R2 Four Basic Components of a Refrigeration System

R2 Four Basic Components of a Refrigeration System
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 R2 Four Basic Components of a Refrigeration System #3 Condensers © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1
11/11/2018 The Condenser The condenser rejects heat absorbed by the evaporator. Three phases of a condenser: De-superheat Reduce discharge temperature Condense Latent heat removal Subcool Sensible cooling Three phases of a condenser: De-superheat This is the cooling of the hot discharge gas to a lower temperature for condensing Condense This is the center section where latent heat is removed so the vapor condenses into a liquid Subcool When the liquid cools below the condensing temp. © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Air Cooled Condenser Operation Walk-in (R22)
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Air Cooled Condenser Operation Walk-in (R22) 50 psig 280 psig Super Heated Vapor 175º 45º TEV 125º Condensing Starts CONDENSER 125º EVAPORATOR 115º Fully Condensed Liquid Condenser operation in a typical walk-in refrigerator using R22 (Assume 95° ambient, 35° box temperature, and a 10° TD evaporator coil) The evaporator absorbs heat from the space and it is returned in the suction line to the compressor. The heat laden suction gas (saturated vapor) enters the compressor at 49 psig and a superheated temperature of 45°. The compressor increases the pressure to 278 psig which is the condensing temperature of 125°. However, the temperature of the hot gas leaving the condenser is higher, or superheated. In this example it is 175 °. The higher temperature means the gas has picked up heat from somewhere other than through just the increase in pressure. This heat came from the heat of compression and the motor heat. When the hot gas passes through the first few rows of the condenser it cools down to 125° where condensing starts. The large middle section of the condenser is used to condense all the refrigerant vapor, releasing the heat picked up in the evaporator. Near the bottom of the condenser all the latent heat in the vapor has condensed into a liquid. Any additional cooling is the release of heat through sensible cooling, or subcooling. Extra rows of tubing are installed in the condenser to accomplish some subcooling. In the example above we know there is 10° subcooling because the condensing temperature is 125°, but the temperature of the liquid leaving the condenser is only 115°. The measurement of subcooling ensures all vapor has condensed. It also increases evaporator efficiency as we will see later in the enthalpy chart. Sub-Cooled Liquid AMBIENT AIR 95o BOX TEMPERATURE 35o © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

11/11/2018 Condenser Split The temperature difference between: The condensing temperature and air entering the condenser Example: 105° condensing temperature (–) 75° air entering the condenser 30° condenser split “Condenser Split” is the difference between the ambient air entering the condenser, and the condensing temperature of the refrigerant in the condenser. Remember, to find the condensing temperature, we determine the head pressure from our gauges, then refer to a P/T chart for the refrigerant in the system. The condenser split is determined by the condenser manufacturer. Factors considered are the conditions under which the unit will be operating, the compression ratio of the compressor, the efficiency required, and the cost. Most standard condensing units (compressor and condenser in one unit) are designed for operation just about anywhere in the U.S. at a reasonable cost. These units have a condenser split of 30° and this is what we use for W.R.O.T. For example, if the ambient air is 95° and the condenser split is 30° the condensing temperature will be 125° ( = 125). In this example, if the refrigerant is R22, on a 95° day the head pressure would be about 278 psig, based on R22 P/T relationship of 125°. Exceptions to W.R.O.T. are freezer condensers which run around a 20 ° to 25 ° split. The lower split means lower head pressures. Lower head pressures mean lower compression ratios. This will be discussed in detail in the “Compressor” section. Remote, multi-circuited condensers, are custom designed and usually have lower condenser splits. Consulting the manufacturer will verify the exact condenser split for each circuit, or system. The high efficiency A/C units have larger condensers. This lowers the condensing temperature and pressures so the compressor uses less power to produce the same btuh produced by standard efficiency units. © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Air Cooled Condensers & Condenser splits
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Air Cooled Condensers & Condenser splits 11/11/2018 Standard Efficiency A/C & Refrigeration Condensers 95º 125º 278# Condenser split =30º Medium to High Efficiency A/C Condensers If you have 95º air entering a standard efficiency condenser you can determine the condensing temperature by adding 30º to it, or 125º. On an R22 system you can determine what the pressure should be by referring to your P/T chart or looking at the handy R22 scale on the face of your gauges. If it differs greatly from what it is supposed to be, you have some troubleshooting to do which we can work on later. A medium to high efficiency condenser should have a 20º TD which would give a 115º condensing temperature to the above example at a pressure of 243#. Note, if we can accomplish the same rejection of heat at a lower TD and pressure there is less work done by the compressor. This is an example of efficiency. The result is a savings in the cost of electricity. 95º 115º 243# Condenser split =20º Less pressure = less work = less energy © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

