350 results about "Variable air volume" patented technology

An improved solution for cooling a data center is provided. In an embodiment of the invention, a data center design that combines physical segregation of hot and cold air streams together with a data hall variable air volume system is provided. The invention is a data center design that resolves air management issues of re-circulation, bypass and load balance. Bypass is airflow supplied by the cooling units that directly returns without cooling servers. Recirculation airflow is server discharge warm air that returns directly without being cooled. Load balance is supplying the required server airflow. An embodiment includes physical segregation of cold and hot air streams and by providing variable air volume to match server load. Air segregation is done by enclosing the hot aisle end and above the cabinets. The air conditioning system provides variable air volume to the data hall (cold side) to meet server demands. The cooling plant consists of variable-air-volume air-cooling system, which cools air by air free cooling (economizer) and is supplemented with mechanical cooling in the warmer seasons.

Control systems for recovery wheels, ventilation systems with recovery devices, buildings having ventilation, and methods of controlling recovery wheels and controlling or modifying ventilation systems. A parameter of ventilation systems or recovery devices, such as the speed of a recovery wheel, may be controlled as a function of pressure, differential pressure, flow rate, or fan speed, for example, to provide appropriate purge flow to maintain purge effectiveness and limit the carry-over of contaminants from a return/exhaust airstream to an outside/supply airstream, for instance, in a variable air-volume system. A purge angle may be set at a minimum position commensurate with a maximum flow rate and recovery-wheel speed may be reduced at lower flows to maintain purge effectiveness. In some embodiments, temperature and humidity are measured, and wheel speed is also controlled as a function of these measurements. Systems may utilize sensors, input devices, digital controllers, variable-speed drives, and alarms.

A control strategy for supply fans in variable-air-volume heating, ventilating, and air-conditioning systems that reduces the static pressure at part-load conditions. The invention consists of a static pressure sensor, an airflow sensor, a supply fan, a fan modulating device, and a controller coupled to the static pressure sensor and the airflow sensor. The controller includes a calculator that calculates the static pressure setpoint as a function of the airflow rate. The static pressure setpoint is lower when the airflow rate is lower. The controller compares the static pressure setpoint with the static pressure, and it commands the fan modulating device so that the static pressure remains close to the static pressure setpoint. Alternatively, the controller includes a calculator that calculates a loss coefficient as a function of the static pressure and the supply rate. The controller compares the loss coefficient with a loss coefficient setpoint, and it commands the fan modulating device so that the loss coefficient remains close to the loss coefficient setpoint. When the airflow rate is sufficiently high, the alternative embodiment switches to a constant-pressure controller.

The invention discloses a variable air volume air-conditioner control system with a variable frequency fan and a digital air valve for adjusting tail end air volume and an implementation method, belonging to the technical field of the control of a variable air volume air-conditioner system. The variable air volume air-conditioner control system structurally comprises a master station DDC (direct digital control) controller, a tail end temperature controller, a filed bus, a tail end variable air volume box (VAV-BOX) and an air valve driver, comprises mater station DDC control and tail end temperature controller control in control types, and adopts a strategy of collective processing at first and decentralized control later. Through a method for adjusting the tail end air volume by the variable frequency fan and the digital air valve, the variable air volume air-conditioner system eliminates throttle energy loss of the air valve without a device for measuring the air volume, has simple control type and no influence on the operation of the whole variable air volume system, and has the advantages of good system stability and obvious energy-saving effect; and the fault on the variable air volume tail end device of certain node has no influence on the normal operation of other variable air volume tail end devices.

An adaptive control device (77) and method (102-108) for control of the operation of an actuator (72), and particularly thermally-powered actuator (72) of the type used in a variable-air-volume diffuser (71). The preferred adaptive control device is an expert system circuit which controls a heater (74) provided on a thermally-powered actuator (72) to implement an adaptive process (102-108) in which a sensed variable, such as room air temperature, is driven toward a target temperature control range (±0.25° F.). Most preferably, the process steps (106) include driving the room air temperature toward a gross (broader) temperature control range (±1.0° F.) by moving a diffuser damper assembly (80) to a substantially fully open or substantially fully closed position. Thereafter, and while inside the gross temperature control range, the process steps (107, 108) include adjustments to the position of the damper assembly (80) are made only when a sensed parameter, preferably the supply air flow rate, is in a stable condition. Most preferably, the damper (80) is temporarily "kicked" farther open or farther closed than necessary, to minimize hysteresis effects, and then adjusted to a posiiton which tends to drive the room air temperature into the narrower, targeted temperature control range.

