RU2766242C1 - Method for supplying intake air combined with air heating of buildings - Google Patents

Abstract

FIELD: thermal engineering.

SUBSTANCE: invention relates to the field of thermal engineering. The method for supplying intake air combined with air heating of buildings includes a combination of ventilation and heating, in which the intake air in the calculated amount enters the supply ventilation unit (supply chamber) using a calculated fan, passes through a filter, where it is cleaned and enters the air heater, in which it is heated to a set temperature according to the norms, thereby solving the issue of supplying the necessary (missing) amount of heat to compensate for the shortcomings of heat according to the calculated heat balance, thus, the thermal regime in the room is controlled and enters the main duct of the design section. The estimated amount of intake air is taken from the main duct and sent to each vertical duct, on which at least two air distributors are installed, located at different heights from the floor level of the working area, and the air outlet from each vertical duct is carried out only through one air distributor, and to ensure minimum heating and ventilation costs for the entire annual cycle of the systems, the choice of the location of the air distributor for the air outlet depends on the outside air temperature.

EFFECT: objective of the invention is optimal air supply combined with air heating or combined with ventilation (cooling) of a room in an industrial or public building.

1 cl, 2 dwg

Description

The invention relates to the field of heat engineering and can be used in supply ventilation systems (for cooling rooms), as well as in air heating systems (for space heating) and air conditioning systems (to create comfort conditions for people in rooms or optimal air parameters for conducting technological processes).

The required parameters of the air environment in the working or serviced area of the premises can be ensured only with the proper organization of air exchange and the supply of the calculated supply air flow to the working (served) area. A decrease in the flow rate of the supplied air causes the formation of unventilated zones in which the air parameters (temperature, mobility, relative humidity and concentration of harmful substances) exceed the permissible values, and this is unacceptable according to sanitary and hygienic standards.

A known method of supplying heated (supply) air in a ductless local air heating system, see fig. 10.1 a, p. 316; in fig. 10.1 b shows the method of supplying supply (heated) air when installing a duct heating system; see the book by A.N. Scanavi, L.M. Makhov "Heating", Moscow, Ed. DIA, 2002, 575 p. On fig. 10.2 (see ibid.), p. 317 shows diagrams of the central air heating system.

The main common drawback of the known methods of air supply is the inability to change the air distribution scheme during operation, i.e. all air distributors are rigidly attached to building structures and therefore it is practically impossible to change the installation height of the air distributor from the floor level during operation. The disadvantages of channel systems include the complexity of organizing flow distribution, i.e. it is difficult to supply the calculated air flow with the calculated temperature to each room.

These methods of air supply are taken as analogues.

A known method (taken as a prototype) supply of fresh air, combined with air heating in a multi-storey building, see patent 2375642 ⁽¹³⁾ C1 IPC F24F 7/08 (2006.01).

The disadvantage of the known method is the inability to change the height of the air supply (air exchange arrangement) to the premises during operation, because the air duct is laid horizontally and rigidly attached to building structures. The presence in the known device of check valves, flow-distributing valves located at different heights (on each floor), duct heaters and other equipment makes the known method unreliable in operation due to the possibility of breakage and complexity of repair.

The objective of the invention is the optimal air supply combined with air heating or combined with ventilation (cooling) of a room in an industrial or public building.

This is achieved by the fact that the calculated amount of supply air is taken from the main air duct and sent to each vertical air duct, on which at least two air distributors are installed, located at different heights from the floor level of the working area, and air is released from each vertical air duct through only one air distributor , and to ensure the minimum cost of heating and ventilation for the entire annual cycle of operation of the systems, the choice of location of the air outlet for air outlet depends on the outdoor temperature.

The invention is illustrated by drawings: Fig. 1 shows a diagram of an installation for supplying fresh air; in fig. 2 is section 1-1 of FIG. one.

