Course project on heat supply of the city district with drawings

Contents

Contents

Introduction

1. DESIGN INPUT

1.1 Characteristics of the construction area

1.2 Determination of design heat flows

1.3 Design Coolant Flow Rates and Network Pump Selection

2. HYDRAULIC CALCULATION OF HEAT NETWORK

2.1 Definition of the main circulation ring

2.2 Hydraulic calculation of heat network

3.1 Hydraulic mode of heat network

3. SELECTION AND CALCULATION OF HEAT NETWORK ELEMENTS

3.1 Pipes

3.2 Isolation valves

3.3 Piping Temperature Extension Compensators

3.4 Pipe supports

3.4.1 Movable supports

3.4.2 Fixed supports

3.5 Selection of thermal network laying elements

3.5.1 Channels

3.5.2 Heat chambers

3.5.3 Compensation niches

3.6 Selection and calculation of thermal insulation

Conclusion

List of sources used

Introduction

In recent years, the priority of developing district heat supply to cities and settlements from large sources of thermal energy (CHP, boiler houses, ACT) has been questioned. Life has shown that, despite the thermodynamic and energy efficiency of district heating, in particular heating, this path also has a number of significant shortcomings. Perhaps the main one is the difficulty of harmonizing the interests of energy producers and consumers.

However, awareness of this fact does not mean making significant adjustments in the coming years in the development of the energy economy of large and small cities of Russia. Existing traditions (organizational and technical), existing infrastructure and much more suggest that, at least a few decades in advance, the development of district heat supply will remain the main focus of providing thermal energy to large settlements and industrial enterprises in Russia and other CIS countries. In this regard, the requirement to improve the quality of design of heat supply systems, the use of new technical solutions in this field remains very urgent.

One of the most labor-intensive and expensive elements of heat supply systems is heat networks. They are complex structures consisting of interconnected pipes, thermal insulation, temperature extension compensators, movable and fixed supports, shutoff and control valves, building structures, chambers and wells, drainage devices, etc. The costs of constructing heating networks in cities account for about 50% of the initial cost of building a CHP. At the same time, many years of experience in operating heat networks of various structures indicates their short-lived nature: the service life of main networks is 1618 years, distribution and intra-quarter - 6-8 years, and many heat pipelines, especially hot water supply, fail after 2-3 years. This is mainly due to the low corrosion resistance of thermal conductors, as well as violations of technology during construction, poor quality of individual operations, etc. This once again confirms the need to improve the methods of calculating and designing heat networks, the use of modern methods and software.

To date, there is no doubt about the need to take into account the technical and economic criteria and reliability level when designing heat supply systems. Quite deep scientific foundations, algorithms and software have been developed to ensure the possibility of such accounting. Moreover, the relevant requirements are enshrined in existing regulatory documents.

However, in the practice of real design, these issues are usually resolved based on the intuition and experience of designers, as well as the standards adopted in each particular organization. This is explained, first, by the lack of appropriate training among specialists, second, by the complexity of algorithms developed to date, the independent development of which is very difficult.

In addition, it should be noted that the solutions known in the literature involve setting a number of cost indicators (specific costs for electrical and thermal energy, laying heat networks, etc.).

Heat chambers

In the places of pipeline assemblies, construction of heat chambers is provided for the location of the serviced equipment (branches, straight pipe sections, valves - sectional gate valve (if any) and valves on branches, flanges, transitions, drain units, supports (if they are provided, etc.). When selecting the standard sizes of chambers for their placement, sufficient (at least minimum permissible distances between equipment elements and construction structures (free passages) must be provided.

To do this, first, the equipment of the units is arranged taking into account its dimensions, the placement of pipes in the channels applying to the CT, the minimum permissible distances in the light between the equipment elements, and then the possibility of using typical solutions, for example, according to a series of 3.006.1-2.87.5, is analyzed.

To collect surface and ground moisture in the chambers, pits are provided under one of (four) hatches.

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