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DE-102024210858-A1 - Refrigerant system

DE102024210858A1DE 102024210858 A1DE102024210858 A1DE 102024210858A1DE-102024210858-A1

Abstract

The invention relates to a refrigerant system (10, 82, 98), in particular a heat pump, with a refrigerant circuit (12) comprising an evaporator (16), a compressor section (18), a condenser (20) and a refrigerant flow divider (22). Additionally, a method for operating a refrigerant system (10, 82, 98) is provided.

Inventors

  • Jan Christ
  • Menno Van der Hoff
  • Lennart Berg
  • Matthias Feiner
  • Wolfram Faas

Assignees

  • Robert Bosch Gesellschaft mit beschränkter Haftung

Dates

Publication Date
20260513
Application Date
20241112

Claims (15)

  1. Refrigeration system (10, 82, 98), in particular a heat pump, with a refrigerant circuit (12) comprising an evaporator (16) in which the refrigerant (14) is evaporated at a first pressure level, a compressor section (18) in which the refrigerant (14) is raised from the first pressure level to a second, higher pressure level, a condenser (20) in which the refrigerant (14) is condensed at the second pressure level, and a refrigerant flow dividing device (22) which divides the refrigerant (14) leaving the condenser (20) into a first partial flow (26) and a second partial flow (28), wherein the first partial flow (26) leaves the refrigerant flow dividing device (22) in gaseous form at a third, intermediate pressure level and can be supplied to the compressor section (18) via a control valve (30), wherein the third pressure level lies between the first and second pressure levels, characterized in that the second partial flow (28) is directed after the refrigerant flow divider (22) in such a way that it transfers heat energy to the evaporator (16) and/or a drip tray (32) of the evaporator (16), in particular heating it or these (16, 32), in particular preventing ice formation on them or thawing existing ice to counteract glaciation or melting the existing ice, and/or that it heats, in particular superheats, refrigerant (14) leaving the evaporator (16) at the first pressure level before it is supplied to the compressor section (18), in particular wherein the second partial flow (28) is subsequently expanded and supplied to the evaporator (16) at the first pressure level.
  2. Refrigerant system (10) according Claim 1 , wherein the refrigerant flow divider (22) is configured with an economizer heat exchanger (48) and the refrigerant flow divider (22) is configured such that the refrigerant (14) leaving the condenser (20) is split into the first partial flow (26) and the second partial flow (28) and fed to the economizer heat exchanger (48), wherein the first partial flow (26) is expanded to the third, intermediate pressure level and cools down in the process before being fed to the economizer heat exchanger (48), and wherein the second partial flow (28) is fed to the economizer heat exchanger (48) at a fourth pressure level, which is above the third pressure level, in particular corresponding to the second pressure level, and wherein furthermore in the economizer heat exchanger (48) the first partial flow (26) transfers thermal energy from the second partial flow (28) absorbs, so that liquid components of the first partial stream (26) are evaporated and the second partial stream (28) is cooled.
  3. Refrigerant system (10) according Claim 2 , characterized in that the refrigerant flow divider (22) between the condenser (20) and the economizer heat exchanger (48) has an expansion valve (50) to expand the first partial flow (26) between the condenser (20) and the economizer heat exchanger (48) to the third pressure level.
  4. Refrigerant system (82, 98) according to Claim 1 , wherein the refrigerant flow divider (22) is equipped with a phase separation device (84), and the refrigerant circuit (12) is configured such that the refrigerant (14) exiting the condenser (20) is expanded in the refrigerant flow divider (22) and supplied to the phase separation device (84), wherein the refrigerant (14) is separated in the phase separation device (84) into a substantially gaseous phase and a liquid phase, wherein the gaseous phase of the refrigerant (14) exits the phase separation device (84) as the first partial flow (26) and leaves the refrigerant flow divider (22) and can be supplied to the compressor section (18) at the third, intermediate pressure level via a control valve (30), wherein the liquid phase of the refrigerant (14) exits the phase separation device (84) as the second partial flow (28) and leaves the refrigerant flow divider (22).
  5. Refrigerant system (82, 98) according to Claim 4 , characterized in that the second partial flow (28) after the phase separation device (84) is at the third, middle pressure level.
  6. Refrigerant system (10, 82, 98) according to one of the preceding claims, characterized in that a heat exchanger (34) is provided between the evaporator (16) and the compressor section (18), in particular wherein the heat exchanger (34) is designed with a droplet separator (104), wherein the refrigerant (14) from the evaporator (16) and the second partial flow (28) after the refrigerant flow dividing device (22) are supplied to the heat exchanger (34).
  7. Refrigerant system (10, 82, 98) according to one of the preceding claims, characterized in that the refrigerant system (10, 82, 98) comprises a control device (38), in particular having an inverter, wherein waste heat from the control device (38) is transferred to the refrigerant (14) on the first pressure level is supplied after the evaporator (16) and before the compressor section (18) and/or the waste heat of the control device (38) is supplied to the first partial flow (26) after the refrigerant flow partial device (22) and before the compressor section (18).
