EP3553403A1 - Hvac system and method for operating an hvac system - Google Patents

Abstract

The present disclosure relates to a method of operating an HVAC system. The HVAC system can include at least one demand subsystem in signal communication with a utility side. The method may include a step of determining a demand (Q) with a demand estimator. The determination can be made by a demand side processor. The variable input of the demand function can comprise a zone property and a control signal (U). The method may include communicating the demand (Q) from the demand subsystem to the supply side. The method may include determining utility side operating power as a function of demand (Q) and utility side parameters; wherein the determination is carried out by a supply side processor included in the supply side. The present disclosure also relates to the demand subsystem, the supply side and the HVAC subsystem configured to carry out the method according to the invention.

Description

FIELD OF TECHNOLOGY

The present disclosure relates to a heating, ventilation and air conditioning system (HVAC system), a subsystem of requirements for an HVAC system, a supply side and a method of operating an HVAC system.

BACKGROUND OF THE TECHNIQUE

A typical HVAC system in an example commercial building may include refrigeration systems, cooling tower, air handling units (AHU) and fan coil units (FCU). A building management system (BMS) controls the devices by specifying setpoints or plans. The FCUs at the zones in the building can be controlled by the BMS directly or locally by a thermostat. In the normal operating mode of a building: i. the desired temperature setpoints of the zones are set in the BMS or at the local thermostat; ii. the refrigeration system starts to work to deliver cooling water (cold water) at a specified temperature; iii. opens the valve on the FCU to allow cooling water flow to cool the room to the desired temperature; iv. the refrigeration system receives return cooling water at a higher temperature; and V. defines the difference between the supply (supply) and return temperature, the cooling load of the building and the operating mode of the refrigeration system. The information is also used to plan the refrigeration stage if the load already exceeds the threshold capacity.

In the refrigeration plant grading process, a buffer is provided to prevent unwanted gradation (timing) due to fluctuation of the return cooling water temperature. The buffering time induces a delay between the increasing demand and the cooling water supply. This slows down the system reaction.

Accordingly, there is a need to provide an HVAC system and method for operating an HVAC system with faster system response time.

SHORT VERSION

The present disclosure relates to a method of operating an HVAC system. The HVAC system may include at least one demand subsystem in signal communication with a supply side. For example, the HVAC system includes a consumer subsystem as a demand subsystem, such as a cold depleting unit. The method may include a step of determining a demand (Q _D ) with a demand estimator. Demand determination may be performed by a demand side processor included in the demand subsystem. The variable input of the demand function may include a zone property and a control signal (u _ctrl ). The method may include communicating the demand (Q _D ) from the demand subsystem to the supply side. The method may include determining a supply side operating power (Q _{s, total} ) as a function of the demand (Q _D ) and supply side parameters; wherein the determination is performed by a supply side processor included in the supply side.

The present disclosure also relates to a demand subsystem and a supply side configured to communicate with each other. The present disclosure also relates to an HVAC system including the supply side and at least the demand subsystem.

The requirements subsystem according to the present disclosure is suitable for an HVAC system configured to operatively communicate with a supply side of the HVAC system. The needs _{subsystem may include} a controller for providing a control signal (u _ctrl ). The requirements subsystem may include a demand side processor configured to be able to compute a demand (Q _D ) with a demand estimator, e.g. By assessing the demand estimator. The variable input of the demand function may include a zone property and the control signal (u _ctrl ). The demand subsystem may include a demand side transmitter for sending the demand (Q _D ) to the supply side.

The supply side may be configured to operatively communicate with at least one needs subsystem according to this disclosure. The Supply side may include a supply side receiver for receiving the demand (Q _D ) from the demand subsystem. The supply system may include a supply side processor (124) configured to be able to determine supply side operating power (Q _{s, total} ) as a function of demand (Q _D ) and supply side parameters.

The HVAC system of the invention may include a supply side and at least the demand subsystem. The HVAC system may include additional demand subsystems of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

