EP2754978A1 - Refrigerating plant with ejector - Google Patents
Refrigerating plant with ejector Download PDFInfo
- Publication number
- EP2754978A1 EP2754978A1 EP13196598.0A EP13196598A EP2754978A1 EP 2754978 A1 EP2754978 A1 EP 2754978A1 EP 13196598 A EP13196598 A EP 13196598A EP 2754978 A1 EP2754978 A1 EP 2754978A1
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- EP
- European Patent Office
- Prior art keywords
- ejector
- condenser
- flow
- compressor
- refrigerant
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B1/00—Compression machines, plants or systems with non-reversible cycle
- F25B1/10—Compression machines, plants or systems with non-reversible cycle with multi-stage compression
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/30—Expansion means; Dispositions thereof
- F25B41/39—Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2309/00—Gas cycle refrigeration machines
- F25B2309/06—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide
- F25B2309/061—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide with cycle highest pressure above the supercritical pressure
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2341/00—Details of ejectors not being used as compression device; Details of flow restrictors or expansion valves
- F25B2341/001—Ejectors not being used as compression device
- F25B2341/0012—Ejectors with the cooled primary flow at high pressure
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2341/00—Details of ejectors not being used as compression device; Details of flow restrictors or expansion valves
- F25B2341/001—Ejectors not being used as compression device
- F25B2341/0014—Ejectors with a high pressure hot primary flow from a compressor discharge
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/07—Details of compressors or related parts
- F25B2400/075—Details of compressors or related parts with parallel compressors
- F25B2400/0751—Details of compressors or related parts with parallel compressors the compressors having different capacities
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/13—Economisers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/23—Separators
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B40/00—Subcoolers, desuperheaters or superheaters
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
- F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
- F25B9/008—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant being carbon dioxide
Definitions
- the present invention relates to a refrigerating plant with ejector
- the refrigerating plant according to the invention has applications in the refrigerating and air conditioning sectors and possibly also in the more specific heat pump sector.
- the plant has applications both in refrigerated cabinets with incorporated refrigerator (known in the sector as plug-in cabinets), and in large-sized plants such as refrigerating stations serving a number of refrigerated cabinets in parallel.
- refrigerated cabinets with incorporated refrigerator known in the sector as plug-in cabinets
- plug-in cabinets large-sized plants
- refrigerating stations serving a number of refrigerated cabinets in parallel.
- a vapour compression refrigerating plant (or heat pump)of the conventional type makes it possible to transfer heat from a cold source to a hot source by means of a refrigerant fluid operating according to a thermodynamic cycle which provides in sequence for an evaporation stage, a compression stage, a cooling stage and an expansion stage.
- the plant is composed of a closed circuit comprising an evaporator, a compressor, a condenser or gas cooler and an expansion device positioned in series.
- the refrigerant fluid absorbs heat from the cold source (ambient to be cooled) in the evaporator passing to the vapour state.
- the fluid is then brought to a higher pressure level in the compressor, to transfer heat to the hot source inside the condenser or gas cooler, to return, lastly, to the evaporator flowing through the expansion device.
- the section of circuit comprised between the compressor and the inlet of the expansion device is defined as the high pressure side of the circuit, while the section of circuit comprised between the outlet of the expansion device and the inlet of the compressor is defined, instead, as the low pressure side of the circuit.
- a compression plant may operate according to a sub-critical cycle or alternatively according to a trans-critical cycle.
- a sub-critical cycle is when the pressure at which heat is transferred to the hot source is below the critical pressure of the refrigerant fluid.
- the refrigerant fluid comes to find itself in (two-phase)conditions of liquid-vapour equilibrium and the heat exchanger performing such stage functions as a condenser.
- the high pressure branch of the plant a univocal relationship thus exists between the pressure and the temperature.
- a trans-critical cycle is when the pressure is higher than the critical pressure of the refrigerant fluid.
- the refrigerant fluid is in super critical (single-phase) conditions and may only undergo cooling without a phase change.
- the heat exchanger which performs such cooling stage functions as a gas cooler and not as a condenser.
- a univocal relationship cannot therefore exist between the pressure and the temperature in the high pressure branch of the plant, these variables being able to assume values independently of each other.
- the plant solution described above comprises an additional heat exchanger as shown in Figures 1 and 2 . More specifically, the refrigerant fluid is compressed (point 2a) by the compressor C, cooled at constant pressure in the condenser/gas cooler D (point 3a) and sub-cooled by a heat exchanger E (Suction Line Heat exchanger, SLHX) to increase its refrigerant capacity (point 4a); the flow of refrigerant is throttled in a throttling device B (point 5a) and sent to the evaporator A (point 6a). In output from the evaporator the refrigerant is superheated (1) to be able to sub-cool the refrigerant in output from the condenser/gas cooler in the SLHX.
- a heat exchanger E Suction Line Heat exchanger
- tube in tube SLHX and capillary tube as throttling device tube in tube SLHX and capillary tube as throttling device
- the receiver of liquid becomes a two-phase receiver and both to avoid the danger of over pressures and to improve the energy performance of the cycle, it is common practice to remove the flash gas with a dedicated removal system which controls the pressure inside the receiver.
- the flash gas is returned to the high pressure side, upstream of the condenser, by means of an auxiliary compressor, as envisaged for example in the Italian patent IT1351459 in the name of Costan S.p.A.
- such configuration with auxiliary compressor provides for the subdivision of the throttling process into two stages and the use of a compressor for the extraction of the flash gas vapour which is generated after the first throttling (throttling which brings the refrigerant to an intermediate pressure).
- the refrigerant (point 3d) passes through the condenser/gas cooler D to be cooled; in output (point 4b) it undergoes a first throttling in a back pressure valve B1 (point 5b), downstream of which a receiver F is located, in which the condition of equilibrium between vapour and liquid occurs.
- the two phases are separated.
- the liquid (point 6b) proceeds towards the evaporator A (point 7b) after being further throttled in a second back pressure valve B2, and subsequently towards the primary compressor C1 (point 1b), while the vapour is compressed in an auxiliary compressor C2 (point 8b).
- the outlets of the two compressors (points 2b and 9b), are mixed before input to the condenser/gas cooler D (point 3b).
- auxiliary compressor in fact volumetric flows which may be even 10-20% of those circulating in the primary compressor group may circulate; the reduced sizes of the plug-in systems would require use of auxiliary compressors of such a small size that as of today they cannot be found on the market.
- the ejector is a machine without moving parts which can be used both as a compressor and as a pump to obtain a raising of the pressure of a fluid by supplying a fluid (of the same type or different) at different pressure and temperature conditions.
- the ejector works according to a basic principle, according to which when a fluid with a high momentum encounters one with a low momentum, it raises the pressure thereof.
- the fluid with greater momentum (high pressure) is called the primary flow or driving flow, while the fluid with lesser momentum (low pressure) is called the secondary flow or driven flow.
- the ejector has a structure with a first converging element, followed by a throat and then by a divergent element (diffuser). The internal energy possessed by the primary flow is transformed into kinetic energy.
- the effect is to lower the pressure to aspirate the secondary flow. Mixing takes place in the convergent section of the ejector and the speed of the two flows becomes uniform. Downstream, in the throat section, a normal shock wave is generated which causes a violent transformation from kinetic energy to pressure energy. The outgoing flow obtained is generally a uniform two-phase mixture. The normal shock wave modifies stagnation pressure, lowering it. This reduces the efficiency of the ejector.
- An alternative to the normal wave is the oblique wave which consists of a less violent transformation which generates a loss of stagnation pressure on the normal component only of the flow crossing it.
- a known plant solution provides for the use of an ejector on the low pressure side (low side) to increase the pressure of the vapour in output from the evaporator thereby reducing the work of the compressor.
- the plant diagram of this configuration is described in figures 5 and 6 .
- the primary flow (driving flow) in input to the ejector G is the refrigerant in output from the condenser D (gas cooler), while the secondary flow (driven flow) in input to the ejector is the refrigerant in output from the evaporator A.
- phase separator F In this configuration, due to the presence of a two-phase liquid-vapour flow at the output of the ejector, a phase separator F needs to be positioned, which separates the saturated liquid to be sent to the back pressure valve B which feeds the evaporator A, from the saturated vapour, to be sent to the compressor C.
- a plant of this type is described in the British patent GB1132477 .
- FIG. 7 Another plant solution provides for the use of an ejector on the high pressure side (high side) to increase the pressure of the vapour in output from the compressor thereby reducing the work of said compressor.
- the plant diagram of this configuration is described in Figures 7 and 8 .
- the primary flow (driving flow) in input to the ejector G is the refrigerant in output from a pump P fed by a fraction of refrigerant (in liquid phase in the case of a sub-critical work cycle, otherwise gaseous for a trans-critical work cycle) in output from the condenser D (gas cooler in the case of a trans-critical work cycle), while the secondary flow (driven flow) in input to the ejector G is the vapour in output from the compressor C.
- an active component such as the pump P must be provided to enable the primary flow to effectively drive the secondary flow.
- a plant of this type is described in the US patent US20070101760 .
- Plant solutions may also be hypothesised wherein in a simple single stage refrigerating cycle with or without heat exchanger SLHX (Suction Line Heat exchanger) an ejector has been introduced as a pressure recoverer, to reduce the compression ratios developed by the compressor to reduce the consumption of the cycle.
- SLHX Service Line Heat exchanger
- a practical application in marketed products is the fact that the ejector is a static device, in other words it has an optimal project design to which predefined input flow (primary and secondary) conditions correspond. Deviations from these optimal conditions lead to a reduction in the efficiency of the ejector and thus of the benefit to the refrigerating cycle.
- a typical example is the modification of the output temperature from the condenser/gas cooler following variations of the environmental conditions in which the refrigerating plant works.
- the purpose of the present invention is to eliminate or at least attenuate the drawbacks of the prior art mentioned above, by making available a refrigerating plant with ejector, which permits a more efficient removal of the flash gas and which is at the same time also applicable to plug-in cabinets using standard compressors available on the market.
- a further purpose of the present invention is to make available a refrigerating plant with ejector which is simple to make as regards construction and operatively simple to run.
- reference numeral 100 globally denotes a refrigerating plant with ejector according to the invention.
- the refrigerating plant 100 operates with a refrigerant according to a vapour compression cycle.
- the cycle may be either sub-critical or trans-critical.
- CO2 may be used as the refrigerant.
- the plant 100 comprises a main circuit 100A and in such main circuit 100A comprises:
- the first and the second expansion devices 111 and 113 are each composed of a back pressure valve.
- the plant 1 comprises an ejector 116 in a secondary branch 100B of the main circuit 100A.
- the ejector 116 is of the converging-diverging type.
- the structure and functioning of the ejector are known to a person skilled in the art and will not therefore be described in detail.
- the ejector 116 comprises a first inlet 116a for a driving flow, a second inlet 116b for a driven flow and an outlet 116c for ejection of the mixture of the two flows.
- the ejector 116 is fluidically connected to the main circuit in the section downstream of the condenser 110 and upstream of the first expansion device 111 to withdraw a fraction of the flow of refrigerant as the driving flow.
- the ejector is fluidically connected to the first receiver 112 to extract from said receiver as driven flow the vapour phase of the refrigerant (flash gas).
- the ejector 116 is fluidically connected to the main circuit in the section between the evaporator 114 and the condenser 110 to discharge the ejected flow of refrigerant.
- the mass flow processed at the primary compressor (or at the first stage) is reduced with a consequent saving in energy of the refrigerating cycle, thereby performing a more efficient extraction of the flash gas.
- the refrigerating plant 100 according to the invention is not only applicable to refrigerating stations, but also to single plug-in refrigerating cabinets using standard compressors available on the market.
- the plant 100 comprises two separate primary compressors: a low pressure one 115b, fluidically connected to the evaporator 114 and a high pressure one 115b, fluidically connected to the condenser 110.
- the outlet 116c of the ejector 116 is fluidically connected to the main circuit between said two primary compressors 115a, 115b.
