I.T.C. Group (ITC), an original equipment manufacturer of freezer and cold storage refrigeration systems based in Bangkok, Thailand, recently commissioned its first prototype transcritical CO2 system.
The system, dubbed ‘Blue Bird‘, was “designed specifically to be a prototype as well as an experimental unit for CO2 transcritical systems operating in a hot and humid climate,” according to ITC engineer Warot Lam.
‘Blue Bird‘ was commissioned last December in the company’s testing facility.
Results have been promising so far, said Lam, with the system delivering the desired temperatures in a high ambient-temperature environment.
“During our testing, the ambient temperature was at around 35-36°C,” said Lam.
‘Blue Bird‘ is a container-sized refrigeration system that consists of three main parts: an 8 m3 cold room (-2°C), a chilled water system (+12°C), and a heat reclaim system for hot water (+60°C).
“It was designed with a total of 3 kW refrigeration capacity, with half serving the cold room and the other half serving the chilled water system,” said Lam.
Thanks to the heat reclaim system, Lam said, “we were able to reduce the size of the gas cooler and increase the overall coefficient of performance (COP) of the system”.
Although December is on average the coolest month for Bangkok, temperatures still hovered around 35°C for several days last month, according to AccuWeather.com.
‘Blue Bird’ unit cooler in 8 m3 cold room.
Though the ‘Blue Bird‘ CO2 system is still in the early prototype stage, ITC considers these inital results to be a significant achievement.
“It is worth mentioning that this ambient temperature is higher than the critical point of CO2 and far higher than the ambient temperature in European countries where many CO2 refrigeration systems operate,” said Lam.
He said that energy use was not monitored during this test.
“As this was our first CO2 transcritical system, and perhaps the first in the Southeast Asia region, it has not been designed to be very sophisticated yet. There is still much room left for improvement,” said Lam.
“This test was merely our very first step to show that I.T.C. has the potential to do a [CO2] transcritical system.”
Ammonia restrictions driving CO2 interest in Southeast Asia
“As we have gone into the field to meet with customers in recent years, we received quite a number of questions regarding the use of CO2 as a refrigerant,” said Lam, outlining ITC’s motivation for developing the system.
“Indeed, this was due to an increasing restriction of ammonia usage by law in many areas. Many customers foresaw that sooner or later it would be difficult to keep using ammonia.”
ITC was established in Thailand in 1982. It manufactures mostly ammonia-based refrigeration systems for the country’s freezing and cold storage industry (for more on ITC and its use of ammonia and CO2 in Southeast Asia, see our interview with ITC Managing Director Apichit Lumlertpongpana in Accelerate Asia Issue #1).
“ITC has done several CO2 subcritical projects before but never with a transcritical system,” said Lam.
“Therefore, we realised that now is the time for ITC to be the first to initiate this trend in the region. That is why we started the ‘Blue Bird‘ project.”
“We realised that now is the time for ITC to be the first to initiate this [CO2 transcritical] trend in the region.“Warot Lam, coordinator/engineer, I.T.C. Group
Serving Thailand’s agricultural industry with natural refrigerants
The sector that holds the most potential for the ‘Blue Bird‘ CO2 transcritical system, according to Lam, is the agricultural sector.
“The whole ‘Blue Bird‘ project was intended to simulate a one-stop service for CO2 transcritical systems to serve the agricultural industry during the post-harvest handling stage,” explained Lam.
“Hot water from the heat reclaim system can be used for processing equipment cleaning in factories. The chilled water system can be used for hydrocooling or cleaning the produce. After that, the hydrocooled produce can be stored inside the cold storage room, where it waits to be shipped or is stored for further processing.”
ITC will continue to test and improve the ‘Blue Bird‘ system.
The company will exhibit the system at the Bangkok RHVAC 2019 exhibition in September, “as well as at other international exhibitions,” said Lam.