Steam Boilers for Hospitals

Guidelines for the design Steam Boilers for Hospitals

Steam Boilers for Hospitals

Introduction

Steam boiler systems are essential for hospital operations. Here we provide comprehensive guidelines for the design of such systems, both centralized and decentralized. These guidelines ensure that systems meet demand, operate efficiently, and comply with safety requirements.

Design Requirements

Load Determination

The first step in designing a steam boiler system is determining the maximum load. This includes assessing current demand, new connected loads, and a margin for future expansion. Accuracy at this stage is crucial to properly size the system and ensure efficient operation.

Boiler System Capacity

The system must be sized to meet maximum demand even if the largest boiler and pump are out of service. This redundancy concept, known as N+1 capacity, ensures that the system can continue operating during maintenance or equipment failure. In addition, boilers must be capable of operating on alternative fuels and be connected to emergency generators to run during power outages.

Location and Safety

Boilers and associated equipment must be housed in safe, climate-controlled, and protected buildings. These facilities must include monitoring systems for combustible gases and carbon monoxide, with both local and centralized alarms.

General Design Criteria

Graphic Standards

Drawings must include symbols, schematics, equipment lists, piping diagrams, and detailed floor plans, following CAD Standard specifications.

Life-Cycle Cost Analysis

It is essential to conduct a life-cycle cost analysis for all equipment and systems. Initial acquisition, construction, replacement, operation, maintenance, and repair costs must be included in the analysis, excluding taxes and insurance.

Heating Plant

Building Requirements

For the construction of heating plants, structural robustness is important to support piping and ducts, as well as accessibility for equipment installation and removal, elevated boiler room floor, ceiling clearance, drainage, and safety considerations. Doors must allow equipment access, and adequate spaces must be provided for various components, staff facilities, and access platforms for maintenance.

Water Treatment Area

A dedicated water treatment area is required, including chemical feed units, storage, mixing, and safety features such as emergency showers and eyewash stations.

Systems and Equipment

Boilers

A minimum of three boilers is recommended for most plants, suggesting two large units and one smaller unit for peak load periods. The choice of boiler type and size must be based on life-cycle analysis and load profile. It is important to minimize cycling in both water-tube and fire-tube boilers.

Pressure Control and Relief

Installation of steam pressure reducing valve (PRV) stations is important, including the use of two PRVs in parallel for significant demand variations and isolation valves for maintenance.

Condensate

Steam condensate return systems must avoid connections between high/medium-pressure gravity return lines and low-pressure or vacuum lines. An expansion tank is required to reduce the pressure and temperature of gravity returns. The condensate storage tank must be sized to handle peak flows without overflowing, with a minimum capacity of 20 minutes at peak production.

Water Treatment and Blowdown

Water Treatment Equipment

“Zero hardness” water is recommended for boiler makeup. If alkalinity exceeds 50 ppm, water treatment is required. Dual-tower softeners should be used to ensure continuity during regeneration, and bulk brine storage is preferred. Chemical feed systems must be separated for each boiler, with pre-mixed chemicals for safety.

Blowdown

Boilers must be blown down at least every eight hours to remove sediments and control chemical additive concentrations. The blowdown tank must be properly located with specifications for inlet, drainage, and temperature control. An automatic temperature control system with a recovery unit or blowdown cooler is recommended to keep discharged water within temperature limits.

Conclusion

The design and operation of steam boiler systems in hospitals require strict adherence to the presented guidelines. These systems must ensure safety, efficiency, and regulatory compliance. By following the specified requirements and criteria, reliable and sustainable operation of critical infrastructure can be achieved.