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>> Systems of ventilation, heating and air conditioning
Systems of ventilation, heating and air conditioning
General information and security measures
Works on service of system should be carried out in the conditions of a specialized workshop.
Function chart of the K/V typical system
At all do not open a working contour To/in, - at contact with skin the coolant can cause frostbite!
The air submitted by system of ventilation to salon of the car, can be warmed up or cooled depending on a choice of the user. The heat exchanger of a heater and the To/in evaporator settle down in salon, under the dashboard. All stream of air submitted to salon goes for heating or cooling through the same casing. The temperature and speed of a stream of air is regulated by means of governing bodies located on the control panel.
Principle of management of a choice of a temperature mode (on an example of a mode of intensive warming up of salon)
Below the list of the main components of systems of heating and salon air conditioning with the short description of their appointment and functioning principles is provided.
The operating relay of shutdown To/in
This relay carries out a role of the electric switch closing a chain of coupling of the К/В compressor. At achievement in temperature of cooling liquid of some critical value the module of engine management (ECM) develops special team on which this relay makes central air shutdown. Five-second compulsory shutdown of the To/in compressor can be initiated also by the management module at engine start, and also in a mode of slow dispersal. The relay is among replaced components.
The forcing fan
At the expense of rotation of a krylchatka of the forcing fan supply of air on an entrance of the heat exchanger of the To/in evaporator further submitted to salon of the car according to installations chosen by the operator (with a preliminary transmission through the heater heat exchanger, or bypassing the last) is provided.
The electromotor of a drive of the forcing fan
The choice of a high-speed mode of the electromotor is carried out by the operator from the control panel functioning of systems of heating/air conditioning. At the managing director turned in the situation OFF the chain of grounding of the electromotor remains to the handle opened and the fan does not function. In first (LO) position of the handle force of a current submitted on the electromotor is limited to three resistors of special resistive assembly, as a result, the krylchatka of the fan rotates in a low-high-speed mode. Further switching between the modes M1, Sq.m and HI provides step-by-step decrease in resistance of resistive assembly with the corresponding increase of speed of rotation of a krylchatka.
The compressor provides coolant movement in a refrigerator path of central air of air. The compressor is located at the left on the block of the engine and is put in action by a belt drive from a pulley of a cranked shaft of the last (via the operating coupling of coupling). Basic elements of the compressor are actually compressor knot distributing knot, the operating coupling of coupling and a driving pulley.
Coupling of coupling of the compressor
The coupling coupling To/in serves as the executive mechanism operating activation of the compressor. The coupling is magnetic and provides compressor activation/deactivation at the command of the operator from the switch on the control panel, and also on the special teams developed in certain conditions by the module of engine management (ECM). The coupling of coupling of the compressor is among maintainable and replaced components.
The condenser is established ahead of a radiator of system of cooling and is the air and liquid heat exchanger providing heat removal from a working body (coolant) of a refrigerator path of central air. Intensity of functioning of the condenser is provided at the expense of a prokachivaniye through the heat exchanger of additional air forced by the special fan. The condenser also is among maintainable and replaced components.
The fan provides adequate selection of heat from the condenser of a coolant pumped over through the heat exchanger even at the motionless car when the running stream of air completely is absent. A food on the driving electromotor of the fan moves via the special operating relay.
The To/in evaporator is placed in the general with the forcing fan, and operating relay of shutdown To/in a casing. The evaporator consists from working by a principle, a return principle of functioning of a radiator of system of cooling, the heat exchanger and the broad valve.
Evaporator heat exchanger
Getting to the evaporator a coolant boils, intensively selecting heat from the air banished through the heat exchanger by the forcing fan. Sharp cooling of an air stream is accompanied by condensation to moisture containing in it. Condensate drops out on heat exchanger plates, from where then is taken away on a drainage path. Thus, the evaporator, besides cooling function, plays also a dehumidifier role. The heat exchanger is among maintainable and replaced components.
The valve provides adiabatichesky expansion being in a phase of liquid of a high pressure of a coolant at hit it in the evaporator. Such expansion considerably increases intensity of a heat-conducting path from air banished through the heat exchanger. At the same time the valve carries out control of an expense of the coolant arriving in the evaporator, allowing to avoid a heat exchanger flood.
