Background technology
The zone central cooling is owing to have the energy use efficiency height, and environmental thermal pollution is low, can effectively reduce advantages such as place capacity and minimizing machine room floor space, just worldwide promotes the use of fast, has become the importance of modern air conditioning development.But in the present regional central cooling system, its secondary cold switching station cold is regulated and is remained in following management and technical problem, makes all advantages of regional central cooling system fail to be not fully exerted and better embodiment:
(1) Subscriber Unit is difficult on the whole to regulating with cold: at present, zone central cooling secondary cold exchange station equipment belongs to not all and the management of commensurate of two families, wherein secondary cold switching station plate type heat exchanger primary side equipment and secondary side leaving water temperature belong to the management control of district cooling unit of operation, secondary cold switching station plate exchanger secondary side equipment belongs to Subscriber Unit management control, Subscriber Unit can't be to adjusting with the freezing supply water temperature of cold building owing to having no right heat-exchangers of the plate type primary side flow of inlet water is regulated and control;
(2) when regional central cooling does not have well-found automatic building control system with cold building, equipment management personnel is difficult to change and inner refrigeration duty changes terminal air-conditioning equipment operational factor adjusted and (began to advocate the summer indoor temperature in 2005 as country and must not be lower than 26 ℃ according to outdoor temperature humidity, but major part can't satisfy this requirement with cold building owing to end-equipment lacks scientific and reasonable control device), in the case, because the leaving water temperature of secondary cold switching station plate exchanger secondary side is pressed constant temperature water supply control by the district cooling operating organization, supply water temperature adopts usually with cold building air conditioning design parameter (i.e. 7 ℃ of supply water temperatures), make that indoor temperature and humidity usually occurring with cold building interior crosses low phenomenon, cause a large amount of cold wastes;
(3) when being lower than the design load with the terminal air-conditioning equipment refrigeration duty of cold building, because secondary cold switching station plate exchanger secondary side adopts constant temperature water supply, and limit owing to factors such as being subjected to pipe network hydraulic equilibrium and minimum confession backwater pressure reduction with the freezing water supply flow of cold building, in the time of can not being varied to the ratio adjusting with refrigeration duty, supply backwater temperature difference usually occurring reduces, it is usually said " big flow; the little temperature difference " phenomenon, the plate exchanger secondary side return water temperature reduces, and then make the primary side leaving water temperature reduce, the Inlet and outlet water temperature difference reduces, zone central cooling pipe network can't be realized the big temperature difference (design is generally about 10 ℃), low discharge supplies water, cause cooling pipe network pump energy consumption to increase, the loss of cold course of conveying increases.
(4) under dry climatic condition, since low excessively with cold building cooling pipe network water supply temperature, make indoor environment humidity low excessively, and central air conditioner system latent heat energy consumption increases.
Summary of the invention
The objective of the invention is to overcome the shortcoming and defect of above-mentioned existing management and technology, regional central cooling secondary cold switching station cold regulating system is provided, it can increase substantially with freezing supply water temperature of cold building and secondary cold switching station plate exchanger secondary side return water temperature, realization is to the integral body regulation and control with cold building cooling amount, reduce with cold building cold consumption and unnecessary waste under sub-load, effectively avoid humiture occurring and cross low phenomenon with cold building interior refrigerated area, make secondary cold switching station plate type heat exchanger primary side leaving water temperature improve simultaneously, the Inlet and outlet water temperature difference increases, flow reduces, thereby make the consumption of district cooling pump power reduce, cooling pipeline loss of refrigeration capacity reduces.
The present invention also aims to provide the control method that adopts above-mentioned zone central cooling secondary cold switching station cold regulating system.
Purpose of the present invention is achieved through the following technical solutions: one's respective area central cooling secondary cold switching station cold regulating system comprises secondary cold switching station controller and the remote monitoring computer that connects respectively by converter thereof, local monitor computer; Secondary cold switching station controller by the analog quantity input module with cold building cooling pipe network water supply temperature sensor, with cold building cooling pipe network return water temperature sensor, with cold building cooling pipe network frequency conversion water circulating pump, supply the backwater differential pressure pickup with cold building cooling pipe network, the outdoor environment Temperature Humidity Sensor connects, pass through digital quantity input module respectively, analog output module, the digital quantity output module be connected with cold building cooling pipe network frequency conversion water circulating pump, secondary cold switching station controller is also respectively by the analog quantity input module, analog output module is connected with secondary cold switching station plate exchanger secondary side circling water flow rate control valve, secondary cold switching station plate exchanger secondary side circling water flow rate bypass regulator valve.
