Dataset on performance of solar powered agricultural produce cooling storage system under tropical conditions

Much of the post-harvest loss of agricultural produce in developing countries is due to lack of proper storage facilities. Agricultural produce such as peppers, tomatoes and fruits are highly perishable in nature; thus, maintaining the optimal air conditions inside the storage cabinet helps extending their shelf lives. The datasets contained in this paper are performance test carried out on agricultural produce cooling storage system under tropical conditions for various cooling pads (jute fibre) thickness and under no load and load conditions. The parameters recorded under these conditions include wet and dry bulb temperatures, relative humidity of the surroundings, relative humidity and temperature within the cooling chamber taken consecutively for 4 days with different pad thickness and for 5 days and 8days under no load and load conditions, respectively. Results obtained show that pad thickness of 80 mm has the highest cooling efficiency of 84.7% and temperature within the cooling chamber was found dropped to 25 °C and average relative humidity of cooling chamber increased to 82.4% as compared to 64.8% for ambient condition.


a b s t r a c t
Much of the post-harvest loss of agricultural produce in developing countries is due to lack of proper storage facilities. Agricultural produce such as peppers, tomatoes and fruits are highly perishable in nature; thus, maintaining the optimal air conditions inside the storage cabinet helps extending their shelf lives. The datasets contained in this paper are performance test carried out on agricultural produce cooling storage system under tropical conditions for various cooling pads (jute fibre) thickness and under no load and load conditions. The parameters recorded under these conditions include wet and dry bulb temperatures, relative humidity of the surroundings, relative humidity and temperature within the cooling chamber taken consecutively for 4 days with different pad thickness and for 5 days and 8days under no load and load conditions, respectively. Results obtained show that pad thickness of 80 mm has the highest cooling efficiency of 84.7% and temperature within the cooling chamber was found dropped to 25 C and average relative humidity of cooling chamber increased to 82.4% as compared to 64.8% for ambient condition.

Data
The temperatures and humidity of cooling chamber and surrounding were collected and a set of experimental data was generated. Tests were first carried out on different cooling pad thicknesses ranged from 20 mm to 80 mm purposely to determine which thickness gives highest cooling efficiency (Tables 1e4). After which, no load and load tests were carried out on the designed post harvested agricultural produce cooling storage system at every 30 minutes through a period of 8 hours for 5 days (no load tests) and 8 days (load tests).

Experimental design, materials and methods
A 500 mm Â 500 mm Â 500 mm (Length x depth x width) postharvest agricultural produce cooling storage system was designed and constructed as shown in Fig. 1. The cooling system basically consists of a cubical shaped storage chamber, a cooling fan, and a cooling pad. The cubical shaped cooling chamber was of dimension 0.125 m 3 made of aluminum on the inside and galvanized mild steel on the outside, it is internally insulated with polystyrene to prevent heat exchange with the environment, a cooling fan and a porous cooling pad made from jute fiber and a submersible pump of 50 W power Specifications Table   Subject Area  Engineering  More Specific Subject area  Mechanical Engineering, Heat transfer and Thermo-fluid Engineering  Type of Data  Tables, Figures and graphs  How Data was Acquired The internal temperature and humidity of cooling chamber were measured using Floureon RC-4HC Data logger device. The data logger was set to record data at every 30 minutes through a period of 8 hours for 8 days. RC-4HC temperature and humidity data logger when connected to computer, the software reads data automatically, and form reports. It has LCD screen which display the temperature, time, over temperature alarm, temperature upper/ lower limit and maximum/minimum temperature. There are two sensors e internal and external used to record temperature over a long time. Temperature measuring range from -30 C to þ60 C with accuracy of ±0.6 C. Humidity range from 0 to 99% RH with accuracy of ±3% RH. Record capacity is RC-4HC 16000 points (MAX) while record interval is from 10 s to 24 h adjustable. The wet bulb and dry bulb temperatures of the surrounding were measured using wet bulb and dry bulb hygrometer alongside with psychometric chart. Digital anemometer was used to determine the air velocity entering into system.

Data Format Raw and analysed Experimental Factor
Performance of the cooling storage system was determined from wet bulb and dry bulb temperatures readings taken under no load and load conditions with different pad thickness varied from 20 mm to 80 mm. Experimental Feature Tests were first carried out on different cooling pad thicknesses ranged from 20 mm to 80 mm purposely to determine which thickness gives highest cooling efficiency. After which, load and no load tests were carried out on the designed post harvested agricultural produce cooling storage system at every 30 minutes through a period of 8 hours for 8 days. Data source location Department of Mechanical Engineering, Covenant University, Ota, Nigeria Data Accessibility Data are available within this article

Value of the Data
The given dataset can be used to provide information on the storage temperature, humidity requirements and the length of time agricultural produce can be kept without a decline in market value. The cooling efficiency calculated can be used for benchmarking performance of such cooling storage in another location under similar condition. The given dataset can be used to assess the impact of the cooling system on the stored agricultural produce. The given data will show researchers in the field of energy management and sustainable development the potential of solar PV to power cooling storage system especially in developing countries where access to electricity is limited.
rating having a flow rate of 240l/hr and a maximum static head of 3 m. A water reservoir of capacity 20 l, at the top of the cooling system transferring water being pumped through a piping system to the cooling pad to keep it continually wet. The system relies solely on the concept of cooling by evaporation [1e3], when the system is set up and is under operation, the dry air from the cooling fan goes directly to the wet surface of the cooling pad and evaporates the water present in the pad, thus drawing energy from its surroundings to produce cooling effect into the cooling chamber [4,5].
In this study, Floureon RC-4HC Data logger device was used measure the internal temperature and humidity of cooling chamber. The data logger was set to record data at every 30 minutes through a period readings were taken. Floureon RC-4HC temperature and humidity data logger when connected to computer, the software reads data automatically, and form reports. It has LCD screen which display the temperature, time, temperature upper/lower limit and maximum/minimum temperature. There are two sensors e internal and external used to record temperature over a long time. Temperature measuring range from À30 C to þ60 C with accuracy of ±0.6 C. Humidity range from 0 to 99% RH  with accuracy of ±3%RH. Record capacity is RC-4HC 16000 points (MAX) while record interval is from 10 s to 24hours adjustable. The wet bulb and dry bulb temperatures of the surrounding were measured using wet bulb and dry bulb hygrometer alongside with psychometric chart. Digital anemometer was used to determine the air velocity entering into system. Cooling efficiency of the cooling storage system was calculated using different jute fiber pads of different thicknesses based on the established formula given as [6,7]: where: T db ¼ ambient air dry bulb temperature in C. T wb ¼ ambient air wet bulb temperature in C. T c ¼ dry bulb temperature of the cooler in C.  Cooling pad of thickness 80 mm was used to examine performance of the storage cooling system under no load and load conditions for 5 days and 8 days, respectively (Tables 5e17).  Table 18 presents computed cooling efficiency of the storage cooling system for the period of 8 days under loading condition. The highest cooling efficiency (91.1%) was recorded on the 5th day of the experiment (see Table 18).   From this study, it was observed that: ➢ The drop in temperature of cooling cabinet of the storage system was relatively high during hot and sunny conditions and relatively low smaller under cloudy and rainy conditions. ➢ Increase in air flow rate enhances the rate of evaporation efficiently. ➢ The agricultural produce (tomatoes, okra and pepper) kept in cooling chamber of agricultural cooling storage system maintained their freshness and firmness after 8 days in comparison to those kept under ambient air conditions.