Refrigeration plant and method for preventing overheating by temperature-based control
AssigneeCarel Industries S.P.A.
InventorsAlessandro Maniero, Matteo Miotto
Life of this patent
Estimating the term…
Abstract
A method of operating a refrigeration plant which comprises sensing means designed to detect or derive an overheating temperature Tsh at an intake of a compressor assembly of the refrigeration plant. The method comprises: a standard operating mode A that sets an optimal value Ropt, for the operating regime of the compressor Rcomp(t); a mode B, which verifies, whether the overheating temperature Tsh exceeds a threshold value Max, to verify whether the operating regime Rcomp(t) of the compressor assembly is greater than a safety value Mpd and, in the case of a positive outcome, to limit the operating regime Rcomp(t) of the compressor assembly to a safety value Mpd, setting the optimal value Ropt, overriding mode A.
Claims19
An operating method of a refrigeration plant, wherein said refrigeration plant includes in sequence:
- at least one evaporator assembly;
- a compressor assembly which, in operation, has a variable and adjustable operating regime Rcomp(t);
- a condenser assembly;
- an expander assembly;
- a control device connected to said compressor assembly to operate it;
- sensing means apt to detect or derive an overheating temperature Tsh at an intake of said compressor assembly and/or downstream of each of said at least one evaporator assembly, connected to said control device;
- wherein said method involves operating said compressor assembly so as to bring its operating regime Rcomp(t) to a target value Ropt;
- said method comprising:
- a mode A, of standard operation of said refrigeration plant, within which said target value Ropt is defined by an optimization algorithm of said refrigeration plant;
- a mode B, of preventing deficient lubrication conditions of the compressor assembly, within which the following sub-steps are carried out serially:
- a sub-step B1 that consists of a verification of whether the operating regime Rcomp(t) is less than a predefined safety value Mpd and, in case of a positive outcome, performing an output operation O after making an initial setting Set1 that includes setting a value of an operating parameter RcompMax equal to said safety value Mpd;
- a sub-step B2 which is performed if the verification of sub-step B1 has given a negative outcome and which provides
- a first verification V1 consisting of verifying whether the overheating temperature Tsh is greater than or equal to a threshold value Max, and, in case of negative outcome, making a fourth setting Set4, which involves increasing the value of the operating parameter RcompMax, and, subsequently, performing said output operation O or,
- in the case of a positive outcome of said first verification V1, performing a second verification V2 comprising verifying whether the operating regime Rcomp (t) is greater than the predefined safety value Mpd and, in the case of a negative outcome, performing said output operation O or
- in case of a positive outcome of said second verification V2, making a second setting Set2 which involves decreasing the value of said operating parameter RcompMax, then performing a third verification V3 which consists of verifying whether the value of said operating parameter RcompMax is greater than or equal to said safety value Mpd and, in case of a positive outcome, performing said output operation O or, in case of a negative outcome, performing said output operation O after making a third setting Set3 which involves setting the value of said operating parameter RcompMax equal to said safety value Mpd;
- wherein said output operation O involves assigning to said target value Ropt a new value, equal to the value of said operating parameter RcompMax, if the latter is less than said target value Ropt itself;
- wherein said mode B is iterated cyclically during the mode A or performed concurrently with the mode A and overrides the latter in the setting of said target value Ropt.
Dependencies are inferred from the claim text.