Building air conditioning and cold supply

Contents

Table of contents

Introduction

Source Data

1. Calculation part

1.1.Define Thermal Load on an Object

1.2. Determination of moisture inflows

1.3. Selection of parameters and quantity of air supplied to

room

1.4. Equipment selection

Conclusion

List of literature used

Graphic part

Summary

A course project was completed on the topic: "A project of an air conditioning system for a trading room for 140 people" with a total volume of 30 sheets.

The design part includes:

determination of heat inflows;

determination of moisture inflows;

selection of parameters and quantity of air supplied to the premises of the trading room;

equipment selection.

The graphic part includes:

plan for the installation of SLE in the trading room;

SLE functional diagram;

axonometric diagram of air ducts.

Introduction

Air conditioning is the creation and automatic maintenance (regulation) in closed rooms of all or individual parameters (temperature, humidity, purity, air speed) at a certain level in order to ensure optimal meteorological conditions that are most favorable for the well-being of people or the conduct of the technological process.

Air conditioning is carried out by a set of equipment called an air conditioning system (SLE). The SCR includes the technical means of air intake, preparation, that is, giving the necessary conditions (filters, heat exchangers, humidifiers or dehumidifiers), movement (fans) and its distribution, as well as means of cold and heat supply, automation, remote control and control. SLE's of large public, administrative and production buildings are usually serviced by integrated automated control systems.

The automated air conditioning system maintains a predetermined air state in the room regardless of fluctuations in ambient parameters (atmospheric conditions).

The main equipment of the air conditioning system for air preparation and movement is aggregated (assembled in a single housing) into an apparatus called an air conditioner. In many cases, all air conditioning equipment is arranged in one unit or in two units, and then the concepts of "SLE" and "air conditioner" are unambiguous.

Before proceeding to the classification of air conditioning systems, it should be noted that the generally accepted classification of SLE still does not exist and this is due to the multivariability of schematic diagrams, technical and functional characteristics, depending not only on the technical capabilities of the systems themselves, but also on objects of application (air conditioned rooms).

Modern air conditioning systems can be classified according to the following characteristics:

by main purpose (object of application): comfortable and technological;

according to the principle of location of the air conditioner in relation to the serviced room: central and local;

by the presence of its own (included in the design of the air conditioner) source of heat and cold: autonomous and non-autonomous;

according to the principle of action: direct-flow, recirculation and combined;

according to the method of control of conditioned air output parameters: with qualitative (single-tube) and quantitative (double-tube) regulation;

by the degree of ensuring meteorological conditions in the serviced room: first, second and third class;

by the number of serviced rooms (local zones): single-zone and multi-zone;

by the pressure developed by fans of air conditioners: low, medium and high pressure.

In addition to the above classifications, there are various air conditioning systems serving special technological processes, including systems with time-varying (according to a certain program) meteorological parameters.

Comfortable SLE are designed to create and automatically maintain temperature, relative humidity, cleanliness and speed of air movement that meet the optimal sanitary and hygienic requirements for residential, public and administrative buildings or premises.

Process VMS are designed to provide air parameters that meet the requirements of production to the maximum extent. Technological conditioning in the premises where people are located is carried out taking into account sanitary and hygienic requirements for the state of the air environment.

The central SCR are located outside the serviced rooms and air conditioning one large room, several zones of such a room or many separate rooms. Sometimes several central air conditioners serve one large room (production workshop, theater hall, closed stadium or ice rink).

Central VMS are equipped with central non-autonomous air conditioners, which are manufactured according to basic (typical) equipment layout diagrams and their modifications.

Central SLE has the following advantages:

possibility of effective maintenance of preset temperature and relative air humidity in rooms;

concentration of equipment requiring systematic maintenance and repair, as a rule, in one place (utility room, technical floor, etc.);

efficient noise and vibration control capabilities. With the help of central VMS, with proper acoustic treatment of air ducts, the device of noise silencers and vibration dampers, it is possible to achieve the lowest levels of noise in the rooms and maintain such rooms as radio and television studios, etc.

Despite a number of advantages of the central SLE, it should be noted that large dimensions and complex installation work on installing air conditioners, laying air ducts and pipelines often lead to the impossibility of using these systems in existing reconstructed buildings.

Local SLE is developed on the basis of autonomous and non-autonomous air conditioners, which are installed directly in the serviced rooms.

The advantage of local SCR is the ease of installation and installation.

Such a system can be used in a number of cases:

in existing residential and administrative buildings to maintain a thermal microclimate in separate office spaces or in residential rooms;

in newly built buildings for separate rooms, the cold consumption mode in which is sharply different from that in most other rooms, for example, in server and other fuel-saturated rooms of administrative buildings. Fresh air supply and exhaust air removal is performed, as a rule, by central supply ventilation systems;

in newly built buildings, if maintenance of optimal heat conditions is required in a small number of rooms, for example, in a limited number of suite rooms of a small hotel;

in large premises of both existing and newly built buildings: cafes and restaurants, shops, design halls, classrooms, etc.

