The efficient heat transfer in LiBr absorption units relies on the coordinated operation of four core parts (Generator, Condenser, Evaporator, Absorber). Each part is equipped with water box, which serves as the interface for external circulating water to exchange heat with the four parts through internal tube bundles. This makes the water boxes critical components for energy transfer in the unit. Therefore, hydraulic testing becomes an essential verification procedure, aims to validate the pressure-containing structural strength and sealing integrity, ensuring long-term operational safety and reliability.

I. Test Preparation

Prior to conducting hydraulic testing, the unit must have passed helium detection, confirming its initial leak-tight integrity. Depending on the pressure design specifications of different parts, applicable pressure test standards and holding durations must be followed. If design pressure ratings differ between parts – for instance, the High-Temperature Generator (HTG) typically operates at a higher design pressure than the Condenser – separate hydraulic tests are required. Generally, a higher design pressure necessitates a longer pressure holding duration. If all water boxes share identical design pressures, they can be tested simultaneously.

II. Test Procedure and Standards

Hope Deepblue LiBr Absorption Unit Hydraulic Test Process:

1. Strength Test: Slowly fill the water boxes with water while monitoring the pressure gauge. When the pressure reaches testing pressure, stop filling and hold the pressure for 30 minutes. This stage verifies the structural strength of pressure parts and the ultimate load capacity of welds.

2. Tightness Test (Design Pressure): Following a successful strength test, reduce the pressure to the normal design pressure and maintain it for another 30 minutes. This phase primarily checks the long-term sealing performance under specified design conditions.

III. Acceptance Criteria and Completion

Throughout both pressure holding phases, operators must meticulously check for: any deformation or abnormal sounds from pressure parts; stability of pressure gauge readings; and any leakage at all welds and connections. If none of these abnormalities are observed during either holding period, the hydraulic test is considered passed. Upon test completion, open drain valves to empty all water from the water boxes.