Two-channel air conditioner for the flexible climate control of a number of rooms

The invention relates to a two-channel air-conditioner (10) for the climate control of a number of rooms (44, 46, 48) and/or room zones, having an air inlet device (52) in every room (44, 46, 48) to be climate controlled, having at least one pair of supply air channels (20, 22) wherein at least one supply channel (20, 22) comprises a cooling and/or heating register (32, 34; 58, 60) having at least one temperature regulator for each room (44, 46, 48) to be climate controlled, which keeps the room (44, 46, 48) to be climate controlled at a room temperature (Troom target) which can be set, having valve units (54, 72), which connect the supply air channels (20, 22) to the air inlet device (52). The invention is characterized in that it allows switching, the cooling or heating register (32, 34; 58, 60) is only opened as needed if the temperature in at least on of the supply air channels (20,22) is insufficient for cooling or heating the room (44, 46, 48) to be climate controlled.

This is the national entry of PCT/EP2009/001273, international application filing date Feb. 23, 2009. Applicant claims priority to German Patent Application No. DE 10 2008 010 656.9 filed on Feb. 22, 2008 which is hereby incorporated by reference.

The invention relates to a two-channel air-conditioner for the climate control of a number of rooms.

Rooms, in particular of buildings, can, for example, be subjected to differing heat and cooling loads because of their orientation to the north or to the south, their orientation with respect to dominant wind directions or because of the devices which are in such rooms. Therefore, one-channel air-conditioners and zones air-conditioners are not always adapted for the climate control of buildings having a number of rooms since the air to be climate controlled has to be supplied, in such cases, at differing conditions into the rooms to be climate controlled.

For this purpose, two-channel air-conditioners have been built in many times in the past. Therein, outside air is sucked in from the outside and is conveyed by an outside air blower after some basic treatment. In the one outside air channel, the outside air is heated by means of an air heater—heating register. Thereby, this channel forms the hot air channel. In the other outside air channel, the outside air is cooled by a surface cooler—cooling register. Thereby, this channel forms the cold air channel. Each individual air outlet in the room to be climate controlled comprises a connection to the hot air channel and the cold air channel through a mixing box. Therefore, the mixing boxes are provided in order to connect the air outlet with the connections at the hot air channel and the cold air channel. The hot air from the hot air channel and the cold air from the cold air channel are mixed with each other in the mixing boxes. For this purpose, a mixing device is inserted into the mixing boxes which device comprises a pneumatic positioning motor, a cold air valve cooperating with the cold air channel and a hot air valve cooperating with the hot air channel. By means of a pneumatic positioning motor, the valve positions are coupled to each other. In case the valve to the hot air channel is opened to 30%, the valve to the cold air channel is, at the same time, opened to 70%. Thereby, always an opening amount of 100% is obtained whereby the quantity of air which is conveyed through the mixing box remains always the same.

By actuating the valves through the positioning motor, the mixing of the hot air and the cold air is controlled while maintaining the amount of air. For example, rooms having a maximum of cooling load receive only cold air—valve to the cold air channel is open to 100%; and, at the same time, the valve to the hot air channel is open to 0%—and rooms having a maximum of heat load receive only hot air—the valve to the hot channel is open to 100% and, at the same time, the valve to the cold air channel is open 0%—and rooms having a partial load receive a mixture of cold air and hot air with corresponding opening positions of the valves.

Such an air conditioning system is, for example, known from the book “Recknagel, Sprenger, Schramek; Taschenbuch für Heizung und Klimatechnik (pocketbock for heating and climate technology), München a. o., Oldenburg Industrieverlag, 2003, pages 1093 to 1096.

It is a deficiency of the two-channel systems mentioned above, that hot air and cold air have to be permanently made available in summer time as well as in winter time in the hot air channel as well as in the cold air channel. Therefore, a register in one channel is activated at all times. Furthermore, a nearly constant amount of air is permanently fed into both channels in known systems at all times. An individual increasing of the amount of air in order to provide faster cooling or heating is not possible. Therefore, the known two-channel air-conditioners have very high energy consumption and are very inflexible. A reduction of the energy consumption is not possible with such systems up to now.

The invention is based on the object to further develop such a two-channel air-conditioner such that the flexibility is increased. Furthermore, the preconditions should be provided in order to substantially reduce the energy consumption, and, in particular, to enable adaption of existing two-channel air-conditioners to the invention.

Further advantages and features of the invention are subject to the sub-claims.

