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CN-121986243-A - Superhigh temperature heat pump

CN121986243ACN 121986243 ACN121986243 ACN 121986243ACN-121986243-A

Abstract

A heating, ventilation, air conditioning and refrigeration (HVACR) system includes a suction modulation valve fluidly connecting an outlet of an evaporator to a suction port of a compressor. The suction modulation valve is configured to control a flow of refrigerant from an outlet of the evaporator to a suction port of the compressor and to control a refrigerant pressure drop based on a result of monitoring at least one of (i) a refrigerant pressure differential at the expansion device and (ii) a refrigerant superheat downstream of the suction modulation valve.

Inventors

  • WANG WUCHAO
  • YU XIAORUI
  • ZHAO QINGXUAN

Assignees

  • 特灵空调系统(中国)有限公司
  • 特灵国际有限公司

Dates

Publication Date
20260505
Application Date
20230606

Claims (20)

  1. 1. A heating, ventilation, air conditioning and refrigeration (HVACR) system, comprising: A refrigerant circuit including an evaporator, a compressor, an expansion device, and a condenser to operate a refrigerant therein; A suction modulation valve fluidly connecting an outlet of the evaporator to a suction port of the compressor, the suction modulation valve configured to control a flow of refrigerant from the outlet of the evaporator to the suction port of the compressor, and The controller is used for controlling the operation of the controller, the controller is configured to: monitoring at least one of (i) a refrigerant pressure differential at the expansion device, and (ii) a refrigerant superheat downstream of the suction modulation valve, and And adjusting the suction modulation valve based on the result of the monitoring to control a refrigerant pressure drop from an outlet of the evaporator to a suction port of the compressor.
  2. 2. The system of claim 1, wherein the controller is further configured to: determining a refrigerant saturation pressure difference at respective temperatures of the condenser and the evaporator before the compressor starts operating, and When the compressor starts to operate, the suction adjusting valve is adjusted according to the refrigerant saturation pressure difference.
  3. 3. The system of claim 1, wherein the controller is further configured to: monitoring the pressure difference of the refrigerant upstream and downstream of the expansion device, and When the compressor starts to operate, the suction regulating valve is activated to a partially closed state at an opening degree according to the refrigerant pressure difference.
  4. 4. The system of claim 1, wherein the controller is further configured to: monitoring the change in the refrigerant pressure differential at the expansion device, and The suction modulation valve is activated to open at an opening degree according to the change of the refrigerant pressure difference.
  5. 5. The system of claim 1, wherein the controller is further configured to: comparing the refrigerant superheat downstream of the suction modulation valve with a predetermined refrigerant superheat level, and And activating the air suction regulating valve to be opened at an opening degree according to the comparison result.
  6. 6. The system of claim 1, further comprising a reheater configured to exchange heat between refrigerant liquid from the condenser and refrigerant vapor from the evaporator to heat the refrigerant vapor.
  7. 7. The system of claim 6, further comprising a refrigerant bypass valve to control the flow of refrigerant liquid from the condenser to the reheater.
  8. 8. The system of claim 1, further comprising a thermosiphon circuit to exchange heat between refrigerant liquid from the evaporator and oil from the compressor to evaporate the refrigerant liquid into refrigerant vapor.
  9. 9. The system of claim 8, wherein the thermosiphon circuit includes a control valve to control the flow of the refrigerant vapor to a suction port of the compressor.
  10. 10. The system of claim 8, wherein the thermosiphon circuit further comprises an oil bypass valve to control a flow of the oil to the thermosiphon circuit.
  11. 11. A method of controlling a heating, ventilation, air conditioning and refrigeration (HVACR) system, the system comprising a refrigerant circuit including an evaporator, a compressor, an expansion device and a condenser for operating a refrigerant therein, the method comprising: fluidly connecting an outlet of the evaporator to a suction port of the compressor through a suction modulation valve configured to control a flow of refrigerant from the evaporator to the suction port of the compressor; monitoring at least one of (i) a refrigerant pressure differential at the expansion device, and (ii) a refrigerant superheat downstream of the suction modulation valve, and And adjusting the suction modulation valve based on the result of the monitoring to control a refrigerant pressure drop from an outlet of the evaporator to a suction port of the compressor.
  12. 12. The method as recited in claim 11, further comprising: monitoring the temperatures of the condenser and the evaporator; determining a refrigerant saturation pressure difference at said temperature of said condenser and said evaporator before said compressor begins to operate, and When the compressor starts to operate, the suction regulating valve is regulated at an opening degree according to the refrigerant saturation pressure difference.
  13. 13. The method as recited in claim 12, further comprising: activating the suction modulation valve to a partially closed state when the refrigerant saturation pressure differential is below a predetermined value, and When the refrigerant saturation pressure difference is greater than the predetermined value, the suction modulation valve is activated to a fully open state.
  14. 14. The method as recited in claim 11, further comprising: monitoring said refrigerant pressure differential at said expansion device when the compressor begins to operate, and And activating the air suction regulating valve to be opened at an opening degree according to the agent pressure difference.
  15. 15. The method as recited in claim 11, further comprising: monitoring the expansion device for a change in the pressure differential, and And activating the air suction regulating valve to be opened at an opening degree according to the change of the pressure difference.
  16. 16. The method as recited in claim 11, further comprising: comparing the refrigerant superheat downstream of the suction modulation valve with a predetermined refrigerant superheat level, and And activating the air suction regulating valve to be opened at an opening degree according to the comparison result.
  17. 17. The method of claim 11, further comprising exchanging heat between a controlled amount of refrigerant from the condenser and refrigerant from the evaporator through a reheater.
  18. 18. The method of claim 11, further comprising exchanging heat between a controlled amount of oil from the compressor and refrigerant liquid from the evaporator through a thermosiphon circuit to evaporate the liquid refrigerant into refrigerant vapor.
  19. 19. The method of claim 18, further comprising controlling a flow of the refrigerant vapor to a suction port of the compressor by a control valve.
  20. 20. The method of claim 19, further comprising at least partially closing the control valve upon detecting that the inspiration valve is in a partially closed state.

