Exclusive interview with Professor J. Chen about hydrocarbon air conditioning and heat pumps in China

Dr. Jiangping Chen, Professor of the Institute of Refrigeration and Cryogenics at Shanghai Jiao Tong University, talked to hydrocarbons21.com about research on propane (R290) air conditioners and heat pumps, the market for hydrocarbon air conditioners in China, and the Chinese HCFC Phase-out Management Plan (HPMP).

hydrocarbons21.com: At the 23rd IIR International Congress of Refrigeration you presented the paper “Experimental study of R290 enhanced system performance in residential air-conditioners and heat pumps”. Can you tell us, what your main conclusions are regarding use of hydrocarbon R290 as the working fluid in air conditioners and heat pumps?

Jiangping Chen: The paper presented is a joint research project with a local air conditioning company, reporting on testing of room air conditioners and heat pumps. Our main conclusion is that propane system performance can still be improved, using technology such as thermal-expansion valves, and internal heat exchangers. Work is still ongoing.

Results showed the performance for cooling of an enhanced R290 is quite good but not as good for heating. In fact for heating performance, it is about 10% lower. Overall we found the lower volumetric capacity of R290 compared to R22 resulted in a lower cooling capacity, but that this could be improved using a suction line heat exchanger (SLHX).

Whilst we are trying to improve performance, the key focus is refrigerant charge because of the safety issue.

Currently, there are now 2 companies in China with the technology for hydrocarbon room air conditioners.

hydrocarbons21.com: What is the focus of the Shanghai Jiao Tong University Institute of Refrigeration? What are the next steps regarding your research?

Jiangping Chen: The work focus at the Institute is on refrigerants for room, commercial and mobile air conditioning systems. The work we undertake supports low GWP refrigerants. As most of these alternative refrigerants are flammable we are trying to evaluate the risk and optimise systems to fit the properties of the refrigerant.

With regards to our research, as a next step we are trying to use microchannel heat exchangers to reduce the refrigerant charge to 150g so that propane systems will comply with European safety standards. Microchannel heat exchangers are already used but the size of those available is not as compact as we expected.

hydrocarbons21.com: How would you evaluate the market for in China for hydrocarbon air conditioners?

Jiangping Chen: Companies like GREE have invested large amounts in developing the technology for hydrocarbon air conditioners, so I think that technically we are ready. In my opinion the public is also ready. In China there is a move to further develop servicing standards and provide teaching and training for personnel dealing with hydrocarbons, to ensure that accidents are avoided when charging air conditioning systems.

The Chinese government has a project to evaluate the risk of propane as a refrigerant. This project will be finished in the coming months, and will evaluate what happens in the case of refrigerant leakage, for example, what is the risk in the case of refrigerant ignition? This risk assessment should be published this October.

hydrocarbons21.com: You mentioned GREE, which recently launched production of hydrocarbon air conditioners. How do you think the Chinese market has reacted to the launch and what future developments do you see as a result?

Jiangping Chen: I was part of the review team for GREE’s project. Overall, sales will depend on the market. China is big country with varying climatic conditions. I think the air conditioners will definitely find a market in South China. For the Northern market, heat pumps will be of greater importance. Here we still have improvements to make with regard to performance, but I do not think that this is a big obstacle.

hydrocarbons21.com: When do you see hydrocarbon heat pumps being commercialised in China?

Jiangping Chen: Some customers have already approached GREE for propane heat pumps, but by and large most are waiting for the publication of the government risk assessment. I imagine GREE will eventually expand production to include heat pumps.

In China 90% of air conditioning systems are actually heat pumps. Whilst propane can have a good performance in heat pumps, this is only true with a higher charge, which impacts system safety. Reducing the charge to take into account safety means heat pump performance is not so good.

hydrocarbons21.com: You mention the importance of developing servicing standards and training, what is the current situation with regard to HVAC&R technician training in China?

Jiangping Chen: I have been involved in a project in China to draft a training handbook, which is almost ready. Publication will depend on the Chinese government. It has already passed the review stage, and although I don’t know the exact publication date I think it will be soon.

China’s HPMP has already been approved, and within the HPMP it is clearly stated that by 2015 China will have 5 million propane air conditioners, therefore we will need a competent servicing industry.

hydrocarbons21.com: Does the Chinese HCFC Phase out Management Plan (HPMP) put an emphasis in natural refrigerants?

Jiangping Chen: I think that for China propane will be the primary natural refrigerant. Although there is interest in R161 (fluoroethane), it is also flammable. So for me propane should be the preferred working fluid - it is not necessary to use R161. Much less is known about the performance of R161. Studying it would require more money and more time to research its performance with oils and its reliability. Some local companies are promoting R161, but I think the road ahead for them is not easy.