Originally Posted by
SteinarN
Well, this solution gives a system with a horrible efficiency :rolleyes:
But to draw this system, start with the low pressure evaporator and draw this complete system with the condenser, but leave the line for the compressor at this point. When this is done draw the evaporator line for the high pressure evaporator, connect the left end of this line to the vertical line expressing the exv at the low pressure evaporator, draw the right end of this line to where it meets the temperature line for the evaporator outlet at correct superheat. Then draw a vertical line from the right end of the high pressure evaporator line and down to the pressure line for the low pressure evaporator. This vertical line express the suction pressure regulator for the high pressure evaporator. Draw a short horizontal line to connect this newly drawn vertical line with the right end of the evaporator line for the low pressure evaporator. The start line for the compressor suction is somewhere on this short horizontal line and exactly where depends on the mass flow ratio between the low pressure and the high pressure evaporator. If the mass flow is equal in the low and high evaporator then this point is roughly on the middle on this short line. Now draw the compressor line and conect it to the right end of the condenser line and you are done. :cool: