SUPERCOOL in indirect cooling systems

Potassium formate – new possibilities

In times when we are dealing with broad legislative changes in the refrigeration industry and in particular regarding refrigerants, indirect cooling systems are increasingly used. A typical cooling medium used in such systems is water, water and glycol solutions, which are well known in the industry, as well as well-recognized advantages and disadvantages, and limitations of use. In indirect systems, the use of potassium formate solution as a cooling medium in the intermediate system is becoming more and more interesting. The COOL company successfully uses the solution under the trade name SUPERCOOL enriched with all necessary refining additives, among others anti-corrosive protecting elements of the hydraulic system. This liquid has a hygienic certificate.

SUPERCOOL has a number of features desirable in refrigeration technologies such as:

  • low viscosity
  • high thermal conductivity coefficient
  • the possibility of applying to all materials suitable for current hydraulic systems with few exceptions

The first two of the above-mentioned features mean that compared to glycol mixtures in the installation, pumps with smaller pressure, coolers with relatively smaller dimensions and smaller pipe diameters can be selected.

A well-balanced cost indirect cooling system is not only a good price offer but also has indisputable technical advantages such as:

  • compared to DX direct cooling systems (e.g. CO2 system) the indirect system failure rate is lower and in the event of a failure - leakage, repair is less complicated and expensive
  • generally serviced intermediate systems do not require as qualified service as in the case of DX systems and in particular DX systems working on CO2.

As a cooling device to supply the indirect system with potassium formate, any type of chiller can be used - and when using a chiller with the R290 (propane) ecological refrigerant from the COOL offer, the entire installation is safe for the environment.

COOL has already made a number of optimized installations using SUPERCOOL based on proprietary AQUACOOL GREEN propane chillers, STEFANI and ONDA coolers and Ebara pumps.

One of the most interesting projects is the cooling plant recently implemented by our company for JANEX in Pruszków near Warsaw.

Generally, the installation consists of indirect cooling systems using the SUPERCOOL fluid operating at a fluid design temperature of -8 ° C in the refrigeration system and -30°C in the freezing system. The source of cold for refrigeration installations are 2 ecological chillers with R290 refrigerant (propane) type VCGV 640HT EC L manufactured by COOL with a total cooling capacity of 800 kW. Additionally they are equipped with heat recovery exchangers.

The 29% potassium formate solution used has a freezing point of -20 ° C. In the hydraulic system, pumps with a constant flow supply the refrigerant to the hydraulic clutch (capacity 1 m3) with cooling consumer circuits. Hydraulic circuits supply air coolers and other technological devices. Classic under-ceiling air coolers were used to cool the cold rooms and shock chambers, and in the air-conditioned rooms and locks coolers with double-sided air discharge.

On the other hand, the COOL ice water chiller with R449a refrigerant type VCR 360 HLT-2P-O with a cooling capacity of 121.4 kW is also a source of cooling for freezing installations. Also this chiller is equipped with heat recovery overheating. The purpose of this chiller is to cool a 43% solution of potassium formate with a freezing point of -40°C from -26°C to -30°C. The potassium formate solution is fed to a hydraulic clutch (capacity 0.8 m3). By means of a circulating pump with variable capacity, depending on the momentary demand for cold, it is fed to individual under-ceiling fan coolers.

The simple concept of indirect circuits seems to be a safe solution when it comes to reliability compared to e.g. complex CO2 direct evaporation systems.

If interested, please contact us.