packageHeatPump_R407c

Information

This package allows the user to build a basic heat pump system by following a step-by-step procedure. The complete heat pump model is composed by the following components: a compressor (scroll-type), two plate heat exchangers one liquid receiver, a valve and two pressure drop model.

• Step1 We start by modeling the condensation of the working fluid with the following components:
  • Flow1Dim: It represents the flow of the working fluid
  • Source_T: it represents the temperature source --> it allows the condensation of the fluid
  • SinkP: pressure sink. It imposes the pressure to the system
  • SourceMdot: Mass flow source. It imposes mass flow and inlet temperature to the system
• Step2 We replace the Flow1Dim component with an heat exchanger component where the secondary fluid is considered incompressible --> Hx1DInc.
  • Choose StandardWater as working fluid for the secondary fluid
  • Choose upwind-AllowFlowReversal as discretization scheme
  • Impose constant heat transfer coefficient in the working fluid side
  • Impose an heat transfer coefficient depending on mass flow in the secondary fluid side
• Step3 Add the Liquid receiver after the condenser. The pressure is imposed by the pressure sink connected to the liquid receiver.
• Step4 Change the pressure sink after the liquid receiver with a volumetric flow sink. In this way the pressure will be imposed by the tank system.
• Step5 Add the Valve component after the liquid receiver
• Step6 Add the evaporator after the valve considering the secondary fluid as an incompressible fluid --> Hx1DInc.
  • Choose Air as working fluid for the secondary fluid
  • Choose upwind-AllowFlowReversal as discretization scheme
  • Impose constant heat transfer coefficient in the working fluid side
  • Impose an heat transfer coefficient depending on mass flow in the secondary fluid side
  • Step7 Add the Compressor compoennt and the Electric drive component which will allow to control the rotational speed fof the compressor. Add finally a constant source from the Modelica library (Constant source) to impose a constant rotational speed to the system.
  • Step8 Close the cycle and simulate over 100 seconds
  • Step9 Add pressure drop that are considered lumped in the lowest vapor density regions of both low and high pressure lines. Simulate over 100 seconds
  • Step10 In order to evaluate the dynamic performance of the system impose a variation in the compressor rotational speed at 50s and a variation in the aperture of the valve at 75s.
  In order to get a better visualization of the results the authors suggest the use of the ThermoCycle viewer which can be easly downloaded from http://www.thermocycle.net/.