home Climate systems

The microclimate of the working environment. Life safety: Microclimate of industrial premises, Test work

The concept of "microclimate" is closely related to similar concepts - "weather" and "climate", which are also part of the group of meteorological factors.

Weather is a change in time and space of the physical state of the atmosphere, which at each moment of time is due to the corresponding values of meteorological parameters: temperature, humidity, speed and pressure. atmospheric air. The concept of climate is defined as an average weather condition characteristic of a given area of the Earth, and the climate is determined by the amount of solar radiation and certain features of the atmospheric circulation, as well as the physical and geographical features of the area (relief, altitude, vegetation, etc.).

The floating force in the duct, that is, the ventilation efficiency in the apartment, depends only on the difference between the air temperature in the duct and the air temperature. Another important factor affecting the operation of gravitational ventilation. This is wind energy, so it is necessary to maintain this type of ventilation. Gravity ventilation can be provided.

Roof exhaust fans. Aerodynamic units that use the kinetic energy of the wind. Thermodynamic scaffolding using thermal radiation and wind energy. Since energy saving has become a priority, energy efficient roof fans are being used to replace energy intensive outdoor fans.

Microclimate is a set of values of the physical characteristics of meteorological factors in a limited space under study. When determining the microclimate, measurements are usually made at a height of 2 m from the floor.

There is a natural and artificial microclimate. In the latter case, a person has the ability to actively influence the conditions around him. This influence is reduced to the creation of an artificial microclimate in the premises, when stable meteorological conditions are maintained, depending on the type of premises and its purpose, as well as on the type of work performed in this room.

Again, it should be emphasized that proper ventilation and therefore exhaust air evacuation is required to ensure airflow in the dwelling. Ventilation system, supported by roof fans, is a system whose idea is to maintain a vacuum whose size guarantees stable ventilation, regardless of the changing conditions of the external atmosphere, and regardless of the way the apartment is used. It is not easy, because the practice of years convinced. This system did not pass the test because the roof fans drew more air from leaky ducts than from ventilated spaces.

Atmospheric pressure plays essential role only under special conditions labor activity person. For example, in aviation, during caisson work, in diving, etc. In other cases, a change in the value atmospheric pressure in relation to its normal value, it turns out to be very insignificant and does not have such a great biological significance as the change in the values of other meteorological parameters.

The installation of roof fans in a thermally upgraded building did not live up to expectations due to excessive noise, especially felt by residents on higher floors. It is also difficult to find a business case for installing roof fans, apart from the investment costs that we have to deal with higher operating costs. A more suitable solution for a thermomodern building is the use of thermodynamic roofs. They increase the thermal resistance to gravity by using solar radiation and the force of the wind to increase flow.

Therefore, the influence of changes in barometric pressure will not be considered further. Studying the effect of changes in barometric pressure on human body the reader can find in the specialized literature on biometeorology, as well as marine and aviation medicine.

Temperature air expresses the degree of its heating, which can be defined as the total kinetic energy of air molecules. In practice, the Celsius scale is most often used to measure temperature, the main reference points of which are the temperatures of melting ice (0 ° C), boiling water (100 ° C), boiling oxygen (-182.97 ° C) and sulfur (444.6 ° C), as well as the melting points of silver (960.8 ° C) and gold (1063.0 ° C). The initial value of the Kelvin temperature scale (the so-called absolute temperature scale) corresponds to a temperature of -273.15 ° Celsius. Other temperature units are currently not used in Polish literature. English literature also uses the Fahrenheit scale. The relationship between temperature values expressed in degrees Celsius and Fahrenheit is as follows:

By correctly folding the surface of the base and covering it with heat-absorbing paint, the base accumulates heat. The air flowing through the base is heated to a temperature above the outside temperature, which increases the driving force of thermal gravity buoyancy. The sands also use the force of the wind to pressurize the nozzle. There is a dynamic vacuum in the channel, the size of which is proportional to the square of the wind speed. The use of thermodynamic bases also prevents changes in the direction of gas flow in the exhaust and ventilation ducts during strong winds, which occurs with classical ventilation with a roof duct.

Humidity air depends on the content of water vapor in it. Depending on the temperature, the air can contain different amounts of water vapor. In this regard, it is necessary to distinguish between the concepts of relative and absolute humidity. Water vapor content (in grams) in 1 m 3 air is called absolute humidity and is usually defined as the pressure of water vapor, expressed in millimeters of mercury (mmHg.).

