Error/warning overview
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Error/warning overview
System Check (SYS)
Errors (ESYS)
ESYS00001
The error message
Meaning
This error shows the fact that there is no pump placed to provide the necessary flow to the production unit/end unit/valves.
This can happen with a multitude of different components. The errors are as follows:
No pump for
Gate X of this buffer
the ventilation cooling unit
this changeover on the cooling/heating side
this end unit
this production unit
No pump in recirculation circuit
No pump on primary side of mixing circuit
No pump on secondary side of the second heat exchanger
No pumps over this control valve
Pump missing on
Primary/secondary side of heat exchanger
Primary/secondary side of heat pump booster
Primary/secondary side of the hydraulic separator
…
ESYS00002
The error message
This error allows you to keep calculating but is an hydraulic error.
Meaning:
There are 2 pumps which are placed in ‘series’. The error shows up because the second pump is placed after a mixing valve. When the valve is fully open the pumps are in series. Pumps in series cause control interference between the pump controls and the three-way valve controls, causing faster degradation of the three-way valve together with reduced control performance in operation.
How to solve:
You can solve this error in multiple ways:
Remove the primary pump and rely on an active distribution circuit.
Replace the active distribution circuit to a passive distribution circuit.
More information on active/passive distribution circuits can be found here: https://hysopt.atlassian.net/wiki/x/4YUhu
It is possible that during renovations, the erroneous situation is effectively in place. Therefore, you can continue working with the error to reproduce the behaviour in simulation. However, it is discouraged strongly to have pumps in series in your designs.
ESYS00003
The error message
Meaning
This error message shows during the system check if a base circuit (a block) is orientated incorrectly.
In the example above, you can see a pump in the supply line that is directed away from the end unit. Thi pump is thus installed in the wrong flow direction (note the arrows shown on the heat exchanger), hence the pump should be flipped (use shortcut 'F') and reconnect the pipes.
How to solve
Ensure that the highlighted base circuit is currently oriented. Use the shortcut ‘F' to flip the base circuit and the shortcut 'r’ to rotate the base circuit. The expected orientation is governed by following rules:
Pumps in the supply line should be directed towards end units.
Pumps in the return line should be directed towards production units.
On all other base circuits, the expected orientation is always displayed with an arrow.
ESYS00004
The error message
Meaning
This error shows if there is a pump placed after a dividing circuit, as this arrangement does not allow for the needed mixing that the valve is supposed to do.
How to solve
The pump should be placed before the diving circuit.
ESYS00005
The error message:
Meaning
This error message shows that there is a pump missing between the boiler and hydraulic separator.
How to solve
Place a pump at the primary side of the hydraulic separator.
ESYS00006
The error message
Meaning
This error points toward an hydraulic error where this is a pump placed after a control valve.
How to solve
It may be that this installation is correct, hence, an accurate check to verify should be done. Otherwise it may be one of 2 issues:
The valve is placed incorrectly and should be (re)moved
The pump is placed incorrectly should be (re)moved
This error can also appear on:
Pumps found after pressure independent control valve
Pumps found after flow regulator
Pumps after two way control valve
Pumps found after satellite unit
Pumps found after differential pressure regulator valve
ESYS00007
The error message
Meaning
This fault can occur while using https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089204289 components, where a pump is only placed on (n)one of the ports.
How to solve
This fault needs to be fixed by adding a pump at either each branch or either having one pump after the parallel production BC.
This can also happen on switched production and switched consumers.
ESYS00008
The error message
Meaning
This fault occurs when the topology of the provided system is unclear, preventing Hysopt from performing a system check. In this case, Hysopt cannot differentiate between end units and production units due to ambiguous topology. If the direction of heat flow from production units to end units is unclear, an effective system check cannot be executed.
This error notifies the user that there may be a production unit placed at an end unit location, an end unit placed at a production unit location, or that a hybrid production block is missing when multiple production units are present. Hysopt needs to know the direction of heat flow based on the positions of end units and production units (e.g., to analyze the correct orientation of pumps). This faulty situation prevents Hysopt from performing the system check.
How to solve
Depending on the root cause, several solutions are added below:
Root cause 1: Multiple production units without using hybrid production blocks
When multiple production units are present, Hysopt expects the user to use a hybrid production block to indicate that the branch split occurs at the production unit side. Otherwise, Hysopt will interpret a branch split as going towards the end units. Additionally, hybrid production blocks are necessary in future calculation steps to specify the design heat flow in more detail. More information on how to use hybrid production blocks can be found in https://hysopt.atlassian.net/wiki/x/QYQhu.
Root cause 2: Production unit placed at an end unit location
In rare cases, a production unit might be mistakenly placed at an end unit location. This can be resolved by changing the production unit to an end unit if it was a mistake, or by applying a hybrid production circuit as explained above.
Root cause 3: end unit placed at a production unit location
Similarly, placing an end unit at a production unit location can cause ambiguity during system analysis. To resolve this, replace the incorrect end unit with a production unit from the library, or add another production unit to the system.
ESYS00009
The error message
Meaning
This error message shows that a PICV is missing between the pump and the change-over end unit or between multiple passive mixing circuits for change-over. The warnings are only shown when multiple change-over end units or passive mixing circuits are connected with each other.
How to solve
Place a PICV at the change-over end unit for proper hydraulic balancing.
ESYS00010
The error message
Meaning
This error message shows that a pump is missing between the production and the change-over end unit when using multiple mergers and a splitter circuit.
How to solve
Place a pump on the cooling system.
Warnings (WSYS)
WSYS01001
The error message:
This error allows you to keep calculating but is a hydraulic error.
Meaning:
There are 2 pumps which are placed in ‘series’. If the error shows upstream, you will find a pump closer to the energy centre. If the notification says downstream, you can find the pump closer to the end units.
How to solve this error:
It may be that this installation is correct, hence, an accurate check to verify should be done. Otherwise, remove one of the pumps to fix this error.
WSYS01002
The warning message
Meaning
As shown in the example above, there are two pumps placed in series at the primary side of the hydraulic separator. This is hence a serial pump arrangement. One of them is advised to be removed to avoid control interference between the pumps. On top of that, placing one pump will be more cost-effective and provide better operational performance.
This is possible on both sides of the hydraulic separator, but also in 3-pipe systems.
How to solve
In order to resolve this warning message, remove on of the pumps that are found in a serial configuration.
Compute Design Flow (Pro)
Errors (EPRO)
EPRO03001
The error message
In following example model, the two radiators are designed with a different temperature regime :
radiator 1 : 70°C/50°C
radiator 2 : 60°C/40°C
On the dividing node, we see the “Supply temperature mismatch“ error.
Meaning
It is physically impossible to have multiple design supply temperatures on the dividing node. Fluid that enters the node, will have the same temperature in both outgoing branches.
This error can occure during the following calculation steps:
https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089367213
https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089367389
https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089367697
How to solve
This error needs to be fixed on the secondary side (downstream) of the dividing node.
Check the supply temperatures that you entered downstream of the node, and make sure that all supply temperatures become equal.
Possible solutions :
adapt the design supply temperatures directly on the https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089205139 or regime changing base circuits like https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089204854/Active+mixing+circuit , https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089204969/Passive+mixing+circuit , …
introduce regime changing base circuits, like https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089204854/Active+mixing+circuit , https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3089204969/Passive+mixing+circuit , …
(expert) introduce the https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3227582540 base circuit.
EPRO03002
The error message
Meaning
This error is not a local error in itself, but shows that there is an error downstream in the system that blcoks the design flow calculation through the system. The error can have multiple root causes of which the most common ones are listed in the paragraph below.
How to solve
Root cause 1: Forgot placing a hybrid production base circuit.
Hybrid production blocks are Base Circuits (BCs) that assist the “Compute Design Flow” calculation step. In “Compute design flow”, the design heat flow is propagated from end unit(s) to production unit(s). When having multiple production units, Hysopt cannot decide independently how the design heat flow coming from end units needs to be distributed among the different production units. For this purpose, hybrid production blocks are introduced. This principle is illustrated in the figure below:
Whenever the user starts creating branches at the production unit side, Hysopt requires the usage of an hybrid production block. The most downstream error visible in the scenario is the piping node at which the branches split towars the production units. The issue can be resolved by placing the corresponding hybrid production configuration from the Hybrid production library wherever the new production unit branch is created.
Please note that a hybrid production circuit is necessary for each branch split that is in the opposite direction to the heat flow. For more information about hybrid production blocks and how to use them effectively, consult https://hysopt.atlassian.net/wiki/x/QYQhu .
Root cause 2: Inconsinstent data input at the most-downstream faulty base circuit
When investigating the base circuit most downstream that is highlighted in red, the local error message at that base circuit will typically give more information on the root cause of the issue. In the example below, the requested heat exchanger properties regarding primary supply temperature are impossible to achieve with the secondary supply temperature from the system. The issue needs to be resolved by updating the temperature inputs at the heat exchanger block to a realistic situation as explained in error message EOPT0008. For more information about a heat exchanger itself, consult https://hysopt.atlassian.net/wiki/x/JgAZxw .
Root cause 3: Base circuit oriented incorrectly
Whenever a base circuit is oriented incorrectly, the power propagation might be disturbed. The error is closely related to https://hysopt.atlassian.net/wiki/spaces/HRM/pages/3227942968/Error+warning+overview#ESYS0003. Whenever the situation occurs, the most downstream base circuit that is highlighted in red will be oriented incorrectly.
In most cases, the incorrect orientation is caused by pumps. The pump icon is an arrow in the direction of the water flow. This gives the following two rules:
For pumps in the supply line, the pump must be oriented from unit towards end unit
For pumps in the return pipe, the pump must be oriented from end unit towards production unit
By reversing the BC including the pump, the error can be resolved.
EPRO03003
The error message
Here you see a heat exchanger which gets this fault (note that in the case of air volume flow you are using a dry cooler, and the same comments for return temperature apply).
This is due to the definition of the heat exchanger. There are 2 options:
a UA value is applied, which Hysopt uses to calculate the primary return temperature based on the secondary design flows/temperatures, the UA value and the primary supply temperature.
primary flow and return temperature are filled in, which Hysopt used to calculate the UA value based on primary and secondary flow. temperature.
As you can see, Hysopt will do a calculation based upon the filled in parameters. If both return temperature and UA-value are filled in and locked, Hysopt is not able to make the calculation. Leave one of them to be calculated by Hysopt to correct this error message.
EPRO03004
The error message
This fault can occur when you are using dry coolers. One of their parameters is the ‘zero load propagation’. As the name states, choosing “yes” means that the dry cooler is not part of the full load design conditions in summer when the building requires cooling. This means that from the moment pipes cross the path from the dry cooler to the production units, this thermal power won’t be accounted for. If however, the user wants to summarise the thermal power of the dry cooler and the other end units, “no” should be selected.
The error can occur if 2 or more zero load propagation combines together, Hysopt doesn’t understand the sum of multiple zero’s. This is something being worked on, but if you meet this fault, has not been fixed yet.
Workaround:
Using the Design conditions override for cooling, ou can use the power propagation and set it to zero. This allows you to calculate the fault.
EPRO03005
The error message
Root cause
This fault occurs when the temperature of the Base Circuit downstream from the error expects an application (e.g. heating) different than the rest of the system (e.g. cooling). In the example below, you can see a cooling system design. However, the Supply Temperature parameter of the bypass component is 75°C which is a typical heating temperature.
The error notifies the user on the mistaken supply temperature input. The error occurs when using Base Circuits (BC) from the Header Configuration sublibrary, in particular all bypass components and open end components.
Solution
Adjust the Supply Temperature parameter on the bypass or open end Base Circuit at the end of the line to the correct design temperature. In the example above, changing the wrong supply temperature of 75°C to 10°C (in accordance with the rest of the cooling design) resolves the issue.
EPRO03006
The error message
This error can show up on a low-loss header when both the supply and return temperatures are filled in. This does not allow for the exact mixing possibility between the primary and secondary sides.
Verify with the project what needs to be filled in. If no mixing is needed on the low-loss header, simply leave blank.
Warnings (WPRO)
Currently empty
Pipe selection (PIP)
Errors (EPIP)
EPIP06001
The error message
Meaning
The error occurs when there are high design volume flowrates where no default pipes diameters (depending on pipe type) are suited for.
How to resolve
There are multiple options to resolve this error.
Lock the pipe diameter at the correct pipe diameter of the highest possible. ensure that pressure losses over the pipes are limited.
Expand the range of the pipe diameter by uploading custom pipe type and pressure profiles in the model settings.
More information about the pipe types and pressure profile can be found by using the following link:
Warnings (WPIP)
Currently empty
Optimise system components (OPT)
Errors (EOPT)
EOPT09001
The error message
This error may occur when executing the ‘optimise system components’-calculation step.
Meaning
The KVS value locked by the user has been set to zero. This would mean that the pressure drop over the valve would be infinite, which the solver can’t use to calculate.
How to solve
Set either the KV(S)-value to the correct value, or allow Hysopt to calculate the correct value. For the KV-value calculations use the build-in KV-value calculator tool.
If you require a valve to be permanently closed, use the base circuit “pipe end” which you can find under header configuration.
EOPT09002
The error message
This message can show up when you are using balance valves.
Meaning
A typical balance valve has a minimum required pressure drop of 3 kPa to ensure that pressure measurements is valid (See parameter Valve minimal pressure drop). This error is thrown whenever the calculated pressure drop over the valve, based on the design flow rate and Kv value , is lower than this Valve minimal pressure drop. This situation will only occur when you have submitted a Valve Kv Value and had the parameter locked.
How to solve
To start with, verify if the submitted Kv value is correct. If the balance valve is effectively placed in-real life, you can lower the Valve minimal pressure drop to 0 kPa to resolve the error. However, bear in mind that a pressure measurement at this valve then might be inaccurate in practice. To resolve the error fundamentally and ensure the Valve minimal pressure drop over the balance valve is met, simply unlock the Valve Kv Value and run through the design calculation steps to calculate a new, optimal Kv setting for this valve. Note that this change might impact other system parameters, like the pump head. Hysopt will ensure that this valve has a pressure drop of at least 3 kPa.
A second situation in which you might encounter this error is when you want to remove a balance valve from a Base Circuit (which cannot be done visually). You have then chosen to put the Valve Kv Value to the maximal value of 1000000000 to have no impact of the component in any calculation. When doing this, the pressure drop will be nearly zero so the error is also triggered. If in this situation, you can mute the error by updating the Valve minimal pressure drop to 0 Pa.
EOPT09003
The error message
This error can show up when having locked a pump head (or pump curve) during the ‘optimise system components’-calculation step.
Meaning
The set pump head is not enough to overcome the loop pressure at the design flow rate. Therefore, the system will not be able to achieve the design flow rate at full load condition, indicated by having an unbalanced underflow after optimise system components.
How to solve
Check the different possibilities for this error:
Is the pump head/pump curve locked correctly?
If not, change these to the correct value
Or let Hysopt calculate the needed pump head by unlocking the value
Are all the pressure drops in the system filled in correctly? You can easily check this by clicking on the pump and using ‘Ctrl+e’. This will show the path of most resistance. Follow this path and use dynamic label to analyse the pressure drops over different components. Compare these to the actual pressure drop and correct the wrong ones and recalculate.
EOPT099004
The error message
This fault occurs during the ‘optimise system components’- calculation steps.
Meaning
This fault occurs if the calculated pressure drop exceeds 20 bar (2000 kPa), as this is set as a maximum in the software.
How to solve
Check if all the pressure drops in the system are filled in correctly. It is advised to download the pump selection report to quickly get a concise overview of the pressure drops over the faulty pump.
You can also easily check the loop pressure drops by clicking on the pump and using ‘Ctrl+e’. This will show the path of most resistance. Follow this path and use dynamic label to analyse the pressure drops over different components. Compare these to the actual pressure drop and correct the wrong ones and recalculate.
It may also be that there are pipes locked on a size which is significantly to small, causing their pressure drop to be to large.
EOPT09005
The error message
you will find that this is not the calculation breaking error, but a note to check this carefully.
Meaning
There is no pump placed that provides pressure to the control valve.
How to solve
This may be accurate, so verify with the actual installation. Place the pump in the correct position.
EOPT09006
The error message
Meaning
The parameterisation of the pumps can be done through 2 methods.
By filling in the design pump head (which Hysopt will use to calculate a pump curve)
By filling in the pump curve (which Hysopt will use to calculate the pump head).
Filling in both pump head/pump curve does not allow Hysopt to perform this calculation, therefore one of the 2 should be unlocked.
EOPT09007
The error message
Meaning
This error message shows if the calculated design flow (defined by the end units) does not fit into the defined pump curve.
In the below fictional example, the maximum volume flow are is 0.07 m³/hr. If the calculated design flow is larger than this value, this error pops up.
How to solve
It could be that the presented situation is actually true. However, it is advised to perform a check on both the calculated volume flow rate as well as the filled-in pump curve. Search for either a calculated volume flow rate that is too high or a wrongly configured pump curve.
A common mistake is submitting a pump curve in in m³/h while needing l/s for example.
EOPT09008
The error message
Meaning
This error occurs on the parameterisation of the heat exchanger. In this example, the design temperature of the end unit is set to 70/50°C, and the primary temperatures of the heat exchanger are set to 70/50°C. Due to the efficiency of the heat exchanger, it is impossible to have equal primary and secondary supply temperatures (this also counts for the return temperatures).
How to solve
The primary temperature needs to be higher than secondary, with a certain ΔT. If the ΔT is sufficient, Hysopt will now be able to calculate a realistic UA-value.
Another solution is to use the relative option that will allow you to define directly the ΔT between the secondary supply temperature and the primary supply temperature.
EOPT09009
The error message
Meaning
This error occurs when Hysopt is unable to select a 2 or 3-way valve, because the calculated volume flow/pressure drop is out of range of a suitable selection. In the example above, you can see that the filled in capacity is 1W at 70/50°C, which calculates a nearly zero m³/hr flow. This was meant to be 1kW but is filled in incorrectly. Hysopt is unable to calculate a valve and hence sends this error message.
EOPT09010
The error message
Meaning
This error can occur when looking at mixing circuits, and is best understood through this simple example.
In this simple system there is an end unit which requires 1 kW at 70/50°C, fed through an active mixer and a boiler. In this case, there is no need for mixing in the design condition and Hysopt will optimise the 3-way valve to a KVs value that guarantees sufficient valve authority. The full load valve position equals 100%, meaning that the valve will be fully open in the design condition.
If however, the “primary supply temperature override” is filled in, (which is needed to define mixing in the design condition when another parallel branch expects a higher design supply temperature), Hysopt can calculate the needed mixing ratio like shown below. You see that the full load valve position is now decreased to 92.58% instead of 100%. This means that in design conditions, the mixing valve will be open for only 92.58% to ensure the mixing from 80°C to 70°C.
Now, if you fill in the “primary supply temperature override” with a value equal to the propagated value (in this example 70°C). Hysopt expects to perform a calculation to design this full load valve position, but cannot as getting 70°C while mixing a supply of 70°C and a certain amount of lower return is just impossible. This will cause the error to pop up that there is no valve position for the desired mixing ratio.
How to solve
The solution to this error is rather simple. If no mixing in the design condition is required, leave the primary supply temperature override empty as shown in the figure below.
EOPT09011
Error message
Meaning
This error can occur when using the “Pre-mix” base circuit or the mixing circuit with premix base circuit.
In case of the premix base circuit: If a pump is placed behind (~downstream from) the premix, the bypass is shortcutted as the ideal working on the system cannot be achieved.
For the mixing circuit with premix, the error occurs when a pump is placed wrongly at the primary side of the base circuit. The mixing circuit with premix is an active distribution circuit and does not allow a pump at the primary side.
How to solve
Both the position of the pump and premix bypass in the system’s topology should be verified and altered if needed.
For the mixing circuit with premix, update the system so that pumps in series are avoided.
EOPT09012
The error message
Meaning
This error shows if pumps are placed behind 2-way valves, PICVs, DPCV etc.
How to solve
The hydronic configuration is mall-designed and should be resolved. More information can be found by performing the system check to find Pumps found after ...https://hysopt.atlassian.net/wiki/spaces/HRM/pages/edit-v2/3227942968#Error-ESYS0006%3A-Pump-found-after-%E2%80%A6
EOPT09013
The error message
Meaning
The error occurs when using the serial consumer block and having the pump on one of the 2 end user sides instead of on the production side. The Hysopt software expects the pumps to be part of the circuit at the incoming arrow, which is hydraulically speaking not different than the initial situation with the pump at one of the end user sides.
How to resolve
To resolve the error, put the pumps on the incoming circuit as depicted below:
EOPT09014
The error message
Meaning
The error occurs when a pump is bypassed (e.g. Header bypass) and a branch connected to the bypassed circuit doesn’t have a pump. The water follows the path of the least resistance, therefore only circulating over the bypass and the boiler. The water will not flow to the Branch, because the pressure drop over the control valve and balancing valve is higher than the pipe route from boiler to bypass.