Calculation of artificial lighting. Street lighting. Calculation of illumination of a production premise

In ancient times, light was perceived by people as a phenomenon that depended on the will of higher beings ... Today it is not a secret for anyone how to control this radiation, what is its essence, how to calculate artificial lighting.

The lack of light rays leads to a significant decrease in efficiency, deterioration of well-being and a decrease in mood. In connection with this important point is the correct, with hygiene requirements, placement and connection of lighting devices. For enterprises, it will be advantageous to purchase energy-saving equipment for both indoor and outdoor use.

Lighting characteristics

In the wavelength range of 380-780 nm, the electromagnetic radiation of the optical spectrum becomes visible. It can be characterized by the following values:

1. Luminous flux (this is part of the optical radiation perceived by man as light). The unit of measurement is the lumen. In the calculations it is denoted as F.

2. The intensity of light (this is the density of the light flux in space, lying in the direction of the axis of the solid angle). Denoted as I, And measured in candela.

3. Corner angle (this is part of the space that is located inside the conical surface). It is measured in steradians. Denoted in the calculations of W.

4. Illuminance shows the value of the surface density of the light flux. Its unit is luxury, and is denoted by E.

5. Brightness is the surface density of the surface light force, which lies in a given direction. This flow is measured in candelas per square meter and is denoted by L.

6. The indicator of glare (P) is a criterion for the dazzling action of light devices.

7. The criterion of the pulsation of illumination (Kp), measured in percent, serves to estimate the relative depth of the oscillations of illumination.

8. The discomfort rate (M) is used as a criterion for assessing uncomfortable brilliance, which causes a feeling of eruption in the eyes when the bright spot is not uniformly located in the field of view.

Measuring instruments

Various luxmeters are used to determine the illumination. For example, the device "Yu-116" allows you to calculate this parameter, created by an incandescent lamp and natural light. Luxmeter is used to control lighting in agriculture, transport, industry and other areas.

Analog-digital instruments are used to measure other values, for example, brightness, pulsation coefficient. An example of them is the pulsometer-luxmeter ARGUS-07. The principle of its action is in converting the light flux, which is created by extended objects, into an electrical continuous signal proportional to the illumination. Further, it is converted into a digital code displayed on the electronic scoreboard.

Types of lighting in production

If the room is illuminated only by lamps, floor lamps, lamps, that is artificial light, then such lighting is called artificial. It is necessary to create comfortable working conditions, normal operation of buildings and territories. It can be divided into the following types:

1. Working.
2. Security.
3. Emergency.
4. The duty officer.

The first is used for lighting offices, places of work outside the building. The second and fourth type of lighting is switched off during non-working hours, and the third one allocates evacuation outputs, various safe moments. Artificial lighting can be common, in which the lamps are placed evenly in the upper area of the office, or combined. In the second case, local lighting is added to the total, which is created by lamps located near the workplace.

The next type of industrial lighting is natural. Here, too, there are several types: side, top, combined. The first is when the sunlight penetrates into the room through the light apertures in the outer walls. At the second, the light passes through the openings in the walls in the places of the height difference of the building or through the lanterns. The third type combines top and side lighting. This type of lighting is especially needed in rooms with the constant presence of a large number of people.

Combined lighting is a combination of natural and artificial. It is used in special cases, when the first to third categories are performed, if space-planning solutions for construction are required or when technical and economic feasibility is confirmed by calculations.

Norms of kinds of illumination

When selecting the values of the parameters of norms, one must rely on the SNiP "Natural and artificial lighting". In this case, the illumination of the premises is regulated by its minimum permitted level, based on the characteristics and type of visual work performed (RR). There are three types of SP:

1. The first includes activities in which you do not need to use optical instruments. The object of discrimination in this case can be at different distances from the eyes.
2. The second permits the use of optical instruments when performing work. The reason lies in the very small size of the object under consideration, which is not perceived by the eye.
3. The third includes works in which it is necessary to perceive information from screens. This type of special requirements apply to the organization of lighting.

If you agree with the SNiP "Natural and artificial lighting", you can distinguish the following characteristics of visual works without using optics: discharge, sub-division. The first is formed in connection with the size of the object of discrimination, and the second - from the combination of contrast and lightness of the object of discrimination with the background. For each characteristic, the illumination, the illumination index, the ripple coefficient and its methods for calculating artificial illumination are normalized.

If the lighting in the room is natural or combined, then for the discharge of the SP the coefficient of natural illumination is given. It is the ratio of natural light to the set value of the external horizontal illuminance, which is created by the light of the open sky.

When natural illumination is lateral and one-sided, a minimum value of KEO arises at a point that is at the intersection of the vertical plane of the section of the room and the conditioned functional surface at a distance of 1 m from the wall, beyond all located from the light apertures. If the lighting is upper or combined, then the average value of the coefficient at the points located at the intersection of the vertical plane of the section of the room and the working surface is taken into account.

Calculation of artificial lighting

The first point in this question is the selection of the type of light source. It is also necessary to determine the illumination system and the corresponding norm. The second point will be the placement in the office of the selected lamp and the calculation of the illumination at certain points. And, finally, the last point is the determination of the unit power of the lamps. The choice of the light source is carried out according to the following rule: economical gas-discharge lamps are used in rooms with air temperature above ten degrees, with high demands on the quality of color rendering and the minimum degree of injuries. If there is no natural light in the office and accurate work is being performed, then fluorescent lighting is used. If it is necessary to use and carry out the calculation of LED lighting, it should be remembered that this type of lamps do not have a stroboscopic effect, that is, light is constantly on. Therefore, it is important to make a correct calculation of the ripple factor in order to exclude high brightness.