Ventilation in the light of rules and facts. The amount of ventilation air in a building structure determines ventilation standards. The ventilation system of the apartment should provide at least. Supply of outdoor air to the living rooms and kitchen with an outside window. Removal of air used in the kitchen, bathroom, toilet and other rooms without windows.

Steam drainage is done in the apartment. The volume of ventilation air for an apartment is determined by the sum of the air flows discharged from the apartment. The flow rate, regardless of the type of ventilation, must be at least. At night, the air flow can be reduced by 40%.

Relative humidity is the ratio of a given water vapor pressure to the saturated water vapor pressure (maximum at a given air temperature), expressed as a percentage. From the point of view of physiology and hygiene, the values of physiological humidity and physiological lack of moisture are especially important. The term “physiological humidity” should be understood as the ratio (in percent) of the actual water vapor pressure to the saturation pressure at a given body temperature. The physiological lack of moisture, respectively, means the difference between the maximum possible water vapor pressure at a given body surface temperature and the actual water vapor pressure in the air.

Within the same dwelling, it is unacceptable to use a parallel mechanical exhaust ventilation with continuous operation and gravity ventilation and the simultaneous use of collective pipes and individual gravity ventilation. In apartments equipped with a fireplace from solid fuel, fireplaces or gas water heaters with gravity flue gas extraction, only gravity or mechanical ventilation may be used.

The supply of outdoor air to the premises must be provided by diffusers with an adjustable opening, through ventilation openings for mechanical ventilation. Every heat treatment process must include flue gas isolation work. This reduces heat loss and prevents moisture from condensing on the channel surface, which prevents corrosion. The chimney insulation is non-flammable and prevents potential fires from chimney. The insulation of the ventilation duct also performs the function of sound absorption, improving the acoustic comfort inside the room.

Air speed - the ratio of the distance traveled by a mass of air to the time, expressed in meters per second.

Send your good work in the knowledge base is simple. Use the form below

Effect of ventilation on human physiology. Ventilation affects every aspect of human physiology. The main requirement for effective ventilation is to provide the body necessary quantity oxygen and draining carbon dioxide and water vapor. The human oxygen demand is the result of the number of breaths per unit time, the volume of inhalation, and the percentage of oxygen in the inhaled and exhaled air. The minimum safe level of oxygen in the air is 19.5%, and falling to 16% results in death.

Residential buildings, which have undergone thermal modernization for most of the year, are mainly equipped with gas installations, which supply gas for instantaneous heating of the c.h. and gas kitchens. Both types of gas appliances require a supply a large number oxygen consumed in the air. At the same time, existing chimney ducts must release exhaust gases into the atmosphere. The air supply to the bathroom comes indirectly from other rooms in the apartment. There is a strict ban on the use of ventilation, ventilation or similar devices in these rooms.

Good work to site">

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Hosted at http://www.allbest.ru/

1 . Industrial microclimate and its impact on the human body

Of course, both a gas water heater and a gas stove must meet all safety requirements. Providing less oxygen than required to burn the gas results in incomplete combustion of the combustible gas. This provokes three phenomena, especially unfavorable for both man and construction.

The result of incomplete combustion is carbon monoxide, which poses a threat to human life and health. Outflow of flammable gases into the atmosphere, which reduces the efficiency of the installation and increases the cost of preparation hot water. Hydrogen, which is present in exhaust gases with insufficient ventilation, can cause an explosive mixture with a concentration of 4%.

Microclimate industrial premises? this is the climate of the internal environment of these premises, which is determined by the combinations of temperature, humidity and air velocity acting on the human body, as well as the temperature of the surrounding surfaces.

In (Figure 1) the classification is shown industrial microclimate.

Picture 1 ? Types of industrial microclimate

The biggest threat to humans is carbon monoxide. A characteristic feature of this gas is its strong absorption by hemoglobin, more than 200 times stronger than oxygen, and when hemoglobin transfers not oxygen to the human brain, but poison - carbon monoxide - the brain dies. Already 0.05% carbon monoxide is a threat to human life. The scale of carbon monoxide poisoning in the country is several hundred people a year! The cause of this condition is insufficient ventilation, and the most common causes are.

Reversal of the gas flow direction in the flue gas duct. Excessive resistance to air suction in the apartment as a result of window sealing. Difficulty in removing flue gases at increased outdoor temperature. Use of auxiliary ventilation devices.

