English

This paper discusses the energy saving principle of frequency conversion chilled water system. Analyzes the energy saving failure reason in actual engineering from the pipe lines and the pump two aspects and gets out the reason is adopting the constant pressure difference control method. Through a simplified chilled water system, compares the pump energy saving efficiencies under constant and variable pressure difference control methods. Get out that the frequency conversion system can reach the maximum energy saving efficiency under variable pressure difference control method.

Based on the generic dynamic building energy simulation environment, EnergyPlus, the simulation model of energy recovery ventilator (ERV) is built in this paper. With different indoor temperature setpoints, the energy performance of ERV along with the availability of ERV is investigated both for Beijing and Shanghai weathers in China in terms of the ratio of heat recovery to energy supply by HVAC devices and ERV. Simulation results show that the seasonal average of the ratio is linear with indoor temperature set-points.

The research technical approach of this paper is based of the application of expert system for monitoring and fault detection in heating and air-conditioning systems. In the paper, introduces some diagnosis methods of the performance fault of heating and air conditioning, analyzes the principle.

Using DeST Program, Simulation of Space Heating/cooling Load of two buildings has been conducted for Geo-Space Heating System using Gradient Utilization Techno- logy in university campus. Simulations were conducted in accordance with the different conditions: Temperatures & RH of Rooms, different sources of Weather Data, intensity of persons, Timetable of operation & Equipment, building constructions. Also measurement has been conducted using the measurement system. Then the comparisons between simulation & measurement were made.

In order to solve the unbalance problem and increase the system efficiency of central heating, a new-style adjusting model in the building internal system —onoff valve adjusting system which is composed of by the on-off valve 、controller、 indoor temperature sensor is put forward.

This paper discuss about characteristics and energy performance of personal air-conditioning system for a general multi-bed patient’s room. Two types of personal air-conditioning systems are evaluated by the laboratory experiment. Energy performance of a peri-counter FCU (a conventional) air-conditioning system is simulated by CFD to compare with that of personal systems. Compared with the conventional system, personal air-conditioning system has an advantage from the viewpoint of amenity improvement, but may consume more energy for cooling in the system.

A methodology for optimizing the operation of heating/cooling plants with multi-heat source equipments is proposed. The methodology decides the optimal combination of the running of multiple heat source equipments to minimize the energy consumption of a heating/cooling plant. The optimal running combination is decided automatically using MATLAB® Stateflow® tool corresponding to cooling and heating loads. The energy consumption at different running combination is simulated using MATLAB® Simulink® tool. A case study is introduced to demonstrate the methodology.

Natural ventilation is generally accepted as the preferred ventilation option as it is a healthy and energy-efficient means of supplying fresh air to a building. In the USA it is seldom being applied as most climate zones are considered unsuited to apply natural ventilation, mostly due to perceived uncontrollability and very humid and hot or very cold seasons. For mid and high rise apartment buildings the option of natural ventilation is virtually disregarded because the tradition of full air conditioning is so well established.

Energy recovery ventilator (ERV) is generally installed in an air-conditioning system to recycle the cooling load of exhaust air. However, air conditioning systems with the single ERV can not meet with outdoor air load and indoor cooling load in summer, which will cause fluctuation of indoor temperature. The goal of this study is to analyze such a fuctuating scenario of the indoor temperature. CFD and subjective evaluation are used in this study.

The principle of the thermal storage in building mass (TSBM) is storing thermal energy in building thermal mass, such as concrete slab, at night and discharging thermal energy naturally in daytime. It is expected that the thermal storage will be effective for reducing the heating load at the beginning of the operation in a cold region. Adding to that, the indoor thermal environment will improve because it heats up the cold floor slab directly. The simulation model was constituted to recreate features of TSBM, which were observed in a field survey in an office building.