The invention is based on the finding that the coupling of the valve devices fails to meet the individual air-conditioning requirements in the rooms to be climate controlled, and that, thereby, waste of energy is encountered. By decoupling the valve units, this problem can be solved in a simple way. It is now possible to introduce the maximum amount of input air from one input air channel as well as the maximum amount of input air from the other input air channel into a room to be climate controlled on demand. A fast adaption to the required conditions and a high flexibility is achieved thereby.

Therefore, according to the invention, the valve units are formed independent from each other such that the amounts of air from the respective supply air channels to the individual rooms to be climate controlled are adjusted independently from each other.

According to an embodiment of the invention, the valve unit is each formed and controlled such that also only one of the supply air channels is connected to the air inlet device of a room to be climate controlled.

Preferably, one of the factors pressure, temperature, moisture, density in the supply air channel may be used as a control parameter for the control/regulation independent from the respective factor in the other supply air channel. Thereby, the flexibility and the possibility to optimize the system are further improved.

According to a further aspect of the invention, it is based on the finding that the cooling register or the heating register in the respective channel has to be activated only on demand whereby it is possible to considerably reduce the energy consumption. Thereby, further multiple possibilities for optimizing the saving of energy are obtained.

Preferably, the two-channel air-conditioner comprises a circuit cooperating with the temperature regulators of the room to be climate controlled which circuit is connected to the temperature sensors in the supply air channels, the temperature sensors in the rooms to be climate controlled and the cooling register or heating register arranged at least in one supply air channel, whereby the circuit outputs a positioning signal opening the cooling register or the heating register only in case the temperature in at least one supply air channel is not sufficient for cooling or heating the rooms to be climate controlled in considering the conveyed amount of air. Thereby, substantial energy costs can be saved in a simple way since the cooling register and/or the heating register are now not permanently activated anymore.

Therein, preferably, the pressure in the supply air channel is controlled depending on the required air quantities through the flaps forming the valve unit and/or a supply air motor.

In particular each supply air channel may comprise a heating register and/or a cooling register or, as an alternative thereto, one supply air channel may comprise a heating register and the second supply air channel may comprise a cooling register.

According to a further embodiment of the invention, the cooling and heating register of the supply air channel are adjustable independently from each other in a predefined temperature range.

Because of the changed valve control for both supply air channels, the former designation to a hot air and a cold air channel as well as the previously required mixing box can be completely dispensed with. Furthermore, further possibilities of the control of the air quantity also with respect to the heating- or cooling demand are obtained thereby.

Further energy costs can also be saved in that the minimum temperature of the supply air in the supply air channels corresponds essentially to the minimum temperature of the system at which it does not become damaged, for example 12° C.

Preferably, also the amount of air supplied to the individual supply air channels, is varying independently form each other. Therein, the amount of supply air for the individual rooms to be climate controlled or room zones may vary depending on the difference between the temperature in the room to be climate controlled (Troom actual) or the room zone to be climate controlled or the predetermined temperature target value (Troom target) as well as depending on the supply air temperature. Therein, the amount of air is increased as needed such that a fast heating or cooling is ensured with an optimum of comfort.

Preferably, moistening and/or de-moistening devices are provided for the supply air at least in one supply air channel which may be activated on demand.

Furthermore, also additional cooling and/or heating units for the supply air may be provided in at least one supply air channel which units are adapted to be switched-in on demand.

A further possibility for the control is provided by means of the values of the density in the room and the supply air channel.

Basically, a device for pre-treating the air may be provided in front of each supply air channel in which device the air is heated, cooled, moisturized or de-moisturized on demand.

According to an embodiment of the invention, the supply air channels are designed for differing supply air quantities. The cooling and/or heating registers and/or the moistening and de-moistening devices may be designed according to the maximum possible air supply quantities in the respective air supply channels as well.

Further advantages, features and possibilities of usage of the present invention can be taken from the following description in connection with the embodiment shown in the drawing.

InFIG. 1, a block circuit diagram of a two-channel air-conditioner10according to the invention is shown. The two-channel air-conditioner10comprises a central supply air channel12. In this central supply air channel12a supply air motor14as well as a heating register16is inserted which is located downstream of the supply air motor14. A temperature sensor18is arranged downstream of the heating register16.

The central supply air channel12is branching off into a first supply air channel20and a second supply air channel22. In the first supply air channel20, a flap24is inserted which is driven by a motor26. In the same way, a flap28is inserted into the second supply air channel22which flap is driven by a motor30. The variable amount of air for the first and the second supply air channel20and22is adjusted by the flaps24,26and by the supply air motor14.