  8. Refrigerant system (10, 82, 98) according to one of the preceding claims, characterized in that the compressor section (18) is a single-stage compressor (36), wherein the first partial flow (26) is supplied directly to the compressor (36) after the refrigerant flow dividing device (22).
  9. Refrigerant system (10, 82, 98) according to one of the preceding claims, characterized in that the compressor section (18) is a two-stage compressor (36) and the first partial flow (26) is introduced into the compressor section (18) after the refrigerant flow dividing device (22) between the two compressor stages.
  10. Refrigerant system (10, 82, 98) according to one of the preceding claims, characterized in that a further expansion valve (24) is arranged upstream of the evaporator (16) to expand the second partial flow (28) to the first pressure level before the second partial flow (28) is supplied to the evaporator (16).
  11. Refrigerant system (10, 82, 98) according to one of the preceding claims, characterized in that the refrigerant system (10, 82, 98) is configured to operate in a first operating mode and a second operating mode, wherein in the first operating mode the refrigerant (14) absorbs heat in the evaporator (16) and in the second operating mode the refrigerant (14) flows against the flow direction of the first operating mode and releases heat in the evaporator (16) in order to defrost it, in particular completely.
  12. A method for operating a refrigerant system (10, 82, 98) with an evaporator (16), a compressor section (18), a condenser (20), and a refrigerant flow dividing device (22) in a first operating mode, in particular wherein the method operates a refrigerant system (10, 82, 98) according to one of the claims above, comprising the following steps: Evaporating (110) a refrigerant (14) at a first pressure level with the evaporator (16), Compressing (112) the refrigerant (14) to a second, higher pressure level by means of the compressor section (18), Condensing (114) the refrigerant (14) at the second pressure level in the condenser (20), Dividing (116) the refrigerant (14) leaving the condenser (20) into a first partial flow (26) and a second partial flow (28) by means of the refrigerant flow dividing device (22), Dispensing (126) the first partial stream (26) from the refrigerant flow dividing device (22) at a third, intermediate pressure level, and in a gaseous state, and feeding (128) the first partial stream (26) via a control valve (30) into the compressor section (18), the method being characterized by the following steps: Dispensing (130) the second partial stream (28) from the refrigerant flow dividing device (22), transferring (132) thermal energy from the second partial stream (28) to the evaporator (16) and/or a drip tray (32) of the evaporator (16) to heat it, in particular to prevent ice formation or to thaw existing ice, to counteract glaciation or to defrost existing ice, and/or transferring (134) thermal energy from the second partial stream (28) to Refrigerant (14) leaving the evaporator (16) at the first pressure level before being fed to the compressor section (18), and heating of the refrigerant (14), in particular subsequent expansion (136) of the second partial flow (28) and feeding (137) the expanded refrigerant (14) into the evaporator (16) at the first pressure level.
  13. Procedure according to Claim 12 with the refrigerant flow dividing device (22) with an economizer heat exchanger (48), which is characterized by the following steps: supplying (118) the refrigerant (14) leaving the condenser (20), divided into the first and second partial flows (26, 28) into the economizer heat exchanger (48), expanding (120) the first partial flow (26) in the refrigerant flow dividing device (22) to a third, intermediate pressure level, wherein the first partial flow (26) cools down before being supplied to the economizer heat exchanger (48), supplying (122) the second partial flow (28) into the economizer heat exchanger (48) at a fourth pressure level, which is above the third pressure level, in particular corresponding to the second pressure level, absorption (124) of heat energy from the second partial flow (28) by the first partial flow (26) in the Economizer heat exchanger (48) so that liquid components of the first partial stream (26) are evaporated and the second partial stream (28) is cooled.
  14. Procedure according to Claim 12 with the refrigerant flow divider (22) with a phase divider (84), characterized by the following steps: expansion (138) of the refrigerant (14) exiting the condenser (20) in the refrigerant divider refrigerant flow divider (22), supply (140) of the refrigerant (14) to the phase separation device (84), separation (142) of the refrigerant (14) into a substantially gaseous phase and a liquid phase in the phase separation device (84), exit (144) of the gaseous phase of the refrigerant (14) from the phase separation device (84) as a first partial flow (26) and discharge (126) of the first partial flow (26) from the refrigerant flow divider (22) and supply (128) of the first partial flow (26) at the third, intermediate pressure level via a control valve (30) into the compressor section (18), exit (146) of the liquid phase of the refrigerant (14) from the phase separation device (84) as a second partial flow (28) and discharge (130) of the second partial flow (28) from the refrigerant flow divider (22).
  15. Procedure according to one of the Claims 12 until 14 , characterized in that the refrigerant system (10, 82, 98) is operated in a second operating mode, wherein the refrigerant (14) flows in a direction reversed to that of the first operating mode in order to transport heat to the evaporator (16) by means of the refrigerant (14), so that the evaporator (16) and/or the drip tray (32) of the evaporator (16) is, in particular completely, defrosted.