• Figur 1 ein Ablaufdiagramm eines Verfahrens gemäß verschiedenen Ausführungsformen der Erfindung zeigt.
• Figur 2 ein Diagramm zur Veranschaulichung eines Verfahrens gemäß verschiedenen Ausführungsformen der Erfindung beim Bedarfssubsystem zeigt.
• Figur 3 ein Diagramm zur Veranschaulichung von wenigstens drei Bedarfssubsystemen in Kommunikation mit einer Versorgungsseite gemäß verschiedenen Ausführungsformen der Erfindung zeigt.
• Figur 4 ein Diagramm zur Veranschaulichung eines HVAC-Systems mit verschiedenen Komponenten gemäß einem Vergleichsbeispiel zeigt.
• Figur 5 ein Diagramm zur Veranschaulichung eines HVAC-Systems mit verschiedenen Komponenten gemäß einem Beispiel der Erfindung zeigt.
• Figur 6 ein Beispiel für den Verlauf einer Versorgungsseitenbetriebsleistung, in diesem Fall der Kühlleistung, nach Einschalten des HVAC-Systems, in einem Vergleichsbeispiel zeigt.
• Jede der Figuren 7 und 8 als ein Beispiel die Kühlleistung in kW (vertikale Achse) als Funktion des Steuersignals (horizontale Achse) für eine FCU mit einer Zonentemperatur T_ZONE = 24 °C in Figur 7 und T_ZONE = 29 °C in Figur 8 zeigt.
• Figur 9 einen Graphen 50 zeigt, der die Kapazität einer Kälteanlage in MW auf der vertikalen Achse und die Zeit in Minuten auf der horizontalen Achse darstellt.
• Figur 10 den Verlauf der Zonentemperatur für drei verschiedene Zonenlasten zeigt.

In the following description, various embodiments of the present disclosure are illustrated with reference to the following figures, wherein:

• FIG. 1 a flow chart of a method according to various embodiments of the invention shows.
• FIG. 2 a diagram illustrating a method according to various embodiments of the invention in the Needs subsystem shows.
• FIG. 3 Fig. 3 shows a diagram for illustrating at least three need subsystems in communication with a supply side according to various embodiments of the invention.
• FIG. 4 a diagram illustrating a HVAC system with various components according to a comparative example shows.
• FIG. 5 a diagram illustrating an HVAC system with various components according to an example of the invention shows.
• FIG. 6 an example of the history of a supply side operating power, in this case the cooling capacity, after switching on the HVAC system, in a comparative example shows.
• Each of the FIGS. 7 and 8 as an example, the cooling capacity in kW (vertical axis) as a function of the control signal (horizontal axis) for an FCU with a zone temperature T _ZONE = 24 ° C in FIG. 7 and T _ZONE = 29 ° C in FIG. 8 shows.
• FIG. 9 Fig. 5 is a graph 50 showing the capacity of a refrigeration system in MW on the vertical axis and the time in minutes on the horizontal axis.
• FIG. 10 shows the course of the zone temperature for three different zone loads.

DETAILED DESCRIPTION

In the following detailed description, specific details and embodiments in which the invention may be practiced will be described. These embodiments are described in sufficient detail to enable one skilled in the art to practice the invention. Other embodiments may be utilized and changes may be made without departing from the scope of the invention. The various embodiments are not necessarily mutually exclusive, as some embodiments may be combined with one or more other embodiments to form new embodiments.

Features described in one embodiment may be equally applicable to the same or similar features in other embodiments. Features described in one embodiment may be equally applicable to the other embodiments, although not expressly described in these other embodiments. Furthermore, additions and / or combinations and / or alternatives as described for a feature in one embodiment may be applicable to the same or a similar feature in other embodiments.

The term "variable input" can refer to the arguments of a function.

The invention illustratively described herein may suitably be used in the absence of any element or elements, any Limitation or any restrictions not specifically disclosed herein. Therefore, for example, the terms "comprising", "including", "containing", etc. are to be construed expansively and without limitation. Accordingly, the word "comprising" or variations, such as "comprises" or "comprising", is understood to imply the inclusion of a given integer or groups of integers, but not the exclusion of any other integer or group of integers , Furthermore, the terms and expressions appearing herein are used as terms of description rather than limitation, and the use of such terms and expressions is not intended to exclude any equivalents of the features shown or described, or portions thereof, but it is recognized that various modifications may be made are possible within the scope of the claimed invention. Thus, while the present invention has been specifically disclosed through exemplary embodiments and optional features, it should be understood that those skilled in the art can make modifications and variations of the inventions embodied and disclosed herein, and that such modifications and variations are considered to be within the scope of this invention ,

The reference numbers in parentheses in the claims are intended to facilitate understanding of the invention and have no limiting effect on the scope of the claims.

The other references in the claims and the description in parenthesis are intended to facilitate understanding of the invention and have no limiting effect on the scope of the invention, in particular not limiting the scope of the claims. These other reference numerals have the same effect as reference numerals. The further reference signs may be deleted from the claims without affecting the scope of the claims. Examples of such further reference symbols are Q _D , Qs, total, T _ZONE , Q _AHU , T _air , A _amb , u _ctrl , u _fan , u _valve , T _sup , T _ret , m, Q ₁₅₂ and Q ₁₅₃ .

