DE19645475B4 - Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer - Google Patents

Abstract

Periodically operating adsorption heat pump, adsorption or adsorption heat transformer with at least two sorbers (101, 103), each consisting of one sorber heat exchanger (1) with tubes (11) as heat exchanging Elements, where heat the adsorbent or adsorbers (101, 103) for heating and desorption of or the desorber (101, 103) with low temperature differences between Heat transfer fluid (16), Sorbermaterial and sorbent (13) is transferred, wherein the Sorberwärmeaustauscher (1) in a space through which the heat transfer fluid (16) flows and a Room in which the sorbent (13) is housed divided is, which is connected to another room steam-permeable, in which Working medium vapor (18) from an evaporator (51, 53) or to a Condenser (51, 53) flows, characterized in that the Sorberwärmeaustauscher (1) from a or more on both sides with additional surfaces (12), such as transverse ribs, Longitudinal ribs with Interruptions, helical attached wool ribbons (31) or wires (32) provided pipes (11) is constructed and thereby at low overall length with only one heat carrier side Passage countercurrent is achieved.

Description

The The invention relates to a process engineering apparatus and in particular the tubes used in this apparatus according to the preamble of claim 1, for with solids, e.g. Silica gel, activated carbon, carbon molecular sieves, Hydrides and preferably zeolites as adsorbent periodically working adsorption heat pumps, adsorption and adsorption heat transformers, the description refers only to the application in adsorption heat pumps and adsorption chillers refers.

at This sorption can be at not too large temperature differences of condenser and Evaporator temperature is a temperature range in which the adsorber temperature equal to the desorber temperature, in which a "spill over the temperatures ", for one particularly effective heat exchange be used. Not only cooling heat but also adsorption of the Adsorber is to a heat transfer fluid, which is a liquid or a gas, in particular air or exhaust gas can be transmitted and the heat transfer fluid continue to transfer to the desorber.

Around a good heat transfer to achieve that Heat transfer fluid in the adsorber as high as possible heated be, including a counter-current arrangement and low temperature differences between heat transfer fluid and adsorbent requirements are. The same applies to the cooling of the heat transfer fluid in the desorber. At the due to the high heating low, heat transfer rate per unit of time it is difficult to have a pure countercurrent heat exchanger with high heat transfer rates to construct.

The thermodynamically possible heating coefficient is well over 2 for adsorption heat pumps with "overflow temperatures", but only one publication (BWK, 47, (1995) Nr.3, p. 94-96) described an adsorption heat pump with 2 adsorbers according to the patent DE 37 007 07 C2 works and experimentally achieved a heating coefficient of more than 2. However, this is equipped with Sorberwärmeaustauschern, consisting of a several meters long, unilaterally provided with an enlarged surface wound tube, which had by touching the coil heat shorts and thus could not achieve optimal countercurrent effect.

In the DE 195 22 250 A1 and DE 195 39 154 A1 describes a method for operating heat pumps and refrigerators using modified compact heat exchangers. These are Plattenwärmeaustauscheradsorber, which are suitable for reasons of strength only for a relatively small pressure difference between the heat transfer fluid side and sorbent side.

Still are the US 50 54 544 A and the US 53 88 637 A to call as state of the art.

Of the Invention is based on the object, Sorberwärmeaustauscher for Adsorptionswärmepumpen adsorption or adsorption heat transformers with at least 2 sorbers with tubes as heat exchanging elements, with which heat of the adsorber or for heating and desorption of the desorber or with low temperature differences between heat transfer fluid and sorbents with low length and low volume with heat carrier side preferably only one passage as a countercurrent heat exchanger in the essential Design features. Even with low heat transfer rate should be achieved at low pressure loss good heat transfer. Of the Sorberwärmeaustauscher should for the installation in a heat pump or chiller be advantageous in which the heat transfer fluid when cooled to adsorber operation and in Adsorberbetrieb on the one hand and in the preheating for Desorption and desorber operation on the other side of the Sorberwärmeaustauscher enters, which forms a cold and a hot side.

These The object is achieved by the characterizing features of claim 1 solved. The additional surfaces of the Pipes should be economical and therefore widely used known technologies can be manufactured and operated.

