Mixed Programming Using FORTRAN and VB of Pipe Network for Heating and Air Condition Water System

2012 ◽  
Vol 610-613 ◽  
pp. 2478-2482
Author(s):  
Yang Cui ◽  
Lei Huang

As the scale of the air conditioning system is constantly increasing, some problems still exist and remain to be solved in the chilled water system. Among them, the leading problems lie in the insufficient research of the overall character on the user side and lack of simulation analysis. Corresponding calculating procedures are mixed programmed using VB and FORTRAN language to conduct to simulating analysis, to testify reliability and feasibility of the method.

2012 ◽  
Vol 170-173 ◽  
pp. 2564-2567
Author(s):  
Huai Ming Ning ◽  
Guo Feng

Heating and Air Condition, Pipe Network, VB,FORTRAN,Mixed Programming Abstract:As the scale of the air conditioning system is constantly increasing, some problems still exist and remain to be solved in the chilled water system. Among them, the leading problems lie in the insufficient research of the overall character on the user side and lack of simualtion analysis. Corresponding calculating procedures are Mixed programmed using VB and FORTRAN language to conduct to simulating analysis, to testify reliability and feasibility of the method.


2012 ◽  
Vol 204-208 ◽  
pp. 4280-4285 ◽  
Author(s):  
Jian Min Sun ◽  
Chun Dong Zhang ◽  
Ze Yang Zhou

Considering the central air conditioning system is highly susceptible to interferences from external environment, this paper established a dynamic mathematical model for chilled water system with the air conditioning area, fan coil unit and air conditioning area interference factors. Selection of chilled water system as a controlled object, designed the energy saving control system for central air-conditioning. The inputs of PID controller are deviation of actual temperature and setting temperature, and the change rate of the deviation; output is operation frequency of pump. Experiment shows that, PID control system in 90% time operating at a frequency of 10Hz-40Hz, average is 32.5Hz. Compared with no control system, the pump power consumption was reduced 33.9%.In conclusion, PID control in the central air conditioning system have a good energy saving effect.


2015 ◽  
Author(s):  
Hamad H. Almutairi ◽  
Jonathan Dewsbury ◽  
Gregory F. Lane-Serff

Residential air conditioning consumes a huge amount of the produced electrical power from fossil fuel power plants in Kuwait. Energy availability and the consequences on Kuwait’s expenditure associated with producing electricity is a hot topic in this oil producing country. The predominant air conditioning type in Kuwait’s residential sector is packaged direct expansion. An intention to shift to chilled water air conditioning system for future’s houses was announced as a promising solution to save energy. This work is presented to demonstrate how lifecycle cost analysis can be performed to underline tentative issues before shifting to a new air conditioning system for houses in Kuwait. No previous attempts have been made to assess the feasibility of chilled water air conditioning system for houses in Kuwait based on lifecycle cost analysis. The work considered the air conditioning requirements for a block of six typical houses as a baseline for the evaluation. The total cooling load of the studied block of houses was used to estimate the annual electrical energy associated with each air conditioning alternative. This was made by the help of DOE EnergyPlus thermal simulation engine through its interface with DesignBuilder software. Actual financial inputs were penetrated in the analysis; which includes installation, operation and maintenance costs for each studied air conditioning alternative. It was found that chilled water system can conserve about 40% of the annual electrical energy required to operate packaged direct expansion air conditioning. But, due to high installation cost, chilled water system is not cost effective for consumers. The outcomes from the lifecycle cost analysis indicated that it would be cost effective for the government to subsidy the installation of chilled water systems for consumers. This will help to conserve electrical energy associated with conventional systems that are currently in use.


2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Zhida Zhao ◽  
Nanyang Yu ◽  
Tao Yu ◽  
Lisha Ye

As an important subsystem in air-conditioning system, water system connects the chiller and terminal equipment. Therefore, it is necessary to develop an accurate thermal model for chilled water pipe to create the suitable indoor temperature and humidity environment. In this paper, the thermal model of the pipe was considered by utilizing the simplified thermal time-delay state-space model with the mass, energy balance, and heat consumption equations. Based on this improved model, the preview control as control strategy for water pipe temperature was proposed, and its robustness and stability were discussed. Subsequently, the performances of this model and control strategy were tested in a fan-coil system simulating with MATLAB and TRNSYS (Transient System Simulation Program). Explicitly, the results show that this model accurately predicts the thermal characteristic, and the average mean squared errors for water temperature were 11.14% and 12.82%, respectively. Meanwhile, the tracking effect of valve controller was better than the control strategy with no preview control.


Author(s):  
Ghanshyam Gaudani ◽  
Alex Quintal ◽  
Dragoljub Kosanovic

Chilled water systems constitute a major portion of energy consumption in air conditioning systems of the large buildings and process cooling of the manufacturing plants. These systems do not operate optimally in most of the cases because of the operating parameters set and/or the components used. The Chilled water system analysis tool software (CWSAT) is developed as a primary screening tool for energy evaluation. This tool quantifies the energy usage of the various chilled water systems and typical measures that can be applied to these systems to conserve energy. The tool requires minimum number of inputs to analyze the component-wise energy consumption and incurred overall cost. Both air-cooled and water-cooled systems can be analyzed with this tool; however, this paper focuses on water-cooled systems. The tool uses weather data of the chilled water system location and loading schedules to calculate the chilled water system energy consumption. The Air-Conditioning and Refrigeration Institute (ARI) standard 550/590 typical loading schedule is also incorporated for the chiller(s) loading. The tool is capable of comparing economics by analyzing the energy consumption and relevant cost of the existing system and the new system with cost reduction opportunities considered like: (1) increase chilled water temperature set point, (2) lowering the condenser cooing water supply temperature set point, (3) replace chiller(s), (4) Apply variable speed control to chilled and/or condenser water pumps, (5) upgrade cooling tower fan speed control, (6) Use free cooling when possible for water-cooled systems. The savings can be calculated separately for each cost reduction opportunity or can be combined. The economics comparison can be a primary decision criterion for further detailed engineering and cost analysis related with system changes. The comparison between actual system energy consumption and CWSAT results are also shown.


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