The abbreviations HVAC, AHU, FCU and BMS as used in the present disclosure are terms having meanings well known in the art. HVAC (Heating, Ventilation, Air Conditioning) stands for heating, ventilation and air conditioning systems. AHU (Air Handling Unit) stands for Air Treatment Unit. FCU (Fan Coil Unit) stands for fan coil. BMS (Building Management System) stands for Building Management System.

In various embodiments, the HVAC system may be divided into a demand side and a supply side.

In various embodiments, the HVAC system may include at least one demand subsystem in signal communication with a supply side. A demand subsystem may be an air conditioner. An example of an air conditioner is a fan coil. Another example of an air conditioner is an air handling unit. An example of a demand subsystem is a Fan Coil Unit (FCU). An example of a supply side includes a building management system (BMS) and a cold generator (eg, a refrigeration system).

In various embodiments, the demand subsystem and one or more additional demand subsystems are included in the demand side. In various embodiments, the HVAC system may include one or more additional demand subsystems, wherein this additional one or each of these additional multiple need subsystems preferably corresponds to the demand subsystems of the invention.

In various embodiments, the needs subsystem may include the demand page processor. The demand side processor is configured to perform the determination of the demand (Q _D ) with the demand estimator, e.g. B. by rating the function. The demand estimator includes the variable input. The variable input of the demand function includes a zone property and the control signal (u _ctrl ). The demand estimator is also referred to herein simply as a "demand function."

In the present disclosure, a temperature such as a zone temperature (T _ZONE ) is used to explain the invention as a possible zone property, but the invention is not limited thereto, and another zone property may be used as the zone property or the zone temperature, for example the humidity of the zone, the relative humidity of the zone, the dewpoint of the zone, the CO ₂ concentration of the zone Zone or combinations thereof. In one example, the property of the zone is the temperature of the zone (T _ZONE ).

In various embodiments, zone property may relate to properties of the air in the respective zone.

In various embodiments, the zone property is an environment variable of the zone. Therefore, the zone property excludes non-variable properties of the zone, such as: zone dimensions, zone volume, zone area, zone heat capacity, or a combination thereof. The zone property may correspond to a property of the air in the respective zone. The term "match" in this context may mean that the zone property is a specific property. For example, "zone property corresponds to zone temperature" may mean that the zone property is the zone temperature. In another example, "zone property corresponds to humidity" may mean that the zone property is the zone humidity.

The temperature is the measured actual temperature (as opposed to a set temperature). For example, the temperature for an FCU is the _zone temperature (T _zone ) measured by the FCU. The control signal may include the signal from a demand side subsystem controller. The input of the controller closes a setpoint, eg. For example, set a temperature set point (T _set ), and zone temperature (eg, the current measured temperature of the zone). The controller generates a control signal that is a function of the input to the controller. The control signal may correspond, for example, to a fan speed or a valve opening. The term "correspond" in this context may mean that the control signal is a fan speed or a valve opening. The control signal may be, for example, a fan speed or a valve opening ratio.

In various embodiments, the demand subsystem may include the sender for sending the demand (Q _D ) to the supply side.

In various embodiments, the supply side may include the receiver for receiving the demand (Q _D ) from the demand subsystem.

In various embodiments, communicating the need to send the demand over the sender may be from the demand side subsystem to the receive side receiver. Thus, the signal communication between the transmitter and the receiver is established.

In various embodiments, the supply side may include the supply side processor. The supply side processor may be configured to be able to determine supply side operating performance as a function of demand (Q _D ). The determination may include other parameters, such as supply side parameters. Typically, the demand (Q _D ) and the supply side parameters are sufficient to calculate the supply side operating power. If additional demand side subsystems exist, demand (Q _D ) also includes additional requirements herein. The term "able to" herein means that the supply side processor, when the HVAC system is in operation and when the demand (Q _D ) is available as received by the receiver, determines the operating power (Q _{s, total} ). The operating power (Q _{s, total} ) is a function of the demand, e.g. B. proportional to the need. The operating power (Q _{s, total} ) can be proportional to the sum of the requirements. The determination of operating performance may include, for example, varying the speed of a motor pump and activating or deactivating additional stages besides a main stage of a refrigeration system. Supply side parameters are, for example, parameters required for the operation of the supply side, which need not be communicated from or to the demand side. Examples of supply side parameters are the relationship between the operating capacity and the capacity of a refrigeration system, the temperature of the return water and limiting factors such as maximum performance of a pump or refrigeration system. The operating power may be determined by a supply side operating power estimation function, also referred to herein simply as the "supply function".

In accordance with the invention, an HVAC system may be provided wherein the HVAC system includes the supply side and the supply side is configured to operatively communicate with at least the demand subsystem, preferably further with the additional demand subsystems.

In various embodiments for the HVAC system, the HVAC system may include at least the demand subsystem, preferably still an additional demand subsystem.

In various embodiments of the invention, the demand subsystem is selected from at least one of: fan convector and air handling unit.

Various embodiments of the invention may relate to a method of operating the HVAC system. The method may include: a) determining the demand (Q _D ) with the demand estimator, wherein the determination is performed by a demand side processor included in the demand subsystem; wherein the demand estimator comprises the variable input, and wherein the variable input of the demand function has the zone property, e.g. B. a temperature, and the control signal (u _ctrl ) includes. The temperature is preferably a _zone temperature (T _zone ), an example of a zone temperature is a room temperature (T _R ), which space may comprise a single zone. The method may include: b) communicating the demand (Q _D ) determined in step a) from the demand subsystem to the supply side. The method may include: c) determining supply side operating power as a function of demand (Q _D ) and supply side parameters; wherein the determination is performed by a supply side processor included in the supply side.

In various embodiments of the invention, the demand subsystem may be an FCU and the temperature is a zone temperature. The zone temperature may be a room temperature (T _R ), e.g. When the room comprises a single zone.

In various embodiments of the invention, the demand subsystem may be an air handling unit (AHU), the demand being an AHU demand (Q _AHU ), and the demand side processor being an AHU side processor included in the air handling unit, the demand estimation function being an AHU demand function. The variable input of the AHU demand function can still include the humidity (AH _amb ).

In various embodiments, preferably when the demand subsystem includes an AHU, the demand subsystem may include a second control signal, wherein the temperature in the demand subsystem is the temperature of the supply _air (T _air ), for example the outside ambient temperature, the control signal (u _ctrl ). a fan speed (u _fan ) corresponds and the second control signal corresponds to a valve opening (u _valve ).

In various embodiments, the demand side may include a demand subsystem that is an AHU, and further a plurality of demand subsystems, each of which is an FCU.

In various embodiments, the demand side may include a plurality of demand subsystems, each being an air handling unit, and further a plurality of demand subsystems, each being an FCU.

In various embodiments, the HVAC system may include a chiller (eg, a chiller) on the supply side. The method according to the invention may determine an operating power of the refrigerator, for. The supply side demand is a function of the liquid feed temperature (T _sup ), the liquid return temperature (T _ret ), and the liquid flow rate (m). The HVAC system may include a liquid for heat transfer to the chiller and, for example, between the supply side and the demand side, the liquid may be liquid, for example substantially comprising water.

In various embodiments, the demand estimator may be independent of other demand side parameters, such as: zone dimensions, zone volume, zone range, zone heat capacity, or a combination thereof.

In various embodiments, the method according to the invention may include adding at least one additional demand subsystem to the HVAC system, and thus to the demand side of the HVAC system. The method may further include establishing the signal communication between the additional demand subsystem and the supply side so that the additional requirements subsystem may perform the following step: communicating the demand from the additional demand subsystem to the supply side.

In various embodiments, the method according to the invention may include a supply side reaction time. The supply side may be configured to operate in: i) a first mode wherein at least one demand (Q _D ) is received; and ii) in a second mode, wherein no demand (Q _D ) is received. The supply side may be configured to increase response time when operating in the first mode and recognizing a second mode, and reducing response time when operating in the second mode and detecting a first mode.

Fig. 1 FIG. 12 illustrates a flowchart of a method according to various embodiments of the invention. FIG. In a method step 10, the determination of the requirement Q _{D is carried out} in the requirement subsystem. In another step of the process, which is performed later than step 10, the demand Q _D determined in step 10 is communicated to the supply side in step 11. In another step later than step 11, in step 12, the supply side operating power is determined based on the demand received by the supply subsystem from the supply subsystem.

