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In recent years, fuel consumption regulations are becoming more severe in every country in the world. Engine size reduction plus turbo is one of the solutions. Our turbo system has an intercooler which cools high temperature gas compressed by a turbocharger. The structure of the intercooler is a tank mounted on both sides of a heat exchanger. The tank connects to the heat exchanger and turbo system allowing EGR (Exhaust Gas Recirculation) gas through the heat exchanger in response to the tightening of exhaust gas regulations. Use of the LPL (Low Pressure Loop) system which refluxes EGR gas is expected to increase from now. Since EGR gas is characterized by high temperature, high pressure, and acidic condensed water, high fatigue strength at high temperature and acid resistivity is required. Therefore aluminum (Al) is generally applied for “intercooler tank” (hereafter referred to as “tank”).

The ejector is a fluid pump that recovers expansion energy, which is wasted in the conventional refrigeration cycle decompression process, and converts the recovered expansion energy into pressure energy. In the ejector cycle, the ejector helps to reduce power consumption of the compressor by using the above mentioned pressure-rising effect. Consequently, the ejector system can improve energy efficiency of the refrigeration cycle. In previous work, the ejector cycle was used to reduce power consumption in refrigeration cycles for a cool-box (a beverage cooling inside the vehicle) and refrigerated truck box. Both of these applications used the ejector to achieve refrigerant pressure/temperature below the vehicle cabin temperature. Now, the ejector has been integrated into the vehicle cabin evaporator to reduce power consumption of the refrigeration cycle for vehicle cabin cooling.

In recent years, vehicle cabin quietness takes a growing importance particularly related to the emergence of hybrid and electric vehicles and “Idle Stop system” vehicles. Demand for quieter car air-conditioner systems is increasingly important also, especially the reduction of the flow-induced noise from the HVAC. In HVAC systems, the rotating blower is one of the main noise sources and the digital solution for predicting and analyzing the blower aeroacoustic noise in the early stage of design is needed for developing a quieter blower. The target of this study is to develop and to validate a flow-induced noise predictive tool for a HVAC blower and to analyze the noise source. In this paper, a low-dissipation, transient, compressible CFD/CAA approach based on the Lattice Boltzmann Method (LBM) is used to predict simultaneously the flow and aeroacoustic radiation of two production blowers.

In order to improve corrosion resistance and thermal efficiency of the air conditioner evaporator, a coating which provides hydrophilicity was formed over the chromate coating. In addition, there has been greater demand for air with fewer smells. This report describes the cause of “dusty odor” and a method to reduce it. The dusty odor is caused by a little corrosion of the substrate aluminum. Hydrophilic coating film dissolves little by little in condensed water, and substrate aluminum is exposed. A method to prevent the odor was developed by forming a coating giving hydrophilicity and durability to the evaporator surface.

This paper describes the newly developed processes of low temperature wafer bonding using plasma activation and deep dry silicon etching technologies. Both processes are a new type of “MEMS” (Micro Electro Mechanical System) process technology suitable for automotive pressure sensors. The conventional pressure sensor was a unified unit consisting of a silicon sensor chip and a glass stage. The diced unified unit was cut from a bonded disk of a processed silicon wafer and a glass stage substrate, and the silicon sensor chip incorporated four piezo-resistors, a diaphragm and bipolar-circuit. However, the pressure sensor had difficulty in accurately measuring pressure in the high temperature range because of the thermal strain caused by the thermal expansion coefficient difference between the silicon sensor chip and the glass stage.