible to obtain negative temperatures on the cooled component during continuous operation, which is necessary for extreme overclocking of processors.

Rice. 4. Freon installation

Flaws:

· The need to thermally insulate the cold part of the system and combat condensation (this is a common problem in cooling systems operating at temperatures below ambient temperature);

· Difficulties in cooling several components;

· Increased power consumption;

· Complexity and high cost.

Waterchillers

Systems combining liquid cooling systems and freon units (Fig. 5).

Rice. 5. Waterchiller

In such systems, the antifreeze circulating in the liquid cooling system is cooled using a freon unit in a special heat exchanger. These systems allow the use of negative temperatures, achievable with the help of freon units, to cool several components (in conventional freon units, cooling of several components is difficult). The disadvantages of such systems include their greater complexity and cost, as well as the need for thermal insulation of the entire liquid cooling system.

Apparatuses with an open evaporation surface are painting baths, baths for impregnating fabrics and paper with dissolved resins, baths for washing and drying parts, open tanks, containers, etc.

A flammable concentration of a mixture of vapors and air above the surface of such an apparatus is formed if the temperature of the liquid T above the flash point of its vapor:

T≥T VSP, (2.1)

The amount of liquid evaporating from the free surface depends on the physical properties of this liquid, temperature conditions, area and time of evaporation, as well as air mobility. A distinction is made between evaporation into a stationary and moving medium.

When evaporating into a stationary medium, the dispersion of vapors is difficult. Of practical interest is the law of changes in vapor concentrations along the height above the surface of the evaporating liquid, the possible dimensions of the explosive zone, and the amount of evaporating liquid.

Above the open surface of liquid evaporation, the law of change in vapor concentration (along the height) can be represented by an nth order parabola (Fig. 2.1). The vapor concentration varies depending on the saturation

Rice. 2.1. Vertical change in vapor concentration during liquid evaporation into a stationary medium

concentration φ s (at the surface of the liquid) to zero (at some distance from it). Let us align the origin of the coordinate system with the point where the vapor concentration is zero. Then

φ=ау n, (2.2)

Where at- coordinate of the point at which the vapor concentration is determined; A- constant determined from the boundary condition φ=φ s at y=h. At a-φ s/h n the law of distribution of vapor concentration over height will have the form:

φ=φ s (у/h) n , (2-3)

where does the average concentration of liquid vapor come from?

. (2.4)

Distance h varies depending on the duration of evaporation. To relate the concentration φ and distance h over time τ let's draw up a differential equation of material balance for flammable liquid vapors, provided that they do not dissipate outside the vertical cylinder with a mirror of evaporating liquid at its base. Then

dG isp =dG a kk, .(2.5)

Where. (Gisp - the amount of evaporated liquid; G a kk- the amount of vapor present (accumulated) in the air.

The amount of evaporating liquid from the free surface can be determined by Fick's law, taking into account the Stefan correction for convective diffusion:

, (2.6)

Where D- diffusion coefficient of liquid vapor in air; dφ>/dy- concentration gradient; p is the vapor density of the liquid.

We obtain the value of the concentration gradient as a derivative of expression (2.3):

, (2.7)

At the surface of the liquid, where y = h,

, (2.8)

Substituting (2.8) into (2.6), we get:

, (2.9)

During" dτ the height of the vapor distribution zone changes by dh. Then the amount of liquid vapor in the air will be equal to:

, (2.10)

Substituting (2.9) and (2.10) into (2.5) and integrating, we obtain

Studies of the volatility of oil and petroleum products have established that the exponent P the curve of changes in vapor concentration (during evaporation under conditions of molecular diffusion) is close to 2. We accept the same pattern for other liquids. Then

Substituting the found value h in (2.3), we obtain an equation for determining the vapor concentration at any point above the liquid surface (depending on the duration of evaporation):

from where the coordinate can be determined at points with any given concentration.

Then the height of the danger zone above the liquid surface will be

The amount of liquid evaporated into still air over any period of time can be determined by substituting (2.13)

The nature of evaporation into a moving medium differs sharply from evaporation into a stationary medium. During convective diffusion, a small-thick boundary layer with a saturated vapor concentration is formed above the liquid surface. Then a sharp drop in concentration occurs. In layers lying above the boundary layer (due to intense mixing of the medium during movement), the vapor concentration becomes approximately the same. The amount of evaporating liquid G used per area F during τ determined by the equation

where ΔG X is the average driving force of mass transfer; K x- mass transfer coefficient.

