Performance characteristics of a high temperature water-to-water heat pump

Abstract

A simulation model is utilized to predict the performance of a high temperature water‐to‐water heat pump, running on Refrigerant 11, over a range of evaporator and condenser water temperature (10 to 40°C and 40 to 70°C) and compressor speeds (500 to 3000 r.p.m.). It is shown that heat pump power output can be effectively controlled by varying compressor speed. Effects of compressor speed, heat source and heat sink (end‐use) temperature on the heat pump efficiency are presented. Special attention is devoted to the values of predicted refrigerant temperature at the compressor discharge. These are compared with the thermal limit of the refrigerant. Modifications to the system, to reduce refrigerant maximum temperature, are also discussed.

Review of vapour compression heat pumps for high temperature heating using natural working fluids

“…The principal components and thermodynamic cycle are the same. The main difference is the temperature of heat delivery which is higher and as such some changes have to be made to the system design to accommodate for this, while of course taking in consideration the environmental impact (Parise & Cartwright, 1988). Operating at high temperatures will require modifications in most if not all of the equipment in conventional heat pumps.…”

“…There is already numerous research into heat pumps operating at temperatures below 80 o C (Arpagaus et al, 2016;Jung et al, 2000; M. H. Kim et al, 2004;Liebenberg & Meyer, 1998; Y. Miyara et al, 1992;Nakatani et al, 1990;Neksa et al, 1998;Parise & Cartwright, 1988) just to mention a few. This is hardly useful for high temperature industrial heating applications that require steam production or other high temperature heating demand.…”

Lithium bromide high-temperature absorption heat pump: Coefficient of performance and exergetic efficiency

“…The limit of thermal stability of R 11 is reached when the discharge temperature is 107°C and, accordingly, the condensation temperature in saturation conditions should be lower (Parise and Carwright, 1988). For this reason, refrigerant R11 is not usable for the purpose proposed.…”