Heating of a residential building, Rostov-on-Don

Contents

Introduction

1. Design Assignment and Input

2. Heat Engineering Calculation of Enclosing Structures

Heat Engineering Wall Calculation

Thermal calculation of attic floor

Heat engineering calculation of the floor above the floor

Heat engineering calculation of windows and balcony doors

Calculation of the heat transfer coefficient of the fence

3. Space Heat Loss Calculation

4. Selection of heating system

5. Thermal Calculation of Heating Appliances

6. Hydraulic calculation of water heating system

List of literature

Design Assignment and Input

Construction area: Rostov-on-Don

Exterior walls: single layer ceramic concrete panels

Elevation Orientation: Y

Height of the technical floor: 2.1 m

Attic floor: flat railway plate 120 mm,

gassilicate γ = 500 kg/m3

Flooring above the technical floor: flat railway slab 120 mm, light concrete γ = 800 kg/m3, cement sand mortar 20 mm, linoleum.

Heating system: water vertical single tube

Ventilation: natural

Connection of water heating system to external heat lines: with mixing of water by means of mixing pump.

Heat carrier T1T2 parameters: 150-70 ºС

Available pressure difference at input ΔP, kPa: 80

Type of heating appliances: M140A

Heat carrier temperature in T1T2 heating system: 95-70 ºС

Introduction

A heating system is arranged in rooms with a permanent long stay of people and in rooms where, according to production conditions, it is required to maintain positive temperatures in the cold period of the year.

The heating system is one of the construction and technical units of the building, which must meet the following basic requirements:

sanitary and hygienic - provide the necessary internal temperatures regulated by the relevant SNiP, without deterioration of the air environment;

economic - to ensure the lowest reduced costs at reduction of metal consumption;

construction - provide for the placement of heating elements in connection with the architectural, planning and structural solutions of the building without violating the strength of the main structures during the installation and repair of heating systems;

installation - provide for the possibility of installation by industrial methods with the maximum use of unified units of factory manufacture with a minimum number of standard sizes and limited use of units and parts of individual manufacture;

operational - be characterized by simplicity and convenience of control and repair, quiet and safe operation;

aesthetic - harmonize well with the interior decoration and not occupy excessive space.

Heating systems are divided into:

local;

central.

Local heating systems or local heating is a type of heating in which a heat generator and a heating device are structurally arranged together and installed in a heating room. A typical example of a local heating system is a room heating furnace.

Central heating systems are systems designed to heat several rooms from a single heat center in which a heat generator is located. In such systems, the generator is placed outside the heating room.

The central heating system can be a district heating system when a group of buildings is heated from a central boiler room or a central heating station.

It is customary to classify heating systems by the predominant type of heat removal of heating devices.

The purpose of heating systems is to provide heat to the building during the cold season. The direct heating function is performed by heating devices, which are the main element of the heating system.

The types and designs of heating devices can be varied. Instruments are cast from cast iron, made of steel, concrete, ceramics, porcelain, in the form of concrete panels with tubular heating elements laid in them, etc. Instruments differ in size and shape, they can be assembled from separate sections and elements. Different heat transfer agents with different parameters can be supplied to them.

The main types of heating devices are radiators, ribbed pipes, convectors and heating panels.

There are 2 types of energy-saving measures:

a) activities directly related to the operation of heating, ventilation and air conditioning systems; high level of thermal protection of buildings for various purposes, improved sealing and thermal insulation of technological equipment, improved technological processes, use of secondary energy resources for technological needs. The use of energy-saving measures of this type always leads to a decrease in the power of heating, ventilation and air conditioning systems;

b) measures that reduce the cost of thermal or mechanical energy during the operation of these systems, increase the efficiency of boiler plants, automate and dispatch the operation of these systems, improve their design solutions, use of secondary energy resources for heating flowing air or water, etc.

When designing new or reconstructing existing heating, ventilation and air conditioning systems, 3 types of technical and economic problems can be solved:

There is only one option for an energy-saving solution and it is made from the point of view of economic efficiency with a "basic" option that did not provide for energy-saving measures;

Several energy-saving measures can be used (or one, but with different amounts of saving energy in different modes of operation); all of them are compared in terms of the economic effect achieved among themselves and with the "base" option; the most economically feasible activity is to be applied;

identifying the economically optimal solution, i.e. the best of all possible under the accepted conditions.

The purpose of this course work is the process of designing water heating systems and a ventilation system for an apartment building. It includes the following main steps:

heat engineering calculation of building enclosing structures;

calculation of room heat loss;

selection of heating system;

design of heating systems;

thermal calculation of heating devices;

hydraulic calculation of heating systems.

Heat Engineering Calculation of Enclosing Structures

Source Data:

Construction site - Rostov-on-Don

Object - residential building

Humidity zone - dry (SNiP 23022003, Annex B)

Humidity of air indoors φ=55%, the design temperature of internal t_int=20 air ℃ (according to design codes of residential buildings)

Room humidity mode - normal (SNiP 23022003, Table 1)

Operating condition of enclosing structures - A (SNiP 23022003, Table 2)

Process indicators and factors:

coefficient taking into account the dependence of the position of the external surface of the enclosing structures with respect to the external air - n = 1 (SNiP 23022003, Table 6)

normal temperature difference - ∆t_n=4℃ (SNiP 23022003, Table 5)

Heat transfer coefficient of the inner surface of the enclosing structure - α _ int = 8.7 W/( m^2∙℃) (SNiP 23022003, Table 7)

heat transfer coefficient of the outer surface of the enclosing structure - α _ ext = 23 W/( m^2∙℃ )

Climatic parameters:

Design ambient air temperature (coldest five days, coverage 0.92) - t_ext=-22℃ (SNiP 230199 *, Table 1)

heating period duration (with average temperature ≤8℃) - z _ ht = 171 SNiP 230199 *, Table 1)

average temperature of heating period (with average temperature ≤8℃) - t _ ht = -0.6 ℃ (SNiP 230199 *, Table 1)

4. Selection of heating system

Depending on the location of the heat source, central and local heating systems are distinguished.

