【 Weak current College 】 on central air conditioning system and energy-saving---Power By 【 China power house network 】

Economic development, civil, public and business building in popularity of central air conditioner, have a serious problem of energy consumption. This article from the wall, air conditioning and heat source, the end of air conditioning, air conditioning water system and air conditioning management aspects raised a number of energy-saving measures and methods. 1, building envelope envelopes, such as walls and the roof have been compared in buildings in General. The following energy-saving aspects of Windows and doors from the elaborate: 1.1 control window wall than through exterior Windows build of heat consumption in occupies a total consumption of Gérard 35% ~ 45% in the guarantee under the premise of indoor lighting; reasonably determine ratio of the wall is very important. As a general rule all toward the window wall ratio shall not be greater than the following numbers: 25%; North East, 30% to 35% in the South. 1.2 improve hermetic room door and ACH from 0.8 h-1 drops to 0.5 h-1, cold consumption of a building can reduce 8%, the design should be airtight good doors and Windows. Installing doors and Windows closed is to improve airtightness of important means. Closed should adopt a flexible sound, with strict, received a strong and durable products. Under Windows, using different seal. If rubber bar, plastic or rubber seal, the combination of its shape can be a bar or a flush. Available paste, packed tight or nail knot method fixed. 2. air-conditioning heat and cold sources central air conditioning energy consumption generally consists of three parts, namely, 1. air-conditioning heat and cold sources; 2. air-conditioning unit and terminal equipment; 3. water or air transportation system. This three-part, heat and cold sources in energy consumption energy consumption accounted for about half of the total energy consumption is the main content of the air conditioning energy saving. Following the ice thermal storage system to host energy-saving. Ice thermal storage system: building air-conditioning cooling load required when all or part of the preparation of non-use of air time, its energy-saving up for air conditioning. The system of the host that the change of total energy consumption is not great, but you can use electricity when low peak electricity, but smaller in height with or without power-balance power peak and Valley-Dutch, slowing the power plant and the construction of supply and distribution facilities, is a recommended method of saving energy. Use cool system, there are two ways to load management strategies can be considered. When the electricity price in different time differences, we can all load transfer to cheap electricity time running. You can choose one can save enough energy to cool the traditional cold water unit, will the entire load to go outside peak, known as "all energy system". This approach is often used for rebuilding project using existing chillers, simply add a cool device and related auxiliary equipment, but be aware that existing chillers are applicable to ice storage system. This approach also applies to special buildings, large cold release required instantaneous, such as the gymnasium building. In the new building, part of the energy storage system is the most practical, is also an investment in effective load management strategies. In the load balanced approach, continuous operation of chiller, it at night for refrigeration and storage, use and storage in the daytime of the cooling capacity for the provision of refrigeration. Will run from 14 hours up to 24 hours, you can get the lowest average load. Required power costs significantly reduced and the chiller cooling capacity can also be reduced by 50-60% or more. By Hangzhou several projects such as: Construction Bank of China Hangzhou branch office building, Hangzhou new King Fuk department store of energy saving practice indicates that the system (economic indicators) in 25-35%. 3 air conditioning units and terminal equipment-madefan-coil and from looking at the overall level of similar foreign products compared to the same, but the comparison with foreign advanced level, the main difference is the power consumption, coil weight and noise. Therefore design necessarily to intended use light weight, unit fan power for cooling (heat) of larger units. Air conditioning units should be chosen unit fan, air pressure, air leak less matches, air transport coefficient of the unit. The following is the air conditioning unit of energy of VAV system: full air conditioning system design of basic requirements is to determine the air conditioning room transporting enough, after a certain deal of air to absorb more heat recovery and indoor humidity, thus maintaining indoor temperatures and humidity. It is the basic formula:-L-air, m3/h; Qq, Qx-air conditioning to absorb all the sensible heat hot heat recovery and heat, W; ρ-air density, kg/m3, desirable 1.2; C-air heat capacity at constant pressure, kj/kg ¡æ, desirable · C = 1.01; in, is — indoor air enthalpy and blast State air enthalpy, kj/kg, tn, ts, — indoor air temperature and air temperature, ℃. As can be seen from the formula, when indoor heat Qx values change and the need to make the indoor temperature tn remains unchanged, air L constant but change in air temperature can also be sent to rheumatism people fixed, changed into the air, that kind of change fixed air supply air temperature of the air conditioning system, typically referred to as fixed air flow system and fixed air temperature, changes in the air conditioning system, referred to as VAV system. For services in more than one room (or range) of air conditioning system, through the air-conditioning equipment in the processed air its supply air temperature must, in order to adapt to a room (or regional) variation of load, often require the establishment and maintenance of thermal devices, to the room (or range) of temperature and humidity in the required scope, otherwise, as to the room (or