These The object is achieved by the characterizing features of claims 2 and 3 solved.

Of the Heat flow in the flow axis of the heat carrier, the is preferably in the direction of the tube axis, should in relation to the transmitted amount of heat with at the same time small tube length, among which a range of about 0.3 to 6 m, preferably understood to 2 m is and low heat capacity of the heat exchanger material kept small. The larger pipe length of 6 m is especially for larger apparatus for constructional reasons meaningful. At the same time, because of the periodic operation one low heat capacity of the sorber he wishes.

This object is achieved by the characterizing features of claims 4 to 8 solved.

Of the Fluid-side pressure drop on the way between sorbent and condenser or evaporator must because of the consequent Temperature drop especially in Sorbersystemen that at low Temperatures and pressures work with water as a work tool, be small. A cheaper one Pressure loss is with good heat transfer, reached the specified sorbent diameter range and the swept sorbent height.

These The object is achieved by the Characteristic features of claims 9 and 10 solved.

pressure losses by cross-sectional changes or deflections should be avoided. This object is achieved by the characterizing features of claim 11 solved.

Of the Adsorberwärmeaustauscher should be for high Operating temperatures which, for thermodynamic reasons, are above 230 ° C, preferably above 250 ° C, be suitable. Also for Practical operation, it is advantageous if for the heat exchanger even higher Temperatures can be allowed. Zeolite tolerates For example, in some applications, higher temperatures for a short time so that construction and regulation of a higher temperatures designed plant can be made more economical. For high temperatures suitable provided with one-sided enlarged additional surfaces Tubes are made by rolling or drawing from solid material. Continue to be for high temperature suitable tubes with welded smooth or broken Round and longitudinal ribs on a large scale produced. additional surfaces with particularly low material thicknesses are mixed with soft solders, already at 183 ° C or at most Melt 232 ° C, good thermal conductivity connected with pipes. soldering, those with over 280 ° C melting soft solders or brazing alloys are known, are used for round tubes but usually not applied.

These The object is achieved by the characterizing features of claim 12 solved.

In Embodiment of the invention are for the construction of Sorberwärmeaustauscher preferably pipes that meet all conditions for an axial flow of Heat transfer fluid fulfill, used. When using liquids as a heat transfer medium the solution with inward flow the heat transfer fluid often beneficial. The solution with internal sorbent arrangement offers particular advantages if as heat transfer fluid Air or flue gases can be used with low pressure and thus a simple design the heat transfer fluid space possible is. A cleaning of the heat transfer fluid space is possible with this arrangement, if the jacket of the heat transfer fluid space removable becomes.

These The object is achieved by the characterizing features of claim 13 solved.

at a prone to contamination of Wärmeaustauschfächen Heat transfer fluid can choose another arrangement which allows easy cleaning. An advantage of this embodiment is that of Procedure no claims the thermal conductivity the provided with additional surfaces Tubes are placed, as these are perpendicular to the flow direction arranged the heat transfer fluid are.

These The object is achieved by the characterizing features of claim 14 solved.

For the production of double-sided ribbed tubes some manufacturers need an inner tube ( 19 ). This tube can be used, for example, with advantage for the supply of heat by condensing steam or by cooling of flue gases or for the transmission of heat of average temperature as useful heat according to claim 15.

In many cases is a limited amount of fluid per unit time as a heat source and / or heat sink to disposal. In other words, the Task is, the fluid to a larger temperature range, for example more than 10 ° C cool and / or to warm.

These The object is achieved by the characterizing features of claim 16 solved.

The The invention will be described in more detail with reference to the following figures. Showing:

1 a sorber heat exchanger consisting of a tube with an inner sorbent arrangement

2 a Sorberwärmeaustauscher consisting of a tube with outside sorbent arrangement

3 and 4 designed as a tube bundle apparatus Sorberwärmeaustauscher

5 and 6 a tube provided with corrugated bands on both sides

7 and 8th a tube provided with wires on both sides

9 and 10 a sorber heat exchanger constructed of tubes flowed perpendicular to the tube axis

11 A counterflow arrangement of Sorberwärmeaustauschern

In 1 is a Sorberwärmeaustauscher existing of a tube with inside sorbent arrangement ( 1 ) shown schematically. On the inside of the tube provided with enlarged surfaces on both sides ( 11 ) are used as additional surfaces ( 12 ), for example, wires between which the sorbent ( 13 ), for example, as a bed, the vapor permeable through a wire mesh, perforated plate or an expanded metal ( 14 ) from the space in which the work equipment ( 15 ) flows, is separated. If a coating of the Sorberwärmeaauchaucheroberfäche with sorbent is provided instead of the bed, the wire mesh ( 14 ) accounted for. On the outside of the tube ( 11 ) flows the heat transfer fluid ( 16 ) through the interspaces of the additional surface formed by wires, for example ( 12 ). The outside limiting coat ( 17 ) can move freely. In the event that atmospheric air or combustion exhaust gas is used as the heat transfer medium, this solution is particularly suitable. In this case, it is easy to have several tubes in a shell ( 17 ) are accommodated with adapted to the available space shell cross-section. If the jacket is removable, cleaning on the heat transfer fluid side is possible.

For the advantageous Use of the Sorberwärmeaustauscher invention it is independent from the circuit only necessary that the heat transfer fluid on cooling Adsorberbetrieb and adsorber operation on one side and at the preheating for desorption and in desorber operation on the other side of the Sorberwärmeaustauscher enters, which forms a cold and a hot side.

When cooled to adsorber temperature and during operation as an adsorber, the heat transfer fluid ( 16 ) and the working medium vapor ( 18 ) in the direction of the arrow. The heat transfer fluid is heated by sensible heat from the cooling and heat of adsorption, for example from 20 ° C to 220 ° C initially and at the end of the adsorption to 160 ° C or less, for example. When preheating for desorption and during operation as a desorber the heat transfer fluid ( 16 ) and the working medium vapor ( 18 ) against the arrow direction. The exiting the adsorber heat transfer fluid further heat is supplied and it occurs on the hot side in the Desorberwärmeaustauscher with a temperature of, for example, 180 ° C to 240 ° C, cools by release of sensible heat and heat of desorption to the desorber and occurs the cold side at a temperature of initially 20 ° C and at the end of the heat exchange period, for example, 80 ° C or warmer off.

When operated with gaseous heat transfer fluids heat transfer rates of 150 to 350 W / (m ² · K) and more relative to the pipe outer surface are economically achievable at atmospheric pressure and moderate pressure loss. When operating with liquids as heat transfer, heat transfer rates of more than 400 W / (m ² · K) can be achieved economically.

Preferably Pipes with a circular cross-section are used. But it can also tubes with other cross-sections, such as oval cross-section or Rectangular cross section can be used if no too high pressure differences exist between adsorbent space and heat transfer fluid space.

In 2 is a Sorberwärmeaustauscher existing of a pipe with outside sorbent arrangement ( 1 ) shown schematically. In this case, the sorbent ( 13 ) on the outside of both sides with enlarged surfaces ( 12 ) provided pipe ( 11 ) housed between wires. The fill is made by a wire mesh, perforated plate or expanded metal ( 14 ) from the steam room ( 15 ) separated. If a coating of the Sorberwärmeaauchaucheroberfäche with sorbent is provided instead of the bed, the wire mesh ( 14 ) accounted for. The outside limiting coat ( 17 ) is gas-tight with the inner tube ( 11 ) connected. To compensate for the different thermal expansion, it can be designed with expansion compensation. On the inside of the tube ( 11 ) flows the heat transfer fluid ( 16 ) through the example by wires enlarged surface ( 12 ). The inner tube ( 19 ) is provided for manufacturing purposes, but can be used as an additional surface for the heat exchange, for example, a heating with steam or cooling of combustion gases in indirect heating of the heat transfer fluid circuit.

When cooled to Adsorbertemperatur and in operation as an adsorber, the heat transfer fluid ( 16 ) and the working medium vapor ( 18 ) in the direction of the arrow. In operation as a desorber and preheating for desorption flows the heat transfer fluid ( 16 ) and the working medium vapor ( 18 ) against the arrow direction.

