Extreme Refrigeration of Ultra-High-Pressure Hydrogen

Frigofluid designed and supplied a prefabricated and containerized cascade refrigeration unit (Mod. S-RW 106.2), specifically calibrated for cooling Hydrogen. The challenge was to achieve an outlet fluid temperature (Hydrogen) of up to -37.90 °C, while managing extremely high pressure (up to 1,050 bar). The solution ensured high performance and low energy consumption, also utilizing the natural refrigerant R744 (CO2) in the low-temperature stage.

Extreme temperatures and sustainability, "cascade" design for final fluid outlet temperatures of -37.90 °C.
Ultra-high pressure management: the plate heat exchanger (PCHE) was built to operate on the Hydrogen side with a maximum pressure of 1,050 bar.
Efficiency and control: reduced energy consumption through the use of electronic expansion valves and a PLC management system.

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Company: Italian company, manufacturer of natural gas infrastructures

Year: 2025

Location: Emilia-Romagna, Italy

Interlocutor type: Final user

Application field: Chemical / Oil & Gas (Hydrogen Cooling)

Story in a nutshell: An Italian company that designs and manufactures compressors and infrastructures for natural gas, biomethane, and hydrogen, covering the entire "well to distribution" flow. It offers tailor-made solutions: CNG plants, mobile stations, containerized and prefabricated systems, flexible, modular, and integrated.

List of customer requirements: - Cooling of Hydrogen from +50.00 °C to -37.90 °C

- Need to manage Hydrogen at a pressure of 1,050 bar

- Request for a high-performance and containerized plant

Output fluid and temperature: Hydrogen at -37.90 °C (inlet: +50.00 °C)

Further requirements: - Cascade system

- Use of natural refrigerant R744 (CO2) in the second stage

- High energy efficiency

- Compliance with Directive 2014-68-EU

Technologies supplied: Containerized cascade refrigeration plant Mod. S-RW 106.2: Bitzer compressors (screw for R513A and 4-cylinder for R744), Plate heat exchanger, PCHE (for 1,050 bar), AISI 304 frame, PLC management system; Refrigerants: R 513A (first stage) and R 744 (CO2, second stage).

Services: - Marketing of the power plant

- Cooler testing at the headquarters

- Sale registration on the F-GAS portal

Key to Success: - Thermal target achieved (-37.90 °C)
- Structural integrity under pressure (1,050 bar)
- Sustainable efficiency (R744 and COP 4.04)
- Full compliance (Directive 2014-68-EU)

1. Context and installation requirement

The project required the realization of a specific industrial refrigeration plant for a process that needed extreme cooling of Hydrogen. The input data provided indicated that the Hydrogen had to be cooled from an inlet temperature of +50.00 °C to an outlet temperature of -37.90 °C.

A crucial element of the requirement was pressure management: the Hydrogen circuit operated at an extremely high pressure of 1,050 bar. To meet this complex request and ensure maximum safety and compliance, a high-performance and robustly constructed refrigeration system was necessary, with tests and inspections carried out according to European Directives, including 2014-68-EU.

Furthermore, the request implied the supply of a turnkey and possibly containerized system for ease of on-site installation and management.

2. Proposed solution

Frigofluid proposed the supply of NR.1 hydrogen cooling unit, model S-RW 106.2.

The technical solution adopted was a prefabricated refrigeration plant with a cascade system, containerized (in a 20-foot container), specifically designed to operate at sub-zero temperatures with maximum efficiency.

Cascade technology and ecological refrigerants: the system is two-stage, designed for efficiency and ecology:

First stage: uses a Bitzer screw compressor and R 513A refrigerant, with an evaporation temperature of -15°C.
Second stage (Low Temperatures): uses a 4-cylinder Bitzer compressor for R 744 (carbon dioxide). R744, a natural (or green) refrigerant, allows achieving evaporation temperatures of up to -41 °C with a cooling capacity of 82,500 W at 65 Hz. The use of R744 for the low-temperature circuit is a central element of Frigofluid’s offer for environmental sustainability.

Components and safety: Extreme pressure management on the Hydrogen circuit is guaranteed by a plate heat exchanger, PCHE, which tolerates up to 1,050 bar.

Finally, operational efficiency is ensured by:

Electronic expansion valves for high performance and reduced electricity use.
Central PLC management system that controls parameters and maintains constant evaporation/condensation pressure, optimizing efficiency.
The plant is assembled on an AISI 304 metallic frame complete with anti-vibration supports.

3. Results and Key Success Factors

The success of the S-RW 106.2 plant lies in its ability to combine extreme refrigeration performance with industrial reliability and environmental responsibility.

Key success factors:

Thermal objective achieved: the system successfully cooled hydrogen to the required outlet temperature of -37.90 °C.
Structural integrity under pressure: the customized design, particularly the use of a PCHE exchanger, allowed safe operation with Hydrogen at 1,050 bar.
Sustainable efficiency: the integration of R744 (CO2) in the low-temperature circuit utilizes an ecological refrigerant. Control technologies (PLC and electronic valves) significantly reduce energy consumption, ensuring a high COP (up to 4.04 for the R744 stage at 65 Hz).
Total compliance with current regulations: the entire containerized refrigeration plant was built, tested, and inspected according to strict European regulations, particularly Directive 2014-68-EU.