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集中供热系统是热集中产生的区域,与热水或蒸汽一起通过管网运输至建筑。热量通过一个热交换器转移到独立物业,然后用在常规加热系统(例如,在公寓,整个公寓地区可能只有一个热交换器)。对于整个城市来说，个人物业和城市公寓区供热系统规模相差很大，在丹麦,集中供热提供的热量约占60%,一些城市如哥本哈根主要利用来自大型发电站的热量和40公里外废物处理工厂产生的能量。

现代集中供热系统与传统的加热系统相比，可以提高成本效益，降低二氧化碳的排放量。这是因为，与个人物业锅炉供暖相比，大规模的集中供热能够降低成本，尤其是当结合发电站和供热装置的能量供应。热量通过管网运输，加上吸收式制冷机就可以冷却,提高系统的效率,有利于夏季使用。

Q) Establish some contractual and procurement difficulties if your Organisation were to be main contractor for installation of a district heating scheme serving 100 pensioners bungalows. Produce a basic procurement cost plan for contractors to price against.

CHAPTER 1: INTRODUCTION

District heating is a system where the heat for an area is produced centrally, and hot water or steam is transported to the buildings through a network of pipes. Heat is transferred into individual properties through a heat exchanger, and then used in conventional heating systems (in flats, for example, there may just be one heat exchanger for the whole block). District heating networks vary widely in scale from individual developments or apartment blocks to whole cities. In Denmark, where district heating accounts for about 60% of the heat supplied, cities such as Copenhagen receive heat from large-scale power stations and energy from waste plants situated up to 40km away.

Modern district heating can be cost effective and reduce CO2 emissions compared to conventional heating systems. This is because generating heat centrally at large scale can reduce costs compared to generating heat in boilers in individual properties, particularly when combined heat and power (CHP) plants are used. Heat transported through the network can also be converted into cooling using absorption chillers, again improving the efficiency of the system and also providing an option to use heat produced in the summer.

District heating is more environmentally friendly than conventional heating, the potential to reduce emissions will depend greatly on the fuel used and the type of central plant that is generating the heat. Modern district heating offers the potential to use a variety of low carbon and renewable heat generation technologies, such as CHP using fossil fuels, biomass or waste, biomass boilers or surplus heat from industrial processes. As an experienced and tested technology, employed effectively in many countries, district heating has evolved significantly from the days when it was first installed. Networks are now highly efficient, with sophisticated heating controls that allow suppliers to maintain the network and consumers to easily manage their heat use. Underground sensors are able to quickly locate any leaks, and back-up generating plant, is used to limit the effect of possible problems with the central generating plant.

CHAPTER 2: AIMS AND OBJECTIVES OF THIS STUDY

The main aim is to establish the contractual and procurement difficulties of the main contractor for installation of the district heating scheme serving 100 pensioners bungalows. The aims and objectives can be summarized as follow本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。