Thermostatic expansion valves type TR6 REFRIGERATION AND AIR CONDITIONING. Technical leaflet

Transcription

1 Thermostatic expansion valves type REFRIGERATION AND AIR CONDITIONING Technical leaflet

2 Thermostatic expansion valves, type Contents Page Introduction Features Valve program Technical data Identification Design and function Application Ordering Check valve capacity Capacity Sizing Dimensions and weights RD1BA122 Danfoss A/S (RC-CMS / HBS),

3 Thermostatic expansion valves, type Introduction thermostatic expansion valves have been designed and developed with features especially for use in application such as: Residential air conditioning systems Split systems Roof top units Heat pumps Light commercial air conditioning systems Chillers Their hermetic tight design meets environmental demands for today and the future. The program is available for R22 and R410A and can be used in systems ranging in capacity up to 6 TR R22 (up to 21 kw). The can be used for all fluorinated refrigerants. Models for other refrigerants can be produced to order. The TR design incorporates a hot-pressed brass body with the entire power element, including the capillary tube and bulb, fabricated from stainless steel. The valves are supplied as standard in straightway versions with fixed orifice and with external equalization. They can be delivered with or without internal check valves and with external superheat adjustment spindle for field retrofit. All valves are in balanced port design making it ideal also for bi-flow operation. is uniquely for OEM s and their applications. The valves can be delivered with special connections and fittings both at the inlet and outlet and at the equalizer connection. The can be delivered with a fixed setting in accordance with the customers' requirement for optimized unit operation for the different applications within air conditioning. Features Compact size - hermetic design. Developed and designed for R22 and R410A. A complete program with or without internal check valve. An internal check valve with a very low pressure drop at full flow. MOP function. Non-adjustable with factory setting. Non-adjustable per customer s specification. Laser-welded power element: longer diaphragm life. high pressure tolerance and working pressure. Stainless steel power element, capillary tube and bulb: high corrosion resistance high strength and vibration resistance fast installation and good thermal contact and transmission Bleed function as an option. With internal check valve for heat pump systems. Without check valve for normal and bi-flow function. Danfoss A/S (RC-CMS / HBS), RD1BA122 3

4 Thermostatic expansion valves, type Valve program Standard versions Refrigerants: R22 and R410A. Range: N 40 F to +50 F / 40 C to +10 C MOP: With or without MOP. Versions for fixed settings: Static superheat in accordance with customers' specifications. Packing in boxes of 16 to 24 pcs. dependent on configuration. Versions for adjustable settings: Static superheat of 7.2 F / 4 K. Packing in single pack boxes. Versions All valves are in straightway versions. With or without internal check valve. Standard connections: 3 /8 in. ODF inlet x 1 /2 in. ODF outlet x 1 /4 in. ODF equalizer. Capillary tube length: 20 in. / 0.5 m Variant versions on request Refrigerants: Other refrigerants. Range: Other temperature ranges. MOP: Other MOP-points. Capillary tube lengths: 12 in. / 0.3 m 31.5 in. / 0.8 m 59 in. / 1.5 m Options for Connections: Inlet/Outlet: 3 /8 in., 5 /16 in., 1 /2 in., 5 /8 in. ODF, ODM, Chatleff, Rotolock, Aeroquip, Flare. Equalizer: Cap tube size: 3 /32 in., 1 /8 in., 3 /16 in., 1 /4 in. Length: 12 in. to 25 in. With or without Flare nut or Nib stub. Technical data Max. operating temperature - Thermostatic element: 212 F / 100 C (R410A max. 155 F / 68 C) - Valve body: 230 F / 110 C Max. working pressure MWP 610 psig / PS = 42 bar Max. test pressure 680 psig / p' = 47 bar MOP valves MOP-points Refrigerant R22 Range N F / C 100 psig / 6.9 bar To avoid charge migration when MOP valves are used, the bulb temperature must be lower than the thermostatic element temperature. R410A 165 psig / 11.5 bar Identification Essential valve data is given on the element label. Main valve data example: = Valve type R410A = Refrigerant 3.0 TR = Rated capacity Q nom. in Tons of Refrigeration MOP 165 = Max. operating pressure MWP 610 psig/ PS 42 bar = Max. working pressure in psig and bar 067L5000 = Code number 464B = Date marking (week 46, year 2004, weekday B = Tuesday) 40 / +50 F = Evaporating temperature range in F 40 / +10 C = Evaporating temperature range in C Fig. 1 4 RD1BA122 Danfoss A/S (RC-CMS / HBS),

5 Thermostatic expansion valves, type Design and function Fig. 2 with fixed setting 1. Bulb 2. Thermostatic element 3. Pressure pin seal 4. Balanced port 5. Check valve 6. Setting spindle for adjustment of static superheat (SS) 7. Equalizer 8. Inlet connection 9. Outlet connection Fig. 3 with adjustable setting Fig. 4 The central pressure pin is fitted with a robust seal (pos. 3) that ensures maximum tightness and minimum friction through the lifetime of the valve. The balanced port (pos. 4) ensures minimal superheat changes when differential pressure varies. This feature makes the valve ideal for biflow operation. Static superheat (SS) can be adjusted with the setting spindle (see fig. 3, pos. 6). The standard superheat setting is 7.2 F / 4K for valves with and without MOP. Valves can also be supplied with a fixed setting. Terminology (fig.4) SS = Static superheat OS = Opening superheat OSH = SS + OS = Operating superheat Example Static superheat SS = 7.2 F (4K) (factory setting) or according to customer specification. Opening superheat OS = 7.2 F (4K) The opening superheat is 7.2 F, i.e. from the point the valve begins to open up to nominal capacity. Opening superheat is determined by the design and cannot be changed. Operating superheat OSH = SS + OS OSH = 7.2 F F = 14.4 F (8K) Operating superheat OSH (fig. 4) can be changed by changing the static superheat (by using the setting spindle). Danfoss A/S (RC-CMS / HBS), RD1BA122 5