The installation for supplying fresh air contains an air intake device 1, a supply chamber 2, an insulated valve 3, an air filter 4, an air heater 5, a fan 6; (other equipment can be installed in the supply chamber, for example, a device for humidifying or dehumidifying the air, etc.). To the duct 7 is attached to the main duct 8, which is connected to the vertical ducts 9, 10 and 11 (see Fig. 1 and 2); three air distributors are connected to each vertical air duct, located at different heights (h ₁ , h ₂ , h ₃ ) from the floor level of the working area. The air distributor 12 is located at a height h ₁ from the floor level of the working area and is connected to the air duct 9 by an air duct 13. The air distributor 14 is located at a height h ₂ from the floor level of the working area and is connected to the air duct 9 by an air duct 15. The air distributor 16 is located at a height h ₃ from the floor level working area and is connected to the air duct 9 air duct 17. Moreover, h ₁ <h ₂ <h ₃ .

To regulate the flow of air passing through the air distributors 12, 14, 16 and to disconnect these air distributors from the air duct 9, dampers or throttle valves with manual or remote control are used. In FIG. 2 at the air distributor 12, for example, the gate 18 is shown, and at the air distributors 14 and 16, for example, throttle valves 19 and 20 are shown with remote control, i.e. an indication (command) to open the valve or close it is carried out remotely using electronic equipment (not shown in Figs. 1 and 2).

The method of supplying fresh air, combined with air heating, is carried out as follows: the supply (outside) air in the estimated amount enters the supply ventilation unit (supply chamber) with the help of a calculated fan, passes through the filter, where it is cleaned and enters the air heater, in which it is heated to a given (calculated) temperature in accordance with the standards, thereby solving the issue of supplying the necessary (missing) amount of heat to compensate for heat deficiencies, according to the calculated heat balance, thereby controlling the thermal regime in the room and entering the main air duct of the calculated section, then from the main air duct the estimated amount of supply air is taken into each vertical air duct, three air distributors are connected to each vertical air duct, located at different heights from the floor level of the working area, air is released from each vertical air duct It is carried out through one air distributor, which ensures the minimum energy costs for heating and ventilation for the entire annual cycle of the system.

Under the minimum energy costs is understood, first of all, the minimum heat consumption for the annual cycle of operation of the heating and ventilation system, subject to the specified parameters of the air environment in the working area of the room.

It is known that the technological _performance of heating and _{ventilation systems} is influenced by various _factors , including: _. ); Note that these parameters affect the formation of the microclimate in the room.

During the heating period, the values of the listed parameters (Q _surplus , Q _sweat , t _r.z. , t _n. ) vary widely.

For example, with an increase in the outdoor temperature, heat losses decrease, and heat emissions from process equipment, lighting, people, etc. practically do not change; therefore, excess heat is formed in the premises, therefore, the air temperature in the working area also rises, which is unacceptable according to sanitary and hygienic, and sometimes according to technological standards. There are several ways to maintain a normalized air temperature in the working area: this is an increase in the flow of supply and exhaust air, a decrease in the temperature of the supply air, etc., and this leads to an increase in cash costs.

In the proposed method, it is proposed to reduce the air temperature in the working area by changing the air distribution scheme, i.e. by choosing a place (mark) for the location of the air distributor, i.e. places (marks) of air outlet into the room.

The choice of a rational scheme for organizing air exchange is easier to solve based on the analysis of a specific problem. Consider an example.

The cold period of the year (the temperature of the supply air is higher than the temperature in the working area, i.e. t _pr \u003e t _r.z. ). In an industrial building there are disadvantages of heat Q _sweat =18000 W; design air temperature in the working area t _r.z. =+18°C; design outdoor temperature t _n \u003d -20 ° C (minus 20 degrees); The amount of supply air G _pr. =21000 kg/h; Heating in the workshop is combined with ventilation.

Let us determine the required supply air temperature in order to ensure the air temperature t _r.z. in the working area. =+18°C.

The temperature in the working area is 18°C, and the supply air temperature is calculated to be 21.0°C. Such a temperature of the supply air to the working area is acceptable in the absence of permanent jobs in the zone of distribution of the supply air jet.

Next, consider the autumn-spring regime; supply air temperature - it is also outdoor t _pr \u003d t _n. - lower than the air temperature in the working area, i.е. t _pr <t _r.z. ; t _n \u003d t _pr <t _r.z.

Consider an example.