Methods for determining the mass transfer coefficient K x and the average driving force of mass transfer Δφ x are studied in the course “Thermodynamics and heat transfer in firefighting”.

Reducing the fire and explosion hazard of production in the presence of devices with an open evaporation surface is provided by the following technical solutions.

1. Changing technological schemes (with the presence of washing, painting baths and other similar devices with an open evaporation surface) in such a way that the entire process, including loading and unloading of material, is carried out in isolation from the surrounding air.

2. Replacing flammable liquids with non-flammable or less flammable liquids or compositions (see Chapter 10 of this textbook).

3. Selection of the most rational form of an open apparatus, allowing for a minimum evaporation surface.

4. Installation of systems for suction and collection of liquid vapors released during evaporation directly from the devices.

5. Availability of special protection devices in case of fire (covers for closing devices, emergency drainage of liquid, local installation fire extinguishing).

It should be borne in mind that devices with an open surface, evaporation, where technology allows, should be replaced by closed devices. However, this does not always lead to a reduction in fire danger. An example is fuel oil storage facilities. When gases from fuel oil freely escape into the atmosphere, it maintains a high flash point and can be fireproof under industrial conditions. The transfer of fuel oil storage facilities from open to closed tanks would significantly increase their fire and explosion hazard.

Computer cooling system- a set of means for removing heat from computer components that heat up during operation.

The heat can ultimately be recovered:

1. To the atmosphere (radiator cooling systems):
   1. Passive cooling (heat is removed from the radiator by heat radiation and natural convection)
   2. Active cooling (heat is removed from the radiator by radiation (radiation) of heat and forced convection (blowing by fans))
2. Together with coolant (liquid cooling systems)
3. Due to the phase transition of the coolant (open evaporation system)

Based on the method of removing heat from heating elements, cooling systems are divided into:

1. Air (aerogenous) cooling systems
2. Liquid cooling systems
3. Freon installation
4. Open evaporation systems

There are also combined cooling systems that combine elements of various types of systems:

1. Waterchiller
2. Systems using Peltier elements

Air cooling systems

Passive

If heat flux density(heat flux passing through a unit surface) does not exceed 0.5 mW/cm², overheating of the device surface relative to the environment will not exceed 0.5 °C (usually up to a maximum of 50-60 °C), such equipment is considered not heat-loaded and does not require special cooling circuits. For components that exceed this parameter, but with relatively low heat generation (chipsets, transistors, RAM modules), as a rule, only passive radiators are installed. Also, when the chip power is not very high or when the computing capacity of the tasks is limited, only a radiator, without a fan, is sufficient.

Original text(English)

Intel’s reference boundary conditions for ICH10 in an ATX system are 60 °C inlet ambient temperature and 0.25 m/s of airflow. See Figure 5 below for more details on the ATX boundary conditions.

In the ATX boundary conditions listed above, the ICH10 will not require a heatsink when power dissipation is at or below 4.45 W. This value is referred to as the Package Thermal Capability, or PTC. Note that the power level at which a heatsink is required will also change depending on system local operating ambient conditions and system configuration.

Intel® I/O Controller Hub 10 (ICH10) Family Thermal and Mechanical Design Guidelines. June 2008. Document Number: 319975-001

The principle of operation is the direct transfer of heat from the heating component to the radiator due to thermal conductivity of the material or using heat pipes (or their varieties, such as a thermosiphon and an evaporation chamber). The radiator emits heat into the surrounding space by thermal radiation and transfers heat by conduction to the surrounding air, which causes natural convection of the surrounding air. To increase the heat emitted by the radiator, blackening of the radiator surface is used.

The most common type of cooling systems today. It is highly versatile - radiators are installed on most computer components with high heat generation. Cooling efficiency depends on the effective heat dissipation area of ​​the radiator, the temperature and the speed of the air flow passing through it.

The surfaces of the heating component and radiator after grinding have a roughness of about 10 microns, and after polishing - about 5 microns. These roughnesses prevent the surfaces from touching tightly, resulting in a thin air gap with very low thermal conductivity. To increase thermal conductivity, the gap is filled with thermally conductive pastes.

