您所选择的燃料，其价格可能取决于你所在地区颗粒厂最可用的废弃生物质。反过来，你选择的设备设计取决于可用的燃料。
Your fuel of choice and its price may depend on the waste biomass most available to pellet mills in your region. In turn, your choice of appliance design depends on the fuel available.
Part1
原料来源Source
在美国，全国各地的颗粒厂回收、分类、粉碎、干燥、压缩、包装木材和其他废弃生物质，使其变成方便处理的燃料。如今，在北美有超过60个颗粒厂，每年生产超过每年61万吨的燃料，在过去5年翻了一番。可以在颗粒炉具经销商、苗圃、建筑供应商店、饲料和花园用品商店，以及一些折扣商场。颗粒通常用40磅的袋子打包，按袋或按吨（50袋装运）出售。有些工厂提供20磅的袋子，更容易手提。In the US, pellet mills across the country receive, sort, grind, dry, compress, and bag wood and other biomass waste products into a conveniently handled fuel. Today, over sixty pellet mills across North America produce in excess of 610,000 tons of fuel per year, a figure that has more than doubled in the last five years. Pellets are available for purchase at stove dealers, nurseries, building supply stores, feed and garden supply stores, and some discount merchandisers. Pellets are usually packaged in forty pound bags and sold by the bag or by the ton (fifty bags on a shipping pallet). Some mills offer twenty pound bags for easier handling
Part2
共同特征Common characteristics
虽然不同的生物质原料的化学成分和水分含量各不相同，颗粒燃料研究所（Pellet Fuel Institute）已经确定其共同特征和开发的燃料标准。这些自愿性行业标准，尽可能保证最终产品的均匀性，是对天然原料的加工，但不是精炼燃料。 PFI等级燃料必须满足以下测试：
Although the chemical constituents and moisture content of different biomass materials vary, the Pellet Fuel Institute has identified common characteristics and developed fuel standards. These voluntary industry standards assure as much uniformity in the final product as is possible for naturally grown materials that become processed, but not refined fuel. PFI graded fuel must meet tests for
PFI等级燃料1、密度：一致的硬度和能量含量（最小40磅/立方英尺）Density: consistent hardness and energy content (minimum 40 pounds/cubic foot) 2、尺寸：长度（最大1½"）和直径（1/4"or 5/16"），以保证可预测的燃料量，并防止燃料干扰。
Dimensions: length (1½" maximum) and diameter (1/4"or 5/16") to assure" predictable fuel amounts and to prevent fuel jamming 3、细粉量：限制颗粒破裂的锯末量，以避免灰尘，同时在操作过程中负荷和颗粒流问题（细粉量经过1/8"筛子，称重不超过0.5%）
Fines: limited amount of sawdust from pellet breakdown to avoid dust while loading and problems with pellet flow during operation (amount of fines passing through 1/8" screen no more than .5% by weight)" 4、氯化物：限制盐含量（不超过300ppm），以避免炉或排气口生锈
Chlorides: limited salt content (no more than 300 parts per million) to avoid stove or vent rusting 5、灰分含量：维修频率的重要因素。Ash content: important factor in maintenance frequency.Part3
优质燃料和准级燃料之间的差异 Differences between premium and standard grade fuel
这两种等级的燃料除了灰分含量，其他所有由PFI标准定义的可测量的特征都是相同的。标准级颗粒燃料（高达3％灰分含量）的原料通常能产生更多的残灰，如有树皮木屑（其含有较多的杂质）或农业残余物像坚果壳。标准颗粒应仅用在指定炉具使用。All of the measurable characteristics defined by PFI standards are the same for both fuel grades except ash content. Standard grade pellet fuel (up to 3% ash content) is usually derived from materials which result in more residual ash, such as sawdust containing tree bark (which contains more impurities) or agricultural residues like nut hulls. Standard pellets should only be used in stoves designated for their use. 优质颗粒燃料（低于1％的灰分含量）通常由硬木或不含树皮的软木木屑制成。西部硬木优质燃料灰分含量约0.3％，东部硬木的则约为0.7%。优质颗粒占目前95%以上颗粒生产，一般都可以在专用标准或优质燃料炉子里烧。随着炉子设计的耐灰性提高，预计可提高标准燃料的可用性。
Premium grade pellet fuel (less than 1% ash content) is usually produced from hardwood or softwood sawdust containing no tree bark. Ash content varies in premium fuels from about 0.3% in some western softwoods to about 0.7% in eastern hardwoods. Premium pellets, which make up over 95% of current pellet production, can generally be burned in stoves calling for either standard or premium fuel. Increased availability of standard fuel is anticipated as stove designs continue to improve ash tolerance. 灰分含量决定燃料等级，由于其在维护频率中的作用。它是影响设备和通风系统除灰维护频率的主要因素。在早期的颗粒炉设计，燃料的兼容性是确定炉子是否运作良好的关键因素。燃料等级和特定灰分含量还有待考虑，但在颗粒炉技术的进步使燃料选择更广泛、更容易。灰筒尺寸、进料和格栅设计、适当通风、正确操作和维护等都影响维护频率。
Ash content determines fuel grade because of its role in maintenance frequency. It is the prime factor that determines maintenance frequency of ash removal from the appliance and venting system. In early pellet stove designs, fuel compatibility was the critical factor that determined whether a stove worked well or not. Fuel grade and specific ash content within a fuel grade are still to be considered, but advances in pellet stove technology are making fuel choice wider and easier. The size of the ash drawer, fuel feed and grate design, proper venting, correct operation and maintenance all play a part in maintenance frequency. 颗粒燃料有许多不同，不包括PFI标准。例如，Btu（英国热量单位）的含量范围可以从低于8000到近9000Btu，这取决于物种和国家区域。
There are a number of variations in pellet fuels that are not included in PFI standards. For example, Btu (heat) content may range from just under 8,000 to almost 9,000 Btu, depending upon species and region of the country.
颗粒原料中的微量矿物质不仅随地区变化，还与种植区有关。一些微量矿物质会促进结焦，灰团块会阻隔燃烧室进气口。燃料在炉内形成渣块的趋势是无法通过实验室分析预测的，因为不同的原材料和影不同燃烧条件变化都会影响过程。渣块会增加日常维护，但使用匹配炉子设计的专用燃料，可以最大限度地减少问题。尽管考虑原料的性质，颗粒厂仍争取做到一致性。每袋燃料有细微变化是不可避免的，但这差异通常是微不足道的，比原材料加工前要小得多。Other characteristics like trace minerals in pellet raw materials vary not only from region to region, but even in close by growing areas. Some trace minerals promote clinkering, the formation of clumps of fused ash that can block air inlets in the burn pot. A fuel's tendency to form clinkers in a stove cannot be predicted by laboratory analysis both because of variations in the raw materials and the different burning conditions that affect the process. Clinkering can increase routine maintenance, but professional recommendations for matching available fuels to stove design can minimize the problem. Pellet mills strive for consistency despite the nature of the raw material. Slight variations in fuel even from bag to bag are inevitable, but the differences are usually insignificant and much smaller than found in the original raw material before processing.