A strategy for determining the critical supply duct pressure in variable-air-volume heating, ventilating, and air-conditioning systems that compensates for duct leakage and variable loads, enabling its use during normal system operation. The strategy consists of a static pressure sensor, an airflow sensor, a supply fan, a fan modulating device, a controller coupled to the static pressure sensor and the airflow sensor, and a data processing algorithm for analyzing results from a function test using these components. The functional test involves changing the supply duct pressure setpoint, waiting for equilibrium, recording pressure, flow, and time, then changing the supply duct pressure setpoint to the next setting in the sequence.

The invention provides a control system of a laboratory variable air volume (VAV) fume hood. The control system is characterized by comprising a fume hood, a Venturi valve arranged on an air exhaust branch pipe of the fume hood, a displacement sensor, a door height warning switch, a face velocity monitoring and control system, a fan variable frequency system, a valve controller and a valve actuator, wherein, the face velocity monitoring and control system comprises a face velocity sensor and a VAV controller; the VAV controller measures the open degree of the fume hood in real time, and meanwhile the face velocity sensor measures the face velocity in real time, converts the face velocity into a voltage signal and then transfers the voltage signal to the VAV controller; the VAV controller compares the actual value with the set value of the face velocity; and if the face velocity is not within the range of the set value, the VAV controller outputs a signal to the valve controller, the valve controller outputs a signal to the valve actuator, and the valve actuator drives a piston of the Venturi valve to move up and down so as to change the ventilation sectional area and adjust the ventilation volume.

A variable-air-volume system for modulating the speed of a supply fan by measuring a plurality of inlet static pressures within the inlet of a corresponding plurality of terminal boxes within the system; calculating a plurality of setpoint errors equal to the difference between the plurality of inlet static pressures and a corresponding plurality of terminal box setpoint pressures; selecting minimum setpoint error out of all of the calculated setpoint errors; and modulating the fan speed as a function of the minimum setpoint error. The system can also utilize a power adjustment factor to modify the terminal box set point pressures.

The utility model provides a method and a system frame for realizing the variable air volume zone control. The system frame is provided with a fan control module, a case control module and a plurality of system frames which can be equipped with the nodal single board slot. The method consists of the step I: the nodal single board on each slot corresponds to the engaged position which is divided into the different separated regions. As corresponding with the separated regions, the variable air volume zone control apparatus with the air heading and the air volume functions are available; step II: after the case control module starts up, the information from the nodal single board and each separated region can be obtained via the intelligent platform supervisory controller which is arranged on each nodal single board; the step III. Based on the above information, the case control module can control the air volume and air heading of the separated region via the fan control module and the zone control apparatus. The utility model can realize the dynamic measurement for the temperature in each nodal plate. As the sub-zone is distributed with the air volume, both the fan speed and the system noise are reduced, so as to improve the reliability of the system.

The invention discloses a temperature-humidity control device for a variable-air-volume air-conditioning system, and a temperature-humidity control method. The temperature-humidity control device comprises a combined air conditioner set, a variable-air-volume system controller and an indoor sensor. The control method comprises the following steps of: electrically connecting an indoor sensor and a built-in sensor to detect indoor humidity, indoor temperature, concentration of indoor CO2 (Carbon Dioxide), outlet air temperature at a humidifying section, outlet air temperature of a heat coil, and outlet air temperature of a cold coil; generating a control signal through the system controller based on detected information along with a series of operations; carrying out frequency-conversion regulation to a fan according to a control signal, and regulating opening of various built-in adjusting valves so as to ensure the constant indoor temperature and humidity as well as the air quality. The temperature-humidity control device and method have the benefits that: a decoupling control of the temperature and the humidity can be achieved, energy is saved, the capacity of resisting disturbance and the reaction speed and the control precision of the system are improved, and the constant indoor temperature and humidity can be kept as well as the air quality. The temperature-humidity control device and method can be widely applied to fields of precision machinery, instruments and meters, medicines and foods, textiles and tobaccos and the like.

