Application Of h6'p Sea Water For Nutrient Cooling System In Hydroponic Culture

Abstract

Abstract Deep Sea Water @SW) has cold temperature, abundant nutrients, and good water quality that is pathogen-free and stable. Its low temperature is one alternative energy methods for nutrient cooling system in hot season for greenhouse cultivation. Cold DSW pumped inside pipe through cultivation bed might decrease temperature of nutrient solution by heat exchange between nutrient solution and DSW. In this experiment, the heat load of cultivation bed was calculated to evaluate the energy consumption for nutrient cooling system of tomato cultivation in summer. The energy consumption for nutrient cooling system between refiigerator and application of DSW using heat exchanger was compared to evaluate saving energy for all-year-around tomato cultivation. At sunny day, heat load for one nutrient film technique bed along 10 m was 7.4 MJ d-'. In practical cultivation, grower are used to cultivate plants on 80 cultivation beds per 10a area of greenhouse thus, heat load was 590.0 MJ d-' per l0a. When a refi-igerator with COP 2.5 is used to maintain nutrient solution at 22 OC, it consumes energy 236.0 MJ d-' or equivalent with 66.1 kW h dl per 10a while using deep sea water as nutrient cooling system needed energy from 97.2 t dm' DSW + 14.6 kW h of pump. This system only need electrical energy 14.6 kW h of circulation pump thus it could save 78 % of electrical energy consumption than using refrigerator. Growers can save energy and production cost compared to refrigerator that consumed electricity. From environmental- perspective, it will reduce electricity consumption that is produced from fossil fuel thus reduce CO2 emission onto earth. Furthermore it can reduce 'greenhouse effect'.