The development of the heat pump aims at a compact heat pump providing heating and cooling in an environmentally acceptable and energetically less consuming way. The heat pump fulfils the following functions : heating in winter time and cooling in summer time and producing sanitary hot water during all seasons. A water-water distribution system is chosen for these purposes. This is the most simple way to make the system reversible between heating and cooling using a 4-way valve in the water distribution system.
The paper does some research work on limitations of design of PCM cool thermal storage in air-conditioning system, and provides some concepts related to the idea, on which the paper explains the capacity of this kind of air-conditioning system to reduce power highest need . Finally, the analysis method is described concretely by an example project in the campus of USTC.
The problem developed and analyzed in this paper is that of the estimation of the uncertainty associated with the results obtained by numerical simulation codes of physical systems induced from input data. Implicitly posed by the authors is the delicate question concerning the use of the output obtained by calculation codes used in prediction situations, and the reliability which can be attributed to such ouput. One example of thermal behaviour of simple physical systems is treated, serving as an illustration.
The paper describes how first-principles models can be used to assist in the commissioning of HVAC systems. The techniques utilise models that are extended to treat different types of faults. A sequence of test signals is applied to the system under test and the measured sensor and control signals are used to estimate parameters of the models relating to certain faults. These parameter estimates are compared with values calculated from design information. Differences are taken to be evidence of faulty or unsuitable equipment, incorrect installation, or inadequate commissioning.
To prevent the problems of internal condensation inside building walls, it is necessary to predict the moisture behavior exactly not only in the hygroscopic region of moisture content but also in the non-hygroscopic region. The purpose of this study is to understand the behavior of condensation in building materials. For a single layer wall, which consists of a single material, previous studies have been done by a variety of authors.
and diagnostic method on a rooftop air conditioning unit. When faults occur in the unit, the measured thermodynamic states differ from the states which are predicted by a model for normal system behavior, generating residuals. The magnitude and statistical uncertainty of the residuals determine the detection sensitivity of the technique. The directional changes in the residuals are statistically compared with a set of rules in order to diagnose a fault.
Hydrocarbon (HC) refrigerants are environmentaly safe, readily available, non toxic, and have good thermodynamic and transfer properties. However, they are also flammable. The subject of this paper is the effect of leakage of refrigerant into the passenger compartment of a vehicle from an assumed fracture in the refrigerant circuit. If the resultant mixture in the passenger compartment is close to stoichiometric, it can be ignited and create sufficient overpressure to damage structures.
Cooled beams are used to provide cooling of the spaces by means of natural or forced convection. Cooling capacity of static beams, which are working by natural convection, strongly depends on the thermal environment of the room they are installed in. The effect of the cooled beams location in the room and distribution of heat sources on the cooling performance of the beams is illustrated by the computational fluid dynamics - CFD calculations with reference to measurements.
The current French energy conservation regulation for non-residential buildings was elaborated at the end of the 80 s. Since then, many parameters have changed (energy prices, emergence of new techniques, growing public concern for the environment, ...). It is the reason why the public authorities have decided to reinforce the energy conservation regulation. The expected result is a global reduction in energy consumption of about 25% as regards the current situation.
Building owners and design offices wish to be provided with relevant and objective data on the quality of BEMS systems (Building Energy Management Systems) available on the market. As for BEMS manufacturers, they would like to have their products recognised in terms of quality. To reach this twofold objective, CSTB and EDF (French Electricity Board) have developed a procedure for assessing these systems. This procedure is based on tests performed on CSTBs SIMulator for Buildings And Devices (called SIMBAD).
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