An air-handling system (preferably a variable air volume system) includes an inflatable air duct with a discharge member whose discharge opening varies with the static pressure or flow rate within the duct. To prevent the duct from deflating at low airflow rates, the discharge opening, in some embodiments, tends to close in response to reduced air pressure associated with the lower airflow. The closing of the discharge opening prevents the static pressure from decreasing as much as the pressure would otherwise if the discharge opening were fixed. In some embodiments, the discharge opening responds to static pressure or airflow within the duct such that the discharge member redirects the discharge air as a function of the static pressure of flow volume. Warmer air at relatively low volume, for instance, can be directed downward, and cooler air at greater airflow rates can be directed upward.

A multifuel internal combustion Stirling engine is described, wherein a compressor piston and a displacer piston reciprocate, within a common cylinder, to enclose a variable air volume, and a variable burned gas volume. Motion of these two pistons, creates a power producing cycle, of compression, combustion, expansion, and scavenge, wherein the burned gases do not contact those cylinder portions over which the compressor piston moves. In this way low engine wear can be obtained when using fuels such as coal, which produces abrasive particulates in the burned gases. A multifuel internal combustion engine of this invention can be readily adapted to operate on a wide variety of fuels, such as, natural gas, diesel fuel, residual petroleum fuel, and coal. Widespread use of these engines would introduce economic competition between these now separately competing fuels. This is a clear route to national energy independence, since coal reserves greatly exceed petroleum reserves, nationally and internationally.

The invention discloses a variable air volume (VAV) air-conditioning system air-supply static pressure optimizing and controlling method and a device thereof. A static pressure setting optimizer inspects valve location signal, namely air valve opening, of a VAV terminal in every air-conditioning area, and a VAV terminal with largest valve location signal is selected from all the valve location signals. A static pressure setting value P is changed by the static pressure setting optimizer to lead the valve location of the VAV terminal to reach or get close to the largest opening. The rotating speed of a air-supply fan in the VAV air-conditioning system is controlled by a static pressure controller according to the difference of the statistic pressure setting value P set by the static pressure setting optimizer and the static pressure value gained by an air passage static pressure transducer, so that the static pressure of the air passages can reach the setting value P. The variable air volume (VAV) air-conditioning system air-supply static pressure optimizing and controlling method of the invention can not only guarantee the comfort requirement for every VAV air-conditioning system area in a heavy load, but also save the energy consumption of the air-supply fan in a relatively light load. The device for realizing the method is simple in structure and reliable in performance.

A fan system for a variable air volume heating and/or air conditioning unit comprising a fan array with a control system to eliminate surge at low operating flows and to maximize operating range. The fan control system includes a fan pressure sensor for determining the pressure rise across the fan array and a fan airflow sensor for determining the total airflow generated by the fan array. A surge controller is programmed to constantly monitor the calculated surge pressure as the fan speed control is modulating the fan speed in response to user demands. As airflow increases or decreases in response to changes in fan speed, so will the calculated surge pressure. The surge control turn fans on and off to ensure that the operating fans are running in their optimum fan speed ranges. Thus, the fans in the fan array are prevented from reaching the surge point.

The invention discloses a variable air volume room temperature control method based on fuzzy PID and a prediction control algorithm. The method comprises the steps that the temperature deviation between an expected room temperature and an actual room temperature is input to a fuzzy adaptive PID controller, PID parameter incremental quantity of the opening degree of a tail end air valve is obtained through calculation, and calibrated opening degree of the tail end air valve is output; the opening degree of the tail end air valve of the fuzzy adaptive PID controller is subtracted from the opening degree of the tail end air valve of a previous moment by utilizing a time delay link to obtain the variable quantity of the opening degree of the tail end air valve; the prediction control algorithm is adopted to obtain the actual opening degree of the tail end air valve through the variable quantity of the opening degree of the tail end air valve, and the room temperature is maintained at a set value and is kept unchanged. The control method combining the fuzzy PID with the prediction control algorithm is adopted to solve the technical problems that parameter setting difficulty is large, working condition adaptive capacity is poor, and adaptive ability is weak in an air conditioning system in the prior art.