Further details correspond to the explanations to 1 ,

In 3 and 4 is a sorber heat exchanger made up of several parallel pipes ( 1 ). It consists of the tubes ( 11 ) with double-sided enlarged surface ( 12 ), the sorbent filling ( 13 ), the wire screen, perforated plate or expanded metal ( 14 ) and the coat ( 17 ). The pipe ( 19 ) is not drawn. This arrangement is economical for large appliances in which the sorbent is placed on the outside of the tubes.

With appropriate design of the apparatus, the sorbent ( 13 ) also on the inside of the tubes ( 11 ). Particularly when using a gaseous heat transfer fluid under normal pressure, an arrangement of the sorbent ( 13 ) also on the inside of the tubes ( 11 ) makes sense, because then the heat transfer fluid can be performed on the pressure unproblematic side.

Further details correspond to the explanations to 1 and 2 ,

In 5 and 6 is a provided with double-sided additional surfaces provided pipe ( 11 ). As additional surfaces are outside and inside corrugated strips ( 31 ), for example, 5 mm wide, for example, copper, brass or steel with the pipe ( 11 ) connected by soldering or pressing good thermal conductivity. As a result, the exchange surfaces can be increased to about 3 to 20 times the outer surface of the tube. The inner tube ( 19 ) is required for production reasons. This tube is particularly suitable for axial flow. A radial flow through the sorbent layer is possible. In particular, when the sorbent is applied as a coating, other enlarged surfaces, such as transverse ribs, for example round ribs or helically applied ribs or longitudinal ribs, which are preferably interrupted in the axial direction, are advantageous on the sorbent side.

In 7 and 8th is a provided with double-sided additional surfaces provided pipe ( 11 ) shown on which as external surfaces outside and inside wires ( 32 ) are preferably soldered from copper. As a result, the exchange surfaces can also be increased to approximately 3 to 20 times the tube exterior surface. As an inner tube is an example of a permeable for working medium vapor tube made of wire mesh, perforated plate or expanded metal ( 14 ) intended. This tube is equally well suited for axial as well as radial flow. Also with this tube, inside and outside different additional surfaces can be attached.

In 9 and 10 a Sorberwärmeaustauscher constructed from perpendicular to the pipe axis pipes is shown. This structure has the advantage that no claims to the thermal conductivity of the pipes ( 11 ). The manifold ( 22 ) must have a low heat conduction in the flow axis of the heat transfer fluid, which is achieved by low wall thickness and choice of a material with low thermal conductivity, such as brass, copper-nickel alloys, steel or in particular chromium-nickel steel. When you put the coat ( 17 ) performs demountable, the tubes heat transfer fluid side can be easily cleaned. Next is the apparatus ( 5 ), which is used as a condenser and then as an evaporator, drawn. On the outside of the tubes ( 11 ) flows the heat transfer fluid at the additional surfaces ( 12 ), which achieve low flow resistance and good heat transfer when flowing perpendicular to the tube axis, such as spirally wound ribs, round ribs or rectangular ribs. On the inside of the tubes is the sorption agent ( 13 ) at or between the additional surface ( 12 ) housed. The pipes are connected to the manifold ( 22 ) connected. In 6 is the apparatus ( 5 ) connected directly to the manifold 22. A direct connection to the manifold has the advantage of a lower pressure loss of the working fluid ( 18 ).

A Assignment of the respective adsorber to the evaporator and the respective Desorber to the condenser is at installation of appropriate changeover valves also possible.

When cooling to adsorber temperature and in operation as an adsorber, the heat transfer fluid ( 16 ) and the working medium vapor ( 18 ) in the direction of the arrow. At this stage, the apparatus ( 5 ) is connected to a heat source and evaporates working fluid which is adsorbed in the adsorber. During preheating for desorption and during operation as a desorber, the heat transfer fluid ( 16 ) and the working medium vapor ( 18 ) against the arrow direction. At this stage, the apparatus ( 5 ) is combined with a heat sink and condenses the desorbed from the desorber work More details correspond to the explanations 1 ,

