| Recently, Liquefied Natural Gas Vehicle (LNGV) associated with public transport industry has a rapid development in China. With the help of it, the automobile air-conditioning which recovering the cold energy of LNG is received as future-full by public transportation sectors, and there have been many research with the item in many research centers. This paper described a new layout design of automobile air-conditioning system applying the cold energy of Liquefied Natural Gas. An experimental device has been established to verify the reliability of the air-conditioning, which firstly using LNG as experiment object. At last, this paper introduced the revamping of LNG bus with recovering air-conditioning.In this paper, firstly we choose 8-meter city bus as the research object, and calculate the summer cool load of the driver's room. Analysis of the cold exergy and the characteristics of Liquefied Natural Gas has been conducted from the viewpoint of thermodynamics. Based on the thermodynamics calculation, the amount of the cold energy recovered is evaluated. The calculation result is shown that the actual recovery cold is about 2.3 kW in terms of the cold recovering efficiency is regarded as 50%, which can satisfied with the needs of the air-conditioning bus in summer. Based with Dr. Wang's theoretic research, this paper develops a new set of bus air conditioner system which can recover the cold energy of LNG. The air conditioner system consists of 4 parts:the cold recovery heat exchanger, the recycle system, the air conditioning terminal and a cold storage system. A new way of storage cold is described in the paper. At last glycol-water liquid is selected as the air conditioning medium. In this paper, we also introduced the redesign and numerical simulation of the key recovery heat exchanger, according to the LNG cold energy recovering recycle. The recovery heat exchanger has a similar type of the coaxial thimble heat exchanger. The exchanger area was gained after calculation. For the purpose of the optimum design, especially in the large temperature difference, a simulation model was established in a simple simulator. Using FIRE which is one of CFD software, we studied the layout of the air conditioner medium's temperature in typical operating condition on different time. The results indicate that the thickness of the medium is no thinner than 10mm, which means that the filling rate by ice is just no more than 10%. So it is hard for the heat exchanger to be blocked by ice. The paper also calculated other device such as air-conditioning pump, water tank, the diameter of pipe and the thickness of heat preservation material.To research the performance of the air conditioning system, a simulative experiment of Liquefied Natural Gas is investigated based on the previous analysis. The paper chooses the LNG as the experiment medium for the first time and measures the temperature distribution in the air conditioning city bus at stabilization operation. The simulative experiment measures the medium temperature of the inlet and outlet of the exchanger, and the pressure of the natural gas. The parameters is shown that the inlet temperature of the cold recovery heat exchanger is 15℃, the outlet temperature of the cold recovery heat exchanger is 21℃, the inlet temperature of the air conditioner terminal is 16℃, the outlet temperature of the air conditioner terminal is 21℃. The air conditioning system designed can operate steadily and refrigerate rapidly. In the end, the designed air conditioner system is applied to a LNG bus revamped in JiNan public transport company. It can be concluded that the air conditioning system is adapt to the LNG bus, which can recover the cold of LNG. The air conditioning system achieve a overall utilization of energy and have a good promotional value at low cost.
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