11/11/2018 Condenser Splits Vary Condenser manufacturer determines split. Some common “rules of thumb”: Standard refrigeration and A/C (10 SEER) = 30° Commercial freezers = 20° to 25° High efficiency A/C = 15° to 20° Remote refrigeration condensers = 10° © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Examples of Condenser Splits
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Examples of Condenser Splits Carrier Rooftop A/C 30° Split Russell freezer 25° Split Trane High Efficiency A/C 20° Split Heatcraft remote 10° Split © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

11/11/2018 Subcooling Subcooling = Condensing temperature – Outlet temperature Example: Standard system at 95° ambient 125° condensing temperature 115° liquid line temperature at condenser outlet 10° subcooling Advantages of subcooling: Prevents flash gas 1° Subcooling = 1/2 % increased system efficiency Note: Large condensers = large pressure drops For accurate subcooling: Take pressure leaving condenser: Liquid line service valve Receiver king valve © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Subcooling and Liquid line pressure drop
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Subcooling and Liquid line pressure drop 11/11/2018 CONDITIONS 90 day 120 condensing temperature 260# pressure Sight glass is clear clear © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Pressure Drop Causes Flashing
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Pressure Drop Causes Flashing 11/11/2018 Pressure drop in vertical liquid lines: ½ psig(#) per foot of rise Example: 30’ rise (3 story house) ½ # x 30’ = 15 # drop –15# = 120° 245# boils at 116 Definitely “flashing” at 120 Flashing = Starving metering device Reduced cooling © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Subcooling Prevents Flashing
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Subcooling Prevents Flashing 11/11/2018 Extra rows of condenser coil = Subcooling Subcool 120 by 5: 260# liquid at 115 Liquid line rise 30’ Pressure drops 15# 245# Liquid 115 Boiling 245# = 116 No flashing © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Ambient-Added Heat to Liquid
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Ambient-Added Heat to Liquid 11/11/2018 245# 115= No Flashing Attics are hot! 150+ 115 liquid gets hotter 245# liquid 116 Flashing in liquid line © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Factory Design: 10 to 15 Sub-cooling
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Factory Design: 10 to 15 Sub-cooling 11/11/2018 Assume 10° subcooling: 120 - 10 = 110 liquid No flashing 30’ Rise: Pressure 110 No flashing Enters 150 attic Liquid line rises to 115 No flashing 245# 116 1 from flashing is too close 15° sub-cooling is safer © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Condensers & Low Ambients
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Low ambient: Air entering the condenser below 60° What is the problem with low ambient? Low head pressure causes metering problems Two methods of controlling head pressure: Fan cycle control See “Controls” section for more information Condenser flooding See “Valves” section for more information Following is a brief description of both Standard refrigeration and A/C equipment are designed to operate above 60° ambient. Below that temperature none of the pressure-temperature relationships hold true and the system does not work correctly. If the ambient air going through the condenser coils is too cold, the condensing temperature drops along with the heat pressure. The metering device is designed to respond to a certain range of head pressures on the inlet of the device in order to ensure the proper pressure on its outlet. Therefore, if the inlet pressure is too low, the pressure to the evaporator will also be low. A starved evaporator is the result, even if there is a high heat load on the evaporator. The solution is to add low ambient controls to the condenser. © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

11/11/2018 Fan Cycle Control A pressure switch controls the condenser fan: When head pressure falls, the fan shuts off When head pressure rises, the fan starts There are three types of head pressure control. Cycling the condenser fan off and on to keep head pressure up. Backing up refrigerant into the condenser (flooding). Installing dampers on the condenser to block air flow. Fan cycling is turning the condenser fan off if the head pressure falls below a certain minimum pressure. Usually, that minimum pressure is equal to the head pressure a 60° ambient With the fan off there is no air flow through the condenser. Without air flow the heat is not released from the condensing gas and the head pressure starts to rise. When the pressure reaches a predetermined higher pressure, the fan starts. The low ambient air being pulled through the condenser will lower the head pressure again. The fan continues to run until the head pressure control stops it. The advantages of a fan cycle control are ease of installation and relatively low cost. The main disadvantage is the wide swings of head pressure (usually 50 psig) cause changes in the pressure on the inlet of the metering device. These pressure fluctuations can cause erratic evaporator feeding by the metering device. © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