In 11 is shown a countercurrent arrangement of Sorberwärmeaustauschern in a Sorptionswärmepumpe- or chiller. When heating and / or cooling of a material flow to a larger temperature difference, this arrangement has the advantage that the temperature increase takes place in two stages and drive energy is saved. The additional expenditure on equipment is low, since the adsorber heat exchanger already consist of several elements and heat transfer fluid can be accommodated in a common housing. There are 4 Sorberwärmeaustauscher ( 101 . 102 . 103 . 104 ), a four-way fitting ( 56 ), a conveyor for heat transfer fluid ( 55 ), a medium temperature heat exchange device ( 57 ) and a high temperature heat exchange device ( 58 ) intended. The apparatuses ( 53 ) and ( 54 ) can as in 11 shown, with appropriate apparatus design and line assignment to the heat source ( 62 ) as an evaporator and when assigned to the heat sink ( 61 ) are operated as a capacitor. When routed to the heat sink ( 61 ), the apparatuses ( 51 ) and ( 52 ) as capacitors and in line assignment to the heat source ( 62 ) are operated as an evaporator.

In operation, cold heat transfer fluid with the conveyor ( 55 ) via the 4-way fitting ( 56 ) by the heat transfer fluid side parallel adsorber ( 103 ) and ( 104 ), in which it heats up while the sorber cool. The sorbers ( 103 ) and ( 104 ) Adsorb working fluid, which in the operating as an evaporator apparatus ( 53 ) and ( 54 ) was evaporated. In the heat exchanger device ( 58 ) the heat transfer fluid is further heated by indirect heat exchange or by direct mixing with a hot heat flow and cools in the desorbers ( 101 ) and ( 102 ), whereby the desorbers warm up and desorb equipment which is used in the apparatus ( 51 ) and ( 52 ), which work as capacitors, is condensed. The heat transfer fluid passes through the 4-way fitting ( 56 ) into the heat exchange device ( 57 ) in which it is further cooled by Nutzwärmeabgabe and gets back to the conveyor ( 55 ). When atmospheric air is used as the heat transfer fluid, the heat transfer fluid can be sent directly to the atmosphere. The conveyor ( 55 ) then sucks air directly. The heat exchange device ( 57 ) can then be omitted. After loading the adsorbers ( 103 ) and ( 104 ) and desorption of desorbers ( 101 ) and ( 102 ), the conveying direction of the heat transfer fluid with the 4-way fitting ( 56 ) switched. As a result, the previous adsorber to Desorbern and the previous evaporator to capacitors and vice versa. At about the same time, the medium of the heat sink ( 61 ), which in the apparatuses ( 51 ) and ( 52 ) Condensation heat absorbed by the new capacitors ( 53 ) and ( 54 ) and the medium of the heat source ( 62 ), which in the apparatuses ( 53 ) and ( 54 ) Heat released by the new evaporator ( 51 ) and ( 52 ).

1

Sorberwärmeaustauscher

5

Condenser / evaporator

11

pipe

12

additional surface

13

sorbents

14

Wire mesh, Perforated metal or expanded metal

15

Working medium vapor space

16

Heat transfer fluid

17

coat

18

Working medium vapor

19

inner tube

22

manifold for working medium steam

31

corrugated strip

32

wire

51,52,53,54

Condenser / evaporator

55

Conveyor for heat transfer fluid

56

Four-way valve

57

Heat exchange device for medium temperature

58

Heat exchange device for high temperature

61

heat sink

62

heat source

101,102,103,104

sorber with built-in heat exchanger

Claims (16)

Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer with at least two sorbers ( 101 . 103 ), each consisting of a Sorberwärmeaustauscher ( 1 ) with pipes ( 11 ) as heat exchanging elements, whereby heat of the adsorbent or adsorbers ( 101 . 103 ) for heating and desorption of the desorber (s) ( 101 . 103 ) with low temperature differences between heat transfer fluid ( 16 ), Sorbent material and sorbents ( 13 ), wherein the Sorberwärmeaustauscher ( 1 ) in a space through which the heat transfer fluid ( 16 ) and a space in which the sorbent ( 13 ), which is connected vapor permeable to a further space, in the working medium vapor ( 18 ) from an evaporator ( 51 . 53 ) or to a capacitor ( 51 . 53 ), characterized in that the sorber heat exchanger ( 1 ) of one or more of both sides with additional surfaces ( 12 ), such as transverse ribs, longitudinal ribs with interruptions, helically applied wool ribbons ( 31 ) or wires ( 32 ) provided pipes ( 11 ) is constructed and thus at low length with only one heat carrier side passage countercurrent is achieved. Periodically operating adsorption heat pump, adsorption or adsorption heat transformer according to claim 1, characterized in that the transverse ribs Round ribs or rectangular ribs exist. Periodic adsorption heat pump, adsorption chiller or Adsorptionswär Metransformator according to claim 1 or 2, characterized in that the ratio of the surface of the additional surfaces ( 12 ) on the outside of the pipe, as well as on the inside of the tube for Glattrohraußenfläche in the economic context is large, which is understood a range of about 2 to 30 and a good heat transfer with low volume by small distances of the surfaces forming components of 0.5 -10 mm, preferably 1 to 4 mm. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to at least one of the preceding claims, characterized in that the heat transfer fluid ( 16 ) flows in the direction of the tube axes and the wall thickness of the tubes ( 11 ) and the additional surfaces ( 12 ) is chosen low to reduce the heat conduction. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to claim 4, characterized in that for the tubes ( 11 ) Pipe material with low thermal conductivity is selected. Periodically operating adsorption heat pump, adsorption or adsorption heat transformer according to claim 5, characterized in that as pipe material copper-zinc alloys, Copper nickel alloys, steel or chromium-nickel steel used becomes. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to claim 4, characterized in that in the additional surfaces ( 12 ) Areas with interruptions in the direction of the tube axes are selected. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to claim 7, characterized in that interrupted as surfaces with interruptions longitudinal ribs, helically attached corrugated strips ( 31 ) or wires ( 32 ) and on the Adsorptionsmittelseite transverse ribs are selected. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to one of the preceding claims, characterized in that the sorbent ( 13 ) as a coating on the tubes ( 11 ) and on the additional surfaces ( 12 ) or as a fill through a wire mesh or perforated plate ( 14 ) from the working medium vapor space ( 15 ) is separated vapor permeable. Periodic adsorption heat pump, adsorption chiller or adsorptive heat exchanger according to claim 9, characterized in that the sorbent ( 13 ) receiving additional surface ( 12 ) at a sorbent diameter of 0.3 to 3 mm has a height of about 4 to 25 mm, wherein the lower layer height at smaller dimensions of the sorbent ( 13 ) and correspondingly small intervals of the additional surfaces ( 12 ) forming components is provided. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to one of the preceding claims, characterized in that the capacitor ( 5 ) with the evaporator ( 5 ) and directly with the working medium vapor space ( 22 ) is connected to the sorber, being selected as the connecting material poor heat conducting metal with low wall thickness. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to one of the preceding claims, characterized in that for connecting the tubes with the additional surfaces ( 12 ) are used over 230 ° C melting soft solders or brazing alloys, which can be completed on one side with out of solid material worked out ribs or welded ribs or with other additional surfaces provided by additional surfaces on the other side. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to one of the preceding claims, characterized in that the sorber heat exchanger ( 1 ) from one or more tubes ( 11 ), the heat transfer fluid ( 16 ) flows in the direction of the tube axis on the tube inside or the tube outside and the sorbent ( 13 ) is mounted on the other side of the tube, wherein for cleaning a removable version of the shell ( 17 ) can be provided. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to one of the preceding claims, characterized in that the sorber heat exchanger ( 1 ) of at least four tubes ( 11 ), which is connected to a manifold ( 22 ) are connected to the working fluid, which has a low heat conduction, the heat transfer fluid ( 16 ) flows perpendicular to the tube axis on the tube outside and the sorbent ( 13 ) is mounted on the inside of the pipe and a removable jacket ( 17 ) is provided. Periodic adsorption heat pump, adsorption chiller or adsorption Heat transformer according to one of the preceding claims, characterized in that a further space ( 19 ) is used for heat exchange. Periodic adsorption heat pump, adsorption chiller or adsorption heat transformer according to one of the preceding claims, characterized in that the vapor chambers of the adsorber ( 101 . 103 ) and the desorber ( 101 . 103 ) are divided into two or more rooms and to as many condenser and evaporator rooms ( 51 . 52 . 53 . 54 ) are connected, which are designed as a condenser-evaporator.