- the aforesaid at least one primary compressor may be a two-stage compressor 115, having a first low pressure stage 115b fluidically connected to the evaporator 114 and a second high pressure stage 115a fluidically connected to the condenser 110.
- the outlet 116c of the ejector 116 is fluidically connected to the main circuit at the compressor 115 between the two compression stages.
- the plant 100 comprises a heat exchanger 117 which thermally connects the section of secondary branch downstream of the outlet 116c of the ejector 116 with the section of main circuit which is comprised between the condenser 110 and the first expansion device 111.
- heat exchanger 117 could be of the type with concentric tubes.
- the refrigerant In output from the condenser 110 (point 5e), the refrigerant is divided; one fraction (secondary flow) is bled (11e) and introduced into the ejector 116 as a driving flow.
- the high energy possessed by the refrigerant in the conditions (11e) is used to aspirate the "flash gas" (12e).
- the divergent element of the ejector permits a re-compression in output (13e).
- the primary flow is preferably throttled in a back pressure valve 111 (point 8e) enters the receiver, is bled in liquid phase (point 9e) and then throttled in the back pressure valve 113 (point 10e). After complete evaporation in the evaporator 114 (point 1e) the primary flow is compressed in the low pressure compressor 115b (point 2e), mixed with the flash gas (point 3e) and then compressed in the high pressure compressor 115a (point 4e).
- the plant configuration according to the aforesaid first embodiment firstly makes it possible to remove the flash gas in a less complicated manner as regards the plant compared to the solutions of the prior art with auxiliary compressors.
- an ejector is less complex than a compressor.
- the presence of the heat exchanger 117 makes it possible to greatly sub cool the (primary) flow of refrigerant, reducing the content of vapour in output from the back pressure valve 111.
- the flow of flash gas bled from the ejector is reduced while, for the same enthalpic difference at the evaporator and same refrigerating power demand, the flow of refrigerant at the first compression stage is constant.
- the flow of refrigerant which is processed by the second compression stage decreases, with a consequent improvement in performance of the cycle.
- the plant configuration comprises components with a reduced economic impact.
- the ejector and the heat exchanger 117 (1HX) are in fact devices of limited cost. This makes the first embodiment of the plant 100 particularly suitable for plug-in cabinets also, in which a low economic impact is essential.
- the plant 100 comprises a second receiver of liquid 119, inserted fluidically in the section of secondary branch downstream of the outlet 116c of the ejector 116.
- the flow of ejected refrigerant separates into the liquid phase and the vapour phase.
- said second receiver 119 is fluidically connected to the main circuit by means of a third expansion device 120 in the section comprised between the second expansion device 113 and the evaporator 114 to recirculate the liquid phase in the main circuit 100A.
- the vapour phase is aspirated by the second high pressure stage 115a of the two-stage compressor 115 or by the high pressure compressor 115a.
- the refrigerant in output from the ejector 116 (point 12f) is in two-phase conditions.
- the second receiver of liquid 119 makes it possible to exploit the refrigerant power contained in the liquid fraction. In the receiver 119 the phases are separated.
- the liquid (point 13f) is bled and throttled (point 14f) in the third expansion device 120 and then added to the main flow (point 9f) to reach the evaporator after a mixing (conditions point 15f).
- the vapour (point 16e) is added to the gas in output from the first compression stage or from the low pressure compressor 115b (point 2f) and the mixed fluid (point 3f) is compressed in the second compression stage or by the high pressure compressor (point 4f).
- the primary flow is throttled in a back pressure valve 111 (point 7f) and enters the first receiver 112. From here it is bled in liquid phase (point 8f) and then throttled in the back pressure valve 113 (point 9f). After mixing with the secondary flow in liquid phase, complete evaporation takes place in the evaporator 114 (point 1f). The refrigerant is then compressed at the first compression stage or by the low pressure compressor 115b (point 2f).
- the plant configuration according to the aforesaid second embodiment also makes it possible to remove the flash gas in a less complicated manner as regards the plant design compared to the solutions of the prior art with auxiliary compressors.
- a receiver is envisaged, the complexity of which is however inferior to that of a compressor.