Passive air cooling of the central and graphic processors requires the use of special (and quite large) radiators with high heat removal efficiency at low air flow rates and is used to build a silent personal computer.

Active

To increase the passing air flow, fans are additionally used (the combination of it and the radiator is called a cooler). To the central and GPUs Mostly coolers are installed.

Also, it is difficult to install a radiator on some computer components, in particular hard drives, so they are forcibly cooled by fan cooling.

Liquid cooling systems

The principle of operation is the transfer of heat from the heating component to the radiator using a working fluid that circulates in the system. Distilled water is most often used as a working fluid, often with additives that have a bactericidal and/or anti-galvanic effect; sometimes - oil, antifreeze, liquid metal, or other special liquids.

The liquid cooling system consists of:

• Pumps - a pump for circulating working fluid;
• Heat remover (water block, water block, cooling head) - a device that removes heat from the cooled element and transfers it to the working fluid;
• Radiator for dissipating the heat of the working fluid. Can be active or passive;
• A reservoir with working fluid, which serves to compensate for the thermal expansion of the fluid, increasing the thermal inertia of the system and increasing the convenience of filling and draining the working fluid;
• Hoses or pipes;
• (optional) Liquid flow sensor.

The liquid must have high thermal conductivity in order to minimize the temperature difference between the tube wall and the evaporation surface, as well as high specific heat capacity in order to ensure greater cooling efficiency at a lower rate of liquid circulation in the circuit.

Freon installations

A refrigeration unit in which the evaporator is mounted directly on the component to be cooled. Such systems make it possible to obtain negative temperatures on the cooled component during continuous operation, which is necessary for extreme overclocking of processors.

Flaws:

• The need to thermally insulate the cold part of the system and combat condensation (this is a common problem in cooling systems operating at temperatures below ambient temperature);
• Difficulty cooling multiple components;
• Increased power consumption;
• Complexity and high cost.

Waterchillers

Systems combining liquid cooling systems and freon units. In such systems, the antifreeze circulating in the liquid cooling system is cooled using a freon unit in a special heat exchanger. These systems allow the use of negative temperatures, achievable with the help of freon units, to cool several components (in conventional freon units, cooling of several components is difficult). The disadvantages of such systems include their greater complexity and cost, as well as the need for thermal insulation of the entire liquid cooling system.

Open evaporation systems

Installations in which dry ice, liquid nitrogen or helium is used as a refrigerant (working fluid), evaporating in a special open container (glass) installed directly on the cooled element. They are mainly used by computer enthusiasts for extreme overclocking of equipment (“overclocking”). They allow you to obtain the lowest temperatures, but have a limited operating time (they require constant replenishment of the glass with refrigerant).

Cascade cooling systems

Two or more freon units connected in series. To obtain lower temperatures, it is necessary to use freon with a lower boiling point. In a single-stage refrigeration machine, in this case it is necessary to increase the operating pressure through the use of more powerful compressors. An alternative way is to cool the installation radiator with another freon (i.e., turning them on in series), due to which the operating pressure in the system decreases and becomes possible use conventional compressors. Cascade systems allow much lower temperatures than single-cascade systems and, unlike open evaporation systems, can operate continuously. However, they are also the most difficult to manufacture and set up.

Systems with Peltier elements

The Peltier element is never used independently for cooling computer components due to the need to cool its hot surface. Typically, a Peltier element is installed on the component to be cooled, and its other surface is cooled using another active cooling system.

see also

• Overclocking computers (Overclocking)
• Clock throttling (throttling)

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Notes

Literature

• Scott Mueller. Upgrading and Repairing PCs = Upgrading and Repairing PCs. - 17th edition - M.: "Williams", 2007. - S. 1299-1328 . - ISBN 0-7897-3404-4.

