Condenser Types and Principle of Operation
Refrigerant evaporator with heat from the condenser in the cooling system of the heat added during the compression process in the compressor is made to be from the system. Thus, pressurized liquid Refrigerant still came and brought the situation will be re-expanding the heat from the evaporator.
Condenser operating principles are explained as follows. surface condensation of steam and gas, depending on the surface characteristics “Drip or film formation” occurs on style. Drop formation with condensation (dropwisecondensatio’s) case is much higher (more than 4-8 times the film formation) heat transmission coefficient can be provided. It is also preferred because they are limited by economic factors and characteristics of Refrigerant condenser manufacturing practice however, movie-style with condensation and formation of condensation lesser extent the drop is together. 3 stages of heat exchange in the condenser can be considered to occur. These;
– Receipt of anger,
– Refrigerant the condensation,
– It is excessive cooling.
Condenser depending on the design will utilize the supercooling condenser area of 0-10%. for receiving anger you need to allocate 5% of the processing area of the condenser.
The three different heat transfer with the heat transmission coefficient in the intermediate temperature condenser depending on the shape will be different. However, despite the excess of the average temperature in the range of receiving phases of anger to be present at a lower heat transfer coefficient, but on the contrary during the supercooling temperature range will be greater than and less heat transmission coefficient. During the condensation between the two values will be the sub-level. against the increase of the heat transfer coefficient experiments using the temperature difference of the reduction (or vice versa) it gives approximately the same multiplication result and it is possible to use the average of these values. simplicity that allows the calculation taking into account in the calculation of the condenser with a heat transmission coefficient of only a single average temperature range values are applied.
Finned radiator type condensers
Condenser Structure and Types
General, there are three different types of condenser:
– Water cooled condensers
– Air cooled condensers
– Evaporative (air-water) condenser
In practice, rather than that which is currently being used will be determined by an analysis to be made economically. establishment and operating costs to be analyzed in this study together. On the other hand, the water-cooled and evaporative condensers condensing temperature will be in the lower level of the refrigeration cycle and thus is certain to be higher thermodynamic efficiency, the analysis to be done, therefore, must be taken into consideration.
Water Cooled Condenser
Especially clean water is plentiful, inexpensive and can be found at low temperatures should be in place institutions and condenser type can be considered as the most economical in terms of both operating costs. Great kapasitedeki cooling sistemlerinde as usually only choice considering. But in recent years, high heat transmission coefficient are provided with air-cooled condensate made of 100 tons / f. Them until the capacity has been utilized. thermal conductivity of the pipe material in the design and implementation of water-cooled condensate, contamination coefficient of water used, the pressure loss of the finned tubes used when the wing efficiency water circuit Refrigerant when considered issues such as excessive cooling the levels. Copper pipes used in the condensate (halogen Refrigerant who) is usually less of the wall thickness of the pipe. Copper heat transmittance less effect of kondüksüyo the condenser all the heat transmission coefficient was high and outside this coefficient rather (Refrigerant side) and inside (water side) will depend on the values of film coefficient. Whereas meat less thermal conductivity (iron pipe) when the pipes are used in condensers, heat transfer in pipe kondiktif all the heat would be too late.
Pollution coefficient of heat transfer surface of the water used in the water-side time to consider the impact of residues that constitute the purpose of reducing the heat transfer moves.
Factors affecting the pollution coefficients are:
– The use of water, in terms of foreign substances in the condititon
– Condensing temperature
– Condenser applied to keep the pipes clean the degree of preventive maintenance
In particular, the coefficient of pollution on the 50C’n condensing temperature should be slightly higher than required by the application. The condensation temperature of 38 C below this value may be slightly below normal. The low water pollution and accelerate the transition speed is 1m / sec should not be allowed to be at the lower speed. It remains a periodic surface temizlenmediği hızlanacaktır increasingly appreciated pollution incident, as required condensers and heat conduction coefficients to go azalacak sıcaklığında sağlanabilecektir CAPACITYa but higher-laden condensate. This will lead to the contamination incident. The resistance of the water side with increased pollution will increase and decrease of water flow rate result condensate will no doubt increase the temperature.
Air Cooled Condenser
In particular, 1 HP up kapasitedeki denecek exception of those bands available by simply prefer this type of condenser nedenmi; consisting of simple, low installation and operating costs, it can be considered as ease of maintenance and repair. There are also characters that fit the application (such as domestic or commercial window-type air conditioners). Most applications are connected integral way to clear the air circulation fan motor pulley tipkompresör and will not need a separate drive motor. also in air cooled condenser heat transfer occurs in three stages.