6 Thermostatic expansion valves, type Application without check valve EVR/EVRH SGI/SGN/SGH DCL/DML Fig. 5. Traditional air conditioning system, cooling only Indoor coil 4-way valve Outdoor coil with check valve SGI/SGN/SGH DCB/DMB with check valve Fig. 6. Traditional air conditioning / heat pump system Indoor coil 4-way valve Outdoor coil DCR without check valve Fig. 7. Simplified air conditioning / heat pump system (bi-flow) Fig. 5 illustrates the diagram of a traditional air conditioning system where the is controlling liquid injection in one direction only. Fig. 6 illustrates a split air conditioning/heat pump system with cooling/heating mode and two thermostatic expansion valves, one for cooling mode and one for heating mode. The thermostatic expansion valves each has a built-in check valve, which has the function of preventing flow in one direction and allowing the flow in the opposite direction. It means that one thermostatic expansion valve is controlling liquid injection into the evaporator and the other thermostatic expansion valve has an open check valve allowing the liquid refrigerant flow in the liquid line. Fig. 7 illustrates a similar system as the previous one, but this time it is a compact unit with a short distance between the evaporator and the condenser, the bi-flow feature of the thermostatic expansion valve can be used. The two thermostatic expansion valves have, therefore, been replaced by one bi-flow valve controlling liquid injection in both directions. The normal flow direction marked with an arrow should be used for the primary function, i.e. cooling or heating. 6 RD1BA122 Danfoss A/S (RC-CMS / HBS),

7 Thermostatic expansion valves, type Ordering Fixed setting Adjustable setting Range N = 40 F +50 F Refrigerant R22 R410A Rated capacity Q nom 1) Orifice no. R22 and R410A Connection 3 /8 in. x 1 /2 in. x 1 /4 in. ODF Inlet Outlet TR kw Fixed setting Adjustable setting LXXXX 067LXXXX LXXXX 067LXXXX LXXXX 067LXXXX LXXXX 067LXXXX LXXXX 067LXXXX LXXXX 067LXXXX LXXXX 067LXXXX LXXXX 067LXXXX Pressure equalisation = ¼ in. ODF 1 ) The rated capacity is based on: Evaporating temperature, t e = 5 C Liquid temperature, t l = 28 C Condensing temperature, t c = 32 C Opening superheat, OS = 4K Check valve capacity Mass flow lb/h Fig. 8 p (psi) Internal check valve for orifice bypass in reverse flow (flow rate as a function of pressure differential) Danfoss A/S (RC-CMS / HBS), RD1BA122 7

8 Thermostatic expansion valves, type Capacity Capacity in TR for range N = F and opening superheat OS = 7.2 F R22 Type Orifice no. Pressure drop across valve delta psi Pressure drop across valve delta psi Evaporating temperature 50 F Evaporating temperature 40 F Evaporating temperature 20 F Evaporating temperature 0 F Evaporating temperature 20 F Evaporating temperature 40 F Capacity in TR for range N = F and opening superheat OS = 7.2 F R410A Type Orifice no. Pressure drop across valve psi Pressure drop across valve psi Evaporating temperature 50 F Evaporating temperature 40 F Evaporating temperature 20 F Evaporating temperature 0 F Evaporating temperature 20 F Evaporating temperature 40 F Correction for subcooling t sub The evaporator capacity used must be corrected if subcooling deviates from 7.2 F. The corrected capacity can be obtained by dividing the evaporator capacity by the correction factor given below. Note: Insufficient subcooling can produce flash gas. Correction factor for subcooling t sub Correction factor 4K 10K 15K 20K 25K 30K 35K 40K 7.2 F 18 F 27 F 36 F 45 F 55 F 63 F 72 F R R410A t sub 8 RD1BA122 Danfoss A/S (RC-CMS / HBS),

9 Thermostatic expansion valves, type Sizing p e ~t e EVR/EVRH Q e SGI/SGN/SGH DCL/DML Fig. 9 Example: Refrigerant R22 Evaporating temperature t e = 40 F P e = 79 psi Condensing temperature t c = 118 F P c = 256 psi Pressure drop in liquid line, drier and distributor system p = 27 psi The corrected evaporator capacity then becomes 4:0/1.06 = 3.77 TR As the selected valve must be equal to or slightly larger than the corrected evaporator capacity of 3.77 TR, the with orifice 5 having a table capacity of 4.1 TR would be a suitable choice. Pressure drop in valve p = = 150 psi Subcooling t sub = 18 F Evaporator capacity = 4.0 TR Correction factor from table = 1.06 Capacity in TR for range N = F and opening superheat OS = 7.2 F R22 Type Orifice no. Pressure drop across valve delta psi Pressure drop across valve delta psi Evaporating temperature 50 F Evaporating temperature 40 F Danfoss A/S (RC-CMS / HBS), RD1BA122 9

10 Thermostatic expansion valves, type Dimensions and weights Fixed setting Fig. 10 Weight 0.57 lbs Adjustable setting Fig. 11 Weight 0.67 lbs 10 RD1BA122 Danfoss A/S (RC-CMS / HBS),

11 Thermostatic expansion valves, type Danfoss A/S (RC-CMS / HBS), RD1BA122 11

12 Thermostatic expansion valves, type 12 RD1BA122 Danfoss A/S (RC-CMS / HBS),