Autonomous VMS are supplied from outside only with electric energy, for example, split system air conditioners, cabinet air conditioners, etc. Such air conditioners have built-in compression refrigerators, operating, as a rule, on freone.22

Autonomous systems cool and drain air, for which the fan blows recirculating air through surface air coolers, which are evaporators of refrigerating machines, and in transition and winter they can heat air using electric heaters or by reversing the operation of the refrigerating machine according to the cycle of the so-called "heat pump."

The simplest option, representing the decentralized provision of temperature conditions in the premises, can be considered the use of air conditioners of split systems.

Non-autonomous SERs are divided into:

air, when using which only air is supplied to the serviced room. (Mini-central air conditioners, central air conditioners);

water-air, when used, air and water carrying heat or cold are supplied to the conditioned rooms, or both (chillerovfankoil systems, central air conditioners with local finishers, etc.).

Single-zone central VMS are used to service large rooms with a relatively uniform distribution of heat, moisture emissions, for example, large halls of cinemas, audiences, etc. Such hard currencies, as a rule, are completed with devices for utilization of heat (heatutilizers) or mixing cameras for use in the served rooms of recirculation of air.

Multi-zone central SLE is used to service large premises where equipment is not evenly placed, as well as to service a number of relatively small premises. Such systems are more economical than individual systems for each zone or room. However, with their help, the same degree of accuracy of maintaining one or two specified parameters (humidity and temperature) cannot be achieved as autonomous SLE (split system air conditioners, etc.).

Direct-flow VMS fully operate in the outside air, which is processed in the air conditioner, and then supplied to the room.

Recirculation VMS, on the contrary, operate without inflow or with partial supply (up to 40%) of fresh outdoor air or in recirculation air (from 60 to 100%), which is taken from the room and after its treatment in the air conditioner is again supplied to the same room.

Classification of air conditioning according to the principle of operation for direct-flow and recirculation is mainly due to comfort requirements, production process conditions or technical and economic considerations.

Central VMS with high-quality control of meteorological parameters are a wide range of the most common, so-called single-channel systems, in which all treated air leaves the air conditioner in one channel and enters one or more rooms.

Air conditioning according to SNiP 2.04. 05-91 *, according to the degree of ensuring meteorological conditions, they are divided into three classes:

The first class provides the parameters required for the process in accordance with the regulatory documents.

The second class provides optimal sanitary and hygienic standards or required technological standards.

The third class provides permissible standards if they cannot be provided with ventilation in the warm period of the year without the use of artificial air cooling.

According to the pressure generated by the fans of the central air conditioners, SLE are divided into low pressure systems (up to 100 kg/m2), medium pressure (from 100 to 300 kg/m2) and high pressure (above 300 kg/m2).

Types of air conditioners:

Split systems (wall, floor-ceiling, column type, cassette type, multi-zone with variable refrigerant flow rate);

Floor air conditioners and air conditioners of the plenum-ventilated split system;

Systems with chilers and fancoyles;

Roof air conditioners;

Cabinet air conditioners;

Precision air conditioners;

Central air conditioners.

Trading Room Conditioning

It has been scientifically proven that visitors to shopping centers (stores) stay longer in the hall if it has a comfortable climate, which means that a properly designed air conditioning and ventilation system.

The choice of the air conditioning system of shopping and entertainment centers depends on the goals and characteristics of their operation. As a rule, trading rooms have a large area and are designed for a mass user. In addition, users of the trading room are not only buyers, but also managers, administrators, sellers. Therefore, it is important to calculate the air conditioning system in such a way that it meets the needs of both the first and second.

The shopping complex air conditioning system shall perform the following tasks:

heating of supply supply or recirculated air in cold season;

cooling of supply air (if necessary) in warm season;

convenient adjustment of air flow rate and its temperature for operation service;

ease of maintenance and repair;

noise level rationing;

comfortable distribution of air in rooms.

The choice of the type of air conditioning and ventilation system is influenced by many parameters, such as the size (volume) of the room, the amount of customer flow, climatic conditions of the area, the range of products sold, etc. For example, for small shopping pavilions and shops, the most common option is to install wall-type splits. For medium-sized rooms, it is advisable to install channel-type splitsystems or multicast splitsystems with centralized control. For individual large spaces, central air conditioning based on various options will be the most optimal.

For shops located in the first floors of residential or other buildings, independent VMS are designed, independent of the ventilation system of these buildings.

Conclusion

During the course work, the design parameters of external and internal air were selected, heat and moisture inflows to the conditioned room were determined, as well as the value of the heat and moisture ratio; determined: SLE capacity by air and taking into account the amount of thermal load; an air treatment scheme was drawn up, air treatment processes were built in the i - d-diagram of wet air and the load on the main elements of the SLE was determined; The main elements of SLE are calculated and selected.

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