US 12,259,165 B2
Method for controlling suction pressure of a vapour compression system
Jan Prins, Nordborg (DK); and Lars Finn Sloth Larsen, Nordborg (DK)
Assigned to DANFOSS A/S, Nordborg (DK)
Appl. No. 17/609,876
Filed by Danfoss A/S, Nordborg (DK)
PCT Filed Aug. 13, 2020, PCT No. PCT/EP2020/072723
§ 371(c)(1), (2) Date Nov. 9, 2021,
PCT Pub. No. WO2021/058193, PCT Pub. Date Apr. 1, 2021.
Claims priority of application No. 19199832 (EP), filed on Sep. 26, 2019.
Prior Publication US 2022/0221207 A1, Jul. 14, 2022
Int. Cl. F25B 49/02 (2006.01); F25B 1/10 (2006.01); F25B 5/02 (2006.01); F25B 41/22 (2021.01)
CPC F25B 49/02 (2013.01) [F25B 1/10 (2013.01); F25B 5/02 (2013.01); F25B 41/22 (2021.01); F25B 2341/0012 (2013.01); F25B 2400/23 (2013.01); F25B 2500/19 (2013.01); F25B 2600/2509 (2013.01); F25B 2700/1933 (2013.01); F25B 2700/197 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for controlling a vapour compression system, the vapour compression system comprising a compressor unit comprising one or more compressors, a heat rejecting heat exchanger, an ejector, a receiver, at least one expansion device and at least one evaporator arranged in a refrigerant path, an outlet of the heat rejecting heat exchanger being connected to a primary inlet of the ejector, an outlet of the ejector being connected to an inlet of the receiver, and an outlet of the evaporator being connected to a secondary inlet of the ejector and to an inlet of the compressor unit, wherein the vapour compression system further comprises a non-return valve arranged in the refrigerant path between the outlet of the evaporator and the inlet of the compressor unit, in such a manner that a refrigerant flow from the outlet of the evaporator towards the inlet of the compressor unit is allowed, while a fluid flow from the inlet of the compressor unit towards the outlet of the evaporator is prevented, wherein a gaseous outlet of the receiver is connected to the inlet of the compressor unit via a bypass valve, the method comprising the steps of:
measuring a pressure, P0, of refrigerant leaving the evaporator,
obtaining a value being representative for a pressure, Psuc, of refrigerant entering the compressor unit,
comparing the pressures, P0 and Psuc, to respective reference pressure values, P0,ref and Psuc,ref,
determining ε0=P0−P0,ref and determining εsuc=Psuc−Psuc,ref,
in the case that ε0>εsuc, controlling the compressor unit based on P0, and
in the case that εsuc>ε0, controlling the compressor unit based on Psuc.