Industrial news No u velles de I "in dustrie

Heat pump range extended

Carrier Distribution Limited have further enhanced the application possibilities of their popular series 30BQ heat pumps by the addition of three larger models to the top end of the range.

These fully reversible heat pumps now have nominal heating capacities, over all 10 models, of 21-183 kW and nominal cooling capacities of 18.3- 184kW. Providing hot water up to 55°C or, in the reverse mode, chilled water for industrial or comfort cooling, the new compact 30QB units offer a range of protective options including specialist paint finishes, weatherproof control panel and treated electrical components, as well as protection against aggressive atmospheres.

COPs up to 3.3 are aided by an optimum defrosting frequency. This fully automatic feature ensures maximum 'on-line' time enabling a swifter return on capital investment. Other features include generously dimensioned, computer designed heat exchangers, easy accessibility for servicing and two fully protected, independent compressors, thereby giving inherent standby capability.

The three new units have been incorporated, alongside current ranges, in Carrier's Electronic Manual, the E20-II. The E20-II is a design aid, invaluable for calculating load estimates, duct and pipe design and energy analysis, as well as the fast and accurate selection of the correct unit for given parameters, including weather, building type and heating/ cooling requirements.

Carrier Distribution Limited, Carrier House, The Crescent, Leatherhead, Surrey KT228DY, UK.

Electronic refrigeration controls

Danfoss have introduced an electronic control system, AK 10, which is a new regulating system for

AK 10 regulating system

controlling and monitoring dry evaporators in the capacity range of up to 8 kW. With the system, which is the first member of a new control family, ADAP-KOOL T, has begun a new epoch within electronic refrigeration controls.

The main function of the AK 10 system is to control liquid injection in the evaporator. Differing from thermostatic and other electronic expansion valves, the AK 10 adaptively controls injection, i.e. it is self-adjusting without a set reference value for superheat.

Via two temperature signals from sensors in both ends of the evaporator, the system finds the optimal reference value for superheat for every operating situation. This principle has considerable advan- tages: superheat is always minimal and stable and does not have to be set manually; and the refrigerant pressure is not a regulation parameter, so that the AK 10 is therefore independent of refrigerant.

The AK 10 system consists of an electronic regulator, an electrically controlled expansion valve and a Pt 1000f~ electronic sensor. The expansion valve is a newly developed solenoid valve based on pulse width modulation and a patented evaporating system. These give the valve a very wide working range. Due to its few components the AK 10 system is easy to install, and its adaptive function makes it quick and easy to run-in. Also, since the electronic regulator incorporates alarm and diagnosis functions, this ensures quick and efficient action when faults and deviations occur.

Dean & Wood Ltd, Mole Business Park, Station Road, Leatherhead, Surrey KT22 7BA, UK.

Agreement to develop CFC substitutes

Atochem (Elf Aquitaine Group) and Allied-Signal Inc. have announced an agreement to jointly develop non- ozone depleting substitutes for chlorofluorocarbons (CFCs). The agreement encompasses research to develop process technology and pilot plant construction leading to full- scale commercialization.

Three substitutes are being evaluated: HFC 134A as an alterna- tive to CFC 12 in automotive, industrial and residential air con- ditioning and in refrigeration applications; and HCFC123 and HCFC 141B as alternatives to CFC 11 in rigid urethane foam- blowing applications, and selected refrigeration uses. The application of HFC 134A and HCFC 123 in aerosols is also being considered.

In a joint statement, Atochem and Allied-Signal Inc. said: Atochem's expertise in vapour-phase processes are complementary to Allied-Signal's strengths in liquid-phase manu- facturing processes. Combining our respective strengths will enable us to expedite the development of n e w

process technology. It will ensure that this technology will be available on a world-wide basis. By pooling our resources to examine all approaches, it will enable us to develop the best and most efficient processes.'

Over 30 full-time scientists, plus support personnel, are involved in the project at Atochem's Centre de Recherche Rh6ne-Alpes (Pierre- Bbnite, France) and at Allied-Signal's Buffalo Research Laboratory (New York, USA). Pilot plants are available at both locations.

The companies have already made quantities of HCFC 123 available to end-users for testing and evaluation. By the end of June, sufficient amounts of HCFC 141B were available for end-use testing. By the fourth quarter of this year, similar quantities of HFC134A will be available.

Rev. Int. Froid 1988 Vol 11 Septembre 345