region) to the air flow is based on their maximum load = air volume and air temperature in the room (or regional) is part of the load, is bound to produce cold phenomenon. Force after cooling to wet processed air is needed to heat treatment, this kind of hot and cold processing of set-off, apparently is a waste of energy. For most comfort air conditioning requirements, and does not require a very strict control of temperature and humidity. VAV system you can overcome these shortcomings, it can change to a room (or regional) in the air flow to meet the needs of local load changes. Of course, the entire system of total air is also changing. Therefore, VAV system is running in an energy efficient air conditioning system. In a large civil architecture, each facing room day maximum load does not appear in the same moment. For constant air flow system, since it sent to the room's airLandscape of the County and the total system is fixed, so only the room of maximum load to design air. The VAV system you can adapt a day in the same time the load towards the room does not have a maximum value, the air conditioning system delivery (actually conveying energy) can be examined by the buildings facing the room between the transfer, thus the total design of air volume and the system can be reduced. In this way, the air conditioning equipment capacity can decrease, can save device costs of investment, but also further reduce energy consumption of the system. 4, chilled water system General conditioning system for the transmission and distribution of electricity, heating in winter period accounted for the entire building dynamic power of 20%-25%; in summer cooling period accounted for 12%-24%, thus saving energy or water systems. Currently, air conditioning water system there are many issues, such as 1. selecting pump is the design value find pump sample nameplate parameter, instead of by the pump performance curve selected pump number; 2. for each water loops to calculating the hydraulic balance. On the pressure differential vastly circuit did not take effective measures, hydraulic, misadjustment phenomenon seriously; large capacity, small temperature difference widespread, design temperature for, generally take back 5 ° c, but the actual summer chilled water system for return water temperature difference better to 4 ° c, poor only 2-2.5 ° c, resulting in the actual flow of water over the design of large 1.5 times so that water consumption has increased significantly. Water system should start from the following aspects: designers should pay attention to the water system design, serious water system design and calculation of the ring road and take the appropriate measures to ensure loop hydraulic balance. Carefully check and calculate the correlation coefficient of chilled water system, the practical implementation of energy-saving design standard value, the active promotion of variable speed pump, winter and summer dual-speed pumps and other energy-saving measures. 5, positive use of soil heat source at present, China's southern region air conditioning system is mainly used as cooling and air-source heat pumps, because of its "outdoor" affected by the ambient air temperature variation of seasonal constraints, in summer cooling load, the greater is the corresponding condensing temperature is higher; it is well known that the refrigeration system cooling water inlet temperature of the host has an important impact on power consumption; General projections, in certain cases, water inlet water temperature by 1 ° c, the compressor power consumption increases as the host of about 2%, improving energy consumption lithium bromide hosts approximately 6%. To do this if you can find a more ideal new heat source forms replaced or substituted the present use of air heat, will undoubtedly have a wide range of applications and significant energy saving effects. And compared to the ambient air on the ground, underground 5 m annual soil temperature stability and approximately equal to the average annual temperature, can be separately in summer and winter seasons offer relatively lower condensing temperatures and high evaporation temperature. Therefore, from the principle, the soil is a better than ambient air heat pump system and heat sources. The study shows that soil heat pump main advantages are: energy saving effect is clear, comparable energy-saving air-source heat pump system is about 20%; buried heat exchanger without defrosting, reducing energy consumption in winter defrosting; because the soil with good thermal performance, and solar combined with improved operating conditions in winter; buried heat exchanger to heat absorption of underground static, reduces the air conditioning system on the ground of heat and noise pollution. So if we can use partial replacement of soil heat pump, the air-source heat pumps must conserve energy with the possibility of forming a new air conditioning products. 6. strengthen the management of central air conditioner uses certain measures to strengthen air conditioning operation personnel training, to improve management quality, air operators operating permit system. The regulation and implementation of energy saving measures, and the operator's technology is directly related to the meeting quality; have the necessary knowledge of refrigeration and air-conditioning; to know according to the outdoor adjustable parameter change; to know how to adjust the will and energy saving. Central air conditioning for metering and charging that is building energy efficiency an essential measures. At present in Europe and the United States and other countries have heat metering is proven technology, according to survey data show abroad: centralized air conditioning metering and charging, the energy saving rate at 8%-15%. Also in the measurement must be made. Energy conservation is key to achieving sustainable development. We need to focus on the total energy consumption of 20% of energy consumption. As an HVAC professional workers, should actively seek all possible restore energy.
Editorial: Feng Rui-Kit