Air temperature in the working area, t _r.z. =+18°С;

The amount of supply air G _pr. =21000 kg/h;

The amount of excess heat _Qex = 10000 W.

Let us determine the required supply air temperature for the assimilation of excess heat:

Outside (aka supply) air with a temperature of 16.3 ° C cannot be supplied to the working area from air distributors installed in the working area, according to sanitary and hygienic requirements; outdoor air should be heated (for example) to a temperature t _r.z. , i.e. up to 18°С; even in the presence of excess heat in the workshop, the air must be heated.

Heat consumption for air heating:

Therefore, 9996 W of heat must be spent to heat the supply air if the air is supplied to the working area. But since there is an excess of heat in the workshop, it is advisable to change the air distribution scheme, i.e. determine from what height from the floor of the working area it is possible to supply outside air without heating it. Considering the possible options for air distribution, we come to the conclusion that the most acceptable in this case is the air supply “from top to bottom” with inclined jets (Scheme D, see the color insert after page 96 in the book by M.I. Grimitlin “Air distribution in rooms”. Publishing house "ABOK North-West" St. Petersburg, 2004). The supply air jet, passing a considerable distance, has time to dissipate, the air in the jet is heated due to heat excess in the room and enters the working area with a higher temperature, while ensuring a normalized air temperature in the working area of the room and saving heat. To implement the selected air distribution scheme (at t _n =t _CR <t _R.C. ) air should be supplied from the air distributor 14 (see Fig. 1 and 2) (with the air distributors 12 and 16 turned off). Therefore, when designing the supply of fresh air combined with air heating, the number of air distributors connected to the vertical duct 9 and the installation height of the air distributors from the floor level of the working area should be determined by calculation, taking into account the outdoor temperature, the amount of excess heat, the height of the room, sanitary and hygienic requirements, etc., but the number of air distributors must be at least two, connected to the air duct 9.

Reducing the heat consumption of heating, ventilation and air conditioning systems is an important national task. Note that the reduction of heat consumption by these systems is possible by the proposed method; moreover, the supply scheme can change during the operation of these systems, without altering the systems, their dismantling. It should be noted that the cost of supply systems that allow implementing the proposed scheme for organizing air exchange during its operation is somewhat higher than that of known systems; increase in cost - due to an increase in the number of air distributors (often louvered grilles) and their installation, and this is a small cost. When installing throttle valves, turning off one air distributor and turning on another can be carried out remotely using the control panel (not shown in the figure), and turning off one air distributor and turning on another can be done several times per shift, because heat releases from process equipment are usually intermittent and heat input from solar radiation is added.

The method of supplying fresh air, combined with air heating of buildings, has the following advantages:

- in the room at any time of the year, the specified air parameters in the working area are provided with minimal energy consumption;

- heat is saved for heating and ventilation systems;

- the use of the proposed method of supplying fresh air does not require large capital costs (an increase in cost only due to a 2-fold increase in the number of air diffusers and their installation);

- when installing throttle valves to turn off the air distributors, during the operation of systems it is preferable, because turning on and off the air distributor is carried out remotely, i.e. from the floor of the working area using the control panel.

In high rooms, switching on and off (i.e. switching to another air supply scheme) should be carried out using the control panel, depending, for example, on heat generation, solar radiation and outdoor temperature, etc.

Claims (1)

The method of supplying supply air combined with air heating of buildings, including combining ventilation and heating, in which supply air in the calculated amount enters the supply ventilation unit (supply chamber) with the help of a calculated fan, passes through the filter, where it is cleaned and enters the air heater, in which is heated to a predetermined temperature in accordance with the standards, thereby solving the issue of supplying the necessary (missing) amount of heat to compensate for the shortcomings of heat according to the calculated heat balance, thereby controlling the thermal regime in the room and entering the main air duct of the calculated section, which differs in that from the main the calculated amount of supply air is taken and sent to each vertical air duct, on which at least two air distributors are installed, located at different heights from the floor level of the working area, and air outlet from each vertical The chimney duct is carried out through only one air distributor, and in order to ensure minimal heating and ventilation costs for the entire annual cycle of the systems, the choice of the location of the air distributor for air outlet depends on the outdoor temperature.

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