The efficiency improvement of household refrigerators is of significance to electricity consumption reduction of residential buildings. The cold loss recovery in household refrigerators is a promising development direction. In this study, a refrigerator improved by heat pipes is designed to reduce the cold loss at freezer walls to enhance the overall efficiency of the refrigerator. A complete steady-state mathematical model is built for characterizing its overall energy saving behaviors by introducing the real structural parameters of a Midea BCD-111 refrigerator and measured temperature boundary conditions. The performances of the improved refrigerator are investigated with typical operating states, variable ambient temperature, and heat pipe design. The simulative results indicate that the cold loss of the freezer of the improved refrigerator can be reduced by 8.3–16.5%, and the energy saving capability is relatively reliable. Results verify that the cold loss recovery of the improved refrigerator is feasible in various operating conditions.

The research is conducted on emulsified fuel applied to engine YC6J190 without any modification of the engine. In this experiment, the contrast of the fuel consumption and the emissions is studied with having water or not. From the results, it can be concluded that the emulsified fuel can reduce the NOx and smoke emissions greatly at the same time, but the fuel consumption is different in different conditions. The emulsified fuel with 20% water is most suitable for this type of engine regarding fuel consumption and emissions. Then dynamic characteristics is tested using the emulsified fuel with 20% water to find that the decline in power and torque output is not apparent. At the end, we conclude that emulsion containing 20% of water would replace diesel as for this type of engine.

An experimental study was carried out on a prototype of a scroll expander used as the air-powered vehicle engine. The speed characteristic was tested based on the test system at the constant suction temperature and pressure. The results show that the air mass consumption rate and the output power both increase with the rotating speed. The maximum air mass consumption rate is 800kg/h and the maximum power achieves 8.112 kW. The effective efficiency increases with the rotating speed but the increment decreases. The maximum efficiency is only 0.26 due to the low manufacturing and assembly accuracy of the expander.

Recent years, automobile air-conditioner control system is particularly important as the automobile air-conditioner is becoming an important indicator to measure the comfort of a car. This paper introduces the hardware and software design of the system based on STC12C5A60S2 microcontroller.The hardware design part includes the circuits design of motor and fan, and the software design part describes the way to realize the modes conversion function. Experiments show that the automobile air-conditioner system can reach high control accuracy and it's practical.

This paper studied the principles of thermal gas mass flow meter. According to the car engine EGR cooler working principle, we found out a kind of heat dissipation gas mass flow meter to measure the mass flow quantity of the gas in the EGR cooler test and analysis system which is a newly applied invention patent. We analyzed various parameters of the gas mass flow meter suitable to the system. Meanwhile, in order to verify reliability of the thermal gas mass flow meter in the system, we adopted CFD method to simulate the EGR cooler by using empirical parameters, and collected several related sensor parameters of the EGR cooler in the condition that the inlet temperature was constantly at 368K while the coolant had 4 kinds of degrees. Combining heat empirical formula, we got the EGR cooler outlet temperature and the overall heat transfer coefficient. After comparing the calculated values of the gas path total EGR cooler outlet temperature and heat transfer coefficients with the experimental values, we found that the outlet temperature values of experiment were smaller than the calculated values by averagely 1.17%, while the average experimental values of the overall heat transfer coefficient were 3.1% larger than the calculated values. Thus, this type of mass flow meter has good stability in the newly applied Chinese patent EGR cooler performance test and analysis system.