Modulation absorption refrigerator in plate design

Abstract

An intermittent ammonia-water absorption refrigerator, designed as a stack of vertical plates, having bypass, temperature control, and heat recovery, consisting of two generators, three absorbers, one evaporator, one condenser, two solution-steam pumps controlled by two control valves wherein, for the structuring of the plate stack, in addition to the thin, two-dimensional moulding plates for generators, absorbers, condenser, and evaporator, thick moulding plates having three-dimensional elements for containers, pumps, and distribution channels are used, and the plate stack consists of three face-bonded partial stacks, of which the outer-most contain containers, pumps, and distribution channels, the center stack having the generators, absorbers, condenser, and evaporator is narrower, such that there is a recessed vertical longitudinal channel on the side of the entire plate stack in which the control elements of the machine are installed.

1 . A controllable steam pump for batch processes with aqua-ammonia solutions comprising:
 an inlet check valve,   two chambers,   one siphon with siphoning function,   one pressure equalization line,   one solenoid valve,   one pressure reducer, and   one outlet check valve,   wherein both pump chambers, the upper chamber of each of which can be fed by the inlet valve, lie below the reservoir, and that the siphon connects the lower end of the upper chamber with the lower end of the lower chamber and the pressure equalization line connects the upper end of the upper chamber with the upper end of the lower chamber, and that the outlet check valve can be fed from the lower end of the lower chamber, while the controllable solenoid valve connects the upper chamber with the pressure reducer in reservoir.   
     
     
         2 . The intermittent aqua-ammonia absorption refrigeration machine in batch processes, configured as a stack of vertical plates which are compressed between two thick outer steel plates, with bypass, heat transfer media and heat recovery, including two generators, three absorbers, one evaporator one condenser, two solution steam pumps according to  claim 1  wherein the generator is connected with a generator pre-chamber and a rectifying column and the bypass generator is connected with a gas cooler, and that the warm absorber and the bypass absorber have downstream reservoirs and the bypass absorber has an absorber pre-chamber, and that apart from the thin, planar and mostly two-dimensional shaped plates that serve for the holding of heat exchanging elements such as generators, absorbers, condenser and evaporator, thick molded plates made of plastic with three-dimensional elements are also used, which are utilized for containers, pumps, and for receiving of distribution channels or generally for thermal insulation, wherein this plate stack consists of three partial stacks that are abutting planarly adjacent, of which the two plate stacks mainly serve for holding temperature controllable containers, pumps and distribution channels, while the center stack primarily consists of heat exchanging elements such as generators, absorbers, condenser and evaporator, and all three partial stacks have the same height, but the two outer stacks have the same width, but are broader than the center stack and all three partial stacks terminate congruent with the upper edges and lower edges and with a common lateral edge, so that a recessed vertical duct is created on the other side of the entire plate stack, in which the control elements of the machine are mounted, and that an increase in performance of the steam pumps occurs based on using the signals from sensors that determine the liquid level in the pump containers. 
     
     
         3 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein the functional components are organized according to their operating temperature, wherein four zones in the vertical direction and three zones in the horizontal direction must be distinguished, wherein the hottest zone with the two generators is positioned at the bottom, above that the somewhat less hot zone with the absorbers, and above that with a spatial interval for thermal insulation, the cold evaporator zone and the condenser zone, while in the horizontal direction the temperature from the zone to zone rises, namely from the warm zone with the warm pump containers across the center zone, where generators and absorbers are arranged such that their cooler plates are facing the zone, while their hotter plates are adjacent to the hot zone which contains gas separators and rectifying columns. 
     
     
         4 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein the control elements are regulated by liquid indicating sensors, which are fitted from the side into the container comprising plates. 
     
     
         5 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein a pre-storage unit is installed upstream of the bypass absorber, into which said pre-storage unit the first steam pump accurately pumps metered solution from the absorber reservoir, so that the solution trickles from this pre-storage unit by gravity into the bypass absorber that lies below. 
     
     
         6 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein the valve bodies of the ball check valves, which are closed by gravity because the ball sits in a perpendicular standing funnel shaped opening, must be produced outside of the thick plates that are provided for them, and must be pressed only subsequently into the respective openings of these thick plates. 
     
     
         7 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein two different temperature control media absorb the absorption heat being released, wherein the first medium is the actual heating medium, which initially heats the generator plates lying in tandem, wherein the heating medium counter-flows to the ammonia solution and cools itself in the process, and thereafter flows again counter-flowing to solution along the plates of the hot absorber lying in tandem and subsequently leaves the machine, while the second medium enters the machine cold and initially flows to the warm absorber and then flows further along the plates of same lying in tandem to gas coolers or rectifying columns of the two generators, where it absorbs further heat. 
     
     
         8 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein in the center partial stack, thin shaped plates in the shape of ammonia plates and water plates which are are stacked in tandem, alternate systematically, wherein a metal separating plate is located between each two shaped plates. 
     
     
         9 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 8 , wherein the section of the ammonia plates that is provided for a generator consists of a rectangular cutout, on both sides of which two connection channels terminate respectively, from each of which one connection tunnel leads through the two intervening separating plates and through the water plate to the next ammonia plate, and that a hole is located on one side of the generator cutout, through which the connection tunnel runs between the two water plates that include the ammonia plate. 
     
     
         10 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 8 , wherein the section of the ammonia plates provided for an absorber having two adjacently positioned rectangular cutouts, each of which contain a serpentine-shaped channel, wherein these channels are connected with each other on the top, and that two connection channels each terminate on both sides of this absorber plate, wherein the line of the two gas connections feeding the gas is connected by means of a vertical connection channel with the bottom end of the serpentine-shaped channel, and where one connection tunnel runs from each connection channel respectively, through the two intervening separating plates and the water plate to the next ammonia plate and that a hole is located on one side of the absorber cutout, through said hole of which the connection tunnel runs between the two water plates that enclose the ammonia plate. 
     
     
         11 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 8 , wherein the section of the water plates that is provided for the temperature control of an absorber or generator consists of a rectangular cutout that contains a serpentine-shaped channel, in which the temperature control medium flows from the bottom to the top and in which two lateral connection channels terminate, and where a connection tunnel leads from each connection channel through the two intermediately positioned separating plates and the ammonia plate to an adjacent water plate, and that two holes are located on the one side of the heat transferring cutout, through which run the connection tunnels between the two ammonia plates that enclose the water plate. 
     
     
         12 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein a reservoir for holding liquid ammonia is located on the outlet of the condenser and upstream of the pressure stage towards the evaporator. 
     
     
         13 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein several of such machines are connected as autonomous modules, each with its own independent ammonia system, to form a larger block, wherein the congruent plate stacks of the individual modules are combined into an overall stack. 
     
     
         14 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein the lines for the media for heating, for re-cooling or for the transfer of the produced cold from one side of the plate block to the other run such, that their inlets or outlets terminate on congruent positions of the opposite end plate, there are branches leading to the individual components to be temperature controlled only on the inside of each module involved. 
     
     
         15 . The intermittent aqua-ammonia absorption refrigeration machine according to  claim 2 , wherein the controllable cooling temperature of the individual modules in a large machine must be adjusted to different temperatures such that the medium to be cooled first flows through the module with the warmest cooling temperature, which is closely below the temperature of the room to be cooled, thereafter through the module with the next colder temperature and so on up to the last module, which is adjusted to the lowest temperature, which is the nominal temperature of the overall system.