Weather conditions working environment (microclimate) affect the process of heat transfer and the nature of the work. The microclimate is characterized by air temperature, its humidity and speed of movement, as well as the intensity of thermal radiation. Prolonged exposure of a person to unfavorable meteorological conditions sharply worsens his state of health, reduces labor productivity and leads to diseases.

Simplifying, the first cause of poisoning is always a lack of airflow into the room. The minimum flow requirements of a gas water heater that must be provided in a bathroom are as follows. As a reminder, this amount of exhaust gases will not flow into the atmosphere unless the same amount of air is delivered. Knowing that there is so much air in the bathroom will probably save many lives or prevent disability.

In order to reduce the risk for the future, the authors propose to take the following actions as part of the thermal modernization of the building. Replace traditional water heaters with enclosed heaters where air is supplied by separate air in the required quantities. Installation of chimneys for thermo-ventilation.

High air temperature contributes to rapid fatigue of the worker, can lead to overheating of the body, heat stroke. Low air temperature can cause local or general cooling of the body, cause colds or frostbite.

Air humidity has a significant impact on the thermoregulation of the human body. High relative humidity (the ratio of the content of water vapor in 1 m3 of air to their maximum possible content in the same volume) at high air temperatures contributes to overheating of the body, while at low temperatures it enhances heat transfer from the skin surface, which leads to hypothermia of the body. Low humidity causes the mucous membranes of the worker's pathways to dry out.

Installation of gas indicators. Ensure the correct size of the bathroom air inlets. It is worth recalling criminal liability: the size of the passage in the exhaust and ventilation ducts, which determine the release of air from the kitchen, bathroom, toilets, is the responsibility of the owner of the building, and the air flow into the apartment corresponds to the apartment of the tenant.

Reducing the ventilation intensity of the apartment also leads to other, completely undesirable, dangers for humans. Insufficient air in the room will not drain the moisture generated in that room. This will lead to the formation of domestic fungi and bacterial flora. A low amount of air obviously means that there is not enough oxygen and all the consequences and especially hypoxia. An excessively limited amount of air due to needs leads to other discomfort, most often related to the well-being of the person living in this room.

Air mobility effectively contributes to the heat transfer of the human body and is positively manifested when high temperatures, but negatively low.

Subjective sensations of a person change depending on the change in microclimate parameters (Table 1).

Table 1 ? Dependence of subjective feelings of a person on the parameters of the working environment

This is a sign of the so-called. sick building syndrome. This is followed by other pollutants and socio-psychological factors such as temperature, noise, exposure and building location. IN last years additional factors have been identified that affect the micro-environment of internal and general human health and life. These are low emissions and smog resulting from the combustion of fuels, mostly solid fuels.

The factor that has a great influence on the environment of the dwelling and the well-being of a person is the appropriate temperature and exactly the temperature that a person experiences. The effect of this is the type of heating, and precisely the way the heat is transferred. It must be transmitted as much as possible by radiation, not by convection. The transfer of heat by radiation heats the surface.

Air temperature, ?С

Relative humidity, %

Subjective feeling

The most pleasant state.

Good, calm condition.

Fatigue, depression.

No discomfort.

Unpleasant sensations.

Need for rest.

How great is the sense of smell in human well-being, you can be sure of the summer season in an impregnable bus. The pollution of one adult working in a sitting position and using a shower 0.7 times a day was labeled 1 olf. But it is not the person who causes the most pollution of this type. A 10 m2 apartment contains pollutants from these sources equivalent to four people. And such air exchange should be provided for this room.

Proper ventilation in buildings and spaces is a fundamental requirement to ensure a high level of indoor climate comfort and the well-being of their users. The effectiveness of ventilation depends on the proper supply of fresh air to the building, ensuring sufficient air flow between rooms and efficient removal of polluted air. The use of appropriate methods to improve ventilation efficiency in buildings undergoing thermal renovation should provide the necessary thermal comfort for the occupants of such buildings.

No discomfort.

Normal performance.

Inability to do hard work.

Increase in body temperature.

Health hazard.

To create normal working conditions in industrial premises, standard values of microclimate parameters are provided: air temperature, its relative humidity and speed of movement, as well as the intensity of thermal radiation.

2 . The main parameters of the microclimate

In the process of work in a production facility, is a person under the influence of certain conditions, or microclimate? climate of the internal environment of these premises. The main normalized indicators of the air microclimate of the working area include temperature, relative humidity, and air velocity. The intensity of thermal radiation of various heated surfaces, the temperature of which exceeds the temperature in the production room, also has a significant impact on the parameters of the microclimate and the state of the human body.