Description

Superhigh temperature heat pump Technical Field The present disclosure relates generally to an ultra-high temperature heat pump. More particularly, the present disclosure relates to an ultra-high temperature heat pump that provides hot water using a heat source. Background Heating, ventilation, air conditioning and refrigeration (HVACR) systems may include a heat pump that utilizes a heat source to provide hot water. In the refrigerant circuit of the heat pump, the refrigerant flows through an evaporator and absorbs heat from a heat source, becoming low-pressure refrigerant that can be applied to a compressor. Refrigerant from the compressor flows through the condenser and releases heat to the process fluid (e.g., water) to provide hot water. Disclosure of Invention The present disclosure relates generally to a heating, ventilation, air conditioning and refrigeration (HVACR) system including a heat pump. More particularly, the present disclosure relates to a heat pump that utilizes a heat source to provide, for example, hot water or steam. Embodiments disclosed herein provide HVACR systems that include ultra-high temperature heat pumps that are capable of providing hot water (e.g., at temperatures of 120 ℃ or above 120 ℃) or steam using a heat source (e.g., at temperatures of 40 ℃ or above 40 ℃). Embodiments described herein may improve the reliability, stability, and efficiency of an ultra-high temperature heat pump by addressing issues including, for example, wet compression and/or low suction/discharge superheat when the system is in a start-up phase, and oil viscosity during steady-state operation. Briefly, in one embodiment, the present disclosure describes a heating, ventilation, air conditioning, and refrigeration (HVACR) system. The HVACR system includes a refrigerant circuit including an evaporator, a compressor, an expansion device, and a condenser to operate a refrigerant therein, and a suction modulation valve fluidly connecting an outlet of the evaporator to a suction port of the compressor. The suction modulation valve is configured to control a flow of refrigerant from an outlet of the evaporator to a suction port of a compressor. The system further includes a controller configured to monitor at least one of (i) a pressure differential at the expansion device and (ii) a degree of superheat of the refrigerant downstream of the suction modulation valve, and to adjust the suction modulation valve to control a pressure drop of the refrigerant from an outlet of the evaporator to a suction of the compressor based on a result of the monitoring. In another embodiment, the present disclosure describes a method of controlling a heating, ventilation, air conditioning and refrigeration (HVACR) system including a refrigerant circuit including an evaporator, a compressor, an expansion device, and a condenser to operate a refrigerant therein. The method includes fluidly connecting an outlet of an evaporator to a suction port of a compressor via a suction modulation valve. The suction modulation valve is configured to control a flow of refrigerant from the evaporator to a suction port of a compressor. The method further includes monitoring at least one of (i) a pressure differential at the expansion device and (ii) a superheat of the refrigerant downstream of the suction modulation valve, and adjusting the suction modulation valve to control a pressure drop of the refrigerant from an outlet of the evaporator to a suction of the compressor based on a result of the monitoring. Various aspects and advantages of the exemplary embodiments of the present disclosure have been summarized. The above summary is not intended to describe each illustrated embodiment. Other features and aspects will become apparent by consideration of the following detailed description and accompanying drawings. Drawings Reference is made to the accompanying drawings, which form a part hereof, and which is shown by way of illustration embodiments in which the systems and methods described in this specification may be practiced. Fig. 1 illustrates a schematic diagram of a refrigerant circuit that may be implemented in an HVACR system, according to one embodiment. FIG. 2 illustrates a schematic diagram of a control system according to one embodiment. FIG. 3 is a schematic diagram of an ultra-high temperature heat pump according to one embodiment. Fig. 4 is a flow chart of a method for controlling a heat pump according to one embodiment. Fig. 5 is a flow chart of a method for controlling a heat pump during a start-up phase or a mode change phase according to one embodiment. FIG. 6 is a flow chart of a method for controlling a reheater of a heat pump, according to one embodiment. FIG. 7 is a flow chart of a method for controlling oil cooling and refrigerant superheat in a heat pump, according to one embodiment. Like numbers refer to like elements throughout. Detailed Description In the following detailed description, reference is made to the