Fig. 2 FIG. 12 is a diagram illustrating a method performed on a demand subsystem according to various embodiments of the invention at the demand subsystem. FIG. A controller 142 is configured to set the setpoint T _{set of} a zone property, for example, a desired zone temperature, e.g. B. set by a user in an office room to receive. The controller is also configured to receive the current T _ZONE value of the zone property. On the basis of these two inputs, the controller determines the control signal u _ctrl in a step 22. The control signal is used by the demand subsystem to set its operating state, which control signal could refer to a valve opening or fan speed. The control signal may be a normalized value from 0 to 1. The control signal u _ctrl is communicated to the demand _{page processor} 144. The demand page processor 144 determines the demand (Q _D ), e.g. By assessing a demand estimator, wherein the demand estimator comprises a variable input, and wherein the variable input of the demand function comprises the current value T _{ZONE of} the zone characteristic and the control signal (u _ctrl ). The current value of the zone property can be measured value, for example from a temperature sensor. The measured value may be measured by a conventional sensor (such as a conventional temperature sensor), where both the controller 142 and the demand side processor may use the same measured value.

In one example, T _{set is} the temperature _setpoint of a zone while T _{ZONE is} the current temperature. The control signal can be determined by u _ctrl = f (T _set , T _ZONE ), for example in cooling _mode , the u _ctrl = a ₁ (T _ZONE - T _set ), where a _{1 is} a normalization _factor . The control signal u _ctrl may be limited, for example, if T _ZONE <= T _set , the control signal may be zero. Thus, if T _ZONE > T _set , the control signal u _{ctrl is} greater than zero, and works the demand side, e.g. B. FCU, with a respective power greater than zero, z. B. with a higher fan speed than zero RPM.

wobei Q_D(u_ctrl,T_ZONE) der Bedarf Q_D ist, a₂ eine Konstante ist (zum Beispiel der Durchschnittswert der Zonentemperatur während normalen Betriebs in derselben Einheit wie T_ZONE, zum Beispiel 27 °C), Q_max die Höchstleistung ist, und die Parameter c₁, c₂, c₃, e₁ und e₂ spezifische Bedarfssubsystemparameter sind, die eingestellt werden können, zum Beispiel durch Simulationen. Gl. 1 wird vorzugsweise für eine FCU verwendet, wobei Q_D der Q_FCU ist, T_ZONE die Zonentemperatur in Celsius ist, Q_max die Höchstleistung in Watt ist, und u_ctrl die normierte Ventilöffnung oder normierte Lüfterdrehzahl ist.In one example, the demand is determined with a function Q _D = f (u _ctrl , T _ZONE ), as follows: $$Q_D\left(u_{\mathit{ctrl}},T_{\mathit{ZONE}}\right)={\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="imgf0002.png,imgf0005.png"\; state="\{\{state\}\}">c</figure-callout>}}_1+c_2\frac{T_{\mathit{ZONE}}}{a_2}\left({\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="imgf0005.png,imgf0006.png"\; state="\{\{state\}\}">c</figure-callout>}}_3\cdot Q_{\mathit{Max}}^{\left(1-{\mathrm{<figure-callout\; id="1"\; label="e"\; filenames="imgf0002.png,imgf0005.png"\; state="\{\{state\}\}">e</figure-callout>}}_1\right)}\cdot u_{\mathit{ctrl}}^{e_2}\right)$$

where Q _D (u _ctrl , T _ZONE ) is the demand Q _D , a _{2 is} a constant (for example, the average of the zone temperature during normal operation in the same unit as T _ZONE , for example 27 ° C), Q _{max is} the maximum power , and parameters c ₁ , c ₂ , c ₃ , e ₁ and e _{2 are} specific required subsystem parameters that can be adjusted, for example, by simulations. Eq. 1 is preferably used for an FCU, where Q _{D is} the Q _FCU , T _{ZONE is} the zone temperature in Celsius, Q _{max is} the maximum power in watts, and u _{ctrl is} the normalized valve opening or normalized fan speed.

In various embodiments, the demand estimator (eg, Eq.1) is a function that provides the needs of the demand subsystem given arguments including temperature and control signal. The function may be applied in step 24 in the required subsystem processor in various forms, e.g. In the form of a mathematical calculation or in the form of an input-output table.

Fig. 3 FIG. 12 is a diagram illustrating at least three need subsystems 151, 152, 153 in communication with a supply side 111 according to various embodiments of the invention. The first needs _subsystem 151 is _configured to determine a first control signal u _{ctrl, 1} in step 31, to determine (with a processor of the first needs subsystem) a corresponding first demand Q _D1 in step 32 and to communicate the first demand to the supply side 111. The second requirements _subsystem 152 is _configured to determine a second control signal u _{ctrl, 2} in step 33, to determine a corresponding second demand Q _D2 (with a processor of the second demand subsystem) in step 34 and to communicate the second demand to the supply side 111. The demand _subsystem 153 is _configured to determine a third control signal u _{ctrl, 3} in step 35, to determine a corresponding third demand Q _D3 (with a processor of the third _{required subsystem} ) in step 36 and to communicate the third demand to the supply side 111. The HVAC system is not limited to three requirement subsystems and could include a single requirements subsystem as well as a plurality of demand subsystems, for example, 10 or more requirement subsystems.

