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 different ways in which to setup 2-stage refrigeration systems as far as temperature signal to the liquid injection valve is concerned.

© Danfoss | DCS (sw) | 2015.12

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

Data sheet | Injection valve type TXI 2

Application examples	Example 1	intermediate pressure as pressure signal to the
	2-stage refrigeration system built up with a
	combined LP/HP compressor.	injection valve.
	In this case the discharge gas temperature on	In this example a TXI 2 injection valve is used, see
	the HP side is used as temperature signal and the	fig. 1.

Fig. 1

Application examples	Example 2
(continued)	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

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

LP: Low pressure

HP: High pressure

PI: intermediate pressure

the HP side can be used as temperature signal and the intermediate­ pressure as pressure signal to the injection valve, see fig. 2.

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 fig. 3.

		LP: Low pressure compressor
	Fig. 3	HP: High pressure compressor
		PI: Intermediate pressure

© Danfoss | DCS (sw | 2015.12

DKRCC.PD.AV0.A3.02 | 520H10558 | 2

Data sheet | Injection valve type TXI 2

Operation

Danfoss 68-651.10

Fig. 4

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 (fig. 4).

Pbulb

Pspring

PI

© Danfoss | DCS (sw | 2015.12

DKRCC.PD.AV0.A3.02 | 520H10558 | 3