Search Results

The world's first continuous variable capacity rotary compressor for automotive air conditioning, DCV-14A, has been developed. Compressors for automotive air conditioning are classified broadly into swash plate type, rotary type, radial piston type, wobble plate type and scroll type. Among these compressors, the wobble plate type is the only compressor that has been made continuously variable capacity. Meanwhile, the development of a rotary variable capacity compressor has been attempted, but it has been successful only in stepwise variation of capacity. The DCV-14A, however, has made continuous variable capacity possible, and it has eliminated problems that the wobble plate type variable capacity compressors have; such as noise, vibration, and insufficient reliability.

The overall vision of this project was to develop a new technology that will be an enabler to reduce design and development time of HVAC systems by an order of magnitude. The objective initially was to develop a parametric model of an automotive HVAC Windshield Defrost Duct coupled to a passenger compartment. It can be used early on in the design cycle for conducting coarse packaging studies by quickly exploring “what-if” design alternatives. In addition to the packaging studies, performance of these design scenarios can be quickly studied by undertaking CFD simulation and analyzing flow distribution and windshield melting patterns. The validated geometry and CFD models can also be used as knowledge building tools to create knowledge data warehouses or repositories for precious lessons learned.

Two kinds of visual tests to recognize the interior air flow of a small pick-up truck are made. One way is the tuft stick grid, and another is numerical simulational analysis. The former is done with arranged tuft. The latter is done by using the super computer. The results of both are very simillar. The tuft stick grid is recognized as a simple, easy, and actual way to see the outline of the vehicle interior flow. Numerical analysis is done as an effective way to see more detail, and to more easily evaluate changes. Another case is calculated in which a doll model is assumed for the passengers. The results are used to predict the air conditioning (A/C) feeling by using the A/C feeling prediction system. The predicted results and the actual A/C feeling test results are similar to each other. As a result, it is said that the numerical simulational analysis is effective in predicting A/C feeling.

In recent years, climate protection has become as important as ozone layer protection was in the late 1980's and early 1990s. Concerns about global warming and climate change have culminated in the Kyoto Protocol, a treaty requiring its signatories to limit their total emission of greenhouse gases to pre-1990 levels by 2008. The inclusion of hydrofluorocarbons (HFCs) as one of the controlled substances in the Kyoto Protocol has increased global scrutiny of the global warming impact of HFC-134a (called R-134a when used as a refrigerant), the current mobile air conditioning refrigerant. Industry's first response was to begin improving current R-134a systems to reduce leakage, reduce charge, and increase system energy efficiency, which in turn reduces tailpipe CO2 emissions. An additional option would be to replace the current R-134a with a refrigerant of lower global warming impact. This paper documents the use of another HFC, R-152a, in a mobile A/C system.