Design and Development Air-Condition and Refrigeration System for Seed Storage

Abstract

The purpose of this research was to design and develop air-condition and
refrigeration systems of seed storage, which reduce storage cost and maintain high quality
of seed. The refrigeration system could control temperature and relative humidity (RH),
operated by condensing and heat up by hot gas from refrigerant for suitable environment
of seed storage. The size of cold storage room’s prototype was 2.2 x 4.0 x 2.2 m (width x
length x height). Polyurethane foam panels (50 mm thickness) were used as wall
insulation. The cooling system consisted of R-22 refrigerant, 4 hp (380V/3Ph/50Hz)
compressor motor with 5.85 kW cooling capacity. Fan of unit cooler had air mass flow rate
at 0.6 kg.sec-1. The heating coil capacity 6 kW was installed for dehumidification. The
coefficient of performance (COP) was determined by using low pressure of refrigerant to
constant at 50 psi and 3 ranges of high pressure i.e. 190-220 psi, 220-250 psi and 250-280
psi. The COPRef were 4.02, 3.13 and 2.8, respectively and electric power consumption was
0.46, 1.12 and 2.17 kW/h, respectively. The results showed that the high pressure of
refrigerant at 190-220 psi was the optimum pressure while the average temperature and RH were 14.95±0.55 ํC and 45.81±0.82 %RH. This prototype of cold room for seed storage could reduce machine cost, save energy for the dehumidifier system, and be easily transported. Therefore, this cold room is suitable for community enterprises, agricultural cooperatives and private sectors, where high quality seed production and cost reduction are required.