Part4
成本Cost
在美国，颗粒按袋（40磅）、按吨（50袋）、垫木包装（60袋）出售。在2010 - 2011年，售价在180-260美元/吨变化（3.60-5.20美元/包），平均约为220美元/吨（4.40美元/包）。价格因地区、可用性和季节变化，就像其他供热燃料一样。In the US, pellets are sold by the bag (40 lb), by the ton (50 bags), and by the skid (60 bags). In 2010–11, typical selling prices ranged from $180 to $260 per ton ($3.60 to $5.20 per bag) and averages about $220 per ton ($4.40 per bag). Price varies by region, availability, and season, just like other heating fuels. 因为袋装颗粒容易堆放、储存，很多谨慎的客户利用较低的淡季价格，提前购买以保证冬季燃料供应。售价只是成本的一部分。首要的问题是能源成本，用美元每百万BTU衡量。购买颗粒平均150美元/吨，在一个特定的颗粒炉燃烧，成本为11.50美元每百万BTU，这低于电供热成本，与其他燃料的平均能源成本相比，有竞争力。家庭取暖的实际成本，必须考虑到其隔热性和密封性、大小和布局、所需的舒适程度、以及当地气候。影响能源成本的其他经济因素，虽然很难量化，但是也值得考虑。生物质颗粒减少化石燃料的使用，往往是从外国进口的。颗粒生产用的每吨废料减少垃圾处理相关的成本上升。
Because bags of pellets stack and store easily, many prudent customers take advantage of lower off season prices and ensure their winter fuel supply by buying early. Selling price, of course, is only a part of the cost picture. The primary issue is the cost of energy, which is measured in dollars per million British thermal units. Pellets purchased at the average $150 per ton and burned in a typical pellet stove cost about $11.50 per million Btu, a figure that is less than the cost of electric heat and competitive with average energy costs of some other fuels. The actual cost of heating a home must take into account the insulation and tightness of the home, its size and layout, the level of comfort desired, and local climate. Other economic factors impacting energy costs, though hard to quantify, are also worth consideration. Biomass pellets reduce the use of dwindling fossil fuels, often imported from foreign countries. Every ton of waste material used in pellets reduces the rising costs associated with waste disposal.
持续不断为每1500平方英尺空间供热，每24小时颗粒炉平均消耗一袋40磅木屑颗粒。颗粒消耗取决于整体家居效率和炉具设置。
Run continuously, the average pellet stove consumes about one 40 lb bag of wood pellets every 24 hours for every 1,500 square feet being heated. Pellet consumption varies depending on overall home efficiency and stove settings
Part5
优势Advantages
颗粒的首要优势是其便利性。袋装颗粒容易堆放、存储。一吨颗粒可堆放在宽长高4英尺的空间内。袋装颗粒可以存放在干燥的车库、地下室、杂物间或棚子。The first appeal of pellets is their convenience. Bags of pellets stack compactly and store easily. A ton of pellets can be stacked in an area as small as four feet wide, long, and high, an area about half the space needed for a cord of wood. Bags of pellets can be stored in a small area of a dry garage, basement, or utility room or shed. 颗粒很方便，因为可以将它们很容易和很干净装入炉料斗。每天只需装一次，当炉子低设置使用时频率更低。小尺寸的颗粒允许精确调节燃料供给。换言之，可以更容易调节燃烧空气，实现最佳燃烧效率，燃烧室的燃料量是可预测的并且是一致的。高燃烧效率也是由于颗粒均匀低的含水量（始终低于10%，相比于积木20-60％的含水量）。均匀的低湿度、控制燃料批次、精确调节燃烧空气意味着高的热量输出，低水平排放量。
Pellets are also convenient because they load easily and cleanly into the stove hopper. Loading the hopper is normally required only once a day and may be even less frequent when the stove is used on low settings. The small size of pellets allows for precisely regulated fuel feed. In turn, combustion air can be regulated easily for optimum burn efficiency since the amount of fuel in the burn pot is predictable and consistent. High combustion efficiency is also due to the uniformly low moisture content of pellets (consistently below 10% compared to 20 to 60% moisture content in cordwood). Uniformly low moisture, controlled fuel batches, and precisely regulated combustion air means high heat output and a very low level of unwanted emissions .
颗粒燃料的使用带来除了清洁燃烧之外的环境效益。作为生物质燃料，颗粒通过可再生原材料提供可持续的能源供应的优势。使用颗粒也有助于减少废物处理的成本和问题。1993-94年，超过650万立方码的废物，被转移到堆填区，将其转化为颗粒的形式用于家庭供暖。作为壁炉传统，能欣赏颗粒燃烧和在家里享受舒适的冬天就是很美好的。
Other environmental benefits besides clean burns result from the use of pellet fuels. As a biomass fuel, pellets offer the advantages of sustainable energy supplies through renewable raw materials. Using pellets also helps reduce the costs and problems of waste disposal. In 1993-94, more than 6.5 million cubic yards of waste were diverted from landfills and converted to home heating in the form of pellets. As part of the tradition of the hearth, pellet burning offers the enjoyment of fire viewing and active participation in providing winter comfort in the home.