Links

Calculating machine (Computer Configuration) Non-volatile memory: disk drives, storage devices and media Output device and Multimedia Information input device (by main function) Games and entertainment Communication devices and (tele)communications Power supply Other

An excerpt characterizing the computer cooling system

Pierre, without stopping home, took a cab and went to the commander-in-chief.
Count Rastopchin had just arrived in the city that morning from his country dacha in Sokolniki. The hallway and reception room in the count's house were full of officials who appeared at his request or for orders. Vasilchikov and Platov had already met with the count and explained to him that it was impossible to defend Moscow and that it would be surrendered. Although this news was hidden from the residents, officials and heads of various departments knew that Moscow would be in the hands of the enemy, just as Count Rostopchin knew it; and all of them, in order to relinquish responsibility, came to the commander-in-chief with questions about how to deal with the units entrusted to them.
While Pierre was entering the reception room, a courier coming from the army was leaving the count.
The courier hopelessly waved his hand at the questions addressed to him and walked through the hall.
While waiting in the reception area, Pierre looked with tired eyes at the various officials, old and young, military and civilian, important and unimportant, who were in the room. Everyone seemed unhappy and restless. Pierre approached one group of officials, in which one was his acquaintance. After greeting Pierre, they continued their conversation.
- How to deport and return again, there will be no trouble; and in such a situation one cannot be held accountable for anything.
“Why, here he is writing,” said another, pointing to the printed paper he was holding in his hand.
- That's another matter. This is necessary for the people,” said the first.
- What is this? asked Pierre.
- Here's a new poster.
Pierre took it in his hands and began to read:
“The Most Serene Prince, in order to quickly unite with the troops that were coming to him, crossed Mozhaisk and stood in a strong place where the enemy would not suddenly attack him. Forty-eight cannons with shells were sent to him from here, and His Serene Highness says that he will defend Moscow to the last drop of blood and is ready to fight even in the streets. You, brothers, don’t look at the fact that public offices have been closed: things need to be tidied up, and we will deal with the villain in our court! When it comes down to it, I need young people from both towns and villages. I’ll call the cry in two days, but now there’s no need, I’m silent. Good with an axe, not bad with a spear, but best of all is a three-piece pitchfork: a Frenchman is not heavier than a sheaf of rye. Tomorrow, after lunch, I’m taking Iverskaya to the Catherine Hospital, to see the wounded. We will consecrate the water there: they will recover sooner; and now I’m healthy: my eye hurt, but now I can see both.”
“And the military people told me,” said Pierre, “that there is no way to fight in the city and that the position...
“Well, yes, that’s what we’re talking about,” said the first official.
– What does this mean: my eye hurt, and now I’m looking at both? - said Pierre.
“The count had barley,” said the adjutant, smiling, “and he was very worried when I told him that people had come to ask what was wrong with him.” “And what, count,” the adjutant suddenly said, turning to Pierre with a smile, “we heard that you have family worries?” It’s as if the Countess, your wife...
“I didn’t hear anything,” Pierre said indifferently. -What did you hear?
- No, you know, they often make things up. I say I heard.
-What did you hear?
“Yes, they say,” the adjutant said again with the same smile, “that the countess, your wife, is going abroad.” Probably nonsense...
“Maybe,” said Pierre, looking around absentmindedly. - And who is this? - he asked, pointing to a short old man in a pure blue coat, with a large beard as white as snow, the same eyebrows and a ruddy face.
- This? This is one merchant, that is, he is an innkeeper, Vereshchagin. Have you heard perhaps this story about the proclamation?
- Oh, so this is Vereshchagin! - said Pierre, peering into the firm and calm face of the old merchant and looking for an expression of treason in it.
- This is not him. This is the father of the one who wrote the proclamation,” said the adjutant. “He’s young, he’s sitting in a hole, and he seems to be in trouble.”
One old man, wearing a star, and another, a German official, with a cross on his neck, approached the people talking.
“You see,” said the adjutant, “this is a complicated story. Then, two months ago, this proclamation appeared. They informed the Count. He ordered an investigation. So Gavrilo Ivanovich was looking for him, this proclamation was in exactly sixty-three hands. He will come to one thing: from whom do you get it? - That’s why. He goes to that one: who are you from? etc. we got to Vereshchagin... a half-educated merchant, you know, a little merchant, the adjutant said, smiling. - They ask him: who do you get it from? And the main thing is that we know from whom it comes. He has no one else to rely on other than the postal director. But apparently there was a strike between them. He says: not from anyone, I composed it myself. And they threatened and asked, so he settled on it: he composed it himself. So they reported to the count. The count ordered to call him. “Who is your proclamation from?” - “I composed it myself.” Well, you know the Count! – the adjutant said with a proud and cheerful smile. “He flared up terribly, and just think: such impudence, lies and stubbornness!..
- A! The Count needed him to point to Klyucharyov, I understand! - said Pierre.
“It’s not necessary at all,” the adjutant said fearfully. – Klyucharyov already had sins, for which he was exiled. But the fact is that the count was very indignant. “How could you compose? - says the count. I took this “Hamburg Newspaper” from the table. - Here she is. You didn’t compose it, but translated it, and you translated it badly, because you don’t even know French, you fool.” What do you think? “No,” he says, “I didn’t read any newspapers, I made them up.” “If that’s the case, then you are a traitor, and I will bring you to trial, and you will be hanged. Tell me, from whom did you receive it? - “I haven’t seen any newspapers, but I made them up.” It remains that way. The Count also called on his father: stand his ground. And they put him on trial and, it seems, sentenced him to hard labor. Now his father came to ask for him. But he's a crappy boy! You know, such a merchant's son, a dandy, a seducer, listened to lectures somewhere and already thinks that the devil is not his brother. After all, what a young man he is! His father has a tavern here near the Stone Bridge, so in the tavern, you know, there is a large image of the Almighty God and a scepter is presented in one hand, and an orb in the other; so he took this image home for several days and what did he do! I found a bastard painter...