The invention relates to a variable air volume control apparatus which compensates an open area ratio to be in direct proportion to an opening ratio at a low opening ratio range according to an open angle of a damper blade to achieve accurate and precise air volume control. The variable air volume control apparatus includes a damper blade disposed rotatably within the duct for opening or closing an air flow path and an actuator for rotating the damper blade. The apparatus also includes an air flow path expansion mechanism having a curved surface for expanding the air flow path in accordance with an open angle of the damper blade. The invention allows obtaining the open area ratio in direct proportion to the opening ratio at the low opening ratio range through simple structural improvements, thereby improving linear characteristics of an air volume change ratio with respect to the opening ratio to more accurately and precisely control the air volume.

A controller for a variable air volume terminal of a variable air volume air conditioning system which comprises a temperature sensing circuitry for generating a temperature process value, a setpoint determining circuitry for establishing a temperature setpoint, an airflow signal circuitry for generating an airflow setpoint in response to the temperature process value and the temperature setpoint. A flow sensing circuitry for generating a flow process value in response to a predetermined set of flow sensing inputs and damper control circuitry for generating a damper motor operation signal to control the damper motor in response to the flow process value and the airflow setpoint. The damper control circuitry comprises a fuzzy logic control mechanism for implementing a set of fuzzy logic rule-based instructions in generating the damper motor operating signal.

The invention relates to a low-noise elevator car internal ventilation and air deflecting system and solves the problems that a conventional elevator car internal ventilation device has the disadvantages of high blower noise and invariable air volume. The system comprises a blower, an air duct and a control unit for controlling the operation of the blower; one end of the air duct is connected to the air outlet of the blower, and the other end of the air duct is connected with the elevator car; the blower is installed in a soundproof box, a ventilation opening is formed on the soundproof box, and the air outlet of the blower is connected with the air duct through the ventilation opening; a silencer is arranged on the air duct; and an air deflecting device is arranged at a port of the air duct, where the air duct is connected with the elevator car. The system has the advantages that the noise is effectively reduced on the basis of maintaining big air volume; the ventilation in the elevator car is more uniform, and the comfort of passengers taking an elevator is improved; and the air volume of the blower can be adjusted according to temperature and passenger capacity, so as to further meet the requirements of the passengers and to be more energy-saving and environment-friendly.

An HVAC system has two variable-air-volume (VAV) systems, a first VAV system for moving fresh air and a second VAV system for moving recycled air. Both the fresh air and recycled air are cooled and dehumidified by a single heat-exchanging coil. The fresh and recycled air streams travel independently in separate ducts until the air streams reach a remotely located mixing box where the air streams mix and ventilate into a room or zone of a building. The HVAC system uses carbon dioxide and temperature sensors in order to regulate the flow of fresh and recycled air to various mixing boxes throughout the building.

The invention relates to a variable air volume intelligent air current control system, belonging to the field of machine room air conditioner energy conservation. The invention is designed for addressing the problem that the existing data center machine room faces more and more'hot spots'. The invention comprises a cell phone for alarming, a remote monitoring computer, an intelligent central controller, an A concentrator, a B concentrator, a plurality of precision aircons and a plurality of equipment cabinets; wherein the precision aircons are electrically connected with the B concentrator, the cell phone for alarming and the remote monitoring computer is connected with the intelligent central controller by a communication network; the invention further comprises a plurality of variable air volume airflow induction units, each equipment cabinet is internally provided with a variable air volume airflow induction unit, the variable air volume airflow induction units are connected with the A concentrator by signal wires, the A concentrator and B concentrator are respectively electrically connected with the intelligent central controller. The variable air volume intelligent air current control system can solve the problem that the existing machine room is hot and the machine room is going to be hot, enables reorganization of airflow structure in the machine room, distribute air volume according to actual needs of the equipment cabinets and lowers power consumption of the data center machine room air conditioner system.