When determining the lighting system, it is necessary to take into account the economy of the combined light system, as well as its hygiene (uniformity and brightness of the light flux). When equipment in the office is uneven, localized lighting is used. The definition of the type of luminaire must be approached in accordance with the rules for the dispersion of brightness in the field of view of workers, and also depending on the state of the air environment.

For a clearer distribution of light, a lighting scheme is created. It can be of several types: simple (connection of a small number of luminaires connected to one switch), selector connection (connection of two independent groups of light sources that are monitored at one point), bidirectional (switching on and off from two points), switching Switches in two directions, and one - on one direction).

Calculation of the shop lighting should take into account the following parameters: determination of the type of light sources and luminaires, their calculation and competent distribution in space, determination of their power and power scheme. In addition to the listed items, it is necessary to pay attention to the types of visual work, environmental conditions, how the working equipment is located, the number of employees, emergency lighting.

Specific power method

Calculation of artificial lighting by this method allows for an approximate calculation of the lighting of a production room with a uniform distribution of luminaires. The power of one lamp is calculated by the formula:

Pl = PyS / pl

Where Py denotes the specific power of the lamp, the value of which is in the reference books. The specific power depends on the type and location of lamps and luminaires, the characteristics of the illuminated room, as well as the height of the suspension. The value of S indicates the floor area, and m is the number of lamps. Results are usually rounded to a higher value.

Method of light flux or utilization rate

This method calculates production lighting in cases where the illumination of the working surface is specified. The method is not applicable for localized outdoor and local illumination if the working surfaces are not horizontal, and also when calculating the directional concentrated light flux.

Calculations are carried out according to the formula:

F = En SZK / Nη

Where F is the light flux; En is the normalized illumination; S is the floor area; N is the number of lamps; Z is the minimum power factor; K is the safety factor; Η is the coefficient of use of the light beams of the lamps.

By the value of the light flux, a luminaire is selected, which may differ from the calculated value in the range from -10 to +20 percent. If the difference is greater than the permitted limits, then the number of luminaires is regulated.

Point method

The method is used to determine the light beams of lamps in cases where reflected light is unimportant. The method is used for any arrangement of the illuminated surface and luminaires. The method is based on the relationship between the illumination of the surface (E), which is created by a point source of light, from the distance to the surface (r), the angle of incidence of the beam (a) and the luminous intensity (I):

E = I cos α / r ²

Calculation of the lighting of the workshop, and specifically the lighting system, includes several stages:

1. Finding the minimum normalized illumination.

2. Selection of the type of light source. Determination of the type of luminaires and their placement in the shop.

3. Selection of control points with the lowest conditional illumination on the office plan.

4. At reference points, calculations are made for conditional illumination. The subsequent calculation of the lighting of the production room is based on the point with the lowest conditional illumination.

5. Using the look-up tables, the incremental light and reserve factors are determined.

6. Find the light flux of the lamps. Based on the results, a standard lamp is selected.

7. Determine the power of the lamp and the entire light installation.

An example of lighting calculation is the following: in the problem, the height h = 4 m, the safety factor k = 1.5, the coefficient of additional illumination u = 1.2, the normalized illumination Emin = 75 lux is given. It is necessary to determine the illumination with the working surfaces near the walls with UPD lamps.

Since in a luminaire of this type there is a deep light distribution, for them λ = 1. The distance between the light installations will be 4 m, and from the extreme luminaries to the walls - 1 m. Place the control points A, B (with the lowest illumination) on the plan and calculate the distance from them to the projections of the nearest luminaires (d). The next point is the definition of conditional illumination and finding the point with the lowest illumination. According to the data, we calculate the value of the lamp's light flux, its difference with the standard value, and also find the lighting.

Calculation of general lighting when working with computers

When the activity of an employee is connected with a personal computer, special rules must be observed when installing lighting. In this case, the eye experiences a double load, because it perceives reflected light from the keyboard and documents, as well as direct from the monitor.

The room must have artificial and natural lighting, with a KEO coefficient of at least 1.2%. It is necessary that the working surface with computers be oriented side by side to the light holes for natural light penetration. Calculation of artificial illumination of the room is carried out with respect to the system of general uniform incidence of light. Direct brilliance is limited from light sources (brightness of windows, lamps and other luminous surfaces is not more than 200 cd / m ² ), and the reflected brightness is regulated due to the correct choice of luminaires and positions of functional places depending on the light base (brightness of the glare on the screen is not more than 40 cd / M ² ).

In artificial lighting, luminescent and compact fluorescent lamps should be used as light sources. If the premises are industrial or public, then metal halide lamps can be used. Fixtures should be with screening grilles and diffusers.

Street lighting solutions

Street illumination is an important task of combining external sites into a single whole, plays the role of a security assistant and orientation in space, and also brings an aesthetic note to the decoration of cities. The lighting equipment for this type of lighting must be selected depending on the features and status of the objects. They can be turned on automatically or with the help of the dispatcher. There are several types of street lighting:

1. Filling. The essence of the method is in the installation and targeting of spotlights. It is used to illuminate the adjacent territories for protection purposes.
2. General. This method includes uniform distribution of fixtures of the same type. It is ideal for lighting paths, parks, areas where people and cars move.
3. Marking. In this form of street lighting, the fixtures are located along the selected lines and shapes. It is used to create visual contours, emphasize the relief, highlight the direction of road and pedestrian roads.