- the plant configuration is complicated by the addition of further elements (i.e. second receiver and third expansion device), the low economic impact thereof makes the configuration of interest also for small sized applications such as plug-in cabinets.
- the plant configuration according to the aforesaid second embodiment also permits a reduction of the mass flow processed at the first stage of compression with a consequent saving in energy of the refrigerating cycle, despite in a less relevant manner than with the first embodiment.
- the separation of the liquid-vapour phases in the second receiver 119 - after the ejector- makes it possible to recover refrigerant power and thus to improve the performance of the refrigerating cycle.
- the secondary branch 100B which the ejector 116 is inserted in may be connected to the main circuit 100A downstream of the aforesaid at least one primary compressor 115 and upstream of the condenser 110.
- the aforesaid at least one primary compressor 115 may be a single stage compressor or a two-stage compressor (with a first low pressure stage and a second high pressure stage).
- the plant 100 may comprise two primary compressors connected in series, of which one low pressure and one high pressure.
- the secondary branch 100B which the ejector 116 is inserted in is connected to the main circuit 100A downstream of the primary compressor or compressors 115.
- the secondary branch is connected in the high pressure part of the main circuit 100A, i.e. in the part which is at the input pressure to the condenser 110.
- the plant 100 comprises at least one auxiliary compressor 118 inserted fluidically in the secondary branch downstream of the outlet of the ejector 116.
- said auxiliary compressor 118 raises the pressure of the flow in output from the ejector to the same pressure level as the refrigerant in input to the condenser 110.
- the plant 100 comprises a heat exchanger 117 which thermally connects the section of secondary branch downstream of the outlet 116c of the ejector 116 and upstream of the auxiliary compressor 118 with the section of main circuit which is comprised between the condenser 110 and the first expansion device 111.
- a fraction is bled (point 10g) and introduced into the ejector 116 as a driving flow.
- the high energy possessed by the refrigerant in the conditions of the point 10g is used to aspirate the "flash gas" (point 11g).
- the divergent element of the ejector permits a re-compression in output (point 12g).
- the refrigerant in output from the ejector 116 is biphasic.
- the heat exchanger 117 (IHX) makes it possible to exploit the complete evaporation (point 13g) to sub-cool the refrigerant of the main flow in output from the condenser 110 (point 5g) as far as the conditions of the point 6g.
- the vapour in output from the exchanger 117 undergoes a compression with the auxiliary compressor 118 as far as the high pressure conditions of the circuit (point 14g), where it mixes with the main flow (point 2g) entering the condenser 110 at the conditions of point 3g.
- the primary flow is throttled in a back pressure valve 111 (point 7g), enters the first receiver 112.
- the refrigerant is bled in liquid phase (point 8g) and throttled in the back pressure valve 13 (point 9g).
- the refrigerant is compressed in the primary compressor 115 (point 2g) and mixed with the flash gas (point 3g).
- the plant configuration according to the aforesaid third embodiment also permits a reduction of the mass flow processed by the primary compressor with consequent saving in energy of the refrigerating cycle.
- the presence of the heat exchanger 117 makes it possible to greatly sub cool the flow (primary) of refrigerant, reducing the content of vapour in output from the back pressure valve 111.
- the flow of flash gas bled from the ejector is reduced while, for the same enthalpic difference at the evaporator and refrigerant power demand, the flow of refrigerant at the first compression stage is constant.
- the flow of refrigerant which is processed by the second compression stage (sum of that of the first stage and of that of flash gas) decreases with a consequent improvement in performance of the cycle.
- the auxiliary compressor works less given that part of the pressure difference is given by the ejector.
- the plant diagram of the aforesaid third embodiment is further complicated by the presence of the ejector and of the heat exchanger IHX.
- these two components have a relatively low economic impact.
- the possibility of using commercial compressors for the auxiliary compressor makes the plant 100 according to said third embodiment also applicable to plug-in cabinets.
- the plant 100 comprises a second receiver of liquid 119 inserted fluidically in the section of secondary branch downstream of the outlet 116c of the ejector 116 and upstream of the auxiliary compressor 118.
- the flow of refrigerant in output from the ejector separates into the liquid phase and the vapour phase.
