Transactions of the Society of Heating,Air-conditioning and Sanitary Engineers of Japan

As a purpose, in order to maintain machinery original normalmovement and stability operation, to discover fault and deterioration and to execute repair, Part exchange, Operative improvement for the early stage, diagnosis of control device is indispensability. In this paper, fault detection & diagnosis system which is propriety for diagnosis of control device of building air conditioning systems by using a rule base diagnosis is proposed among a lot of technologies of fault detection and diagnosis. And the system for diagnosis of control device is applied to building air conditioning systems and the effectiveness and problems is cleared. Therefore an inspection result is reported.

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These studies aim at development a design and performance prediction tool for the ground source heat pump system. This paper constitutes Part1 in the series of these studies. Authors described the outline and features of the tool developed for the GSHP system with a borehole ground heat exchanger. In addition, performance prediction of the GSHP system for a resident house in Sapporo was performed and installation effect was estimated by the developed tool. A result of calculations shows that the GSHP system can reduce 56% of LCCO_2 compared to the oil boiler heating system.

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Based on the longstanding measurement result of DHC system, which had a plan of commissioning from pre-design, the following results were shown by commissioning in operation and maintenance stage. 1) As the result of a longstanding measurement and the commissioning, it was shown that DHC system had been operate with high primary energy conversion COP (about 1.2) without influence of aged deterioration, 2) As the result of the commissioning, temperature difference become about 10 degrees C and it led to realization of large-temperature-difference water supply. 3) With realization of large-temperature-difference water supply, the large thermal storage tanks were operated with high efficiency as the original plan. 4) As the result of high efficiency operation of the large thermal storage tanks, much of energy consumption shifted to midnight and chillers were operated with high load factor.

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In the previous paper, we have proposed the fin efficiency model of the 2-dimensional straight fin and the convenient latent heat model which identifies the latent heat added upon the fin surface with an increase of the heat transfer coefficient regarding the heat transfer with condensation of moist air. In this study, for wide-range of conditions we have proposed a new heat transfer model with condensation including presence of dry area on the fin surface. We have also proposed a generalized model of the bypass-factor of latent heat even in the condition that the bypass-factor of latent heat is not equal to that of sensible heat. These models use the approximation function of temperature distribution on the fin surface. Then, we have constructed a conventional calculation procedure for the heat transfer with condensation using these models. We have investigated the validity of these models comparing with the numerically derived data directly from the heat conducting equation of the fin. As a consequence, it was proved that this procedure gives quite good approximation for any practical conditions.

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