ISES Solar World Congress 2019 Paper: “Analysis of a solar hybrid cooling system for industrial applications”

Title: Analysis of a solar hybrid cooling system for industrial applications

Language: English

Authors: Uli Jakob (*1) and Falko Kiedaisch (*1)

*1: Dr. Jakob energy research GmbH & Co. KG (JER), Pestalozzistr. 3, 71384 Weinstadt (Germany)

Abstract: This paper presents the analysis of a new Fresnel solar thermal collector (FCSP) system with a Hybrid Heat Pump (HHP) for solar cooling purposes in industry using TRNSYS simulation. The HHP is a combination of a thermally driven adsorption chiller and electric compression chiller in a cascaded configuration, to achieve highly increased Energy Efficiency Ratios (EER) for the operation of the solar assisted HHP system. The benefits of the solar assisted HHP system is mainly based on constantly low heat rejection temperature of the compression chiller, compared to conventional ambient heat rejection systems, as the adsorption chiller is responsible for the heat rejection of the entire hybrid cooling system. The evaluation of a demo case in Barcelona, Spain showed, that EERs between 7-8 can be reached, hence, the electric power consumption of the cooling system can be reduced by 29 % in transitional seasons and by 44 % during summer. As a result of this approach, it is determined that full load operation conditions of minimum 3,800 h and ambient heat rejection
conditions with above 20°C have to occur constantly through operation period, to enable an overall economic operation of the solar assisted HHP System. As an example, for the investigated industry process in Barcelona specific cooling costs of 0.031 EUR/kWh can be reached at operating hours of 4,748 h/a. Moreover, it was analysed that the solar assisted HHP system is likely feasible for the implementation into industrial process typologies with both, heat and cold demands.

Industrial cooling based on solar heat at the demo sites

Article by Alex Grande, from IDP

Powering of industrial processes, if based on renewable technologies, may offer greater potential for CO2 emission reductions. Solar thermal energy is a promising sector which has been widely studied during the last two decades, becoming a candidate of the highest potential among renewable energy technologies, especially for industrial heating and cooling processes, because some technologies, such as heat pumps and mechanical vapour recompression, are particularly effective in hybrid systems.

The use of direct solar heat in industry is often hampered by barriers like lack of nearby available surface and seasonal imbalances. However, recent solar steam developments applied in the cooling demand services is growing worldwide with a wider variety of use, mainly within the industry. Some technologies, such as heat pumps are particularly effective. The two demonstration sites selected to tests Hycool system (Bo De Debó and Givaudan) are industries where custom-designed packages will be built, installed and tested.

Bo De Debó is a specialised industry in preparing precooked fresh dishes based on meat, fish and vegetable products, for being frozen, vacuum-packed or canned, and then sealed. In this site, Hycool will pre-cool the water in a buffer tank where it should be cooled down with other chiller in order to get 3-5ºC needed for the production of “gazpacho” (a kind of vegetables juice) and food washing processes. The residual heat from the system will be used to produce hot water for cleaning operations.

CSP-Panels to be installed in the roof of Plant 3, in Bo de Debo facilities in Sant Vicenç de Castellet

Givaudan is the global leader in the creation of flavours and fragrances. In close collaboration with food, beverage, consumer product and fragrance partners, Givaudan develops tastes and scents that delight consumers the world over. The Hycool system will provide the cold water needed to refrigerate the glycol stored in a buffer tank before it’s pumped to the vacuum pump water rings. The residual heat from the system will be used to produce steam to be injected in the factory net.

The old chilling system that will be substituted for the Hybrid Heat Pump from the new Hycool system, in Givaudan facilities (Sant Celoni – Spain).

In summary, the solar thermal energy provided by the Hycool System will allow our pilot sites:

  • To reduce their productions costs by using a free source of energy
  • To increase their system efficiency by using the residual thermal energy for producing heat water or steam
  • To reduce their global CO2 emissions by reducing the use of fossil fuels for producing that heat