- the second receiver 119 is fluidically connected to the main circuit 100A by means of a third expansion device 120 in the section comprised between the second expansion device 113 and the evaporator 114 to recirculate the liquid phase in the main circuit.
- the vapour phase is aspirated by the auxiliary compressor 118.
- a fraction of refrigerant is bled (point 9h) and then introduced into the ejector 116 as a driving flow.
- the high energy possessed by the refrigerant in the conditions of the point 9h is used to aspirate the "flash gas" (point 10h).
- the divergent element of the ejector permits a re-compression in output (point 11h).
- the refrigerant in output from the ejector 116 (point 11h) is in two-phase conditions.
- the second receiver of liquid 119 placed downstream of the ejector 116 (point 11h) makes it possible to separate the two liquid and vapour phases and thus exploit the refrigerant power contained in the liquid fraction.
- the liquid (point 12hf) is bled and throttled (point 13h) and then added to the main flow (point 8h) to reach, after mixing, the evaporator at the conditions of point 14h.
- the vapour (point 15h) is compressed by the auxiliary compressor 118 and returned to a condition of high pressure (point 16h) and added to the gas in output from the primary compressor (point 2h).
- the primary flow instead, is throttled in a back pressure valve 111 (point 6h) and enters the first receiver 112. From here it is bled in liquid phase (point 7h) and then throttled in the back pressure valve 113 (point 8h). After mixing with the secondary flow (point 14h), complete evaporation is performed in the evaporator 114 (point 1h) and it is introduced into the primary compressor 115.
- the plant configuration according to the aforesaid fourth embodiment also permits a reduction of the mass flow processed by the primary compressor with consequent saving in energy of the refrigerating cycle, despite in a less relevant manner than the first embodiment of the invention.
- the auxiliary compressor works less given that part of the pressure difference is given by the ejector.
- the separation of the phases in the second receiver 119 permits a recovery of refrigerating power with consequent improvement of the performance of the refrigerating cycle.
- the plant 100 comprises at least one pump 121 fluidically inserted in the aforesaid secondary branch 100B upstream of the first inlet 116a of the ejector 116.
- the pump 121 raises the pressure of the driving flow of the ejector 116 so that the pressure of the flow ejected is the equivalent to that of the refrigerant in input to the condenser 110.
- the energy of the refrigerant is increased which, after coming out of the condenser 110 (point 4i), is bled from the main flow (point 9i), as far as the conditions of point 10i, by means of a pump 121 (in particular hydraulic) to be fed to the ejector 116 as a driving flow.
- the pump operates 121 in such a way that the driving flow has a pressure level such that, not only is it able to bleed the flash gas (point 11i), but it is also able to make the flow in output from the ejector (point 12i) have a pressure equal to that of the main flow in output from the compressor 115 (point 2i); the two flows are mixed and enter the condenser (110) (point 3i).
- the main flow (point 5i) is throttled in a back pressure valve 111 (point 6i) and collected in the first receiver 112. From here the refrigerant is bled in liquid phase (point 7i) and throttled in the main expansion device 113 (point 8i). After completing the evaporation in the evaporator, the refrigerant enters the compressor (point 1i). As already said the vapour phase present in the first receiver 112 is aspirated as driven fluid by the ejector 116.
- the plant configuration according to the aforesaid fifth embodiment also permits a reduction of the mass flow processed by the primary compressor with consequent saving in energy of the refrigerating cycle.
- auxiliary compressor is replaced with two components, the ejector and the pump, with consequent complication of the plant. These two components are however relatively inexpensive. In this particular configuration too, the plant thus proves adaptable for both large sized plants (refrigerating stations) and small sized plants (plug-in cabinets).
- the invention makes it possible to achieve several advantages which have been expounded in the description.
- the refrigerating plant 100 with ejector according to the invention permits a more efficient removal of the flash gas and is at the same time also applicable to plug-in cabinets using standard compressors available on the market.
