DEVELOPMENT OF BUILDING ENERGY MANAGEMENT SYSTEM FOR GAS AND ELECTRIC APPLIANCE

摘要

Since energy prices in Japan have been soaring after the Great East Japan Earthquake but energy consumption, particularly in the commercial sector, has been increasing annually, energy conservation in buildings is of paramount importance. Energy conservation in large-scale buildings has almost been achieved by installing building-automation systems and by educating their operators. Although energy conservation in small-medium scale buildings has not yet progressed much, it has just recently started picking up some pace. A large variety of building-energy management systems (BEMS) for small-medium scale buildings has been developed and will come into the market in the upcoming years. In small-medium scale buildings in Japan, many gas-engine driven heat pumps (GHPs) are installed along with electrically driven heat pumps (EHPs) as individual air conditioning systems. GHP is an air-conditioning system which has high-efficiency, low electric power consumption and low running costs. More than 600,000 units of GHP have been installed since 1985. Lately, a new type of GHP called "GHP XAIR" has been developed. The GHP XAIR has a top class annual performance factor (APF) and a feature called "Energy-Saving Operation" which can decrease energy consumption by an average of around 20 % without sacrificing comfort, when compared with its general operation. In addition to the installation of the GHP XAIR, a new BEMS called Rakusho BEMS has been developed to promote energy conservation in small-medium scale buildings. The Rakusho BEMS can control not only electrical facilities such as EHP, lighting and ventilation, but also gas facilities such as GHP and micro CHP. It can also visualize gas and electricity consumption, and can calculate, in advance, the amount of energy required. Furthermore it can analyze all measured data stored in the cloud server and provide useful energy consulting services to the users of the buildings without energy management experts. The Rakusho BEMS has the following remarkable features: - It can connect and communicate with GHP XAIR, and this makes it possible to achieve a large energy savings, of about 20 %, by using a variety of additional functions such as Predicted Mean Vote (PMV) control and schedule control. - It is also efficient in conserving electrical power by EHP control and ventilation control linked to CO_2 concentration. - It is applicable to the Demand Response Program. Since 2013, several Rakusho BEMS have been installed in business-use buildings, commercial buildings and workout gyms. It will be one of the core systems for our Gas and Power business in the future.