Danfoss ECL 310 Application guide

Application guide

Cascade control of heat exchangers

District heating distribution station

Distribution station

Application

A district heating utility wants to build a distribution station between the power plant and a residential area.

The distribution station should be able to supply approx. 100 residentials ~ 1 MW capacity and be future-prepared to expand the supply capacity when the residential area grows.

The district heating utility wants to establish the distribution station with 2 heat exchangers (or more) instead of one big one to achieve maximum eﬃciency and to control the heat temperatures by means of electronic controllers.

We recommend

• A362 application key

• ECL Comfort 310 controller

• ECL Portal

• Heat exchangers, XB71, brazed type

• AMV + AME actuators

• Motorized control valves (VS, VM, VB, VFM...)

• Pressure independent control valves (AVQM, AFQM)

For this application Danfoss has develop ed the A362 application key. Together with the ECL Comfort 310 controller it oﬀers weather compensated control of the ﬂow temperature in a heating circuit (residential area) based on advanced cascade control of 2 heat exchangers (HEX).

Up to 6 heat exchangers can be cascade controlled by 1, 2 or 3 ECL Comfort 310 controllers, each equipped with the application key A362. The ECL controllers are interconnected by means of the ECL 485 Bus.

Control valve characteristics are taken into consideration, and ﬂow in unused heat exchangers circuit can be stopped.

The ECL Comfort 310 controller can be connected to the ECL Portal for remote monitoring and control of the distribution station.

With the ECL Portal it is possible to monitor and control one or more ECL Comfort 310 controllers remotely from a pc or a smartphone app.

The ECL Portal is an eﬀective tool for ser vice personnel of district energy stations to streamline service, commissioning, maintenance and control tasks. Also, alarm messages can be sent directly to users via e-mails.

This internet-based SCADA solution requires no local server and will automatically conﬁgure its user interface and functionality to support the application in the controller.

Heat exchangers to be chosen for this application can be gasketed or brazed heat exchangers with 1-pass or 2-pass. They are available with both thread and ﬂange connections.

ECL Comfort 310 controller with key

Optional sliding return temperature limitation. Scheduled shift for inversed cascade (HEX-1 - HEX-2 and HEX-2 - HEX-1) can be set. Override inputs for start of HE X-1 and HEX-2 are available. M-Bus based signal can be used for ﬂow / energy limitation. Alarm functions are related to ﬂow and ﬂow temperatures.

In a 1-pass exchanger all connections are placed on the same side thus making installation very easy.

A 2-pass exchanger has connec tions on front and back, and smalle r temperature diﬀerence between primary and secondary side can be obtained.

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Application example:

Application example: A362.1 cascade control with 2 heat exchangers

System with 2 x HEX, each managed by means of one 0 - 10 Volt controlled motorized control valve (MCV) and one 3-point controlled MCV with position feedback. Each HEX circuit has its own circulation pump, but a common circulation pump can be used.

Additional accessories and options

S12 (0 - 10 V)

S13 (0 - 10 V)

ECL 310

+ ECA 32

S10

87H1757.10

S15

S16

V3 (0 - 10 V)

Danfoss

AMV + AME actuators

AMV and AME actuators are primarily designed to regulate valves in the respond to the demand of a controller in e.g. district heating, district cooling and HVAC systems.

They can be controlled by electronic

Other features:

• High temperature resistance

• Easy mechanical and electrical connection

• Robust design

controllers with modulating or 3-point control output.

Actuators have built-in thermic and overload protection of the electro motor. This radically reduces the risk of

AMV + AME actuators are mostly used with VS, VM, VB and VFM valves or with pressure independent valves AVQM and AFQM.

operational failure in either the valve or the system as a whole.

Electric actuator AMV/AME 65x

Feel free to contact us or visit www.heating.danfoss.com or https://store.danfoss.com for further information about Danfoss Heating products.

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