11/11/2018 REFRIGERATION CONDENSER Using Fan Cycle Control R22 REMOTE CONDENSING UNIT - AMBIENT 78° 60o 168# 220# Install Fan Control DIFF. HIGH EVENT SWITCH LOW EVENT IS HIGH EVENT MINUS DIFF 500 400 300 200 100 50 25 150 Pressure falls Compressor C.C. HEATER Fan cuts off Rewire If the air entering the condenser (ambient) is too cool then the pressures drop so much that the metering device cannot control the flow of refrigerant. Most systems start having metering problems when the ambient goes below 60º. At 60º an R22 refrigeration system would have a condensing temperature of 90º (60+30). The head pressure would be about 168#. In the above example we will show how to keep the average minimum pressure above 60º by cycling the fan motor on the condenser. To do this we have the fan cut off when the head pressure drops too low, and come back on when the head pressure builds back up. For instance, when the system in the above example drops to 168# (60° ambient) the fan shuts off. The head pressure starts to rise and we could cut the fans on when it gets above 185# (equal to 66 ° ambient), but that would cause the fans to short-cycle on and off too rapidly. So, we have the fan stay off until the pressure builds up to about 220#. We call this the control’s “cut-in” pressure. When the control contacts close, or “cut-in”, the fan starts. The pressures fall until the control opens (“cut-out”), stopping the fan at 168#. Then the cycle starts all over. Fan cycle controls are easy to install. Just find a way to access the high pressure side of the system and redirect the wires going to the fan to break one power leg through the fan control. CONDENSER RECEIVER 60º Amb.+ 30º TD = 90º (168#) 78º Amb.+ 30º TD = 108º (220#) Minimum Ambient = 60o Ambient = 78o © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Flooded Condenser Head Pressure Control
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Flooded Condenser Head Pressure Control Condenser flooding: Effect is the same as overcharging the unit HPR (Head Pressure Regulating) valve: Restricts liquid flow out of condenser Backs up refrigerant in the condenser Raises head pressure Bypasses hot gas (and some liquid) to receiver Condenser flooding raises head pressure as if the condenser were covered with a blanket Flooding, or backing up liquid, is similar to over-charging a system. Uses a HPR (Head Pressure Regulating) valve Maintains head pressure by restricting the flow of refrigerant trying to leave the condenser Bypasses hot gas to maintain pressures in receiver Advantages: very stable head pressures Disadvantages: difficult to diagnose & replace © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Remote unit with HPR valve
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Remote unit with HPR valve 11/11/2018 Compressor C.C. HEATER Ambient ABOVE 60o No Bypass CONDENSER Condensing pressure above valve rating RECEIVER This is a view of the entire system when the ambient is above 70º Under these conditions the HPR valve is about as useful as an elbow in the liquid line from the condenser outlet to the receiver. Outdoor Ambient 80o EVAPORATOR COIL © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Remote unit with HPR valve
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Remote unit with HPR valve Compressor C.C. HEATER Ambient BELOW 60o Some discharge gas is bypassed to receiver Refrigerant is backed up in the condenser CONDENSER Condensing pressure is below valve rating RECEIVER This is a view of the entire system when the ambient is below 60º Under these conditions the HPR valve is backing up the liquid in the condenser. This has the same effect as covering the condenser with a blanket because the ambient air cannot remove the heat from the refrigerant. When the pressures in the condenser rise to the setting of the HPR the valve opens and bypasses some hot gas from the discharge line. This mixes with the cool liquid in the condenser and travels down to the receiver. The purpose of an HPR valve is to keep the temperature of the refrigerant up in the receiver so the TEV will have sufficient inlet pressure to function properly. Outdoor Ambient 40o EVAPORATOR COIL © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Water Cooled Condensers - “Tube-in-Tube”
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Water Cooled Condensers - “Tube-in-Tube” Water flows in the inner tube, Refrigerant flows in the outer tube. (Two surfaces for heat rejection) Two types: Coil Two separate tubes, one inside the other, coiled Flanged Two separate tubes, in straight sections, with removable flanges for cleaning Two types: Coil type Two separate tubes, one inside the other, coiled Cleanable type, with flanged ends Two separate tubes, in straight sections, with removable flanges for cleaning Water flows in the inner tube, Refrigerant flows in the outer tube. Heat is rejected into the air from the outer surface, and into water from the inner surface. > © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Water Cooled Condensing Unit
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Motor Cooling Tube-in-tube “coiled” condenser Head Pressure Regulating Valve Water IN Hot gas IN, Hot water OUT Water Cooled Condensing Unit Water OUT Courtesy of Russell Coil Co. © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Water Cooled Condenser (no regulator)
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Water Cooled Condenser (no regulator) Following animation: Water enters at 85° Leaves 10° warmer Condensing temperature is 10° warmer than the leaving water © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Water Cooled Condenser (No Regulator)
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Water Cooled Condenser (No Regulator) 11/11/2018 105o 95o Condensing Temp. Leaving R22 Compressor Entering water 210# 105o 85o Head pressure A water cooled condenser is much more efficient than an air cooled because the water’s density absorbs much more heat from the compressor vapors. The water entering the condenser picks up heat from the discharge line. The more heat it absorbs the higher the temperature of the water. Most water-cooled condensers are sized to pick up enough heat to raise the temperature of the water by 10° before leaving the condenser. The discharge vapor leaving the compressor quickly loses its superheat to the water coils. The refrigerant continues to cool down to the standard 105º condensing temperature which is equal to a pressure of 210# for R22. The condenser is sized to condense a certain amount of vapor and to allow for about 10 ° subcooling, as well. The temperature of the water leaving the condenser should be 10º lower than the condensing temperature. If it is colder, then the condenser has a scale build-up inside acting like an insulator. Scaling requires more water to maintain the same head pressure. At some point the scale will get so thick that the water flow cannot maintain the head pressure. When doing maintenance on water cooled equipment check the water temperature at the outlet of the condenser. If you can’t check the water, put your temperature probe on the pipe, then tape and insulate it. The reading should be within 1 or 2 degrees of the actual leaving water temperature. A rule of thumb for water usage is: City Water: 1.5 gpm of 75º water per 12,000 BTUH and Tower Water is 3 gpm Summary 85º Incoming tower water 95º Leaving water 105º Condensing temperature 210# Head pressure 95° Subcooled liquid (10° subcooling) 95o Subcooled liquid © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Incoming water temperature rises
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Incoming water temperature rises As incoming water temperature increases: Leaving water temperature increases Condensing temperature increases © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Water Cooled Condenser (No Regulator) 11/11/2018 105o 95o Condensing Temp. 100o 110o Leaving R22 Compressor Entering water 210# 105o 90o 110o 85o 228# Head pressure The temperature of the incoming water rises. Just like warmer air coming into an air cooled unit, the pressures in the system rise accordingly. 95o Incoming water rises to 90º Leaving water rises to 100º Condensing increases to 110º Head pressure increases to 228# 100o Subcooled liquid © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Incoming water temperature falls
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Incoming water temperature falls As incoming water temperature falls: Leaving water temperature falls Condensing temperature falls © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Water Cooled Condenser (No Regulator) 11/11/2018 110o Condensing Temp. 100o 85o 95o Leaving R22 Compressor Entering water 228# 110o 75o 95o 90o 183# Head pressure When incoming water temperatures fall, the condensing pressures fall, as well. 100o Incoming water drops to 75º Leaving water drops to 85º Condensing decreases to 95º Head pressure decreases to 183# 85o Subcooled liquid © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Incoming water too cold
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Incoming water too cold Like cold ambients to air cooled condensers cold water lowers condensing temperatures on water cooled units (sometimes too much). © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Water Cooled Condenser (No Regulator) 11/11/2018 Condensing Temp. 65o 75o Leaving R22 Compressor Cold EnteringWater 75o 55o 133# Head pressure Very cold water causes a serious drop in head pressure. The system will not operate properly. Something needs to be done to correct this problem. 65o 55º Incoming tower water 65º Leaving water 75º Condensing temperature 133# Head pressure Subcooled liquid © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Install a water regulating valve
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Install a water regulating valve Regulates flow of incoming water in response to head pressure setting © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Water Cooled Condenser (Add Regulator)
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Water Cooled Condenser (Add Regulator) 11/11/2018 105o 95o Condensing Temp. 65o 75o Leaving R22 Compressor Cold EnteringWater 105o 75o 210# 55o 133# Head pressure Installation of a water regulating valve solves the problem of low temperature inlet water. The valve regulates the flow of water based on the head pressure. As the head pressure drops the valve will restrict the flow of water coming in to raise the head pressure. 95o 65o Adjust WRV to maintain 210# HP Subcooled liquid Condensing increases to 105º Leaving water increases to 95º © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Tube-in-Tube Coiled Condenser
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Tube-in-Tube Coiled Condenser Following picture of cut-a-way view: Water uses the inner pipe Refrigerant circulates around it © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Coil-type Water Cooled Condenser
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Coil-type Water Cooled Condenser Mineral deposits Hot gas IN Water OUT Water IN No Buildup Liquid OUT © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

