Danfoss TXI 2 Data sheet

Data sheet

Injection valve

Type TXI 2

The TXI2 is an injection valve for desuperheating in 2-stage refrigeration systems operating on R22/R407C and other similar refrigerants where the hot gas temperature and the intermediate pressure are the controlling variables.

Application In principle there are two dierent ways in which to setup 2-stage refrigeration systems as far as temperature signal to the liquid injection valve is concerned.

DKRCC.PD.AV0.A3.02 | 520H10558 | 1

Data sheet | Injection valve type TXI 2

Application examples

(continued)

Example 1

2-stage refrigeration system built up with a combined LP/HP compressor.

In this case the discharge gas temperature on the HP side is used as temperature signal and the

Fig. 1

Example 2

2-stage refrigeration system with 2 separate refrigerating compressors in series. In this set up a solution with injection valve type TXI 2 can be used, because the discharge gas temperature on

intermediate pressure as pressure signal to the injection valve.

In this example a TXI 2 injection valve is used, see g. 1.

LP: Low pressure HP: High pressure PI: intermediate pressure

the HP side can be used as temperature signal and the inter mediate pressure as pressure signal to the injection valve, see g. 2.

Fig. 2

Example 3

Same setup as in example 2 with 2 separate refrigerating compressors in series. As in this setup there is an accessible control signal where there is correspondence between pressure and temperature, regulation of the strongly

Fig. 3

LP: Low pressure compressor HP: High pressure compressor PI: Intermediate pressure

superheated condition of the refrigerant can be undertaken by a traditional thermostatic expansion valve e.g. Danfoss type TX 2 for R22/R407C refrigeration systems, see g. 3.

LP: Low pressure compressor HP: High pressure compressor PI: Intermediate pressure

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Data sheet | Injection valve type TXI 2

Operation

Fig. 4

Danfoss 68-651.10

bulb

spring

The valve function is controlled by the intermediate pressure (PI) acting under the diaphragm and the bulb pressure derived from the discharge gas temperature across the diaphragm (g. 4).

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Data sheet | Injection valve type TXI 2

Operation

(continued)

The intermediate pressure (PI), setting spring and bulb temperature form a working range which, expressed in a co-ordinate system, makes up a working area, see g. 5.

Fig. 5 Valid for code no. 068-3249 only

Fig. 5 Valid for code no. 068-3258 only

Within the limits of this area, the working point required is found (PI/t

bulb

The location of the working point depends on the spring force set and in addition to that dependent on the proportional band (the superheat) and the valve capacity (size of orice).

Therefore, the sizing is decisive for a satisfactory result.

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Data sheet | Injection valve type TXI 2

Sizing

To size TXI 2 the refrigerating capacity required to remove the superheat at the intermediate stage must be known as well as the required discharge

evaporating temperature t0 (PI) of the intermediate stage and the pressure drop across TXI 2, the correct orice size can be determined.

gas temperature on the discharge side.

Besides this the pressure drop ∆p across the injection valve must be determined as the dierence between the condensing pressure and the pressure at the intermediate stage.

With the values for the required capacity, the

Example:

Required refrigerating capacity Q = 5 kW Evaporating temperature at intermediate state t0 = –25°C Pressure drop across TXI 2 ∆p = 12 bar' Discharge gas temperature (HP) = 110°C

Valve type

TXI 2 - 0.2 00 0.69 0.83 0.94 1.02 1.08 1.12 1.14 1.15

TXI 2 - 0.3 01 1.21 1.51 1.71 1.85 1.96 2.04 2.09 2.11

TXI 2 - 0.6 02 1.66 2.13 2.42 2.62 2.77 2.87 2.94 2.97

TXI 2 - 0.8 03 2.98 3.82 4.33 4.69 4.96 5.15 5.27 5.33

TXI 2 - 1.2 04 4.36 5.59 6.35 6.89 7.30 7.60 7.80 7.91

TXI 2 - 1.5 05 5.55 7.10 8.06 8.74 9.26 9.64 9.89 10.02

TXI 2 - 2.0 06 6.80 8.68 9.84 10.67 11.30 11.77 12.08 12.25

Orice

No.

2 4 6 8 10 12 14 16

Evaporating temperature –25°C

Pressure drop across valve ∆p bar

Capacity in kW

TXI 2 with orice 03 ts that example as the values in the capacity tables are shown with a proportional band of 6 K.

Valve type

TXI 2 - 0.2 00 0.79 0.96 1.1 1.2 1.2 1.3 1.3 1.3

TXI 2 - 0.3 01 1.6 2.0 2.3 2.5 2.6 2.7 2.8 2.8

TXI 2 - 0.6 02 2.2 2.9 3.3 3.6 3.8 4.0 4.1 4.1

TXI 2 - 0.8 03 3.9 5.1 5.9 6.4 6.8 7.1 7.3 7.3

TXI 2 - 1.2 04 5.8 7.6 8.7 9.5 10.1 10.5 10.8 10.9

TXI 2 - 1.5 05 7.4 9.6 11.0 12.0 12.8 13.3 13.6 13.8

TXI 2 - 2.0 06 9.1 11.8 13.5 14.7 15.6 16.2 16.6 16.8

Valve type

TXI 2 - 0.2 00 0.88 1.0 1.1 1.1 1.2 1.2 1.2

TXI 2 - 0.3 01 17 1.9 2.0 2.2 2.3 2.3 2.3

TXI 2 - 0.6 02 2.4 2.7 2.9 3.1 3.2 3.3 3.3

TXI 2 - 0.8 03 4.2 4.8 5.2 5.5 5.8 5.9 6.0

TXI 2 - 1.2 04 6.2 7.1 7.7 8.2 8.5 8.7 8.8

TXI 2 - 1.5 05 7.9 9.0 9.8 10.3 10.8 11.0 11.2

TXI 2 - 2.0 06 9.6 11.0 11.9 12.6 13.1 13.5 13.7

Orice

No.

Orice

No.

2 4 6 8 10 12 14 16

4 6 8 10 12 14 16

Evaporating temperature –10°C

Pressure drop across valve ∆p bar

Evaporating temperature –20°C

Pressure drop across valve ∆p bar

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Data sheet | Injection valve type TXI 2

Capacity in kW

Valve type

TXI 2 - 0.2 00 0.69 0.83 0.94 1.02 1.08 1.12 1.14 1.15

TXI 2 - 0.3 01 1.21 1.51 1.71 1.85 1.96 2.04 2.09 2.11

TXI 2 - 0.6 02 1.66 2.13 2.42 2.62 2.77 2.87 2.94 2.97

TXI 2 - 0.8 03 2.98 3.82 4.33 4.69 4.96 5.15 5.27 5.33

TXI 2 - 1.2 04 4.36 5.59 6.35 6.89 7.30 7.60 7.80 7.91

TXI 2 - 1.5 05 5.55 7.10 8.06 8.74 9.26 9.64 9.89 10.02

TXI 2 - 2.0 06 6.80 8.68 9.84 10.67 11.30 11.77 12.08 12.25

Valve type

TXI 2 - 0.2 00 0.79 0.90 0.96 1.0 1.1 1.1 1.1

TXI 2 - 0.3 01 1.4 1.5 1.7 1.8 1.8 1.9 1.9

TXI 2 - 0.6 02 1.9 2.2 2.7 2.5 2.6 2.6 2.7

TXI 2 - 0.8 03 3.4 3.9 4.2 4.4 4.6 4.7 4.8

TXI 2 - 1.2 04 5.0 5.7 6.2 6.5 6.8 7.0 7.1

TXI 2 - 1.5 05 6.4 7.2 7.8 8.3 8.6 8.8 9.0

TXI 2 - 2.0 06 7.8 8.8 9.6 10.1 10.5 10.8 11.0

Valve type

TXI 2 - 0.2 00 0.60 0.71 0.80 0.86 0.92 0.95 0.98 0.99

TXI 2 - 0.3 01 0.90 1.11 1.25 1.35 1.43 1.49 1.53 1.55

TXI 2 - 0.6 02 1.23 1.55 1.74 1.88 1.97 2.05 2.09 2.12

TXI 2 - 0.8 03 2.20 2.78 3.12 3.36 3.54 3.68 3.77 3.81

TXI 2 - 1.2 04 3.20 4.04 4.56 4.93 5.21 5.43 5.58 5.67

TXI 2 - 1.5 05 4.07 5.14 5.79 6.26 6.62 6.90 7.09 7.20

TXI 2 - 2.0 06 4.98 6.28 7.07 7.65 8.09 8.44 8.68 8.82

Orice

No.

Orice

No.

Orice

No.

2 4 6 8 10 12 14 16

4 6 8 10 12 14 16

2 4 6 8 10 12 14 16

Evaporating temperature (PI) –25°C

Pressure drop across valve ∆p bar

Evaporating temperature (PI) –30°C

Pressure drop across valve ∆p bar

Evaporating temperature (PI) –40°C

Pressure drop across valve ∆p bar

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Data sheet | Injection valve type TXI 2

Setting

Technical data

Ordering valve

Ordering accessories

TXI 2 cannot be set until the refrigerant system is started up. Setting after start-up is carried out when the discharge gas temperature has been recorded and the intermediate pressure is known or measured. By means of the diagram, g. 5, the actual working point is found. From the location of the working point in the diagram, g.

Perm. working pressure PS/MWP: 34 bar Capillary tube: 1.5 m.

Type

TXI-2

Connections

[in.]

/8 × 1/

SAE are +100 → +130°C 0 - 2 bar 0.3 068-3249

/8 × 1/

SAE are +100 → +130°C 1 - 5 bar 0.3 068-3258

/8 SAE are × 1/2 solder +100 → +130°C 1 - 5 bar 0.3 068-3343

/8 × 1/

SAE are +80 → +110°C 1 - 5 bar 0.3 068-3360

Temp. range

Orice assembly

Orice no.

00 068-2003

01 068-2010

02 068-2015

03 068-2006

04 068-2007

05 068-2008

06 068-2009

Code no.

TE 2

5, it should be decided whether to increase or decrease the spring force.

Alteration of the spring from slack to tight setting corresponds to 6 revolutions of the TXI 2 setting screw.

Pressure range

(pi)

Weight

Code no.

Flare nuts

Symbol

Connection for copper tubing with

outside cam.

Reducer for copper tubing with

outside diam.

in. mm. in. mm.

6 011L1201

10 011L1235

12 011L1203

Code no.

6 011L1207

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Dimensions and weight

9.8

Dimensions in mm

Weight: 0.354 Kg

Danfoss

68-652.10

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Danfoss TXI 2 Data sheet

Specifications and Main Features

Frequently Asked Questions

User Manual