Unit 14. Refrigerant blends.

I. Warm-up:

What is used as a refrigerant?

Why do scientists develop new refrigerants?

Which refrigerants are highly efficient ones?

II. Read and translate the text:

Vocabulary notes:

With regard to -	відносно
To undertake -	взяти зобов’язання
To require -	вимагати
Domestic refrigerators -	побутові холодильники
Highly efficient -	високо ефективний
Compatible with -	сумісний з
Flammable -	займистий
To upgrade -	вдосконалювати
Application -	застосування
In compliance with -	відповідно до
Prevention measures -	запобіжні заходи
Consumption -	споживання

Text.

With regard to the economic difficulties in conversion to refrigerant 134a, the "Kholod-Byt" Association, jointly with research organizations in respective areas (NIITP, MEI, etc.) and refrigerating equipment manufacturers, undertook a complex of R&D activities respecting ozone-safe refrigerants alternative to refrigerant 134a. These substances require much lower costs in conversion to their application in production of domestic refrigerators and compressors for them, and provide for a high technical level of the finished products as such. The application of these substances does not require major changes to refrigerator designs.

A preliminary analysis has shown that such substances may be refrigerant blends fully based on the so-called "transitional" group substances as well as refrigerant blends using hydrocarbon components. The orientation to Ukrainian developed refrigerants and domestic production of the substances as such has been chosen.

MEI developed a CM1 refrigerant (R22+R218+butane) that has proved to be highly energy efficient during tests with different refrigerator models. The refrigerant is compatible with the KhF12-16 type mineral lubricating oil. It is not flammable and does not require major changes to the refrigerator design and production technology. It also has specifications (TU 95 2654-97).

There has been analyzed in detail and tested a Cl refrigerant blend (refrigerant 152a+isobutane) developed by NIITP (TU 2412-040-00480689-94). It has proved to be highly energy efficient, which ensures refrigerator performance at the level of operation with refrigerant 12 with no further upgrade. A certain obstruction in application of this substance is the necessity of upgrading the DRE design to ensure the compliance with requirements of the IAC standards for domestic refrigerators using flammable refrigerants and the necessity of additional fire prevention measures in refrigerator production.

There have been performed extensive laboratory and factory tests of binary refrigerant blends of the "refrigerant 22+refrigerant 142b" type and ternary refrigerants based on them with addition of refrigerant 21. The analyzed results of the tests of this blend and ternary refrigerants on its basis have proved to be satisfactory with respect to the energy consumption of refrigerants and prospects for improvement of these characteristics at the subsequent upgrade of refrigerating units and compressors.

In practical terms, the real alternatives to refrigerant 134a in its application area are now such well studied non-flammable refrigerant blends as the (R22+R142b) blend produced by the Kirovo-Chepetsk Chemical Works (TU 2412-008-07623164-99, -98) and the C10Ml type blends on its basis developed by the Russian Research Center "Applied Chemistry" (TU 2412-003-32837395-98). These refrigerants are suitable both for the new refrigerator production and for the retrofit of the equipment in operation. These products are commercially available in Ukrainian market, have an acceptable price level, have been studied well enough and Freon 12 production has been closed the most real candidate for refrigerant 134a replacement in the home market. There have been developed fundamentals of the technology of operation with these substances being zeotropes and requiring a more distinct storage, charging and testing technology. Moscow plant AMO "ZIL" has fully converted to refrigerator production using C10M1 ozone-safe refrigerant blend.

III. Comprehension check-up:

Make the right choice:

“Kholod-byt” Association and research organizations developed new refrigerants because of … :

economic difficulties to cut costs while their application in domestic fridges;

providing new ideas;

changing the design of refrigerators.

The application of new substances … :

was not possible in domestic refrigerators;

didn’t require changes in refrigerators design;

provoked the change in the operation of a refrigerator.

New refrigerants are based on … :

isobutan;

ozone;

hydrocarbone components.

One of the advantage of CM1 refrigerant is its being … :

flammable;

inflammable;

compatible with ozone.

CM1 refrigerant proved to be … :

expensive;

in compliance with IAC standards;

highly efficient.

Put the sentences into the right order:

New refrigerant blends are suitable for the new refrigerator production and for the retrofit of the equipment in operation.

New refrigerants have been thoroughly tested.

A new refrigerant, requiring lower costs in domestic refrigerator production were developed by “Kholod-Byt” and research organizations.

CM1 refrigerant proved to be highly efficient.

Refrigerant blends are based on “transitional” group substances like the ones using hydrocarbon components.

The new products are available on the Ukrainian market.

Mark true (T) and false (F) statements. Correct the false ones:

“Kholod-Byt” Association jointly with research organizations developed a new type of domestic refrigerators.

The new substances are refrigerant blends based on isobutan.

They are not flammable and highly efficient.

Refrigerant blends are used for cooling towers only.

DRE design should be upgraded to ensure the compliance with the requirements of the IAC standards.

IV. Vocabulary knowledge check-up:

Match the words to their definitions:

1) domestic	a) to improve
2) highly efficient	b) usage
3) application	c) used at home
4) to comply with	d) showing good results
5) to upgrade	e) to correspond

Fill in the missing prepositions, where necessary:

The characteristics … the new refrigerants are to be … compliance … the requirements … international standards.

The application … refrigerant blends ensures low costs … domestic refrigerators production.

The new refrigerants are suitable … the new refrigerator production and the retrofit … the equipment … operation.

These products are available … the Ukrainian market.

Ozone-safe refrigerants are alternative … refrigerant 134a.

Put the words into the correct order to make sentences:

Substances, refrigerant blends, have been developed, the, by, “kKholod-Byt”, called, new.

Refrigerant, CM1, analysed, tested, have been, and.

New, application, doesn’t require, the, major, refrigerator, change, of, in, design, substances.

To be, efficient, CM1, proved, highly.

5) Available, the, in, market, Ukrainian, products, are, and, level, have, acceptable, price, an, the.

V. Controlled Practice: