BuildSysPro.IBPSA.Fluid.Actuators.BaseClasses.ValveParameters

# .BuildSysPro.IBPSA.Fluid.Actuators.BaseClasses.ValveParameters

Model with parameters for valves

## Information

Model that computes the flow coefficients of valves. This base class allows the following modeling options, which have been adapted from the valve implementation in Modelica.Fluid to specify the valve flow coefficient in fully open conditions:

- `CvData = IBPSA.Fluid.Types.CvTypes.Av`: the flow coefficient is given by the metric `Av` coefficient (m^2).
- `CvData = IBPSA.Fluid.Types.CvTypes.Kv`: the flow coefficient is given by the metric `Kv` coefficient (m^3/h).
- `CvData = IBPSA.Fluid.Types.CvTypes.Cv`: the flow coefficient is given by the US `Cv` coefficient (USG/min).
- `CvData = IBPSA.Fluid.Types.CvTypes.OpPoint`: the flow is computed from the nominal operating point specified by `dp_nominal` and `m_flow_nominal`.

The treatment of parameters `Kv` and `Cv` is explained in detail in the Users Guide.

In contrast to the model in Modelica.Fluid, this model uses the protected parameter `Kv_SI`, which is the flow coefficient in SI units, i.e., it is the ratio between mass flow rate in `kg/s` and square root of pressure drop in `Pa`. The value of `Kv_SI` is computed based on the parameters `Av`, `Kv`, `Cv`, or, if `CvData = IBPSA.Fluid.Types.CvTypes.OpPoint`, based on `m_flow_nominal` and `dpValve_nominal`. Conversely, if `CvData <> IBPSA.Fluid.Types.CvTypes.OpPoint`, then `dpValve_nominal` is computed based on `Av`, `Kv`, or `Cv`, and the nominal mass flow rate `m_flow_nominal`. Therefore, if `CvData <> IBPSA.Fluid.Types.CvTypes.OpPoint`, then specifying a value for `dpValve_nominal` is a syntax error.

## Revisions

- January 22, 2016, by Michael Wetter:
  Corrected type declaration of pressure difference. This is for #404.
- August 12, 2014, by Michael Wetter:
  Changed attribute `min` of `dpValve_nominal` to `0`. This is needed as for example in IBPSA.Fluid.Actuators.Valves.Examples.TwoWayValveTable, `dpValve_nominal=0`.
- August 8, 2014, by Michael Wetter:
  Changed the `initial algorithm` to an `initial equation` section. Otherwise, OpenModelica attempts to solve for the parameter values using numerical iteration, and fails in doing so.
- May 29, 2014, by Michael Wetter:
  Removed undesirable annotation `Evaluate=true`.
- March 25, 2013, by Michael Wetter:
  Removed stray backslash in write statement.
- February 28, 2013, by Michael Wetter:
  Reformulated assignment of parameters, and removed `Kv_SI` as a public parameter because it is always computed based on other parameters. This change avoids a translation error in Dymola 2014 beta1 in the pedantic mode, and a translation warning otherwise.
- February 18, 2009 by Michael Wetter:
  First implementation.

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