“Shell & Tube” water-cooled condensers
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 “Shell & Tube” water-cooled condensers Shell and tube: Tank (shell) for condensed liquid Straight water tubes through the shell End caps (water boxes) distribute water Note: Shell and tube water cooled condensers are also called “condenser-receivers”. © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Shell & Tube W/C condenser
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Shell & Tube W/C condenser Shell & Tube W/C condenser Hot gas IN Water IN Liquid OUT Courtesy of Russell Coil Co. Water OUT © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Shell & Tube –Cross section
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Shell & Tube –Cross section Shell & Tube - Cross section Shell is a condenser and liquid receiver Cleaning rod broken off in tube Scale buildup in tubes Tubes circulate water to condense hot gas © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Shell & Tube Condenser – “Water Box” 11/11/2018 Shell & Tube – Water Box Water Circuits Note: the gasket is not installed correctly Water passages will be blocked on the other end. End Plate © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Wastewater and Re-circulated water systems
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Wastewater and Re-circulated water systems Wastewater systems: City water “wasted” down the drain Uses 1.5 gpm/ton (at 75° water) Re-circulated systems (towers): Circulates 3 gpm/ton (at 85° water) Wastewater used for small refrigeration and ice machines. It can be expensive for the customer. Water usage at 75 ° water is about 1.5 gallons per ton of air conditioning, ore 1 gallon per horsepower for refrigeration. A 1hp ice machine (600 pound capacity) will use approximately 2000 gallons of water every 24 hours (1.5 gal. X 1440 minutes/24 hours). If charged $3 per 1000 gallons used the customer will be paying $180 per month for the cooling of the unit, not to mention the cost of electricity. To prevent the waste of water, cooling towers are used to recirculate the water from the condenser. The condenser heat is removed by the water to the outside where it is rejected by air passing over the water. A cooling tower’s capacity is linked to wet-bulb temperature (humidity) of the outside air. Towers can cool leaving condenser water to within 7° of the outside air wet-bulb temperature Example: 78° web-bulb air cools water to 85° This would be the maximum inlet water temperature to maintain the 10° inlet to outlet temperature of the water that will produce a condensing temperature of 105°. The tower must circulate water at the rate of 3 gpm/ton. Tower sizes start at 2 tons (24,000 Btuh) which is about 3 H.P. for refrigeration equipment. This is minimum equipment size where the savings in cost of water would pay for the cost of installing a cooling tower. © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