In the middle of this new story, Pierre was called to the commander-in-chief.
Pierre entered Count Rastopchin's office. Rastopchin, wincing, rubbed his forehead and eyes with his hand, while Pierre entered. The short man was saying something and, as soon as Pierre entered, he fell silent and left.
- A! “Hello, great warrior,” said Rastopchin as soon as this man came out. – We’ve heard about your prouesses [glorious exploits]! But that's not the point. Mon cher, entre nous, [Between us, my dear,] are you a Freemason? - said Count Rastopchin in a stern tone, as if there was something bad in this, but that he intended to forgive. Pierre was silent. - Mon cher, je suis bien informe, [I, my dear, know everything well,] but I know that there are Freemasons and Freemasons, and I hope that you do not belong to those who, under the guise of saving the human race, want to destroy Russia.
“Yes, I’m a Freemason,” answered Pierre.
- Well, you see, my dear. You, I think, are not unaware that Messrs. Speransky and Magnitsky have been sent where they should be; the same was done with Mr. Klyucharyov, the same with others who, under the guise of building the temple of Solomon, tried to destroy the temple of their fatherland. You can understand that there are reasons for this and that I could not exile the local postal director if he were not a harmful person. Now I know that you sent him yours. crew for the rise from the city and even that you accepted papers from him for safekeeping. I love you and do not wish you harm, and since you are twice my age, I, as a father, advise you to stop all relations with this kind of people and leave here yourself as soon as possible.
- But what, Count, is Klyucharyov’s fault? asked Pierre.
“It’s my business to know and not yours to ask me,” cried Rostopchin.
“If he is accused of distributing Napoleon’s proclamations, then this has not been proven,” said Pierre (without looking at Rastopchin), “and Vereshchagin...”
“Nous y voila, [It is so,”] - suddenly frowning, interrupting Pierre, Rostopchin cried out even louder than before. “Vereshchagin is a traitor and a traitor who will receive a well-deserved execution,” said Rostopchin with that fervor of anger with which people speak when remembering an insult. - But I did not call you in order to discuss my affairs, but in order to give you advice or orders, if you want it. I ask you to stop relations with gentlemen like Klyucharyov and get out of here. And I'll beat the crap out of whoever it is. - And, probably realizing that he seemed to be shouting at Bezukhov, who had not yet been guilty of anything, he added, taking Pierre by the hand in a friendly manner: - Nous sommes a la veille d "un desastre publique, et je n"ai pas le temps de dire des gentillesses a tous ceux qui ont affaire a moi. My head is spinning sometimes! Eh! bien, mon cher, qu"est ce que vous faites, vous personnellement? [We are on the eve of a general disaster, and I have no time to be polite to everyone with whom I have business. So, my dear, what are you doing, you personally?]
“Mais rien, [Yes, nothing,” answered Pierre, still without raising his eyes and without changing the expression of his thoughtful face.

An open heating system is the simplest and most energy-independent system with natural circulation. This system is based on the laws of thermodynamics. At the outlet of the boiler, increased pressure is created, then the hot water passes through the pipes to an area with lower pressure, losing temperature as it passes.

