Absorption refrigeration unit and control method

Abstract

The invention provides an absorption refrigeration unit and a control method. According to the absorption refrigeration unit and the control method, through detection of the volume of dilute solutionsin an evaporator with a detection component, since solutes contained in the dilute solutions are unchanged, and if the volume is decreased, it is considered that the concentration of the dilute solutions in the current state is improved compared with the initial concentration; if the volume is increased, it is considered that the concentration of the dilute solutions in the current state is reduced compared with the initial concentration, so that the quantity of refrigerants returning to the evaporator from a condenser is regulated through a regulating component properly; thus, the dilute solutions in the evaporator are maintained in a preset volume range; and in this way, it can be ensured that the concentration of the dilute solutions in the evaporator is constant in a concentration range of a certain demand all the time. The refrigeration unit is lower in use cost, and is not easily disturbed by solution impurities; the control is reliable, and it can be ensured that the refrigeration unit safely runs in the fixed range of the specific gravity of the refrigerants with no need of measuring the specific gravity of the refrigerants.

Description

technical field [0001] The invention relates to the field of heat exchange, in particular to an absorption refrigeration unit and a control method. Background technique [0002] For traditional absorption refrigeration units, the refrigerant is water, and the freezing temperature of water is usually 0°C. When the evaporation temperature is low, for example, 2°C, the safety margin is 2°C. When the external conditions change , if the flow of cold water is reduced, there is a risk of freezing of the heat exchange tubes. [0003] At present, for lithium bromide absorption chillers that produce cold water at around 0°C, antifreeze is usually added to the cold water in the external system to lower the freezing point of the water, while the refrigerant circulating inside the unit usually passes the lithium bromide solution into the refrigerant, passing through the refrigerant The conductivity measured by the conductivity meter is converted into the specific gravity of the refriger...

AI Technical Summary

Problems solved by technology

The measurement device is expensive, and the conductivity of the refrigerant solution is easily affected by impurities such as iron filings. The concentration of the refrigerant solution is constantly being adjusted, which requires high control accuracy.

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