Relative humidity is the ratio of the actual amount of water vapor in the air at a given temperature to the amount of water vapor that saturates the air at that temperature.

If there are various heat sources in the production room, the temperature of which exceeds the temperature human body, then the heat from them spontaneously passes to a less heated body, i.e. to a person. There are three ways of heat propagation: conduction, convection and thermal radiation.

Thermal conductivity is the transfer of heat due to the random (thermal) movement of microparticles (atoms, molecules) that are in direct contact with each other. Convection is the transfer of heat due to the movement and mixing of macroscopic volumes of gas or liquid. Thermal radiation? this is the process of propagation of electromagnetic oscillations with different wavelengths, due to the thermal motion of atoms or molecules of a radiating body.

In real conditions, heat is transferred not by any one of the above methods, but by a combined one.

The heat entering the production room from various sources affects the air temperature in it. The amount of heat transferred to the ambient air by convection (Qk, W) during a continuous heat transfer process can be calculated according to Newton's heat transfer law, which for a continuous heat transfer process is written as:

where b? convection coefficient, ;

S? heat transfer area, m?

t? source temperature, ?С;

tv? ambient air temperature, ?С.

The amount of heat transferred by radiation (Qi, J) from a more heated solid to a less heated body is determined by:

where is s? radiation surface, m?;

f? time, s;

C1-2? mutual radiation coefficient, ;

AND? average slope.

A person in the process of labor is constantly in a state of thermal interaction with the environment. For the normal course of physiological processes in the human body, it is necessary to maintain an almost constant temperature (36.6 ° C). The ability of the human body to maintain a constant temperature is called thermoregulation. Thermoregulation is achieved by the removal of heat released by the body in the process of life into the surrounding space.

Heat transfer from the body to the environment occurs as a result of: heat conduction through clothing (Qt); body convection (Qk); radiation to surrounding surfaces (Qi), evaporation of moisture from the skin surface (Qsp); heating of exhaled air (Qv), i.e.:

Qtotal \u003d Qt + Qk + Qi + Qsp + Qv

This equation is called the heat balance equation. The contribution of the heat transfer routes listed above is not constant and depends on the parameters of the microclimate in the production room, as well as on the temperature of the surfaces surrounding the person (walls, ceiling, equipment). If the temperature of these surfaces is lower than the temperature of the human body, then heat exchange by radiation goes from the human body to cold surfaces. Otherwise, heat transfer is carried out in the opposite direction: from heated surfaces to a person. Does heat transfer by convection depend on the temperature of the air in the room and the rate of its movement of evaporation? relative humidity and air velocity. The main share in the process of removing heat from the human body (about 90% of the total amount of heat) is contributed by radiation, convection and evaporation.

The normal thermal well-being of a person when performing work of any category of severity is achieved subject to the thermal balance. Let us consider how the main parameters of the microclimate affect the heat transfer from the human body to the environment.

The effect of ambient temperature on the human body is primarily associated with the narrowing or expansion of blood vessels in the skin. Under the influence of low air temperatures, the blood vessels of the skin narrow, as a result of which the flow of blood to the surface of the body slows down and heat transfer from the surface of the body decreases due to convection and radiation. At high ambient temperatures, the reverse picture is observed: due to the expansion of the blood vessels of the skin and an increase in blood flow, heat transfer increases significantly.

IN normative documents the concepts of optimal and permissible microclimate parameters are introduced.

Optimal microclimatic conditions are such combinations of quantitative parameters of the microclimate that, with prolonged and systematic exposure to a person, ensure the preservation of normal functional and thermal state body without straining the mechanisms of thermoregulation.

Permissible conditions are provided by such a combination of quantitative parameters of the microclimate, which, with prolonged and systematic exposure to a person, can cause transient and rapidly normalizing changes in the functional and thermal state of the body, accompanied by a tension in the mechanisms of thermoregulation that does not go beyond the limits of physiologically adapted capabilities.

GOST 12.1.005-88 “Working area air. General sanitary and hygienic requirements” presents the optimal and valid parameters microclimate in the production room, depending on the severity of the work performed, the amount of excess heat in the room and the season (season).

In accordance with this GOST, there are cold and cold periods of the year (with an average daily outdoor temperature below +10 ° C), as well as a warm period of the year (with a temperature of +10 ° C and above). All categories of work performed are divided into: light (energy consumption up to 172 W), moderate (energy consumption up to 172–293 W) and heavy (energy consumption more than 293 W). According to the amount of excess heat, industrial premises are divided into rooms with insignificant excesses of sensible heat (Qi.t.? 23.2 J/m?s) and rooms with significant excesses of sensible heat (Qi.t. ). Industrial premises with a slight excess of sensible heat are classified as "cold shops", but with significant? to "hot".