Servo-driver of a zaslonka of an air inlet
At activation by the operator of a mode of air circulation from the control panel the special servomotor provides removal of the managing director of the zaslonka blocking a path of giving in salon of fresh air. Activation of such mode allows to avoid penetration into the car of badly smelling air, and also to carry out intensive cooling of the salon filled with air, heated by direct sunshine during a car parking.
The mode of circulation should be activated only for insignificant time as air repeatedly banished on the closed cycle quickly becomes stuffy.
The air drained in the evaporator is banished through the heater heat exchanger. Warming up of air is carried out at the expense of heat selection from the hot heat-carrier of system of cooling of the engine banished through the heat exchanger. The choice of a temperature mode is carried out by the operator by rotation of the corresponding handle operating the provision of a mixing zaslonka, regulating a consumption of air banished through a heater.
Connecting hoses and lines of a refrigerator path
Connection among themselves working elements of To/in system is carried out by means of the whole complex of flexible hoses and the metal lines which are using, respectively, in low-pressure head and high-pressure head contours of a working path of central air. Lines of communication of a refrigerator path are among replaced components.
The receiver dehumidifier is located on an exit from the condenser and carries out accumulation of a liquid coolant and removal of moisture present at it. Further, the drained working body arrives in the evaporator.
The equipment of a refrigerator path service ports allows to carry out a discharge and the К/В system charging. The service union of a contour of a high pressure is built in the metal line of communication leaving a receiver dehumidifier. The low-pressure head service union is switched on in a piece of the flexible hose connecting the returnable line of the evaporator to the compressor.
Security measures at service of components of central air
The working path of To/in system is under pressure! Do not try to disunite any shtutserny I will corrode or to remove separate components without a preliminary discharge of system in the conditions of a specialized workshop. As a working body in system the R134a type coolant is used, - make sure that at station there is the necessary equipment suitable for use at service of central airs, working at a coolant of this type. At a rassoyedineniye of shtutserny sockets of a refrigerator path surely put on goggles!
Service of central air should be made only by forces specially the trained staff trained in safe working methods, with use of the appropriate equipment with observance of rules of the depressurization acquainted with receptions of collecting and order of storage of an automobile coolant.
The coolant of R134a which is widely using now, is much less aggressive, than applied before R12. Nevertheless, it remains hazardous to health, - causing burns at hit in eyes and on open sites of a body. Though the coolant of R134а is not toxic, its pairs at inhalation can cause asthma - at all do not make a system discharge indoors. Remember that pair of coolant it is heavier some air, - try not to get into time of a discharge of system in a viewing hole;
At contact паров a coolant with an open flame poisonous gas which, mixing up in a certain proportion with air is allocated, can become explosive. Coolant steam inhalation through the lit cigaret can lead to the most unpredictable consequences;
Do not allow coolant hit in the atmosphere. Unlike R12 the coolant of R134а does not cause destruction of an ozone layer, however promotes development of greenhouse effect in the atmosphere;
In To/in system the sealing elements made of a special material, intended for work with a coolant of concrete type (for R134а - green color) are used. For the purpose of prevention of casual hit to the working highway of a coolant not that type when filling system special transitional nozzles are used;
The discharge of system should be carried out on firm HUNDRED KIA;
Before carrying out any works connected with heating of any knots of the car (welding, the soldering, drying after painting, etc.), the To/in system should be discharged. Need for a discharge of system arises also at performance of service of its components;
At service of components of To/in system surely put on goggles;
At coolant hit on skin or in eyes do not pound the struck place, - immediately wash out it plentiful amount of cold water, then address to medical care;
The coolant is in a new cylinder under pressure. Store a cylinder at temperature not above 50°С! Try not to drop a cylinder from height and not to allow other situations which can lead to its damage;
Service of components of To/in system should be carried out in well aired room, - the coolant differs high летучестью and the congestion паров is capable to give it to difficulty of breath;
At all do not make condenser or evaporator pro-cleaning by means of water vapor, - apply to this purpose only cold water or the compressed air!