Removal of non-condensable gases from a closed loop process

Abstract

A method which allows the ejection of non-condensable gases, notably air, from a closed loop power generation process or heat pump system, is disclosed. A vessel in which a working fluid is absorbed or condensed can be separated from the power generation processes by valves. Residual gas comprising CO2, non-condensable gas such as air, water and alkaline materials including amines may be compressed by raising the liquid level in said vessel. The concurrent pressure increase leads to the selective absorption of CO2 by alkaline materials. In simpler embodiments, mainly air is removed from one- or two-component processes. Following the compression, non-condensable gas may be vented, optionally through a filter. The method is simple and economic as vacuum pumps may be omitted. The method is useful for any power generation and Rankine cycle, and particularly useful for the power generation process known as C3 or Carbon Carrier Cycle.

1 . A gas removal unit for removing non-condensable gases from a system implementing a closed-loop thermodynamic process involving a condensable working medium, the system including (i) a heat exchanger for generation of a hot gaseous working medium and (ii) a main condensation vessel/heat exchanger for condensation of the condensable working medium from the hot gaseous working medium to a condensed working medium, the gas removal unit comprising:
 a vent line;   a first valve connected to the vent line; and   a condensation vessel connected to:
 the vent line through which the non-condensable gases are to be released via the first valve; and 
 the main condensation vessel/heat exchanger through a second valve, a third valve and a fourth valve, 
   wherein the third valve and the fourth valve allow ingress of a condensed working medium from the main condensation vessel/heat exchanger into the condensation vessel, and   wherein the second valve allows ingress of a gaseous working medium from the closed-loop thermodynamic process into the condensation vessel.   
     
     
         2 . The gas removal unit according to  claim 1 , wherein the fourth valve allows the ingress of the condensed working medium from the main condensation vessel/heat exchanger into the condensation vessel as a spray. 
     
     
         3 . The gas removal unit according to  claim 1 , further comprising:
 a first temperature sensor that monitors a first temperature in the condensation vessel;   a second temperature sensor that monitors a second temperature in the main condensation vessel/heat exchanger;   a third temperature sensor that monitors a third temperature in the condensed working medium before the condensed working medium is supplied into the condensation vessel as a spray; and   a first pressure sensor that monitors a first gas pressure in the condensation vessel.   
     
     
         4 . The gas removal unit according to  claim 1 , further comprising a cooler for actively cooling the condensed working medium entering into the condensation vessel from the main condensation vessel/heat exchanger. 
     
     
         5 . The gas removal unit according to  claim 1 ,
 wherein the gas removal unit is connected with the vent line, and   wherein the gas removal unit comprises diaphragms or membranes essentially impermeable to gases other than the non-condensable gases and a cold trap.   
     
     
         6 . The gas removal unit according to  claim 1 ,
 wherein the gas removal unit is connected with the vent line, and   wherein the gas removal unit comprises diaphragms or membranes essentially impermeable to gases other than the non-condensable gases and a filter.   
     
     
         7 . The gas removal unit according to  claim 1 ,
 wherein the gas removal unit is connected with the vent line, and   wherein the gas removal unit comprises diaphragms or membranes essentially impermeable to gases other than the non-condensable gases and a scrubber.   
     
     
         8 . The gas removal unit according to  claim 1 ,
 wherein the gas removal unit is connected with the vent line, and   wherein the gas removal unit comprises diaphragms or membranes essentially impermeable to gases other than the non-condensable gases and a burning/flaring unit.   
     
     
         9 . A non-condensable gases removal system comprising:
 a system implementing a closed-loop thermodynamic process involving a condensable working medium, the system comprising:
 a heat exchanger for generation of a hot gaseous working medium; and 
 a main condensation vessel/heat exchanger for condensation of the condensable working medium from the hot gaseous working medium to a condensed working medium; and 
   a gas removal unit comprising:
 a vent line; 
 a first valve connected to the vent line; and 
 a condensation vessel connected to:
 the vent line through which the non-condensable gases are to be released via the first valve; and 
 the main condensation vessel/heat exchanger through a second valve, a third valve and a fourth valve, 
 
   wherein the third valve and the fourth valve allow ingress of a condensed working medium from the main condensation vessel/heat exchanger into the condensation vessel,   wherein the second valve allows ingress of a gaseous working medium from the system into the condensation vessel, and   whereby (i) the third valve can be open to equilibrate the pressure in the condensation vessel and the main condensation vessel/heat exchanger, (ii) the fourth valve can be open to start a spraying of a condensed working medium from the main condensation vessel/heat exchanger into the condensation vessel, and measuring a first temperature in the condensation vessel and a second temperature in the main condensation vessel/heat exchanger, (iii) the third valve can be closed to separate the main condensation vessel/heat exchanger from the condensation vessel, while the fourth valve remains open to supply the condensed working medium to the condensation vessel, such that a level of the condensed working medium in the condensation vessel rises, (iv) the fourth valve can be closed to stop the supply of the condensed working medium to the condensation vessel, and (v) the first valve can be open to release and remove non-condensable gases through the vent line.