Downstream of the flap24in the first supply air channel, firstly, a cooling register32, thereafter, a heating register34and, finally, a moistening device36are arranged. Finally, a temperature sensor38, a moisture sensor40as well as a pressure sensor42are inserted into the first supply air channel22downstream of the moistening device36. The first supply air channel is adapted to be connected to the rooms44,46and48each.

For this purpose, a branch channel50is provided each which is connected to a air inlet52in the middle of the respective room44,46,48. The branch channel50is a part of the first supply air channel20. In this branch channel50, a flap54is provided which is adapted to be actuated by a motor56.

In the same way as in the first supply air channel20, also the second supply air channel22is arranged. Downstream of the flap, a cooling register58, a heating register60as well as a moistening device62are arranged. The moistening device62is followed by a temperature sensor64, a moisture sensor66as well as a pressure sensor68.

From the second supply air channel22, a second branch channel70each is branching of which is connected to the air inlet52of the respective rooms44,46,48. In the second branch channel70, a flap72is arranged which is actuated by a motor74.

A temperature sensor76, a moisture sensor78as well as air quality sensor80are each provided in the rooms44,46,48. The temperature in the room44,46,48is controlled by means of the individual sensors. In the control circuit, a respective target value is pre-defined for the respective room. Therein, the cooling register32,58, the heating register34,60and the moisture device36,62are activated in the respective supply air channel20,22only in case the temperature for cooling or heating the room to be climate controlled or the degree of moistening is not achieved at least in one of the supply air channels20,22. As a rule, the air inlet52in the room44,46,48to be climate controlled, is only connected to one supply air channel20or22. Therefore, the air is not mixed anymore contrary to the previously known state of the art, but is taken either from the first supply air channel20or the second supply air channel22.

The amount of air is respectively adjusted by the flaps54and72. The quantity of supply air for the respective rooms44,46,48to be climate controlled varies depending on the difference between the temperature in the room to be climate controlled and the pre-defined temperature as well as depending on the supply air temperature. For this purpose, the respective temperature sensors18,38and76are provided.

The pressure in the supply air channels20,22is controlled depending on the required amount of air in the rooms44,46,48to be climate controlled, by means of the flaps24,28,54,72as well as the supply air motor14.

The cooling registers32,58, the heating registers34,60as well as the moistening devices36,62are only activated when the temperature in the respective supply air channels20,22and/or the values of the density and/or the values of the moisture are not in conformity with the targets.

The cooling registers32,58as well as the heating registers16,34and60are adapted to be adjusted in a pre-determined temperature range.

The flaps54and72form a kind of valve installation. It is formed such that, according to the demand, also only one of the supply air channels20,22is connected to the air inlet52in the rooms44,46,48to be climate controlled. By means of the flaps54and72, furthermore, the amount of air from the respective supply air channel20,22is controlled independently from each other.

The air-conditioner according to the invention is able to maintain a variable temperature in each supply air channel, wherein a minimum supply air temperature may be adjusted to a minimum target value and/or the maximum supply air temperature may be adjusted to a maximum target value.

The first supply air channel20and the second supply air channel22may comprise cross-sections of different size for supply air quantities of different amount and for cooling and/or heating registers having differing power. In the following, the first supply air channel20is designed for a lower supply air volume. The cross-section of the first supply air channel is smaller. The second supply air channel22is designed for a larger supply air volume. The cross-section of the second supply air channel22is larger.

The rooms44,46,48have to be heated at an outside temperature of 0° C. In case the first supply air channel20is sufficient in order to cover up for the heating demand of the rooms44,46,48, the second supply air channel22is decoupled from the rooms44,46,48, i.e. the flaps72,28are closed. The flaps54of the first supply air channel20are open. The heating register34in the first supply air channel20can also be open, whereas the heating register in the second supply air channel22is closed.

The outside temperature is, for example, −10° C. In this case, it may happen that the heating power in the first supply air channel20, as described in example 1, is not sufficient anymore in order to heat up the rooms44,46,48. In this case, the first supply air channel20which comprises a lower heating power because of the smaller heating register34and because of the lower maximum supply air volume stream, can be closed. The second supply air channel22which has a higher heating power as compared to the First supply air channel20, is opened, i.e. the flaps74are opened. The flaps54and24of the first supply air channel20are closed. The heating register34of the first supply air channel20is also closed. The heating register60of the second supply air channel22is opened.

There is, for example, an outside temperature of −20° C. All rooms44,46,48have an increased heating demand. In this case, it may be that the heating power of the second supply air channel22with the heating register60provided therein, is not sufficient in order to heat up the rooms44,46,48. Now, the first supply air channel20is additional opened in which the flaps54and24are opening up and the heating register34is also opening up.

In case of a reduction of the heating power, the channels may be controlled down in analogy to the examples 1 to 3. The switching of the supply air channels20,22according to the examples 1 to 3 is used in analogy in case of cooling. In the rooms44,46,48, there is a cooling demand everywhere. The same is true for the case of cooling.

The invention is characterized with respect to the previously known state of the art in that the temperature in the two supply air channels20,22can vary extremely each, for example from 12° C. to 45° C. Furthermore, also the respective supply air quantity can vary from a minimum, i.e. the minimum fresh air supply in the respective rooms, to a maximum, i.e. the maximum heating or cooling or moistening or de-moistening.

According to an embodiment of the invention, the first supply air channel20may comprise a smaller cross-sectional area than the second supply air channel22. Thereby, differing amounts of air may be supplied in both supply air channels20,22to the rooms44,46,48. This is important in particular for differing heating and/or cooling demand.

In case the cooling demand or the heating demand is very high in the rooms44,46,48as has been described above with reference to the examples 1 to 3, the supply air channel22having the larger cross-sectional area, is activated. In case the cooling or heating demand is lower, the supply air channel20having the smaller cross-sectional area, is activated.

However, it is now also possible that a mixed operation takes place, i.e. that one or the other of the rooms44,46,48is cooled or one or the other of the rooms44,46,48is heated respectively. Depending on the larger cooling demand or heating demand for the room44,46,48, the larger supply air channel, i.e. the second supply air channel22is activated for the cooling or heating demand, and, correspondingly, the first supply air channel20is activated at a lower supply air volume for the cooling or heating demand.

For example in winter time, the second supply air channel22is a hot air channel, i.e. the rooms44,46,48are heated by this channel. The first supply air channel20having the smaller supply air volume, is activated for cooling, i.e. the rooms44,46,48are cooled through this supply air channel20on demand.

In summer time, the second supply air channel22having the larger supply air volume, is, for example, than the cooling channel, and the first supply air channel20having the smaller supply air volume, is the heating channel. Correspondingly, the rooms44,46,48are cooled or heated through one or the other channel.

Among others, the temperature value of the temperature sensor38in the first supply air channel20as well as the temperature value of the temperature sensor64in the second supply air channel22are used for opening and closing the respectively assigned flaps54,72in the first or the second supply air channel20or22. In case cooling or heating takes place in both supply air channels20,22, the flaps54,72associated each to the supply air channels20,22, are opened or closed pro-rata. In case both channels have the same supply air temperature, the flap positions of the flaps54,72are the same for the respective room44,46,48. This means that, at high heating/cooling demand, both flaps are opened to 100%, in case the heating/cooling demand is essentially covered, the flaps are, for example opened only to 30%. The opening values of the flaps may vary from one room to the other.

In analogy to the heating and cooling case of the rooms44,46,48, the supply air channels can also be activated and de-activated for moistening and de-moistening.

According to the invention, it is now possible that the valve units54,72may be adjusted independently from each other. Thereby, far reaching possibilities are resulting. For example, it is now possible that the maximal possible supply air from the one channel as well as from the other channel is let into the room to be climate controlled in order to allow a fast heating or cooling, for example. Thereby, the flexibility of the system but also the reaction speed may be increased. Preferably, one of the factors pressure, temperature, moisture, density in the supply air channel may be adjusted independently from the respective factor in the other supply air channel.

It is also a further aspect that, by decoupling the valve units, an on demand supply of at least one supply air channel20,22with a further one-channel system provided upstream, is possible. By means of the independently adjustable valve units54,72, pressure variations incurred, can be balanced.

LIST OF REFERENCE SIGNS

10two-channel air-conditioner12central supply air channel14supply air motor16heating register18temperature sensor20first supply air channel22second supply air channel24flap in the first supply air channel26motor in the first supply air channel28flap in the second supply air channel30motor in the second supply air channel32cooling register34heating register36moistening device38temperature sensor40moisture sensor42pressure sensor44room to be climate controlled46room to be climate controlled48room to be climate controlled50branch channel of the first supply air channel52air inlet in the room to be climate controlled, air inlet device54flap in the first branch channel56motor for the flap in the first branch channel58cooling register60heating register62moistening device64temperature sensor66moisture sensor68pressure sensor70second branch channel72flap in the second branch channel74motor for the flap in the second branch channel76temperature sensor78moisture sensor80air quality sensor