Parallel

Parallel production

Base circuit and parameters

Parallel production makes it possible to configure multiple productions that work simultaneously in one system. This system topology is often referred to as a cascade. The following figure shows the Hysopt Base circuit with corresponding parameters. On the base circuit, you can find gate 1 and gate 2 from the numbers on the icon, respectively denoted as primary or secondary gate. For reason of clarity, we will call the connection at the right side of the base circuit Gate 3.

 

image-20240528-152827.png
Overview of parallel production Base Circuit (left) and the parameter list (right)

Notice that the direction of the red/yellow arrows indicates the direction of the energy flow.

Usage

The design heat flow arriving at Gate 3 needs to be distributed amongst Gate 1 and Gate 2. To define this heat flow distribution, the user can submit input values in the parameter list. The parameter lists asks the user to give information about the heat flow at Gate 1. From the known heat flow at Gate 3 and the input about Gate 1, the heat flow at Gate 2 can subsequently be deducted based on the chosen Power propogation mode. The most common power propagation mode is ‘Regular’. For more info on power propagation modes see Power propagation examples.

An example is shown below for the Power propagation mode ‘Regular’ in which the sum of Gate 1 + Gate 2 always equals the design flow at Gate 3:

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Example usage of parallel production - Absolute input

Instead of defining the heat flow at the primary gate based on an absolute value, the user can also propagate a certain primary power percentage relative to the design flow rate at Gate 3. Subsequently, the design flow rate of Gate 2 can be deducted from the power propagation mode, the design flow at Gate 3 and the information with regards to Gate 1.

Primary power percentage will always overrule the Heat flow on primary circuit when the Primary power percentage has been given a value. The Heat flow on primary circuit thus becomes irrelevant if a Primary power percentage is submitted.

An extensive example on how to use the relative input for multiple parallel production circuits is shown below:

Parameter overview

The parameter window has three different parameters that determine the operation of this base circuit. Namely ‘Heat flow on primary circuit’, ‘Primary power percentage’ and ‘Power propagation’.

Parameter

relates to

Value range

Parameter

relates to

Value range

Heat flow on primary circuit

The absolute power coming from gate 1

[0 ; 100] MW

Primary power percentage*

The relative power coming from gate 1 to total demand

[0 ; 100] %**

Power propagation

How the power is divided over the gates***

Drop-down menu with three options****

* This parameter is optional and does not need to be filled in.

** When you fill in 100%, you will get an error. It is advised to fill in ‘Full load on primary gate’ on the parameter power propagation.

*** This division is necessary due to the calculation method Hysopt uses, which flows from the end units down to the production units. This division between multiple pipes requires parameterisation through the hybrid blocks.

**** The three options are: ‘Regular’, ‘Full load on primary gate’ and 'Full load on both gates’. See example 2 for more info about the effect of each option.

The following examples show how each of these parameters impacts the operation of this base circuit.

Examples

All these examples use the same installation with an equivalent radiator capacity of 200 kW. The only thing that changes are the parameters on the parallel production base circuit.

Example 1

For the first example, the left model has a heat flow of 120kW filled in on the "Heat flow on primary circuit", therefore the bottom boiler takes up 120 kW. The right model has a heat flow of 120 kW filled in and also a power percentage of 20%. As you can see in the example, the power propagated on the primary circuit is 20% of 200 kW. This shows that filling in the power percentage has priority over the filled-in heat flow on the primary circuit.

Example 2

For the second example, all the models have a heat flow of 120kW filled in on the "Heat flow on primary circuit". The difference is that the three models have different ‘power propagation' filled in.

When the Parallel production base circuit is set on ‘regular’, the heat flow that is filled in at ‘heat flow on primary circuit’ is filled in on the primary gate and the rest, 200kW minus 120kW, is filled in on the secondary gate. When the base circuit is set on ‘Full load on primary gate', the full power is set on the primary gate and everything before the primary gate is sized on the full load. The secondary gate and everything before it is sized on the full load minus the value that is filled in at ‘Heat flow on primary circuit’. When the base circuit is set on ‘Full load on both gates', the full power is set on both gates and everything before these gates is sized on the full load. Hence, this shows that filling in the ‘power propagation’ parameter has priority over the ‘Heat flow’ and the ‘Primary power percentage’ parameter. Only when the 'power propagation is set at 'regular’, the other two parameters are taken into account.

Common errors:

Error message

Translation of the error

solution

Error message

Translation of the error

solution

The value of ‘Heat flow on primary circuit’ is higher than the heat flow that is needed behind the base circuit.

Lower the value of 'Heat flow on primary circuit' until it is below the needed heat flow behind the base circuit.

 

The Hysopt software calculates everything from the end units to production units and this message says that it could not do his calculations for the last 6 nodes.

Hover with your mouse over the red node/base circuit closest to the end units to get additional information about the error.

 

The ‘Heat flow on primary circuit’ is the same as the heat flow that is needed behind the base circuit

Lower the value of ‘Heat flow on primary circuit' until it is below the needed heat flow behind the base circuit

The ‘Primary power percentage’ is set on 100%

Lower the percentage in 'Primary power percentage’

Switched production

Base circuit and parameters

Switched parallel production makes it possible to configure multiple productions that work individually in one system. The following figure shows on the left the base circuit of switched production and on the right the parameter window that pops up when you click on the base circuit. The numbers on the base circuit indicate which gate is the primary and secondary gate. This base circuit is used when you have a production unit that is only used when the other one is no longer sufficient. For example, a backup boiler that is used when the heat pump is no longer sufficient.

Note how the production unit that takes most of the load is connected to the secondary gate (the red arrow) and the backup production unit is connected to the primary gate (the yellow gate)

Parameter overview

The parameter window has two parameters that determine the operation of this base circuit, namely Primary production regime' and ‘Primary production heat flow.

Parameter

relates to

Value range

Parameter

relates to

Value range

Primary production regime

the temperature regime of the first gate

[-40 ; 200] °C ; [223 ; 473] K ; [-58 ; 392] °F

Primary production heat flow

The absolute power coming from gate 1

[0 ; 100] MW

The parameters of the three way on-off valve and the actuator doesn’t change the operation of this base circuit. The kvs-parameters determine the pressure drop over the valve and that impacts the sizing of the pump but not the operation of this base circuit. The actuator parameter is only relevant when you choose manufacturers in the ‘catalog'-menu. For more information on the three way valve’s parameters, the user is referred to https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3363864595.

Examples

All these examples use the same installation with an equivalent radiator capacity of 200 kW. The only thing that changes are the parameters on the parallel production base circuit.

Example 1

For the first example, both models have a heat flow of 120kW filled in on the "Heat flow on primary circuit". The difference is that the models have a different ‘primary production regime' filled in.

When the primary production regime’ changes, it has an impact on the (calculated) values of the circuits before the primary gate. This value has no impact on the other circuits of the installation.

Example 2

For the second example, both models have the same regime filled in. The difference is that the models have different ‘primary production heat flow' filled in.

When the primary production heat flow’ changes, it has an impact on the (calculated) values of the circuits before the primary gate. This value has no impact on the other circuits of the installation.