Experimental Study On Novel Heat Exchangers And Alternative Refrigerants For Household Air-conditioners

The existence of abundant mineral resources promises a country to experience asustained and rapid development of national economy. And in the past few decades,an exponential growth in demand for a great quantity of minerals has occurred due tothe rapid economic development and increasing complexity of products. Furthermore,there will be an undisputed exacerbation of this situation that the coming metalsshould meet the requirements of not only sufficient numbers but also higher qualitywith better accessibility, as a result of the upturn living standards and scientificprogresses in the future.Among the mineral resources, household air conditioning industry’s dependenceon copper material is especially obvious. However, the sustainability of copper supplyemerges to be severe that copper is regarded as a scare mineral resource with only60years of expected availability at current production levels. Air conditioning industryhave been facing great challenges with the accompanied overliing disadvantages,rising copper price and fierce competition for instant. Additionally, R22, as one typeof HCFC, have been dominating the domain of refrigerants and will cause manyenvironmental issues after being released into the atmospher, such as the greenhouseeffect and the ozone layer hole. Therefore, reducing the copper consumption per airconditioner and seeking for a new type of eco-friendly refrigerant can bring positiveprospects on boosting its international competition and promising the field asustainable development.To find solutions to the above situation, this paper choose the thread finned tubeheat exchanger as the basis component, and firstly invesgate the cycle performance ofthe air conditioners based on ACC heat exchangers as well as heat exchangers madeof copper and aluminum with the same framework in a air enthalpy laboratory. Afterwards, analysis of the performance of the indoor5mm heat exchanger as asubstitute to the conventional indoor7mm heat exchanger is determined. And the5mm heat exchanger is selected to assemble a air conditioner system thereafter, basedon which then a set of experimentations is conducted to observe the cyle performanceof four different refrigerants. Conclusions can be draw with the experimental resultsas below:(1) Compared to the same type copper heat exchanger used in the system of thispaper, the material cost saving of ACC heat exchangers is nearly63%. The highestcapacities and COP are slightly lower than the conventional copper system but muchmore relatively higher than the aluminum system.(2) The5mm heat exchanger with helical angle of6°can provide the airconditioner adopting it the best performance. Its performance can be comparable tothe system adopting conventional7mm heat exchanger after adjust the flow path ofthe outdoor heat exchanger.(3) The COP of both R32and R290has almost the same increment than R22(both11.0%higher than R22) as well as R410A (both5.3%higher than R410A) inheating mode. And in cooling mode, their COP is26.8%and20.4%higher than R22,7.3%and2.1%higher than R410A.(4) The cycle performance is improved (5.3%higher in capacity,5.1%higher inCOP) and safety is also promoted with a6%(315g) reduction of charge quantity afterthe R290system is equiped with a suction line heat exchanger.