Variable Frequency Pump Sets: Safeguarding the Air-Conditioning Circulation System of Hospitals

Variable Frequency Pump Sets: Safeguarding the Air-Conditioning Circulation System of Hospitals

Project Background

The Relocation Project of the Second People's Hospital of Tonglu County is a key livelihood project in Hangzhou. The planned total construction area of the new hospital campus is 85,000 square meters (with a final construction area of 78,600 square meters), and it is designed to have 600 beds. As a benchmark project for the upgrading of county-level medical services, the project sets higher requirements for medical environment control: it needs to meet the latest standards of "Code for Design of General Hospital Buildings" GB51039 to achieve the function of combining normal and epidemic prevention, ensure the independent operation of the fever clinic, and reduce the annual energy consumption index by 30% compared with the old hospital campus. The air-conditioning circulation system is like a "blood circulation system", and the circulation pump is the core "heart". In this project, the technical team of Bangpu, based on local conditions and combined with the on-site working conditions, has formulated a complete pump set scheme for the circulation system for the project.

Project Difficulties

The stable operation of the hospital's air-conditioning circulation system is subject to higher requirements than that of conventional buildings such as shopping malls and residential buildings. Maintaining an appropriate temperature for the medical treatment environment, inpatient environment, and the operation of various departments is like maintaining a "blood circulation system", with the circulation pump being the core "heart". The project team is faced with three major technical difficulties:

1.Large load fluctuation: There is a significant difference in the opening hours of areas such as the outpatient and emergency department and the inpatient department. For example, the outpatient and emergency department has periodic peak hours, while areas like the inpatient department have low loads at night.

2.Strict epidemic prevention requirements: Based on the need for conversion between normal and epidemic prevention scenarios as instructed by the Center for Disease Control and Prevention, the air-conditioning circulation of the fever clinic must be independent of other areas in the hospital.

3.High energy efficiency standards: The project needs to meet the national two-star standard for green hospitals.

Implementation of the Scheme

After technical demonstration, we adopted the following schemes for the project:

Variable frequency pumps: To cope with load changes, a "variable frequency + power frequency pump set" mode was adopted. The variable frequency pump automatically adjusts its rotation speed according to the actual load, reducing power consumption when the load is low, with electricity savings reaching 20% to 40%. This ensures balanced cooling/heating supply in various areas, avoids temperature fluctuations, and improves the comfort of patients and medical staff as well as the stability of the medical environment. In addition, the variable frequency start-up features soft start and soft stop functions, which effectively reduce water hammer impact, pipeline vibration, and pump body damage, and extend the service life of water pumps, pipelines, and valves. The standby pump is activated in emergency situations and has a low frequency of use; using a power frequency pump can further save costs.

Independent circulation + terminal disinfection: In accordance with relevant design standards, the project's air-conditioning circulation system adopted a scheme of "circulation pump + terminal disinfection". An independent circulation pump set was configured for the fever clinic area, paired with electric valves and check valves. Moreover, 24-hour negative pressure monitoring and continuous UV disinfection are implemented to avoid cross-contamination.

In construction electromechanical related projects, formulating a scheme design in combination with actual working conditions is the primary consideration. In this project, the long-term stable operation of the equipment is directly related to the daily life of a large number of patients and medical staff. What the project needs is not only a set of water pump equipment, but also a complete set of system solutions that are in line with the actual needs of the hospital and integrated into daily operations. The realization of energy-saving control through frequency conversion equipment and the precise matching of zoned circulation with actual operation needs not only improve the operation efficiency, but also provide a strong guarantee for the safe, stable and efficient operation of the hospital.

In the future, we will continue to safeguard more livelihood projects with professionalism and responsibility.