simulation

This paper presents the simulated results of human evacuation in a large space building. Two different models, Cellular Automata (CA) model and social force (SF) model are adopted. The simulated evacuation time and main characteristics of human evacuation are simulated and these results by the two models are compared. To check the practicability of the models for actual complicated cases, the simulating time is also compared. The results denote that both the two models can simulate the “arch” and “faster-is-slower” effect for human evacuation.

In order to determine the optimal combination of the heating source equipments in an existing office building, simulations of six different combination cases were conducted using the newly developed mathematical models of each component. From the simulation results, the optimal combination case can reduce the energy consumption by 19.7%, running cost by 12.8% and carbon-dioxide emissions by 29.6%, compared to the present operational combination.

A liquid desiccant fresh air processor is presented whose driven force is low-grade heat (65~70℃ hot water). Inside the processor, the desired cooling source for air’s dehumidification is indoor exhaust air’s evaporative cooling energy. Multi-stage structure is used to get higher total heat recovery efficiency of indoor exhaust air. The mathematical model of the fresh air processor is set up and realized by SIMULINK procedure. As the practical liquid desiccant fresh air processor is developed, its performance is tested with average COP (cooling load divided by heat source) 1.3.

In the internally-cooled liquid desiccant dehumidifier (ICLDD), cooling medium is introduced to carry away the vaporization latent heat, which enhances effectiveness of heat and mass transfer process between liquid desiccant and air. Numerical method is adopted in this paper to analyze the performance of ICLDD. Theoretical model of heat and mass transfer process is established and verified by available experimental results.

Definition of heating/cooling capacity ratio (HCR) of the heat pump air conditioner has been put forward in  this study, and the relationship between supply HCR (HCRS) and demand HCR (HCRD) has been illustrated.

This study aims to reveal the advantages of district heating and cooling system (DHC) in energy efficiency as an urban energy system in the future. In this study, an existing absorption-chiller-and-boilertype DHC plant, which utilizes large-scale combined heat and power (CHP), is chosen for a case study. We evaluate the energy-saving potential of the plant in the future by a simulation model.

The elements and classification of ground source heat pumps (GSHP) are expounded and its prospects in the Yangtze River Area of China were also indicated in the paper. The energy consumption of a model building in the area was simulated with eQUEST tool. Furthermore, the monthly and annual HVAC electric consumption of air source heat pumps (ASHP) and GSHP are contrasted and analyzed, and it is concluded that the GSHP is more efficient than conventional ASHP in the Yangtze River Area.

Simulation techniques have been playing a more and more important role in research and development of reliable and energy efficient building automatic control solutions. Furthermore, simulation is appraised as being viable to judge building automation and control solutions. Therefore, to test and evaluate control strategies, Siemens Building Technologies (SBT) developed a building and HVAC (heating, ventilation and air-conditioning) plant model library.

This paper explores the simulation of the thermal performance of a radiant floor for heating and cooling that is connected with an underground heat exchanger installed under the concrete floor of a house. In the heating season, an electric boiler is used to maintain the operative temperature at the set point value by varying the supply water temperature to the radiant slab. In the cooling season, the water from the radiant floor is circulated through an underground heat exchanger installed under the concrete slab.

In Japan, wooden detached residential houses are common; the wood components within a wall may undergo decay because of condensation in the wall or flushing defects, which can be a concern. The temperature distribution throughout the house, such as a high temperature in the attic space, can cause discomfort to the occupants. A double-skin system of room-side air gaps is considered to be an effective technique to handle these problems.