District heating of the Municipality of Cuéllar

Buena Práctica / Bonne Pratique /

Boa Prática

NOMBRE

NOM

NAME

District heating of the Municipality of Cuéllar

Localización

Localisation

Localização

Cuellar (Segovia, Castilla y León)

Tipología – Naturaleza

Typologie – Nature

Tipologia – Natureza

Use, transformation and demand

Users avoid handling and storing fuels.
The supervision of boilers and the need for periodic recharges are avoided.
Overall, the efficiency of the system is greater.
Problems associated with lack of performance in old boilers or the need to control the quality and quantity of supplies are avoided.
The proposed method of operation will not affect the current facilities of the users, who remain in the current situation, being able to use them at any time.

Periodo de aplicación

Période d’application

Período de aplicação

1998 – Present

Principales objetivos

Principaux objectifs

Período de aplicação

Reduction of energy costs

Use of local biomass

Generation of local employment

Descripción detallada de la práctica o proyecto

Description détaillée de la pratique ou du projet

Descrição detalhada da prática ou projeto

Technically, the centralized system implemented in the town of Cuéllar consists of three main elements: the thermal power plant, the distribution network and the interconnection systems of the heating network with the user’s consumption elements. The system is completed with the necessary control elements to ensure supply conditions, emission levels and the measurement of user consumption.

The Thermal Power Plant is provided with two boilers, one of 5.2 MW and a second auxiliary boiler of 0.7 MW, in which the fuel is burned in the form of chips of 3 or 4 cm in length. By means of a group of pumps, the hot water coming from the boiler is introduced into a network of pipes three kilometers long where the water that has been heated in the boilers flows. Water is sent to homes, thanks to pumps, at 90 ° C and returns to the plant at 70 ° C. This distribution network consists of a double pipe heating system, one way that transports the hot water to the users and another one that returns the water already cooled to the plant after use. It is precisely the interconnection of the network with the user elements the last element of the system. Users connect to the network in parallel, all having the same supply conditions. The interconnection of the equipment is carried out by means of plate exchangers: on the one hand there is the primary circuit through which the water from the plant passes, and on the other hand the secondary circuit that brings the heating water to the radiators. These two circuits are connected currently in the plate exchangers for greater energy efficiency. For the Hot Sanitary Water is a similar operation by means of inter-accumulators in which the HSW that reaches the users is stored. There is no mixture of fluids at any time. It is important to highlight that the water of the plant is a closed circuit, it does not reach the faucets and radiators of each house, they are two independent circuits that do not mix, only exchange heat energy.

The system works completely automatically, it is the users’ consumption that controls the start-up of the different elements of the thermal power plant, so when a user makes a consumption it is automatically reflected in the return water temperature of the network, the plant is in continuous operation to provide the fluid with the necessary energy and that the flow temperature remains constant. All this in order to achieve comfort conditions with a continuous supply 24 hours a day at a temperature of 90 ° C. Supply of thermal energy to:

Municipal facilities: Sports hall (Capacity 1,500 people) Cultural center (12 rooms) Public School (600 students)
5 Collective housing blocks (225 properties)
14 single-family homes of high standing
Technical characteristics:
Boiler of 4,500,000 Kcal. (Winter) Boiler of 600,000 Kcal. (Summer)
100 m3 storage silo
Supply system
Lifting belt
Electric pumps
Multicyclone, smoke scrubber
Distribution network
Auxiliary control equipment
3Km network. long with pre-insulated carbon steel pipe. (Imported from Nordic countries)
Heat loss: 1º to -5º outside temperature