11/11/2018 Cooling Towers Induced draft: Fan pulls air through the tower Cools the water, rejects its heat © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Induced Draft Cooling Tower
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Water IN Induced Draft Cooling Tower FAN Most towers use a fan to move air through the tower Forced draft: pushes air through the tower Induced draft: pulls air through the tower Physically smaller than natural draft Cycling fan helps control head pressure Evaporative towers have the refrigeration condenser located in the tower. Called “evaporative” because the water spray cools the condenser coils directly as the water evaporates. It combines the efficiency of the water cooled system without the mineral buildup inside the water cooled condenser. The external buildup of deposits is easier to handle in the open water cooled tower. Sometimes evaporative towers are located inside buildings with the air ducted into and out of the tower. Note: All towers require “blowdown” so that highly mineral concentrated water must be drained off. Water OUT © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Forced draft cooling towers
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Forced draft cooling towers Fan pushes air through the tower © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Forced Draft Cooling Tower
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Forced Draft Cooling Tower F A N © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Evaporative condenser cooling tower
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Evaporative condenser cooling tower Evaporating water cools the condenser Condenser is located inside the tower © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Evaporative Condenser
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Water IN Evaporative Condenser Hot gas IN Liquid OUT Water OUT Courtesy of Baltimore Air coil © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

11/11/2018 Condensing Units Combine the condenser and compressor Often includes accessories: Receiver Driers Pressure controls And more © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Condensing Unit R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Condenser Discharge line U-bends Liquid Line Compressor Sight Glass Filter Drier Receiver Courtesy of Master-Bilt® King Valve © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Remote Condensing Units
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 11/11/2018 Condenser coils Compressor Courtesy of Master-Bilt® © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Residential Condensing Unit
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Residential Condensing Unit 11/11/2018 Trane High Efficiency Heat Pump Courtesy of Trane® © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

Walk-in with top mounted condensing unit
R2 Four Basic Components of Refrigeration - Subject 3 Condensers v1.1 Courtesy of Master-Bilt® 11/11/2018 Walk-in with top mounted condensing unit © 2004 Refrigeration Training Services-R2 Subject 3 Condensers v1.2 © 2004 Refrigeration Training Services No reproduction or unauthorized use allowed

R2 Four Basic Components of a Refrigeration System

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R2 Four Basic Components of a Refrigeration System

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Presentation on theme: "R2 Four Basic Components of a Refrigeration System"— Presentation transcript:

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