Next, the cooled coolant is returned back to the heating boiler, where it is heated again. Natural coolant circulation occurs. The system operates exclusively on water, since the use of antifreeze for heating leads to their rapid evaporation.

In an open heating system, an expansion tank is required, since heated water expands. The expansion tank is used to receive excess water during expansion and return it to the system when cooling, as well as to remove water when its volume is excessive. The tank is not completely sealed, so water evaporates As a result, it is necessary to constantly restore its level. An open heating system does not use a pump. The system is quite simple. Consists of pipes, steel expansion tank, radiators and boiler. Diesel, gas and solid fuel boilers are used, except electric ones.

In an open heating system, water circulates slowly. Therefore, during operation, pipes must warm up gradually to avoid their damage and boiling of the coolant. This can lead to premature wear of the equipment. If heating is not used in winter, the water from the system must be drained to avoid pipeline freezing.

In order for the coolant to circulate at the required level, it is necessary to install the heating boiler in a lower place in the system, and install it in the highest place. expansion tank, for example, in the attic. In winter, the expansion tank must be insulated. When installing a pipeline in an open heating system, it is necessary to use a minimum number of turns, fittings and connecting parts.

In a closed heating system, all elements of the system are sealed, and there is no evaporation of water. Circulation is carried out using a pump. The so-called system with forced circulation The coolant includes pipes, boiler, radiators, expansion tank, circulation pump.

In a closed heating system, as the temperature rises, the expansion tank valve opens and takes in excess coolant. When the temperature drops coolant, the circulation pump pumps it back into the system. This heating system maintains pressure within predetermined limits. Thanks to this, it is possible coolant deaeration function.

For stable operation Closed heating systems also use an expansion tank made of high-strength metal. This is a closed tank consisting of two halves rolled towards each other.

Inside there is a membrane (diaphragm) made of high-strength heat-resistant rubber. There is also a small gas volume(can be nitrogen, which is pumped in at the manufacturing plant, or air, which accumulates in the system as needed). The membrane divides the tank into parts: one part is where excess water flows when heating the heating system, the other part contains nitrogen or air that does not come into direct contact with the water. Thus, heating fluid enters the expansion tank and penetrates the membrane. As the coolant cools, the gas behind the membrane begins to push it back into the system.

Differences between open and closed heating systems

There are the following distinctive features of open and closed heating systems:

1. At the location of the expansion tank. In an open heating system, the tank is located at the highest point of the system, and in a closed system, the expansion tank can be installed anywhere, even next to the boiler.
2. The closed heating system is isolated from atmospheric flows, which prevents air from entering. This increases service life. By creating additional pressure in the upper nodes of the system, the possibility of formation of air jams in radiators located on top.
3. An open heating system uses pipes with a large diameter, which creates inconvenience, the pipes are also installed at an angle to ensure circulation. It is not always possible to hide thick-walled pipes. To ensure everyone hydraulic rules it is necessary to take into account the slopes of flow distribution, lifting height, turns, narrowing, connection to radiators.
4. A closed heating system uses smaller diameter pipes, which reduces the cost of construction.
5. It is also important in a closed heating system install the pump correctly, which will avoid noise.

Advantages of an open heating system

• easy system maintenance;
• the absence of a pump ensures silent operation;
• uniform heating of the heated room;
• quick start and stop of the system;
• independence from power supply, if there is no electricity in the house, the system will be operational;
• high reliability;
• no special skills are required to install the system; first of all, the boiler is installed; the power of the boiler will depend on the heated area.

Disadvantages of an open heating system

• the possibility of reducing the service life of the system if air enters, as heat transfer decreases, resulting in corrosion, water circulation is disrupted, and air pockets form;
• air contained in an open heating system can cause cavitation, which destroys system elements located in the cavitation zone, such as fittings and pipe surfaces;
• possibility of freezing coolant in the expansion tank;
• slow heating systems after switching on;
• necessary constant level control coolant in the expansion tank to prevent evaporation;
• impossibility of using antifreeze as a coolant;
• quite bulky;
• low efficiency.

