Method and means for heating buildings in a district heating system with waste heat from a thermal power plant

Claim 3

A method, as set forth in claim 1, including the further steps of using air as the fluid medium, passing the heated air from the enclosed heat exchange zone through enclosed flow paths to the individual rooms in the building, heating the rooms with the heated air, and withdrawing the heated air and discharging it to the atmosphere.

Claim 4

A method, as set forth in claim 2, including the steps of providing an outlet to the atmosphere for the air from the enclosed flow paths prior to introducing the heated air into the individual rooms, and regulating the flow of heated air after it leaves the heat exchange zone so that an amount of air not required for heating the individual rooms can be discharged to the atmosphere.

Claim 5

A method, as set forth in claim 1, including the further steps of using water as the fluid medium for heating the individual rooms, circulating the heated water after its passage through the enclosed heat exchange zone through heat transfer members in the individual rooms for heating the air therein, and withdrawing the heated air from the individual rooms for discharging excess heat to the atmosphere.

Claim 6

A method, as set forth in claim 1, including the steps of varying the thermal power supplied to the district heating system by varying the quantity of water circulated in heat exchange relation with the steam, and automatically controlling the temperature in the individual rooms of the building by maintaining a desired temperature within the individual rooms.

Claim 7

A method, as set forth in claim 5, including the step of varying the temperature of the water after its passage in heat exchange relation with the steam.

Claim 8

A method, as set forth in claim 5, including the step of varying the temperature of the water prior to its passage in heat exchange relation with the steam.

Claim 9

A method as set forth in claim 1, including the steps of varying the tHermal power supplied to the district heating system from the power station by adjusting one of the pressure and temperature conditions of the water supplied to the enclosed heat exchange zone after its passage in heat exchange relation with the steam from the power station, and monitoring the adjusted conditions.

Claim 10

A method, as set forth in claim 8, including the steps of monitoring the pressure of the heated water flowing to the enclosed heat exchange zone, and increasing the supply of water to the heat exchange zone to a maximum value when the monitored pressure reaches a predetermined value.

Claim 11

A method, as set forth in claim 9, including the step of selecting a predetermined pressure for each building in the district heating system in accordance with the relative pressure conditions effecting the building and the pressure conditions in the flow path for recirculating the water into heat transfer relation with the steam from the power station.

Claim 12

A method, as set forth in claim 1, including the steps of setting a minimum limit for the thermal power supplied to the district heating plant by the power station, and monitoring the ambient temperature for adjusting the thermal power supplied to the district heating system for assuring an adequate amount of heat for the buildings in the district heating system.

Claim 13

A method, as set forth in claim 3, including the steps of automatically controlling the quantity of air taken into the building at a minimum level, monitoring the amount of hot air discharged from the building to the atmosphere, and adjusting the amount of air taken into the building in accordance with the amount of hot air discharged from the building.

Claim 14

A method, as set forth in claim 3, including the steps of preheating the air supplied to the enclosed heat exchange zone by passing the air in indirect heat transfer relation with hot air being discharged from the building.

Claim 15

A method, as set forth in claim 13, including the step of admitting the air to be heated in the heat exchange zone at a location downstream from the location of the preheating step.

Claim 16

A method, as set forth in claim 14, including the steps of monitoring the atmospheric temperature, and cutting out the preheating step when the atmospheric temperature rises above a certain value while maintaining the water circulating to the enclosed heat exchange zone in the building at a certain value.

Claim 17

A method, as set forth in claim 3, including the steps of withdrawing a substantially constant flow of air from each building in the district heating system, supplying heating air and atmospheric air to each of the rooms, regulating the supply of heating air and atmospheric air into each room by thermostatically monitoring the air in each room, flowing a substantially constant amount of air through the heat exchange zone in each building and releasing the difference between the flow of air through the enclosed heat exchange zone and the flow of air withdrawn from each building prior to supplying the heated air from the heat exchange zone to the individual rooms in the building.

Claim 18

A method, as set forth in claim 8, including the steps of limiting the pressure of the heated water supplied to the heat exchange zone by communicating the heated water with an open container and controlling the flow of the heated water through the heat exchange zone.