Description

State of the art The present invention relates to a refrigerant system, in particular a heat pump, and to a method for operating a refrigerant system, in particular according to the invention. Heat pumps, as examples of refrigerant systems, transport thermal energy from a lower to a higher temperature level. For this purpose, a refrigerant (also called the working fluid) absorbs thermal energy at a lower temperature level from a source (typically the environment, e.g., ambient air, the ground, or a body of water), raises the temperature of the refrigerant, and releases the thermal energy at the higher temperature level. For example, refrigerant systems are used in heating mode to heat residential buildings, transporting heat from an environmental source, such as the ambient air, into the building. In cooling mode, a refrigerant system can be used to cool a residential building by removing heat from the building. Propane, a natural refrigerant, is commonly used in heat pumps today. Propane enables efficient heat transfer and is environmentally friendly and cost-effective. Other refrigerants are also common and can be used in accordance with the invention. The typical basic structure of a refrigerant system comprises an evaporator, a compressor, a condenser, and an expansion unit. During heating operation, the refrigerant absorbs heat from, for example, the ambient air in the evaporator. This causes the refrigerant to evaporate. Subsequently, the refrigerant is compressed from a lower pressure level to a higher pressure level in the compressor, thereby being heated further. The refrigerant then liquefies in the condenser, releasing heat to the surroundings. In the expansion unit, the refrigerant is depressurized to a lower pressure level and cooled before being returned to the evaporator. In particular, to ensure more efficient heat supply at high target temperatures, further components can be added, such as a so-called economizer. The economizer may include a heat exchanger. Typically, in this type of economizer, the refrigerant flow after the condenser is split into a main and a bypass stream and fed to the heat exchanger. The bypass stream of refrigerant is expanded to a lower pressure level before being fed to the heat exchanger. In the heat exchanger, the bypass stream absorbs heat from the main stream. This subcools the main stream, giving it a higher heat absorption capacity when it enters the evaporator. The bypass stream can then be fed to the compressor after the heat exchanger. A refrigerant system with an economizer and heat exchanger is used in WO 2008/105868 A2 shown. The object of the present invention is to provide a refrigerant system and a method for operating a refrigerant system that operates efficiently and enables a long service life for the system components. This problem is solved according to the invention by the claimed refrigerant system and the claimed method. Disclosure of the invention According to the invention, a refrigerant system, in particular a heat pump, is provided with a refrigerant circuit. The refrigerant system comprises an evaporator, a compressor section, a condenser, and a refrigerant flow divider. In the evaporator, which is in particular a heat exchanger, the refrigerant is preferably completely evaporated at a first pressure level. During this process, the refrigerant absorbs heat, for example, from the ambient air. Absorption of heat from another device, such as another refrigerant circuit, is also conceivable. In the compressor section, the gaseous refrigerant is increased from the first pressure level to a second, higher pressure level. Additionally, the refrigerant is heated during compression. Suitable compressors include, for example, rotary compressors, reciprocating compressors, screw compressors, and/or scroll compressors. In the condenser, which is primarily designed as a heat exchanger, the refrigerant is condensed at the second pressure level and, in particular, completely liquefied. The refrigerant flow divider splits the refrigerant leaving the condenser into a first partial flow and a second partial flow. The first partial flow leaves the refrigerant flow divider in gaseous form at a third, intermediate pressure level and can be fed to the compressor section via a control valve. This third, intermediate pressure level lies between the first and second pressure levels. Specifically, the first partial flow can have a lower temperature upon leaving the refrigerant flow divider than the refrigerant in the compressor, so that when the first partial flow is fed into the compressor... The refrigerant already present in the compressor section is intermediately cooled. This intermediate cooling prevents the refrigerant from reaching excessively high temperatures during compression, which would damage the compressor section and, in particular, prevent the oil that lubricates the components from degrading. Furthermore, the compressor section requires less wo