Advantages of a closed heating system

• easy installation;
• there is no need to constantly monitor the coolant level;
• opportunity antifreeze application without fear of defrosting the heating system;
• by increasing or decreasing the amount of coolant supplied to the system, you can regulate temperature in room;
• due to the absence of water evaporation, the need to replenish it from external sources is reduced;
• independent pressure regulation;
• the system is economical and technologically advanced, has a longer service life;
• possibility of connecting additional heating sources to a closed heating system.

Disadvantages of a closed heating system

• the most important drawback is the system’s dependence on the availability constant power supply;
• the pump requires electricity to operate;
• For emergency power supply, it is recommended to purchase a small generator;
• if the tightness of the joints is broken, air may enter the system;
• dimensions of expansion membrane tanks in large enclosed spaces;
• the tank is filled with liquid by 60-30%, the smallest percentage of filling occurs in large tanks; at large facilities tanks with a design volume of several thousand liters are used.
• There is a problem with the placement of such tanks; special installations are used to maintain a certain pressure.

Everyone who is going to install a heating system chooses which system is simpler and more reliable for him.

Open heating system, thanks to ease of use, high reliability, used for optimal heating small rooms. These can be small one-story country houses, as well as country houses.

A closed heating system is more modern and more complex. It is used in multi-storey buildings and cottages.

Liquid cooling systems

The principle of operation is the transfer of heat from the heating component to the radiator using a working fluid that circulates in the system. Distilled water is most often used as a working fluid, often with additives that have a bactericidal and/or anti-galvanic effect; sometimes - oil, antifreeze, liquid metal, or other special liquids.

The liquid cooling system consists of:

Pumps - pumps for circulating working fluid

Heat remover (water block, water block, cooling head) - a device that removes heat from the cooled element and transfers it to the working fluid

Radiator for dissipating the heat of the working fluid. Can be active or passive

A reservoir with a working fluid that serves to compensate for the thermal expansion of the fluid, increasing the thermal inertia of the system and increasing the convenience of filling and draining the working fluid

Hoses or pipes

(Optional) Fluid flow sensor

The liquid must have high thermal conductivity in order to minimize the temperature difference between the tube wall and the evaporation surface, as well as high specific heat capacity in order to ensure greater cooling efficiency at a lower rate of liquid circulation in the circuit.

Freon installations

A refrigeration unit in which the evaporator is mounted directly on the component to be cooled. Such systems make it possible to obtain negative temperatures on the cooled component during continuous operation, which is necessary for extreme overclocking of processors.

Flaws:

The need to insulate the cold part of the system and combat condensation

Difficulty cooling multiple components

Increased power consumption

Complexity and high cost

Waterchillers

Systems combining liquid cooling systems and freon units. In such systems, the antifreeze circulating in the liquid cooling system is cooled by a freon unit in the heat exchanger. These systems allow the use of negative temperatures, achievable with the help of freon units, to cool several components (in conventional freon units, cooling of several components is difficult). The disadvantages of such systems include their greater complexity and cost, as well as the need for thermal insulation of the entire liquid cooling system.

Open evaporation systems

Installations that use dry ice, liquid nitrogen or helium as a refrigerant, evaporating in a special open container installed directly on the cooled element. They are mainly used by computer enthusiasts for extreme overclocking of equipment (“overclocking”). They allow you to obtain the lowest temperatures, but have a limited operating time (they require constant replenishment of the glass with refrigerant).

Cascade cooling systems

Two or more freon units connected in series. To obtain lower temperatures, it is necessary to use freon with a lower boiling point. In a single-stage refrigeration machine, in this case it is necessary to increase the operating pressure through the use of more powerful compressors. An alternative way is to cool the installation radiator with another freon (i.e., connecting them in series), due to which the operating pressure in the system is reduced and the use of conventional compressors becomes possible. Cascade systems allow much lower temperatures than single-cascade systems and, unlike open evaporation systems, can operate continuously. However, they are also the most difficult to manufacture and set up.

Systems with Peltier elements

The Peltier element is never used independently for cooling computer components due to the need to cool its hot surface. Typically, a Peltier element is mounted on the component to be cooled, and its other surface is cooled using another cooling system (usually air or liquid). Since the component can cool to temperatures below ambient air temperature, condensation control measures must be taken. Compared to freon units, Peltier elements are more compact and do not create noise and vibration, but are noticeably less efficient.