brian eiland
08-18-2009, 02:06 PM
...Being able to save energy is better than the need for generating more.
AC using ejector technology debuts
The new Prius, introduced by Toyota in Japan in late May 2009, features the world's first passenger vehicle air conditioning system that uses ejector technology. The ejector, which is a small refrigerant injector developed by DENSO Corporation, contributes to a significant overall reduction in power consumption.
"With increasing demand for technologies to reduce carbon dioxide emissions and preserve the environment, DENSO has been accelerating its efforts to develop more efficient air conditioning systems," says Akio Shikamura, managing officer responsible for DENSO's Thermal Systems Business Group. "The new air conditioning system reduces the compressor's power consumption by up to about 25% compared to conventional car air conditioning systems, and thus contributes to fuel savings."
Much of the energy consumed by a vehicle's air conditioning system is used by the compressor to compress the refrigerant. In conventional air conditioning systems, an expansion valve is used to reduce the pressure of the refrigerant before passing it through the evaporator to cool the air.
DENSO's new system uses an ejector instead of an expansion valve. The ejector recovers expansion energy, which was previously lost in the expansion valve, and converts it into pressure energy. This reduces the compressor's workload and helps reduce the air conditioner's overall power
DENSO applied ejector technology to truck refrigeration units starting in 2003 and, more recently, to household CO2 heat-pump water heaters.
Until the Prius application, the conventional ejector was not small enough to be installed in vehicle air conditioning systems. DENSO overcame this challenge inside the new air conditioning system by integrating the ejector into the evaporator tank, where refrigerant flows. The new design eliminates the need for the ejector to have a thicker structure to withstand external pressure and also eliminates pipe connection parts needed to connect the ejector with the evaporator, which helps reduce the size of the ejector. The ejector cycle system (ECS) evaporator, which is equivalent to the size of a conventional evaporator, can also be applied to conventional air conditioning systems.
How it works
The ejector, used in the ejector cycle instead of a conventional expansion valve, expands high-pressure refrigerant by using energy that previously was lost.
A gas-liquid separator separates expanded refrigerant into gas and liquid so that gas refrigerant is directly drawn into the compressor at a higher pressure, while liquid refrigerant flows into the evaporator to exchange heat with air.
Benefits and features
1) Small compressor power consumption—The ejector uses energy, which is lost in a conventional expansion valve, to increase the pressure of refrigerant drawn into the compressor, resulting in compressor power consumption up to almost two-thirds smaller than the power consumption required in a conventional expansion valve cycle.
2) High evaporator performance—Only liquid refrigerant flows into the evaporator, reducing pressure loss and improving evaporator performance.
3) Small size and light weight—Compared to the expansion valve cycle with similar refrigeration capacity, the overall weight of the ejector cycle is reduced by 40% thanks to the remarkable minimization of the compressor, condenser, and evaporator. The weight reduction also increases fuel efficiency.
Want more information?
DENSO (http://www.globaldensoproducts.com/cc/ec/ejector_cycle.html)
AC using ejector technology debuts
The new Prius, introduced by Toyota in Japan in late May 2009, features the world's first passenger vehicle air conditioning system that uses ejector technology. The ejector, which is a small refrigerant injector developed by DENSO Corporation, contributes to a significant overall reduction in power consumption.
"With increasing demand for technologies to reduce carbon dioxide emissions and preserve the environment, DENSO has been accelerating its efforts to develop more efficient air conditioning systems," says Akio Shikamura, managing officer responsible for DENSO's Thermal Systems Business Group. "The new air conditioning system reduces the compressor's power consumption by up to about 25% compared to conventional car air conditioning systems, and thus contributes to fuel savings."
Much of the energy consumed by a vehicle's air conditioning system is used by the compressor to compress the refrigerant. In conventional air conditioning systems, an expansion valve is used to reduce the pressure of the refrigerant before passing it through the evaporator to cool the air.
DENSO's new system uses an ejector instead of an expansion valve. The ejector recovers expansion energy, which was previously lost in the expansion valve, and converts it into pressure energy. This reduces the compressor's workload and helps reduce the air conditioner's overall power
DENSO applied ejector technology to truck refrigeration units starting in 2003 and, more recently, to household CO2 heat-pump water heaters.
Until the Prius application, the conventional ejector was not small enough to be installed in vehicle air conditioning systems. DENSO overcame this challenge inside the new air conditioning system by integrating the ejector into the evaporator tank, where refrigerant flows. The new design eliminates the need for the ejector to have a thicker structure to withstand external pressure and also eliminates pipe connection parts needed to connect the ejector with the evaporator, which helps reduce the size of the ejector. The ejector cycle system (ECS) evaporator, which is equivalent to the size of a conventional evaporator, can also be applied to conventional air conditioning systems.
How it works
The ejector, used in the ejector cycle instead of a conventional expansion valve, expands high-pressure refrigerant by using energy that previously was lost.
A gas-liquid separator separates expanded refrigerant into gas and liquid so that gas refrigerant is directly drawn into the compressor at a higher pressure, while liquid refrigerant flows into the evaporator to exchange heat with air.
Benefits and features
1) Small compressor power consumption—The ejector uses energy, which is lost in a conventional expansion valve, to increase the pressure of refrigerant drawn into the compressor, resulting in compressor power consumption up to almost two-thirds smaller than the power consumption required in a conventional expansion valve cycle.
2) High evaporator performance—Only liquid refrigerant flows into the evaporator, reducing pressure loss and improving evaporator performance.
3) Small size and light weight—Compared to the expansion valve cycle with similar refrigeration capacity, the overall weight of the ejector cycle is reduced by 40% thanks to the remarkable minimization of the compressor, condenser, and evaporator. The weight reduction also increases fuel efficiency.
Want more information?
DENSO (http://www.globaldensoproducts.com/cc/ec/ejector_cycle.html)