https://opus.lib.uts.edu.au/bitstream/10453/30657/4/Final%20Revision_2_Unmarked%20without%20endnote%202014%2007%2028.pdf

Fouling and its control in membrane distillation-A review

Review on improvement for air source heat pump units during frosting and defrosting

Principles of enhanced heat transfer: By R. L. Webb, Wiley, New York, 1994, ISBIN #0-471-57778-2 556 pp

This paper reviews the major research on refrigerant injection techniques in detail. Liquid and vapor refrigerant injection techniques are discussed and compared. The current research on refrigerant injection techniques falls into two categories: system level research and component level research. The system level research is focused on low ambient temperature heating, heat pump water heating, high ambient temperature cooling, cycle comparison, and control strategy development. Internal heat exchanger and flash tank cycles are the two typical cycles for refrigerant injection. These two cycles are discussed and compared in detail. The component level research is focused on employing different types of compressors, variable speed compressors, the injection process, and the flash tank. Different types of compressors employing refrigerant injection are presented. Based on the literature study, the potential future research directions are presented and discussed. The flash tank cycle control strategy and refrigerant charge management strategy are worth further research efforts. Compressor design can be improved in order to optimize the performance with refrigerant injection. The appropriate design of flash tanks plays a vital role in achieving appropriate two-phase flow patterns in the flash tank. Computational Fluid Dynamics (CFD) modeling can be a useful tool to facilitate the design of the flash tank.

Refrigerant injection for heat pumping/air conditioning systems: Literature review and challenges discussions

Techno-economic analysis of air source heat pump applied for space heating in northern China

A study on the performance enhancement of heat pump using electric heater under the frosting condition: Heat pump under frosting condition

A variable capacity refrigeration system which does not require a costly inverter compressor and does not exhibit low energy efficiency at high capacity. The system employs a constant speed compressor that operates continuously when the system is energized, irrespective of the heat load, and a refrigerant bypass path including a secondary expansion device, a heat exchanger, and a flow control device which is operable to permit a portion of the refrigerant exiting from the condenser to flow through the bypass path to an inlet of the compressor when the heat load is below a predetermined threshold, whereby the heat exchanger operates as a secondary evaporator, and to prevent refrigerant exiting from the condenser from flowing through the bypass path to the compressor inlet when the heat load is not below the predetermined threshold. In one embodiment, the flow control device is further operable to permit a portion of the refrigerant exiting from the compressor to flow through the bypass path to the primary evaporator through the primary expansion device when the heat load is not below the predetermined threshold, whereby the heat exchanger operates as a secondary condenser. In several embodiments, a pressure differential is maintained between the refrigerant in the heat exchanger and the evaporator. The pressure differential is accommodated by a vacuum generating device such as a vortex generator, a venturi or the like, or by a flow restrictor such as a capillary tube. In several embodiments, the heat exchanger is thermally coupled to the compressor to remove heat from the refrigerant as it flows through the compressor.

Variable capacity refrigeration system with a single-frequency compressor

Effect of electronic anti-fouling treatment on fouling mitigation with circulating cooling-tower water

An improved refrigeration system utilizing one or more vortex tubes. Vortex tubes produce liquid refrigerant from saturated-state vapor refrigerant in a vapor-compression refrigeration cycle. The efficiency of a refrigeration system can be improved by placing a vortex tube before the evaporator. The efficiency of a refrigeration system may also be improved by placing a vortex tube in the condenser approximately one-quarter of the way from the inlet of the condenser. The efficiency of a refrigeration system may also be improved by placing a vortex tube before the compressor.

High efficiency refrigeration system

The performance of a refrigeration system is often reduced due to insufficient refrigerant charge or due to the use of an inverter compressor. The performance loss is associated with the operating condition, which is not at the optimum, thus yielding less than the maximum EER (energy efficiency ratio). A vortex generator restores the optimum operating condition in the refrigeration system with insufficient refrigerant charge or using an inverter compressor.

Cheolho Bai

Papers

A study on the performance enhancement of heat pump using electric heater under the frosting condition: Heat pump under frosting condition

Variable capacity refrigeration system with a single-frequency compressor

Effect of electronic anti-fouling treatment on fouling mitigation with circulating cooling-tower water

High efficiency refrigeration system

Vortex generator to recover performance loss of a refrigeration system