According to the type of coolant used for heating rooms, heating systems are divided into water, steam and air.

Heating systems can be either natural or artificial coolant circulation.

Pumping water heating systems are now the most widely used. They are used in residential, public, communal and industrial buildings.

Steam heating systems can be used with appropriate justification in industrial and public buildings.

Air heating systems are most convenient for large rooms. They are used in industrial and public buildings, agricultural structures, using air recirculation or combining heating with general supply ventilation.

Connection of water heating pump systems of buildings to thermal networks is carried out in thermal points.

There are three schemes for connecting water heating systems to heat networks:

- independent scheme;

- dependent scheme with water mixing;

- dependent direct-flow circuit.

The choice of a particular scheme is determined primarily by both the temperature of hot water in the heat networks and the temperature at which water can be supplied to heating devices.

In accordance with the requirements of sanitary standards in residential and public buildings, the temperature of water supplied to heating devices in most cases should not be higher than 95 ° C. With centralized heat supply, hot water in heat networks, as a rule, has a temperature of 130 or 150 ° C.

Water heating systems of most housing and communal buildings (8085%) are currently connected and continue to be connected to heat networks according to a dependent scheme with water mixing using a water jet elevator. At the same time, water-jet elevators are used only in buildings no higher than nine floors.

Dependent scheme of connection of heating system to heat networks using mixing pump is used at insufficient difference of coolant pressure in heat station or for implementation of local qualitative control of heat removal of heating devices.

The dependent direct flow circuit usually finds application when the water in the heat network has a temperature of 95 ° C. Water with this temperature usually comes from a local hot water boiler.

The dependent straight-flow scheme is the simplest and cheapest. According to an independent scheme, the upper zones of the heating system in high-rise buildings are usually connected to the heat networks.

In general, the water heating system includes the following elements: a heat station (or heat generator), main heat pipelines, distribution heat pipelines (risers and branches), pipelines, heating devices, an expansion tank, air collectors or air cranes, shut-off valves.

According to the scheme of connection of distribution heat pipelines with heating devices of the water heating system, it distinguishes:

- single tube;

- double-tube;

- bifilar.

Depending on the position of the distribution pipelines of the water heating system, there are:

- vertical (with risers)

- horizontal (with branches).

According to the location of the main heat pipelines (highways) of the water heating system, the following are distinguished:

- with upper wiring;

- with lower wiring;

- with overturned water circulation.

In the direction of water movement in the supply and return lines of the water heating system there are:

- with dead end (counter)

- with associated (in one direction) water movement in highways.

Currently, pumping single-tube and bifilar water heating systems have become predominantly widespread.

Vertical single-tube systems are recommended for buildings with three floors or more.

Single-tube systems with upper wiring are arranged in buildings with attics. In this case, air removal from the system is centralized outdoors.

Single-tube systems with lower wiring (with U-shaped risers) are used in attic-free buildings with technical underground and basements. Air is removed from these systems through air cranes installed in plugs of upper radiators and in upper points of risers with convectors.

Single-tube systems with overturned water circulation are arranged mainly in high-rise buildings (ten floors or more), in buildings with heated attic rooms (with "warm" attics) or upper technical floors. In such systems, it is recommended to use heating devices with heating elements made of steel pipes (for example, convectors).

In vertical single-tube water heating systems, risers (like instrument units) are used of three types: flowing, with closing sections and flow-controlled.

Heating systems with flow risers are the most economical. They are used in cases where individual regulation of heat removal of heating devices is not necessary. In residential buildings, flow risers can be installed in staircases and bathrooms. In the living rooms of these buildings, flow risers can be provided when convectors with air control valves are installed in them.

Heating systems with flow-controlled risers are provided in cases where individual control of heat removal of heating devices is required.

Risers with closing sections are used instead of flow-controlled ones, in cases when it is required to reduce pressure losses in instrument units, despite a relative increase in the area of ​ ​ the heating surface of the devices.

It is recommended to use horizontal single-tube systems in extended buildings, in buildings with tape glazing, in buildings in which each floor has a different technological purpose or its own thermal mode.

Bifilar systems with horizontal facade branches are most often used in industrial and agricultural buildings.

Vertical two-tube pump systems with lower wiring can be used in buildings having more than two to three floors and in buildings consisting of multi-storey parts.

Double-tube systems with upper wiring can be arranged in low-rise buildings (one - two floors), especially with natural water circulation. Such systems are used for apartment heating with a horizontal range of no more than 15 m.

Vertical heating systems of multi-storey buildings are recommended to be used with dead end water movement in the main heat lines. This pattern reduces the length and diameter of the lines.

We accept: a central heating system with a water coolant used to heat the room. Heating system with natural coolant circulation.

The scheme of connecting the water heating system to the heat networks is used without mixing water according to a direct-flow scheme.

According to the scheme of connection of distribution heat pipelines with heating devices, the water heating system is adopted as a single-tube.

Depending on the position of distribution pipelines, the water heating system is accepted as vertical (with risers).

At the location of the main heat pipelines (highways), the water heating system is accepted with upper wiring.

курсовая работа.dwg