Title: Development%20of%20EUC%20(End%20User%20Computing)%20System%20for%20the%20Design%20of%20HVAC%20(Heating,%20Ventilation%20and%20Air%20Conditioning)
1Development of EUC (End User Computing) System
for the Design of HVAC (Heating, Ventilation
and Air Conditioning)
- O.Yoshida, M.Andou
- Tokyo Gas Co., Ltd.
2Contents
- Introduction
- Feature of the EUC system
- Wide variety of DB (data-base)
- Original user-subroutines
- Verification of DB
- Conclusions
3Introduction
- CFD methods have become a promising tool to
optimise design parameters of HVAC by predicting
thermal environment in buildings. - While many advantage are expected, CFD codes
still require lots of expertise and time for
designers to model and predict indoor
environment. - Wider application of CFD has been expected, in
particular, to the field of EUC that designers
and even sales engineers can easily take
advantage of.
An EUC system for the optimal design of HVAC has
been developed.
4Feature of the EUC System
- Utilisation of PHOENICS
- Flexible pre-processor
- Powerful solver
- Easy VR post-processor
- Uniquely customised to predict indoor environment
in faster, more accurate and user-friendly
manners
- Wide variety of DB (data-base) for the analysis
of HVAC - Original user-subroutines
- Verification of DB
5Wide Variety of DB (Data-base)
- The system incorporated DB compiled during
various cases of predictions and experiments.
- The DB provides typical specifications of a
variety of air-conditioners and buildings as a
set of Q1 files.
- It also maintains previous Q1 and PHI files as
reference, which can be readily upgraded to
predict similar problems .
6Original User-subroutines
- Along with the DB, series of practical
user-subroutines have been developed using
GROUND. - These user-subroutines are applicable to predict
ideal performance and operating conditions of
air-conditioning units under desired optimal
thermal environment. - Optimisation of input conditions such as efflux
temperature is conducted to obtain desired
thermal environment in a room.
7Original User-subroutines - ExamplePrediction of
Optimal Efflux Temp.
- Mean temperature at the height of 0.6m for each
of perimeter and interior areas needs to be 22?
to achieve desired thermal environment.
Unit_P(Q9m3/min)
Unit_I1(Q6) Unit_I2(Q6)
Interior (Area_I)
Perimeter (Area_P)
- Efflux temperatures are separately controlled
with reference to respective area temperature.
8Original User-subroutines - Example Algorithm
9Original User-subroutines - Example Temperature
Distributions
10Verification of DB
- Prediction accuracy of DB of the system was
verified a-priori, by comparing with detailed
measurements.
- Know-hows to generate a numerical grids have been
compiled to secure practical accuracy with
minimum calculation time .
11Verification of DB - Example Artificial Climatic
Room
12Verification of DB - Example Heating Conditions
13Verification of DB - Example Numerical Analysis
- PHOENICS 3.2
- Steady states
- Rectangular grids
- 383233 40128cells
- Elliptic-staggered equation
- k-epsilon turbulence model
- Hybrid differencing schemes
- Boussinesq buoyancy model
14Verification of DB - Example Center Plane of Air
Conditioner
15Verification of DB - Example Center Plane of
Model Room
Measured
Computed
16Verification of DB - Example Temperature Profiles
17Conclusions
- An useful EUC system for the optimal design of
HVAC has been developed using PHOENICS. - The system incorporated DB for the analysis of
HVAC as a set of Q1 files . - Along with the DB, practical user-subroutines
have been developed. - Prediction accuracy of the system was verified
a-priori, by comparing with detailed
measurements. - Computed result with incorporate DB was in good
agreement with measured result.