Estimation apparatus of heat transfer medium flow rate, heat source machine, and estimation method of heat transfer medium flow rate

摘要

A flow rate of a heat transfer medium is computed without a flow meter. In a control apparatus (30), a storing portion (36) stores an aerodynamic characteristic map indicating a line causing a rotating stall and lines showing a sonic velocity in a refrigerant sucked in by a compressor (12) on a map displaying a variable θ reflecting a suction volume of the compressor (12) and a variable Ω reflecting a head of the compressor (12); a estimation portion of chilled water flow rate (30b) computes the variable Ω, derives the variable θ according to the variable Ω from the map, computes a heat amount exchanged between the refrigerant and the chilled water in an evaporator (24) based on the suction volume of the compressor (12) according to the computed variable θ, and computes the flow rate of the chilled water based on the heat amount.

主权项

1. An estimation apparatus of heat transfer medium flow rate for estimating a flow rate of a heat transfer medium in a heat source machine including: a variable-speed centrifugal compressor for sucking and compressing a refrigerant; a condenser for condensing the compressed refrigerant using a heat source medium; and an evaporator for evaporating the condensed refrigerant and carrying out heat exchange between the refrigerant and the heat transfer medium, the estimation apparatus of heat transfer medium flow rate comprising:
a storing portion for storing an aerodynamic characteristic map indicating a rotating stall line causing a rotating stall and a plurality of machine Mach number lines showing a sonic velocity in the refrigerant sucked in by the compressor on a map displaying a first parameter reflecting a suction volume of the compressor and a second parameter reflecting a head of the compressor; a first parameter computation portion for computing the second parameter and deriving the first parameter according to the second parameter from the aerodynamic characteristic map; and a heat transfer medium flow rate computation portion for computing an amount of heat exchanged between the refrigerant and the heat transfer medium in the evaporator based on the suction volume of the compressor according to the first parameter derived by the first parameter computation portion and a density of the refrigerant sucked into the compressor, and computing a flow rate of the heat transfer medium based on the amount of the heat, wherein the storing portion stores a plurality of aerodynamic characteristic maps that differ according to the number of revolutions of the compressor, and the first parameter computation portion derives the first parameter according to the second parameter from the aerodynamic characteristic map corresponding to the number of revolutions of the compressor.