[TRNSYS-users] Partload operation of Water to Water Heat Pump (Type 668)

[Fred Betz]

The other heat pumps Type505 and Type 665 have an air stream, and I need a water-to-water heat pump.

Is there another heat pump I am missing?


Fred Betz  PhD., LEED AP
Sustainable Systems Analyst



AEI | AFFILIATED ENGINEERS, INC.
5802 Research Park Blvd. | Madison, WI  53719

P: 608.236.1175 | F: 608.238.2614
fbetz at aeieng.com<mailto:fbetz at aeieng.com>  |  www.aeieng.com<http://www.aeieng.com/>



From: David BRADLEY [mailto:d.bradley at tess-inc.com]
Sent: Monday, October 18, 2010 10:52 AM
To: Fred Betz
Cc: TRNSYS-users at cae.wisc.edu
Subject: Re: [TRNSYS-users] Partload operation of Water to Water Heat Pump (Type 668)

Fred,
  Type668 models a single stage heat pump. There are other versions of the heat pump model designed to simulate the performance of multistage heat pumps and there are controller models to go with them.
Best,
 David


On 10/15/2010 14:04, Fred Betz wrote:
Does anyone know of a way to make part load operation work in Type668?

The performance maps are based on entering conditions on the evaporator and condenser side. However, there is no direct way to make type668 run at 10%, 50%, etc.

The work around I have used in the past is dividing the performance map by 50% to reflect two stages of operation and so on. Then setting up valves and controls to route the flow correctly.

The HP I am modeling has a 10:1 turn down ratio and I don't want to make 10 heat pumps each with 10% of the total capacity of a single unit.

Please advise,

Fred


Fred Betz  PhD., LEED AP
Sustainable Systems Analyst



AEI | AFFILIATED ENGINEERS, INC.
5802 Research Park Blvd. | Madison, WI  53719

P: 608.236.1175 | F: 608.238.2614
fbetz at aeieng.com<mailto:fbetz at aeieng.com>  |  www.aeieng.com<http://www.aeieng.com/>








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David BRADLEY

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Thermal Energy Systems Specialists, LLC

22 North Carroll Street - suite 370

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