Heat supply to the districts of the city

Contents

Entry

1. Design Task

Calculation and explanatory note

1.2 Graphic part of the project

2 Methodological Guidelines for Implementation of Project Sections

2.1 Determination of calculated heat hourly flow rates by types of heat loads

2.2 Construction of hourly schedules of heat consumption for heating, ventilation and hot water supply depending on the temperature of external air

2.3 Plotting of water temperatures and water flow charts in the heating network depending on the ambient air temperature for all types of loads, including the total water flow chart and the average suspended return water temperature graph

2.4 Construction of annual schedule of heat consumption by duration of outside air temperatures

2.5 Development of a schematic diagram of heat supply, including a diagram of water heating at the CHP and a diagram of the network makeup

2.6 Choice of type of heating network laying, building structures, type of heat insulation and heat insulation structures, mechanical equipment of heating networks

2.7 Hydraulic calculation of the main main line of the heat network and one response nearest to the CHP

2.8 Construction of piezometric diagrams of the main main heating system line and branches for winter and summer operation modes

2.9 Selection of network pumps at CHP

2.10 Determination of makeup water volume. Selection of makeup pumps

2.11 Selection of main heaters and peak hot water boilers at CHP

2.12 Selection of type of movable and fixed supports. Calculation of forces acting on one of the fixed supports

2.13 Calculation of angle working for self-compensation

2.14 Calculation of the gland compensator (the first from the CHP at the main master) and one U-shaped compensator (any according to the scheme)

2.15 Selection of thermal insulation design and calculation of the thickness of the main thermal insulation layer for the head section of the thermal network

Construction of longitudinal profile 1 km

2.16 Calculation of CTP heating unit (for closed heat supply system - for hot water supply, for open heat supply system - for heating)

3 Literature recommended for course study

Appendix A

Appendix B

Appendix B

Set Course Project

Develop a heat supply system for the districts of the city, including a heating plant of the CHP, main heating networks, and central heating centers of the microdistrict.

Plot Heat Flow, Graphically Show Heat Network Wiring Route, Plan

The coolant is water heated in the main and peak heaters of the CHP.

All residential areas are connected to single-tube heating networks.

Calculation and explanatory note

Determine estimated (average and maximum) hourly heat consumption for heating, ventilation and hot water supply of residential areas.

Plot the heating, ventilation and hot water flow rates per hour depending on the ambient temperature.

Plot water temperatures and water flow charts in the heat network depending on the ambient temperature for all types of loads, including the total water flow chart and the weighted average return water temperature graph.

Construct an annual schedule of heat consumption according to the duration of outside air temperatures.

Develop a schematic scheme of heat supply, including a scheme of water heating at the CHP and a scheme of network makeup.

Choose the type of heating network laying, building structures, thermal insulation and thermal insulation structure, mechanical equipment of the heating network.

Perform hydraulic calculation of the main main line of the heat network and one branch nearest to the CHP.

Build a piezometer for winter and summer modes of operation of the thermal network. On the pesometer indicate the heads of the network and make-up pumps.

Pick up the network pumps. Build a summary characteristic of parallel operation of pumps and a characteristic of the heat network. Define the network work point.

Determine the volume of makeup water. Select make-up pumps. For open heat supply systems, develop a water treatment scheme.

Determine the capacity of the main heaters and peak hot water boilers at the CHP. Calculate the type and number of main heaters and select a hot water peak boiler. Perform deaerator calculation for open heat supply system.

Select the type of movable and fixed supports in channels and chambers. Calculate the forces acting on one of the supports (the first stationary support from the CHP on the main highway).

Calculate one angle that works for self-compensation.

Calculate one gland compensator (the first from the CHP on the main main line) and one U-shaped compensator (any according to the scheme).

Select the thermal insulation design and calculate the thickness of the main thermal insulation layer for the head section of the thermal network.

Calculate CTP heating unit (for closed heat supply system - for hot water supply, for open heat supply system - for heating).

The scope of the explanatory note includes graphs and diagrams.

Schedule of hourly heat consumption for heating, ventilation and hot water supply depending on ambient air temperature.

Plots of temperature and flow rates of water in heat conductors depending on the temperature of the outside air for all types of thermal load.

Annual schedule of heat consumption by duration of outside temperatures.

Piezometric graph for winter and summer modes of thermal network operation.

Schematic diagram of heat supply, including feed, water treatment and heating plant of CHP.

Design diagram of the thermal network.

Schematic diagram of CTP heating unit.

Choice of type of heating network laying, building structures, type of thermal insulation and heat insulation structures, mechanical equipment of heating networks

Water-water heat networks of the city's districts are single-tube, simultaneously supplying heat to heating, ventilation and hot water supply. Installation of the heating system is underground, channel, impassable. Heat networks are equipped with one- and two-side gland compensators, movable and fixed supports, heat chambers, gate valves, tees, taps, steel pipes of water and gas supply SNiP 2.07.01.

Construction of piezometric graphs of the main heating main and branches for winter operation

In closed heat supply systems, the flow rate of water in both pipelines of the heat network during the entire heating period and over the time of day is almost unchanged, so the piezometric graph is symmetrical about the axis of symmetry.

In connection with what is said for a closed heat supply system, it is enough to build symmetrical piezometers of summer and winter operating modes in the project.

When constructing piezometric schedules of closed heat supply systems, general requirements are taken into account:

- maximum head in the return pipeline shall not exceed 60 [m of water. Art.] in dynamic and static modes;

- head in the return pipeline and statistical level shall ensure filling of building heating systems;

- supply line piezometer shall not cross water boiling lines at its maximum temperature at any point of the route;

- supply line piezometer shall not cross the allowable pressure line according to pipeline strength conditions at any route point;

- reverse line piezometer must not cross terrain on any section of the route;

- head at suction of network pumps must be not less than 5 [m of water. article]

Hydraulic calculation of heat network is used to construct piezometric graph. The graph is plotted in the following sequence:

- in the lower part of the sheet of millimeter paper of A3 format, a scale of the length of the main heating network line is applied at a scale of 1:5000. A 1:100 scale of head is applied at the transverse edge;

- according to the city contours, apply the profile of the main main line of the heating network and branch, as well as the height of the connected subscribers in the highest and lowest points of the relief;

- apply maximum and minimum allowable head lines in the supply and return lines of the heat network;

- selecting a statistical pressure line for filling conditions of the highest subscriber system with a head margin of 5 [m. st.].;

- build a head line in the reverse line of the thermal network from the CHP to the most recent design quarter, this line can be located above the statistical pressure line or cross it (depending on the location of the neutral point at the station - on the suction or jumper of network pumps);

- build a head loss line in the design quarter, for a closed heat supply system, head losses will be made up of head loss on hot water heaters (in the 1st and 2nd stage heaters, or only in the 1st stage heater - depending on the connection scheme of the heaters), head losses in the quarterly heating networks (10 [m water. st]) and the necessary head for the operation of the elevator (15 [m water. Article] according to [1]); For an open heat supply system, head losses will consist of head losses in heating heaters, taking into account losses in piping 5 [m. article];

- build the head loss line in the supply line of the heating system;

- build a line of head losses in CHP heaters (2530 [m water is accepted. Art.] for winter mode);

- building a summer mode piezometer (similar); head losses in the quarter and heating plant of the CHP take 1012 [m water]

In closed heat supply systems, subscriber hot water supply systems are hydraulically isolated from the heat network. Therefore, for economic reasons, the summer mode piezometer is placed much lower than in winter mode, but the head in the return pipeline should not be lower than 5.0 m at any point of the route.