To maintain normal microclimate parameters in working area apply: mechanization and automation of technological processes, protection from sources of thermal radiation, installation of ventilation, air conditioning and heating systems. An important place is also given to the proper organization of work and rest for workers performing labor-intensive work in hot shops.

The mechanization and automation of the production process makes it possible to drastically reduce the labor load on workers (the mass of cargo lifted and moved manually, the distance of cargo movement, to reduce transitions due to the technological process), to completely remove a person from production environment, shifting his labor functions to automated machines and equipment. To protect against thermal radiation, various heat-insulating materials are used, heat shields and special ventilation systems (air showering) are arranged. Thermal protective equipment should provide thermal exposure at workplaces of no more than 350 W / m? and the surface temperature of the equipment is not higher than 35? C at a temperature inside the heat source up to 100? C and not higher than 45? C? at a temperature inside the heat source above 100?

The main indicator characterizing the effectiveness thermal insulation materials, ? low coefficient of thermal conductivity, which for most of them is 0.025? 0.2 W / m K.

Various materials are used for thermal insulation, for example, asbestos cloth and cardboard, special concrete and brick, mineral and slag wool, fiberglass, etc. As thermal insulation materials for steam and hot water pipelines, as well as for cold supply pipelines used in industrial refrigerators, mineral wool materials should be used.

Heat shields are used to localize sources of thermal radiation, reduce exposure at workplaces, and also to reduce surface temperatures.

To quantify the protective effect of the screen, the following indicators are used: the heat flux attenuation ratio (m); screen efficiency (ze). These characteristics are expressed by the following dependencies:

where are E1 and E2? the intensity of thermal exposure at the workplace, respectively, before and after the installation of screens, W/m?.

There are heat-reflecting, heat-absorbing and heat-removing screens. Heat-reflecting screens are made of aluminum or steel, as well as foil or mesh based on them. Heat-absorbing screens are structures made of refractory bricks, asbestos cardboard or glass. Heat shields? These are hollow structures cooled from the inside by water.

A kind of heat-removing transparent screen is the so-called water curtain, which is arranged at the technological openings of industrial furnaces and through which tools, processed materials, workpieces, etc. are introduced into the furnaces.

3 . Creation of the required microclimate parameters

3.1 Ventilation systems

To create the required microclimate parameters in the production room, ventilation and air conditioning systems, as well as various heating devices, are used. Ventilation is a change of air in the room, designed to maintain appropriate meteorological conditions and the purity of the air environment.

Ventilation of rooms is achieved by removing heated or polluted air from them and supplying clean outside air. General exchange ventilation, designed to provide specified meteorological conditions, replaces the air in the entire room. It is designed to maintain the required parameters of the air environment throughout the entire volume of the room. The scheme of such ventilation is shown below (Figure 2).

Figure 2? Scheme of general ventilation (arrows show the direction of air movement)

For effective work general ventilation systems while maintaining the required microclimate parameters, the amount of air entering the room (Lpr) should be practically equal to the amount of air removed from it (Lout).

The amount of supply air required to remove excess sensible heat from the room (Qex, kJ/h) is determined by the expression:

where Lpr? the required amount of supply air, m?/h;

C? specific heat capacity of air at constant pressure, equal to 1 kJ / (kg deg);

ref? supply air density, kg/m?;

tvy? temperature of the removed air, ?С;

tpr? supply air temperature, ?С.

To effectively remove excess sensible heat, the supply air temperature should be 5?6 ?C lower than the air temperature in the working area.

The amount of supply air necessary to remove the moisture released in the room is calculated by the formula:

where is Gvp? mass of water vapor released in the room, g/h;

ref? supply air density.

According to the method of air movement, ventilation can be both natural and mechanically induced; a combination of these two methods is also possible. At natural ventilation The air moves due to the temperature difference between the indoor and outdoor air, as well as as a result of the action of the wind.

Methods of natural ventilation: infiltration, ventilation, aeration, using deflectors.

With mechanical ventilation, air is moved by means of special blowers-fans, which create a certain pressure and serve to move air in the ventilation network. Most often in practice, axial radiators are used.

