Refrigeration system and fall film evaporator

Abstract

A speed governor assembly and an elevator system. The speed governor assembly includes: a sheave; a centrifugal mechanism mounted on the sheave and rotating together with the sheave; an overspeed protection switch at a first distance from a radial outer side of the centrifugal mechanism; a core ring disposed coaxially with the sheave; and a triggering arm rotating together with the core ring; wherein the centrifugal mechanism engages with the core ring and drives the core ring and the triggering arm to rotate when the sheave reaches a second speed, and the rotation of the triggering arm can contact and trigger the overspeed protection switch.

1 . A refrigeration system, comprising:
 a refrigeration loop having an air outlet of a compressor, a condenser, a throttle element, a falling film evaporator, and an air inlet of the compressor which are connected in sequence by pipes, wherein the falling film evaporator comprises a housing, a distributor located at an upper portion inside the housing, and a heat exchange pipeline located below the distributor;   an oil return branch having an oil intake point connected to a lower portion of the falling film evaporator and an oil return point connected to the air inlet of the compressor; and   a bypass branch having a bypass inlet connected to downstream of the throttle element and a bypass outlet connected to the lower portion of the falling film evaporator and used for introducing part of gas-liquid two-phase refrigerant into the falling film evaporator.   
     
     
         2 . The refrigeration system according to  claim 1 , wherein the bypass inlet is disposed on or upstream of the distributor. 
     
     
         3 . The refrigeration system according to  claim 1 , wherein the bypass inlet is higher than the bypass outlet in a vertical direction. 
     
     
         4 . The refrigeration system according to  claim 1 , wherein the bypass branch has a plurality of bypass inlets and/or a plurality of bypass outlets. 
     
     
         5 . The refrigeration system according to  claim 4 , wherein the plurality of bypass outlets are arranged in an evenly spaced manner on a lower portion of the housing of the falling film evaporator. 
     
     
         6 . The refrigeration system according to  claim 1 , wherein the bypass outlet is arranged at the bottom of the housing of the falling film evaporator. 
     
     
         7 . The refrigeration system according to  claim 1 , comprising a plurality of the bypass branches. 
     
     
         8 . The refrigeration system according to  claim 1 , wherein a smallest flow cross-sectional area of a pipe of the bypass branch is 0.5%-20% of a flow cross-sectional area of a pipe of the refrigeration loop downstream of the throttle element. 
     
     
         9 . The refrigeration system according to  claim 1 , wherein a pipe of the bypass branch has a circular and/or rectangular and/or trough-type cross-section. 
     
     
         10 . The refrigeration system according to  claim 1 , wherein the oil return branch has a plurality of oil intake points. 
     
     
         11 . The refrigeration system according to  claim 10 , wherein the plurality of oil intake points are arranged in an evenly spaced manner on the lower portion of the housing of the falling film evaporator. 
     
     
         12 . The refrigeration system according to  claim 1 , wherein the oil intake point is arranged at the bottom of the housing of the falling film evaporator. 
     
     
         13 . The refrigeration system according to  claim 1 , wherein an ejector is disposed on the oil return branch, the ejector having a first ejection inlet connected to the oil intake point, a second ejection inlet connected to an inlet side of the condenser, and an ejection outlet connected to the air inlet of the compressor. 
     
     
         14 . The refrigeration system according to  claim 1 , comprising a plurality of the oil return branches. 
     
     
         15 . The refrigeration system according to  claim 1 , wherein an auxiliary driving apparatus for sucking the two-phase refrigerant from the bypass inlet to the bypass outlet is disposed on the bypass branch. 
     
     
         16 . A falling film evaporator, comprising:
 a housing;   a distributor disposed at an upper portion inside the housing;   a heat exchange pipeline disposed inside the housing and below the distributor;   an oil intake point disposed at a lower portion of the falling film evaporator; and   a bypass branch having a bypass inlet connected to the distributor and a bypass outlet connected to the lower portion of the falling film evaporator and used for introducing part of gas-liquid two-phase refrigerant into the lower portion of the falling film evaporator.   
     
     
         17 . The falling film evaporator according to  claim 16 , wherein the bypass branch has a plurality of bypass inlets and/or a plurality of bypass outlets. 
     
     
         18 . The falling film evaporator according to  claim 17 , wherein the plurality of bypass outlets are arranged in an evenly spaced manner on a lower portion of the housing of the falling film evaporator. 
     
     
         19 . The falling film evaporator according to  claim 16 , wherein the bypass outlet is arranged at the bottom of the housing of the falling film evaporator. 
     
     
         20 . The falling film evaporator according to  claim 16 , comprising a plurality of the bypass branches. 
     
     
         21 . The falling film evaporator according to  claim 16 , wherein a pipe of the bypass branch has a circular and/or rectangular and/or trough-type cross-section. 
     
     
         22 . The falling film evaporator according to  claim 16 , comprising a plurality of the oil intake points arranged in an evenly spaced manner on the lower portion of the housing of the falling film evaporator. 
     
     
         23 . The falling film evaporator according to  claim 16 , wherein the oil intake point is arranged at the bottom of the housing of the falling film evaporator.