stellt die Erfindung für die Bestimmung der Versorgungsseitenbetriebsleistung (in Schritt 37) Übernehmen der von der Bedarfsseite empfangenen Bedarfe (Q_D1,Q_D2,Q_D3,...) und Anwenden, z. B. Bewerten der folgenden Versorgungsfunktion bereit: $$Q_{s,\mathit{total}}=f\left(Q_{D1},Q_{D2},Q_{D3},\mathrm{...}\right)$$

wobei der variable Eingang der Versorgungsfunktion einen oder mehrere von den jeweiligen Bedarfssubsystemen von der Bedarfsseite empfangene Bedarfe (Q_DX) einschließen kann. Wenigstens einer der Bedarfe kann der Bedarf einer FCU (Q_FCU) sein. Einer der Bedarfe kann ein Bedarf einer Luftbehandlungseinheit (Q_AHU) sein. Anstelle der aggregierten verzögerten Reaktionszeit auf der Versorgungsseite (z. B. an der Kälteanlage), gegeben durch den Rücklaufflüssigkeitskreislauf und die Durchschnittsbildung der Temperaturmessungen auf der Versorgungsseite (z. B. an der Kälteanlage), kann die erfindungsgemäße Versorgungsseite daher ihre Versorgungsseitenbetriebsleistung ohne Verzögerung bestimmen. So kann eine Erhöhung der Versorgungsseitenbetriebsleistung bei Bedarf mit minimaler Reaktionszeit erfolgen, und die Absenkung kann ebenfalls mit minimaler Reaktionszeit erfolgen. Auf diese Weise sorgt die Erfindung für eine schnellere Reaktion und ermöglicht gleichzeitig Energieeinsparungen.In contrast to the conventional way of determining the operating performance of the supply side (eg the need for a refrigeration system) by means of the function according to Eq. 2: $$Q_{s.\mathit{total}}=f\left(\dot{m},T_{\mathit{sup}},T_{\mathit{ret}}\right)$$

provides the invention for the determination of the supply side operating power (in step 37) taking over the demands received from the demand side (Q _D1 , Q _D2 , Q _D3 , ...) and applying, e.g. B. Evaluate the following utility function: $$Q_{s.\mathit{total}}=f\left(Q_{D1},Q_{D2},{\mathrm{<figure-callout\; id="3"\; label="Q\; D"\; filenames="imgf0005.png,imgf0006.png"\; state="\{\{state\}\}">Q\; </figure-callout>}}_D,\mathrm{...}\right)$$

wherein the variable input of the utility function may include one or more requirements (Q _DX ) received from the respective demand subsystems from the demand side. At least one of the needs may be the need for an FCU (Q _FCU ) be. One of the needs may be a need for an air handling unit (Q _AHU ). Therefore, instead of the aggregated delayed reaction time on the supply side (eg, the refrigeration system) given by the return fluid circuit and the averaging of the temperature measurements on the supply side (eg, the refrigeration system), the supply side of the present invention can determine its supply side operation without delay , Thus, an increase in supply side operating power can be made as needed with minimal reaction time, and the lowering can also be done with minimal reaction time. In this way, the invention provides for a faster response while allowing energy savings.

In various embodiments, the supply function (for example, equation 3) is a function that provides the supply operating power (Q _{S, total} ) for given arguments including the demand (Q _DX ). The utility function can be applied in the supply side processor in various forms, e.g. In the form of a mathematical calculation or in the form of an input-output table.

The above-mentioned functions Eq. 1, Eq. 2, Eq. 3 are each exemplary embodiments of the invention, but the invention is not limited thereto. With the teachings of the present disclosure, those skilled in the art can devise various functions within the scope of the invention.

FIG. 4 shows a diagram illustrating an HVAC system with various components according to a comparative example. The HVAC system may be divided into a supply side 111 and a demand side 141. The supply side may include a chiller 112 (eg, a refrigeration system) and a building management system (BMS) 114, which may be configured to be in signal communication 103 with the chiller 112. The supply side may include one or more demand subsystems, for example, a first FCU 151, a second FCU 152, a third FCU 153, and an AHU 160. The HVAC system may further include a circuit for conveying the liquid (eg, refrigerant, such as refrigerant) Water), which circuit may include a feed subcycle 101 and a return subcycle 102. During cooling, the refrigeration system 112 delivers, for example, cooled liquid to the feed subcirculation 101 to the demand side 141. The refrigeration system receives the return liquid via the Return subcircuit 102, and the return liquid can be cooled at the refrigeration system and fed again to the feed subcircuit 101.