To create the required microclimate parameters in a certain area of the production facility, local forced ventilation. It does not supply air to all rooms, but only to a limited part. Local forced ventilation can be provided by the installation of air showers and oases, or an air-thermal curtain.

Air showers are used to protect workers from air thermal radiation with an intensity of 350 W / m? and more. The principle of their operation is based on the blowing of a humidified air stream operating with a jet, the speed of which is 1 × 3.5 m / s. This increases the heat transfer from the human body to the environment.

Air oases, which are part of a production facility, limited on all sides by portable partitions, create the required microclimate parameters. These sources are used in hot shops.

To protect people from hypothermia in the cold season, air and air-thermal curtains are arranged in doorways and gates. The principle of their operation is based on the fact that at an angle to the cold air flow entering the room, the air flow is directed ( room temperature or heated) that either slows down and changes the direction of the cold flow, reducing the likelihood of drafts in the production room, or warms cold stream(in the case of an air-thermal curtain).

3 . 2 Air conditioning

At present, to maintain the required parameters of the microclimate, air conditioning units (conditioning) are widely used. Air conditioning is the creation and automatic maintenance in industrial or domestic premises, regardless of external meteorological conditions, of constant or changing according to a certain program of temperature, humidity, purity and speed of air movement, the combination of which creates comfortable conditions labor or is required for the normal course of the technological process. Air conditioner? it's automated ventilation unit, which maintains the specified microclimate parameters in the room.

3 . 3 Heating systems

To maintain the set air temperature in the premises during the cold season, water, steam, air and combined heating systems are used.

In water heating systems, water is used as a heat carrier, or superheated above this temperature. Such heating systems are the most effective in sanitary and hygienic terms.

Systems steam heating usually used in industrial premises. The heat carrier in them is water vapor of low or high pressure.

In air systems for heating, air heated in special installations (heaters) is used. Combined heating systems use the heating systems discussed above as elements.

3. 4 Instrumentation

Microclimate parameters in industrial premises are controlled by various instrumentation. To measure the air temperature in industrial premises, mercury (to measure temperatures above 0 ° C) and alcohol (to measure temperatures below 0 ° C) thermometers are used. If constant recording of temperature changes over time is required, devices called thermographs are used.

Measurement of relative air humidity is carried out by psychrometers and hygrometers; a hygrograph is used to record the change in this parameter over time.

An aspiration psychrometer consisting of dry and wet thermometers placed in metal tubes and blown with air at a speed of 3–4 m/s, as a result of which the stability of thermometer readings is increased and the effect of thermal radiation is practically eliminated. Relative humidity is also determined using psychometric tables. Aspiration psychrometers, such as MV-4M or M-34, can be used to simultaneously measure indoor air temperature and relative humidity.

Another device for determining relative humidity is a hygrometer, which is based on the property of some organic substances to elongate in humid air and shorten. By measuring the deformation of the sensitivity of the element, one can judge the relative humidity in the production room. An example of a hygrograph is a device of the M-21 type.

Is the speed of air movement in the production room measured? anemometers. The operation of a vane anemometer is based on changing the rotation speed of a special wheel equipped with aluminum wings located at an angle of 45? to a plane perpendicular to the axis of rotation of the wheel. The axle is connected to a rev counter. When the air flow speed changes, the rotation speed also changes, i.e. increases (decreases) the number of revolutions for a certain period of time. From this information, the airflow rate can be determined.

The intensity of heat is measured by actinometers, the action of which is based on the absorption of thermal radiation and the registration of the released thermal energy. The simplest thermal receiver? thermocouple. It is an electrical circuit of two wires made of various materials(both metals and semiconductors). Two wires of different materials are welded or soldered together. Thermal radiation heats one of the junctions of the two wires, while the other junction serves as a comparison and is maintained at a constant temperature.

microclimate organism ventilation air conditioning

List of sources

1. Life safety / Ed. L.A. Ant. - 2nd ed. revised and additional - M.: UNITI-DANA, 2003. - 431 p.

2. Belov S.V. Life safety: a textbook for universities S.V. Belov, A.V. Ilnitskaya, A.F. Koziakov. - 4th ed. correct and additional M.: Higher school, 2004. - 606 p.

3. Life safety: textbook for universities N.P. Kukin, V.L. Lapin, N.L. Ponomarev. - 2nd ed. correct and additional M.: Higher school, 2001. - 319 p.

Hosted on Allbest.ru

...

The microclimate of the working environment. Life safety: Microclimate of industrial premises, Test work

Send your good work in the knowledge base is simple. Use the form below

Similar Documents