– Receiving anger Refrijerandan
– Excessive cooling
This is approximately 85% of kondenserinasl service will serve as the event of the condenser condensate field. anger be an area of around 5% and 10% of supercooling (subcooling) serve.usually used in an air-cooled condenser Refrigerant store to get new condensing Refrigerant from the condenser to store and has now come to procedural case. It purpose is to spend the condenser useful space for fluid storage. Air condensers, for halokarbonrefrijer who usually copper / aluminum fins in order, and sometimes copper / copper fin and copper or steel pipe / steel wings are manufactured in reserves. Aluminum alloy pipe / wing manufacturing is also possible to come across. pipe diameters used ¼ “to ¾” ranged. Varies between 160 and 1200 square meters, causing him to count the wings, but most available frequency limits, between 315 to 710 kalmaktadır. Such as air condenser heat transfer area of the average needs of 2.5m / sec. The air passage rate per ton / refrigerated (3024 kcal / h) ranged from 9 to 14m square. Very little, except of course the air-flow condenser air needs tutulursa average beaker kcal / h to 0:34 to 0.68m3 / h between değişmekte it is necessary fan power beaker 1000 kcal / h to around 0.03 0.06hp being. Fan speed from 900 to 1400 r / d should be between. Condenser fans radial type usually used where quiet is desired axial type.The Refrigerant condensation temperature should be considered to be located on the air inlet temperature 10- 20C.
General condition of the pipe, the fin spacing, depth (the pipe string) received fields such as design features airflow requirements, air resistance and thus the fan size, fan power and will affect the cost of the volume of the line group. Today condenser dizayn the form of hot Refrigerant be given to several independent circuits of a top collector, yoğuştuk by providing descend by gravity and excessive cooling down again, taking the form of a collector.
Air-cooled condensers, groups according to the order form;
– Compressor with grouped
– It was followed organize in a manner that placed a long distance from the compressor. (Split condenser)
It is divided into two classes. the passage of air from the condenser may be organized in a manner that is in vertical and horizontal directions. On the other hand, air blower, air may be introduced to stimulate absorbent or repellent effect. A cooling system is given the expected substantially condensing pressure and temperature can be kept within specified limits Abilmesiyle. This is closely related to the condenser work regime. preventing excessive condensation temperature and pressure of the condenser is a condition commonly associated with being seen that as the air with sufficient cooling area. Therefore, especially in cold weather and temperature sufficient flow circuit operating status relates to the presence of air. In the case of a very low condensation temperatures and pressures that problems depends on whether there is enough Refrigerant flow out.
For example, the termostatic expansion valve to drop enough pressure drop in the capacity because often, very low condensing pressure preventative measures are taken, it is possible to collect them both groups.
– Check the Refrigerant side
– To control air tarafını
The cooling effect of air and water with enjoyment made based on the principle of evaporative condensers maintenance and service difficulties, get dirty quickly, it is used increasingly less vulnerable to malfunction reasons occur frequently. Evaporative condenser consists of three parts:
– Cooling coil
– Water circulation and spray system
– Air circulation system
Cooling coils of passing Refrigerant goes into the gas tank condenses as in air-cooled condensers.Air passing through the outer surface of the coil, a portion of the evaporation of atomized water in the opposite direction brings the cooling effect still occurs (as is the same with the cooling tower). Thus, the condensation temperature of the condenser and hence pressure is reduced to a lower level.outer surface of the coil, in order to meet the effect of the formation of low coefficient of heat transfer film is provided with ribs to enhance field. However, in modern evaporative condensers, pipe outer surface achieve high heat transfer coefficient to achieve a good result in wetness and wingless straight pipes are used. whether continuous manner with a pump in water from the water collection chamber in the lower level of the condenser to a nozzle group printed at the top of the cooling coil and sprayed from nozzles. This water evaporates about 3-5% (approximately 6 to 7.5 liters / h per ton / for refrigerated) is transferred into the air, the water tank, water continuously through the float valve is provided. However, this addition of water in the condenser and the output increases normally continuously reaches the highest level. The temperature of the water taken from Refrigerant temperature starts to drop the temperature by receiving heat of vaporization of water showed an increasing trend. As a result, the water temperature rises at the entrance of the cooling coil (air wet bulb temperature is rising quite in this section) and subsequently begins to fall instead of approaching the temperature of the inlet air. Collecting pool water temperature, a stable operation is reached much change.
Evaporative condensers usually on the roof and outside of the building, but put into building air inlets and outlets may also be provided with channels from galvanized sheet. winter operation of the device outside of the building measures should be taken against freezing is concerned. In applications in building cold wet air volume passing through the channel that will be taken in case of condensation in the duct should be kept in mind, and measures must be taken to disposing of the water. app building will conserve energy when applied as an integrated exhaust fan and an exhaust system. As the air cooled condenser with evaporative condensers work well during cold weather should prevent the formation of condensation pressure is too low.
The intended applied this arrangement;
– Starting and stopping of the fan motor,
– A damper settings and use a servomotor, the air flow to replicate reduce the air flow
– It can decrease the speed of the fan motor can be considered as reproduction.
A denserin thermal performance, the only air evaporative kon dry or age thermometer temperatures or air entry-exit enthalpy difference cannot be represented on the basis of. Because the die temperature of water sprayed and blown air entrance shows very different values as outputs.