Claim 19

A method, as set forth in claim 8, wherein the step of controlling the flow of the heated water is carried out by monitoring the temperature conditions of the hot water flowing to the heat exchange zone.

Claim 20

A method, as set forth in claim 17, wherein the step of controlling the flow of the heated water is carried out by monitoring the pressure conditions of the heated water flowing to the heat exchange zone.

Claim 21

A method, as set forth in claim 3, including the step of accumulating the water flowing in the district heating system to and from heat exchange with the steam from the power station.

Claim 22

District heAting system including a plurality of buildings containing individual rooms to be heated, comprising a thermal power plant utilizing steam to generate electricity and including a first heat exchanger arranged to receive the steam after it has been used in generating electricity for transferring waste heat from the steam, distribution pipes connected to said first heat exchanger for flowing water from said first heat exchanger after it has passed in heat transfer relation with the steam to the buildings in the district heating system, and return pipes for recirculating the water from the buildings to the first heat exchanger, wherein the improvement comprises a second heat exchanger located in each building, said distribution pipes and return pipes connected to said second heat exchanger for circulating the heated water therethrough, conduit means connected to said second heat exchanger for flowing air therethrough in indirect heat transfer relation with the heated water, first channels connected to said second heat exchanger for conveying heated air to individual rooms in the building, and a second channel connected to said first channels upstream from the point at which they supply air to the individual rooms for conveying heated air to the atmosphere.

Claim 23

District heAting system including a plurality of buildings containing individual rooms to be heated, comprising a thermal power plant utilizing steam to generate electricity and including a first heat exchanger arranged to receive the steam after it has been used in generating electricity for transferring waste heat from the steam, distribution pipes connected to said first heat exchanger for flowing water from said first heat exchanger after it has passed in heat transfer relation with the steam to the buildings in the district heating system, and return pipes for recirculating the water from the buildings to the first heat exchanger, wherein the improvement comprises a second heat exchanger located in each building, said distribution pipes and return pipes connected to said second heat exchanger for circulating the heated water therethrough, conduit means connected to said second heat exchanger for flowing air therethrough in indirect heat transfer relation with the heated water, first channels connected to said second heat exchanger for conveying heated air to individual rooms in the building, and a second channel connected to said first channels upstream from the point at which they supply air to the individual rooms for conveying heated air to the atmosphere.

Claim 24

District heating system, as set forth in claim 21, wherein thermostatically controlled dampers are positioned at the inlet ends of said first channels opening into the individual rooms for regulating the quantity of heated air supplied into the rooms.

Claim 25

District heating system, as set forth in claim 22, wherein third channels are connected to the individual rooms in the building for supplying atmospheric air into the rooms, and a thermostatically controlled damper arranged in each of said third channels for regulating the quantity of atmospheric air supplied into the rooms.

Claim 26

District heating system, as set forth in claim 21, wherein a air preheater is positioned in the path of the air flowing into said second heat exchanger, and air flow conduits connected to the individual rooms in the building and to said preheater for flowing air removed from the individual rooms through the preheater in indirect heat transfer relation with the air being directed into said second heat exchanger.

Claim 27

District heating system, as set forth in claim 21, wherein an open supply tank is connected in said distribution pipes for supplying heated water to said second heat exchanger for maintaining the water pressure in the second heat exchanger constant, flow control means located in said return pipes between said second and first heat exchangers, and means located in said second channel and connected to said flow control means for regulating said flow control means in accordance with at least one of the temperature and pressure conditions of the air flowing through said second channel.

Claim 28

District heating system, as set forth in claim 25, wherein means are arranged for controlling the pressure of the heated water in said distribution pipes, and means for monitoring the pressure of the heated water in said distribution pipes and connected to said flow control means for regulating said flow control means for producing a maximal flow in said return flow pipes.

Claim 29

District heating system, as set forth in claim 26, wherein said means for monitoring the pressure in said distribution pipes in different buildings are set to operate at different pressures.