- the refrigerating plants 100 is constructionally simple to make and operatively simple to run.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Jet Pumps And Other Pumps (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT000004A ITPD20130004A1 (it) | 2013-01-15 | 2013-01-15 | Impianto frigorifero con eiettore |
Publications (1)
Publication Number | Publication Date |
---|---|
EP2754978A1 true EP2754978A1 (en) | 2014-07-16 |
Family
ID=47790335
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP13196598.0A Withdrawn EP2754978A1 (en) | 2013-01-15 | 2013-12-11 | Refrigerating plant with ejector |
EP13196599.8A Active EP2754979B1 (en) | 2013-01-15 | 2013-12-11 | Refrigerating plant with ejector |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
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EP13196599.8A Active EP2754979B1 (en) | 2013-01-15 | 2013-12-11 | Refrigerating plant with ejector |
Country Status (3)
Country | Link |
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EP (2) | EP2754978A1 (it) |
ES (1) | ES2581063T3 (it) |
IT (1) | ITPD20130004A1 (it) |
Cited By (14)
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CN104949372A (zh) * | 2015-05-29 | 2015-09-30 | 浙江工业大学 | 具有气液分离器的新型压缩辅助喷射制冷*** |
CN105509357A (zh) * | 2015-12-30 | 2016-04-20 | 嵊州高翔冷链设备股份有限公司 | 一种多用途压缩冷凝机组 |
CN106500383A (zh) * | 2016-10-27 | 2017-03-15 | 山东大学 | 一种喷射器运行区间的优化控制方法 |
CN107990580A (zh) * | 2017-11-07 | 2018-05-04 | 西安交通大学 | 一种多次分离喷射增效的自复叠热泵***及运行模式 |
EP3372920A1 (en) * | 2017-03-02 | 2018-09-12 | Heatcraft Refrigeration Products LLC | Integrated refrigeration and air conditioning system |
JP2019138577A (ja) * | 2018-02-13 | 2019-08-22 | 株式会社デンソー | 冷凍サイクル装置 |
EP3722707A1 (en) * | 2019-04-08 | 2020-10-14 | Carrier Corporation | Air conditioning system |
CN111829201A (zh) * | 2019-04-18 | 2020-10-27 | 青岛海尔空调电子有限公司 | 制冷*** |
US11231209B2 (en) * | 2016-05-16 | 2022-01-25 | Epta S.P.A. | Refrigeration plant with multiple evaporation levels and method of managing such a plant |
CN114739038A (zh) * | 2022-04-18 | 2022-07-12 | 西安交通大学 | 一种采用双级喷射器增效的梯级换热热泵循环*** |
CN114739037A (zh) * | 2022-04-08 | 2022-07-12 | 西安交通大学 | 一种双喷射器多回路蒸发的蒸气压缩循环***及工作方法 |
CN115096011A (zh) * | 2022-06-20 | 2022-09-23 | 江苏凌氢新能源科技有限公司 | 一种级联式引射器多重蒸发器制冷*** |
WO2023279157A1 (en) * | 2021-07-06 | 2023-01-12 | Mbgsholdings Pty Ltd | Refrigeration system and method |
US11725858B1 (en) | 2022-03-08 | 2023-08-15 | Bechtel Energy Technologies & Solutions, Inc. | Systems and methods for regenerative ejector-based cooling cycles |
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CN104764245B (zh) * | 2015-04-02 | 2017-01-25 | 清华大学 | 一种超临界流体喷射冷却***及其使用方法 |
US10823461B2 (en) | 2015-05-13 | 2020-11-03 | Carrier Corporation | Ejector refrigeration circuit |
EP3862657A1 (en) | 2020-02-10 | 2021-08-11 | Carrier Corporation | Refrigeration system with multiple heat absorbing heat exchangers |
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CN103003642B (zh) * | 2010-07-23 | 2015-07-08 | 开利公司 | 喷射器循环 |
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- 2013-12-11 EP EP13196598.0A patent/EP2754978A1/en not_active Withdrawn
