The Thermochemical System

Context

For more than ten years, the two founders of Coldway- thermo engineers originating for the National Research Laboratory (CNRS) - Laurent RIGAUD and Francis KINDBEITER have developed specialized know-how of this industrial process called thermochemical system. They bring new aspects to the system of solid-gas absorption and supply an alternative and different approach of cooling and/or heating in order to satisfy a growing need of mobility, quality, traceability and reliability for the health and food industry and logistics.

Amongst the absorption cycles, the solid-gas systems are particularly interesting not only for their heat management and cooling production possibilities, but also for their autonomy.

Based on the heat transfer of reversible chemical reactions, of the chloride ammoniac type, these processes meet with concerns linked to environment protection, whether it is about the protection of the ozone layer or the control of the greenhouse effect: they do not use any CFC or HCFC fluids or any other substitute banned by international agreements.

The Thermochemical System

Phase 1: Cooling and heat production

This process is based on liquid ammonia evaporation into a gas which then reacts with salts. It is composed of three elements, an evaporator containing liquid ammonia, a valve and a reactor containing salts reagents. In phase 1 :

- When opening the valve, the ammonia stored in the evaporator evaporates, causing cooling.

- Ammonia gas goes to the reactor where it is trapped within the solid salts located in the reactor.

- The reaction causes a heat release on reactor side.

- The evaporating temperature may reach -30°C and the absorption temperature may reach +100°C.

 Phase 2: Regeneration of the system

Once the reserve of ammonia is exhausted, the system is  rechargeable. In phase 2 :

- The reactor containing the solid in which ammonia is trapped.

- A heat production starts the reloading phase.

- On applications developed up to now, a resistor heating causes the desorption of ammonia gas from condensing in the evaporator.

- At the end of this phase, ammonia is stored in the evaporator and the valve must then be closed.

- The process may then begin a new cycle

Main properties

- Autonomous cooling and/ or heating production, without electricity.

- Energy storage (of cold or heat), without time limitation.

- Powerful energy restitution of cold and/or heat immediately after opening of the electro valve

- Simple functioning

- Robust thanks to it’s stainless steel envelope

- No moving pieces therefore little service and maintenance

- No noise and vibration

- Respecting the environment (no CFC gases or substitutes)

- Possibility to recharge the system by using renewable energies (solar energy, heat recovery,…)

The COLDWAY technology, products and know-how

are protected by a portfolio of international patents.