FIG. 5 shows a diagram of FIG. 4 however, at least one, preferably each, of the needs subsystems 151, 152, 153, and 160 includes a demand side processor that is responsible for determining the respective demand Q ₁₅₁ , Q ₁₅₂ , Q _153, and Q ₁₆₀ and communicating the need for the supply side, Example to BMS 114, is configured. In various embodiments, the supply side may include a supply side processor 124 that is configured to determine the supply requirement and thus to determine the supply side operating power.

In various embodiments, the liquid may be part of the closed loop, with the closest loop having a pump for providing the liquid stream. The pump may be part of the supply side, and may be integrated with the chiller or disconnected from the chiller.

FIG. 6 shows an example of the course of the supply side operating power, in this case the cooling power, after switching on the HVAC system. FIG. 6 shows an upper graph 60 and a lower graph 61. In both the upper graph and the lower graph, the time on the horizontal axis is plotted in hours. On the vertical axis of the upper graph 60, the cooling capacity (in MW) is plotted, and on the vertical axis of the lower graph 61, the zone temperature is plotted in Celsius. The upper graph shows a dotted line 63 (with dots represented by "X"), which is a graph of cooling performance versus time as measured for a comparative example. The solid curve 62 represents the course of the simulated cooling performance versus time for the same comparative example. Measured and simulated courses are very comparable. Dashed line 64 represents the step setpoint.

The HVAC system will be turned on for approximately 7.5 hours. Although the demand is available at startup, the system can provide the immediate cooling demand from the Water temperature difference do not recognize. The second stage does not begin until about 8 because the buffer has expired at that time and the staged setpoint 64 has been crossed.

Each of the FIGS. 7 and 8 shows as an example the cooling power in kW (vertical axis) as a function of the control signal (horizontal axis) for an FCU with a zone temperature T _ZONE = 24 ° C in FIG. 7 and T _ZONE = 29 ° C in FIG. 8 , These curves can be measured or simulated for a system. After the relationship between the cooling power and the control signal u _{ctrl is known} for a given zone temperature T _ZONE , the demand Q _D can be determined simply by knowing the control signal u _ctrl and the zone temperature T _ZONE . The invention can also be realized with a zone property other than the zone temperature given as an example herein.

FIG. 9 Figure 4 shows a graph 50 with the capacity of a chiller in MW on the vertical axis and the time in minutes on the horizontal axis. Curve 51 is the measurement of the capacity of the refrigerator of a conventional system, while curve 52 is the measurement of the capacity of the refrigerator of the method according to the invention. Curve 53 is the estimated requirement according to the present invention.

It can be seen that the second stage with the method according to the invention achieves a maximum performance compared to the comparative example very quickly. According to the invention, since the chiller receives the demand information from the demand side, it can quickly adjust the performance of the chiller stages to the required demand while the chiller in the comparative example reacts to the temperature of the return water, which is very slow in comparison. Thus, the example according to the invention regulates very quickly to a stable power, and even switches off the second stage. The comparative example, however, turns off the second stage much later. In conventional systems, there may be a further delay (eg in the form of a hysteresis or in the form of a moving average, eg the temperature of the return water) to avoid sudden changes in cooling performance, for example due to water temperature spikes in the system or Errors in temperature measurements. Because of this delay, the conventional HVAC system responds very slowly.

Fig. 9 shows that for the conventional system, after starting (at 10 minutes) the first stage of the chiller, when working at full power, the full capacity can not be handled and therefore the second stage starts at about 25 minutes. The reason for the increased reaction time is the chill cycle process buffer as discussed above. On the other hand, as the need for the method and / or system according to the invention is known, the refrigeration device provides the precise operating performance and thus the exact cooling capacity, as shown in FIG. Further, the chiller uses the first and second stages from startup with gradually decreasing the capacity to accommodate the gradually decreasing demand to stop the second stage (at about 15 minutes) much earlier than the conventional system. The system of the invention can achieve the desired zone conditioning temperature at the estimated demand side much earlier.

