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An expert fuzzy-PID fusion type controller is designed for VAV air conditioning system base on plenty of experience of practical projects. The principle of a typical VAV air conditioning system is introduced firstly. And the control characteristic curves of different VAV terminal units are given. The design thinking and course of expert fuzzy-PID controller for the VAV system is described importantly...
In this paper, water distribution network model of typical central air conditioning system is established, all aspects of pipe network simulation carried out by various segments of the system pressure distribution and velocity distribution, such as analysis of the entire network of transportation and distribution characteristics. Through the analysis of pressure and pump power transformer and flow...
Effect of three different fresh air modes on the indoor pollutant dispersion is analyzed by the method of CFD (computational fluid dynamics) simulation and experiment. The fresh air modes include natural ventilation, hybrid ventilation and mechanical ventilation with total heat exchanger. Performance of the fresh air modes is compared considering the factors like fresh air volume, heat/cold load and...
Basing the similarity theory, the scale effect model of the spraying water cooling system of according the prototype of the Gymnasium in University of Shanghai for Science and Technology was experimental studied in this research and the following conclusions could be drown: At summer sunny day in Shanghai which the solar radiation value of the experimental period were between 16.4-17.3 MJ??m-2. At...
This paper presents an identification method of the value of concentration in certain areas of rooms for edible mushroom culture medium, in the case where the introducing of the air represents the effect of the superposition of a flow convection (natural or artificial) and diffusion and of its recirculation, which acts as a feedback circuit. The result helps to understand how to conduct a recirculation...
In this paper, a math model of liquid desiccant air conditioning system is established, which is used for theoretical study and simulative calculation of the regeneration performance of desiccant solution in the padding tower. The regenerating experiment is operated at the lab with liquid desiccant air conditioning system. By comparing the data of calculation and experiment, the factors influencing...
The decorative material in automobile compartment sends out Benzene to cause the harm for health of the crew member, studies low of Benzene transportation in automobile compartment is precondition for formulating the control measures. In the present study we uses the multi-component model to numerical simulate status that decorative material on the chair sending out benzene, and analyze different...
This paper evaluates the economic effect of the Demand Response (DR) with Thermal Storage Air-conditioning (TSA) systems in electricity markets using market models based on the California Power Exchange (Cal-PX) and the Australian National Electricity Market (NEM). Our main objective is to evaluate the reductions in the Market Clearing Price (MCP) and wholesale purchase costs for all market participants...
The temperature and humidity decoupling control method was presented in this paper to resolve the coupling problem between temperature and humidify in central air-conditioning variable dew point control system. By introducing absolute humidity as an intermediate variable to control the machine dew point, temperature and humidify of system can be decoupled. Two input and two output transfer function...
The frequent flow induced corrosion of hydrocracking air cooler system always results in a significant economic loss of the petroleum enterprise. Aimed at the issue, the design of hydrocracking air coolers real-time system is completed on the basis of the frame of the corrosion control system. Aspen Plus software is embedded in the system for the modeling and simulation of the corresponding parameters...
The objective of this paper is to investigate a low complexity method for controlling systems with binary inputs that have costs related to switching. The control objective for this type of systems is often a trade off between the deviation from the reference and the number of switches (weariness energy efficiency etc.). For such systems a steady state solution might never be attained, but rather...
This paper studies the temperature control for an automobile air-conditioning (AC) system, especially the control of air flow rate in the circulation. Based on energy balance and mass conservation laws, the control strategy is proposed by analyzing the heat exchange between heat gains form outdoor environment and the AC equipment. To be more precise, sensible heat exchange characterized by room sensible...
In this work, we address the experimental evaluation of different soft-starting time-based strategies efficiency in reducing the dip in voltage and the inrush current of a window type residential AC unit line. The soft-starter is based on power electronic devices controlled through a firing signal generated by a programmed microcontroller during the first 500 ms. Direct and soft starting simulations...
Air flow organization and thermal comfort of an air conditioning office were numerically simulated with k-epsiv turbulence model. The finite volume method and SIMPLE arithmetic were adopted to disperse and solve the differential equation. Distribution law of mean age of air, temperature nephogram, velocity nephogram, PMV nephogram and PPD nephogram was studied in this paper. Simulation results indicated...
Air quality does much to people's health. Based on measured air flow rates, effects of different ventilation and extraction conditions, including velocity, temperature of ceiling ventilation, longitudinal ventilation and extraction on air quality at subway station platform are simulated by CFD, then strategies to optimize this air quality can be (1) decrease ventilation temperature, (2) increase ventilation...
With serious energy crisis and high demand for Indoor Air Quality (IAQ), natural ventilation has taken more and more attention, which is recognized to be an effective and economic method to decrease the risk of Sick Building Syndrome (SBS), as well as reducing air-conditioning opening time, and thus saving energy. In view of window's characteristics having a great effect on ventilation, the paper...
This paper presents an energy management system to reduce the energy consumption of a vehicle when its air conditioning system is in use. The system controls the mass flow rate of the air by dynamically adjusting the blower speed and air-gates opening under various heat and loads circumstances. Simulations were conducted for a travelling vehicle operating the air conditioning system without and with...
In order to use loads in an active and intelligent way to resolve technical problems in the networks or contribute to ancillary services, this paper presents a development of air-conditioning control that allows to reduce the peak consumption by maintaining thermal comforts. This control is based on the variable set-point temperature of air conditioning adapted to the permissible power. This power...
With the large use of residential air conditioner (A/C) motors during the summer peaks, the potential of motor stalling events have increased in the recent years. The stalled motor loads have been found to be the most important cause of delayed voltage recovery following severe system disturbances, such as a subtransmission fault. The proper modeling of the stalled motors is a very important factor...
Simulation, by resorting to suitable models, is often used by electric utilities in studies related with load forecasting, system reliability, power flow and demand-side management activities, among others. Nowadays, in restructured electricity market scenarios, activities involving buying and selling energy can also be studied through simulation. Different goals for those studies require different...
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