- 2013-12-11 EP EP13196599.8A patent/EP2754979B1/en active Active
- 2013-12-11 ES ES13196599.8T patent/ES2581063T3/es active Active
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GB1132477A (en) * | 1965-09-22 | 1968-11-06 | Joseph Kaye & Company Inc | Multiple-phase ejector refrigeration system |
EP1870648A1 (en) * | 2005-04-05 | 2007-12-26 | Denso Corporation | Ejector type refrigerating cycle unit |
US20110005268A1 (en) * | 2008-04-18 | 2011-01-13 | Denso Corporation | Ejector-type refrigeration cycle device |
WO2010117973A2 (en) * | 2009-04-09 | 2010-10-14 | Carrier Corporation | Refrigerant vapor compression system with hot gas bypass |
CH703290A1 (de) * | 2010-09-29 | 2011-12-15 | Erik Vincent Granwehr | Wärmepumpe. |
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Cited By (21)
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CN104949372A (zh) * | 2015-05-29 | 2015-09-30 | 浙江工业大学 | 具有气液分离器的新型压缩辅助喷射制冷*** |
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CN105509357B (zh) * | 2015-12-30 | 2018-03-27 | 嵊州高翔冷链设备股份有限公司 | 一种多用途压缩冷凝机组 |
US11231209B2 (en) * | 2016-05-16 | 2022-01-25 | Epta S.P.A. | Refrigeration plant with multiple evaporation levels and method of managing such a plant |
CN106500383A (zh) * | 2016-10-27 | 2017-03-15 | 山东大学 | 一种喷射器运行区间的优化控制方法 |
WO2018077048A1 (zh) * | 2016-10-27 | 2018-05-03 | 山东大学 | 一种喷射器运行区间的优化控制方法 |
CN106500383B (zh) * | 2016-10-27 | 2019-07-05 | 山东大学 | 一种喷射器运行区间的优化控制方法 |
US11009266B2 (en) | 2017-03-02 | 2021-05-18 | Heatcraft Refrigeration Products Llc | Integrated refrigeration and air conditioning system |
EP3372920A1 (en) * | 2017-03-02 | 2018-09-12 | Heatcraft Refrigeration Products LLC | Integrated refrigeration and air conditioning system |
CN107990580A (zh) * | 2017-11-07 | 2018-05-04 | 西安交通大学 | 一种多次分离喷射增效的自复叠热泵***及运行模式 |
JP2019138577A (ja) * | 2018-02-13 | 2019-08-22 | 株式会社デンソー | 冷凍サイクル装置 |
WO2019159638A1 (ja) * | 2018-02-13 | 2019-08-22 | 株式会社デンソー | 冷凍サイクル装置 |
EP3722707A1 (en) * | 2019-04-08 | 2020-10-14 | Carrier Corporation | Air conditioning system |
US11326789B2 (en) | 2019-04-08 | 2022-05-10 | Carrier Corporation | Air conditioning system and control method thereof |
CN111829201A (zh) * | 2019-04-18 | 2020-10-27 | 青岛海尔空调电子有限公司 | 制冷*** |
WO2023279157A1 (en) * | 2021-07-06 | 2023-01-12 | Mbgsholdings Pty Ltd | Refrigeration system and method |
US11725858B1 (en) | 2022-03-08 | 2023-08-15 | Bechtel Energy Technologies & Solutions, Inc. | Systems and methods for regenerative ejector-based cooling cycles |
CN114739037A (zh) * | 2022-04-08 | 2022-07-12 | 西安交通大学 | 一种双喷射器多回路蒸发的蒸气压缩循环***及工作方法 |
CN114739038A (zh) * | 2022-04-18 | 2022-07-12 | 西安交通大学 | 一种采用双级喷射器增效的梯级换热热泵循环*** |
CN114739038B (zh) * | 2022-04-18 | 2023-01-10 | 西安交通大学 | 一种采用双级喷射器增效的梯级换热热泵循环*** |
CN115096011A (zh) * | 2022-06-20 | 2022-09-23 | 江苏凌氢新能源科技有限公司 | 一种级联式引射器多重蒸发器制冷*** |
Also Published As
Publication number | Publication date |
---|---|
ES2581063T3 (es) | 2016-08-31 |
ITPD20130004A1 (it) | 2014-07-16 |
EP2754979A1 (en) | 2014-07-16 |
EP2754979B1 (en) | 2016-04-06 |
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