Application of fire control in hospital building a

2022-08-05
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The application of force control in hospital building automation system

intelligent buildings originated in the United States and then flourished around the world. Although China started late, it has developed rapidly

building equipment automation system (BAS) is an important part of intelligent building. Due to the application of a large number of electronic equipment in intelligent buildings, the power load of intelligent buildings is far greater than that of traditional buildings. Because of its high power consumption, air conditioning and lighting systems have become the core equipment controlled by bas. The establishment of a perfect building automation system can effectively reduce energy consumption. At the same time, the information of all design conditions for two models of equipment is collected to the operation station for centralized monitoring and management

the following takes the building automation system of Daqing people's Hospital as an example to introduce the implementation method of the building automation system

I. project overview and main control contents

Daqing people's hospital was built in July 2000, with a total construction area of 65750 square meters. There are 14 large central air conditioning units in total. Two chillers. The air conditioning system includes 6 sets of 10000 class air conditioning units, 5 sets of 100 class air conditioning units and 3 sets of fresh air units. Class 10000 air conditioning units serve class 10000 and class 100000 operating rooms, class 100 air conditioning units serve class 100 operating rooms and auxiliary areas, and all units are distributed in each air conditioning room in the building. In addition to controlling the air conditioning system, it is also required to uniformly manage and control the daily lighting in the outpatient hall and work area

1. air conditioning system

the main function of air conditioning system is to maintain indoor constant temperature and humidity. For clean air conditioning, we should also shoulder the important task of air purification in the area. The air conditioning system mainly controls the opening of refrigeration, preheating, heating and humidification valves to adjust the temperature and humidity. Because the process of air heating and cooling is slow, attention should be paid not to overshoot. In addition, the temperature, humidity, pressure and other values shall be monitored and recorded, so as to find the best operation mode through the analysis of the long-term curve

in addition, the system serves the hospital and has the particularity of work nature. The control of air conditioning unit mainly realizes the following functions

control the start and stop of forced draft fan

monitor the operation status and fault alarm of the electrical part of the forced draft fan through the normally open passive contact

monitor the clogging alarm status of primary and intermediate efficiency filters to ensure the normal operation of the unit and save daily inspection manpower

monitor the differential pressure of the forced draft fan and determine the operating state of the mechanical part of the forced draft fan

monitor the surface temperature of the heat exchanger, give an alarm when the temperature is too low and link relevant equipment to ensure the safe use of the heat exchanger

monitor supply/return air temperature/humidity

control the opening of the water valve of the preheating coil according to the return air temperature, and maintain the temperature of the new return air at a certain value after mixing

control the air supply temperature (adjustable set point) by automatically adjusting the two-way electric control valve of heating coil and surface cooling coil

control the air supply humidity (adjustable set point) by controlling the opening of humidifying steam valve

monitor the environmental pressure in the operating room, and send an alarm to the staff when it is lower than the required positive pressure value

control the opening of pretreatment fresh air valve and return air valve in the United States, Germany and France

chillers

chillers provide cold water for the air conditioning system in summer. Among the cooling capacity consumed by the air conditioning system, the energy consumed by chillers that can complete high-speed and low-precision conversion accounts for a large proportion. Therefore, chillers are the major energy consumers of the air conditioning system, and the quality of the control system design will directly affect the energy-saving effect. The chiller consists of 2 refrigeration units, 2 cooling fans, 3 cooling pumps and 3 refrigeration pumps. The routine monitoring functions of the chiller include:

controlling the start and stop of the chiller, monitoring the operation status and fault alarm

control the start and stop of chilled water pump, monitor the operation status and fault alarm of water pump

control the start and stop of the cooling water pump, monitor the water pump operation status and fault alarm according to the needs of the steel wire rope test

measure the total supply/return water pressure of the chilled water pipe

control the start and stop of cooling tower fan, monitor the operation status and fault alarm

control the start and stop of make-up water pump, monitor the operation status and fault alarm

monitor the high/low liquid level of expansion water tank

monitor the flow status of chilled/cooling water

monitor the supply/return water temperature of chilled water and cooling water

monitoring chilled water return flow

accumulated operation time of refrigerator, chilled water pump, cooling water pump, make-up water pump and cooling tower

calculate the cooling load of the air conditioning system by calculating the total supply/return water temperature and return water flow of the chilled water

determine the starting and stopping combination and number of chillers according to the actual cooling load, so as to achieve the best energy-saving effect

control the start, stop and operation quantity of cooling tower fans according to the supply and return water temperature of cooling water

control the opening of the chilled water bypass valve to maintain the required supply and return water pressure difference

3. lighting system

the lighting system of the hospital is divided into 13 areas. It is required that the lighting of each area can be controlled independently, and the lighting status of each area can be monitored in the control room. Automatically turn on and off the lighting at a predetermined time; Distinguish between working and non working hours according to the procedures defined on the calendar

II. Control scheme and implementation method

1 Control scheme

at present, the air conditioning control system mainly has two control modes: direct digital controller (DDC) and fieldbus. Based on the simplicity and flexibility of DDC control, combined with the actual situation that the control points of this system are few, and each air conditioning system and refrigeration unit are far from the central control room (the farthest distance is 1100 meters), we adopt DDC control mode. Although the input and output points of one DDC can not meet the requirements of each system, because the DDC has strong expansion ability, it can attach different types of expansion modules, and the number of i/o points can also meet the requirements, which can fully meet the requirements of DDC connection

ddc distribution scheme:

each air conditioning unit uses a DDC to control the operation of the unit; One DDC is used for control of water chiller and lighting system respectively. In addition to the lighting system, DDC control cabinets are installed in each machine room

special requirements:

some particularity of hospital work shall be considered in the scheme design

the lighting area shall be properly divided. Too large is not conducive to control, and too small will increase the control cost. Reasonable regional division can effectively save energy. Not for emergency and other important parts

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