FIG. 10 shows the course of the zone temperature for three different zone loads. In each of the graphs of FIG. 10 For example, the temperature in ° C on the vertical axis, the time in minutes on the horizontal axis, the dashed curves are the zone temperature curves of a zone cooled by a conventional method and / or system, and the solid lines are the zone temperature curves of the same by one method and / or system cooled according to the present invention. FIG. 10 shows in the middle of a reference zone, wherein it can be clearly seen that the cooling with the method and / or system according to the invention is much faster. The upper graph shows the same gradients for a zone that is less loaded, and the lower graph shows the same gradients for a zone that is more stressed. The arrows indicate reaching 25 ° C, it being understood that the invention is better in all three states and reaches a comfortable temperature of 25 ° C 5 to 10 minutes earlier than the prior art.

Claims (13)

A method (1) of operating an HVAC system (100) comprising at least one demand subsystem (140) in signal communication with a supply side (111), the method (1) comprising: a) determining a demand (Q _D ) with a demand estimator, wherein the determination is performed by a demand page processor (144) included in the demand subsystem (140); wherein the demand estimator comprises a variable input, and wherein the variable input of the demand estimator comprises a zone property and a control signal (u _ctrl ); b) communicating the demand (Q _D ) from the demand subsystem (140) to the supply side (111); and c) determining a supply side operating power (Q _{s, total} ) as a function of the demand (Q _D ) and supply side parameters; wherein the determination is performed by a supply side processor (124) included in the supply side (111). The method (1) of claim 1, wherein the demand subsystem (140) is an air conditioner, wherein the air conditioner is preferably a fan convector (151, 152, 153) or an air handling unit (160). The method (1) according to any one of claims 1 or 2, wherein the zone property corresponds to a zone temperature (T _ZONE ). Method (1) according to any one of the preceding claims, wherein the zone property corresponds to a humidity (AH _amb ). Method (1) according to any one of the preceding claims, wherein the control signal (u _ctrl ) corresponds to a fan speed (u _fan ). Method (1) according to any one of the preceding claims, wherein the control signal (u _ctrl ) corresponds to a valve opening (u _valve ). The method (1) of any of the preceding claims for operating the HVAC system (100), the HVAC system (100) further comprising a supply side chiller (112), the method (1) further comprising:
Determining an operating power of the refrigerator, wherein the operating power of the refrigerator is a function of at least the inlet temperature of the liquid (T _sup ), the return temperature of the liquid (T _ret ), the flow rate of the liquid (ṁ) and the demand (Q _D ). The method (1) of any one of the preceding claims, wherein the demand estimator is independent of at least: zone dimensions, zone volume, zone area, zone heat capacity, or a combination thereof. Method (1) according to any one of the preceding claims, further comprising: Add at least one additional demand subsystem (152, 153) to the HVAC system (100) and Establishing the signal communication between the additional demand subsystem (152, 153) and the supply side (111) such that the additional requirements subsystem (152, 153) is capable of performing the following step:
Communicating the demand (Q ₁₅₂ , Q ₁₅₃ ) from the additional demand subsystem (152, 153) to the supply side (111). Method (1) according to any one of the preceding claims, wherein
the supply side (111) has a reaction time, and
the supply side (111) is configured to work in: a first mode, wherein at least one of the demand (Q _D ) or an additional demand (Q ₁₅₂ , Q ₁₅₃ ) is received; and a second mode wherein no demand (Q _D ) is received; wherein the supply side (111) is configured to increase the response time when operating in the first mode and recognizing a second mode, and decreasing the response time when operating in the second mode and recognizing a first mode. A demand subsystem for an HVAC system (100) configured to operatively communicate with a supply side (111), the supply side (111) comprising: a supply side receiver for receiving a demand (Q _D ) from the demand subsystem (140); and a supply side processor (124) configured to be able to determine supply side operating power (Q _{s, total} ) as a function of demand (Q _D ); the requirements subsystem comprising: a controller (142) for providing a control signal (u _ctrl ); a demand side processor (144) configured to be able to determine a demand (Q _D ) with a demand estimator, the demand estimator comprising a variable input, and wherein the variable input of the demand estimator has a zone property and the control signal (u _ctrl ); a demand side transmitter for sending the demand (Q _D ) to the supply side (111). An HVAC system (100) comprising:
a supply side (111) configured to operatively communicate with at least one demand subsystem (140) according to claim 11, the supply side (111) comprising: a supply side receiver for receiving the demand (Q _D ) from the demand subsystem (140); and a supply side processor (124) configured to be able to determine supply side operating power (Q _{s, total} ) as a function of demand (Q _D ). An HVAC system (100) according to claim 12, further comprising
at least one demand subsystem (140) according to claim 11, and preferably, wherein the subsystem (140) is selected from at least one of: fan coil (151, 152, 153) and air handling unit (160).

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