Adopt the control method of one's respective area central cooling secondary cold switching station cold regulating system, its step comprises:
(1) chooses with the most representative refrigerated area of cold building and terminal air-conditioning equipment, the constant parameter of the terminal air-conditioning equipment of representative refrigerated area is deposited in the data field of secondary cold switching station controller by remote monitoring computer or local monitor computer;
(2) in secondary cold switching station system running, representative refrigerated area humiture setting value is input to the data field of secondary cold switching station controller by remote monitoring computer or local monitor computer, secondary cold switching station controller is constantly gathered with cold building outdoor environment humiture value by the analog quantity input module, and in conjunction with indoor temperature and humidity setting value, carry out corresponding calculation process, obtain the required freezing supply water temperature value of the terminal air-conditioning equipment of the cold building of current usefulness with the variation of personnel amount in the cold building;
(3) serve as the control target with this required freezing supply water temperature value, keep with the freezing water supply total flow of the terminal air-conditioning equipment of cold building constant, and under the prerequisite of secondary cold switching station plate exchanger secondary side effluent temperature constancy, the cold switching station controller of secondary is regulated secondary cold switching station plate exchanger secondary side circling water flow rate and bypass flow ratio by analog output module, use the freezing supply water temperature of the terminal air-conditioning equipment of cold building to equate, realize adjusting with the freezing supply water temperature of the terminal air-conditioning equipment of cold building with required freezing supply water temperature value;
(4) when causing with the terminal air-conditioning equipment number change of cold building when changing with the freezing water supply total flow of the terminal air-conditioning equipment of cold building, secondary cold switching station controller moves platform number and frequency by digital quantity output and analog output module adjustment with cold building cooling pipe network frequency conversion water circulating pump, keep freezing constant, realize adjusting with the freezing water supply total flow of the terminal air-conditioning equipment of cold building for backwater pressure reduction with cold building cooling pipe network.
The step of described adjusting secondary cold switching station plate exchanger secondary side circling water flow rate and bypass flow ratio comprises:
(1) improves when the indoor temperature and humidity setting value is whole, the outdoor environment humiture reduces or reduces with personnel amount in the cold building, cause the whole reduction of terminal air-conditioning equipment refrigeration duty, when need improving the freezing supply water temperature of the terminal air-conditioning equipment of the cold building of current usefulness, with current required freezing supply water temperature value is the control target, secondary cold switching station controller reduces secondary cold switching station heat-exchangers of the plate type secondary side circling water flow rate control valve opening by analog output module, secondary cold switching station heat-exchangers of the plate type secondary side circling water flow rate is reduced, plate type heat exchanger heat exchange amount reduces, secondary cold switching station controller increases secondary cold switching station heat-exchangers of the plate type secondary side circling water flow rate bypass regulator valve aperture by analog output module simultaneously, use the freezing water supply total flow of the terminal air-conditioning equipment of cold building to remain unchanged, equate with required freezing supply water temperature value with the freezing supply water temperature of the terminal air-conditioning equipment of cold building;
(2) reduce when the indoor temperature and humidity setting value is whole, the outdoor environment humiture raises or increases with personnel amount in the cold building, cause the whole increase of terminal air-conditioning equipment refrigeration duty, when needing to reduce with the freezing supply water temperature of the terminal air-conditioning equipment of cold building, with current required freezing supply water temperature value is the control target, secondary cold switching station controller strengthens secondary cold switching station heat-exchangers of the plate type secondary side circling water flow rate control valve opening by analog output module, secondary cold switching station heat-exchangers of the plate type secondary side circling water flow rate is increased, plate type heat exchanger heat exchange amount increases, secondary cold switching station controller reduces secondary cold switching station heat-exchangers of the plate type secondary side circling water flow rate bypass regulator valve aperture by analog output module simultaneously, use the freezing water supply total flow of the terminal air-conditioning equipment of cold building to remain unchanged, equate with required freezing supply water temperature value with the freezing supply water temperature of the terminal air-conditioning equipment of cold building.
The present invention compared with prior art has following advantage and beneficial effect:
(1) solved under existing regional central cooling secondary cold switching station plate exchanger secondary side constant temperature water supply management control mode, when reducing, because the terminal air-conditioning equipment management control low excessively cold waste problem that causes of refrigerated area humiture that causes not in place with the terminal air-conditioning equipment refrigeration duty of cold building;
(2) under with the terminal air-conditioning equipment sub-load of cold building condition, increased substantially with freezing supply water temperature of cold building and secondary cold switching station plate exchanger secondary side return water temperature, make that plate type heat exchanger primary side flow of inlet water reduces, leaving water temperature reduces, ensured the realization of the district cooling pipe network big temperature difference, Small Flow Control target, the district cooling pump energy consumption is reduced, and outdoor pipe network loss of refrigeration capacity reduces;
(3) under the open-air seasoning weather conditions, owing to improve, can effectively reduce indoor moisture loss with cold building cooling pipe network water supply temperature, avoid ambient humidity low excessively, improve environmental degree of comfort, reduce the consumption of air-conditioning system latent heat load cold simultaneously.
The specific embodiment
Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention are not limited thereto.
Embodiment one
As shown in Figure 1, traditional regional central cooling secondary cold switching station is by secondary cold switching station plate type heat exchanger 1, secondary cold switching station plate type heat exchanger primary side supply water temperature sensor 2, secondary cold switching station plate type heat exchanger primary side leaving water temperature sensor 3, secondary cold switching station plate type heat exchanger primary side water supply flow control valve 4, secondary cold switching station heat-exchangers of the plate type primary side water supply flow meter 5, secondary cold switching station plate exchanger secondary side leaving water temperature sensor 6, with cold building cooling pipe network water supply temperature sensor 7, with cold building cooling pipe network return water temperature sensor 8, with cold building cooling pipe network frequency conversion water circulating pump 9, interconnect composition with cold building cooling pipe network for backwater differential pressure pickup 10.
As shown in Figure 2, adopt the regional central cooling secondary cold switching station of the present invention zone central cooling secondary cold switching station cold regulating system, it is equipped with secondary cold switching station plate exchanger secondary side circling water flow rate control valve 11, secondary cold switching station plate exchanger secondary side circling water flow rate bypass regulator valve 12.
As shown in Figure 3, one's respective area central cooling secondary cold switching station cold regulating system is that RS232/485, converter 17 are that RS232/ (TCP/IP) is connected and forms with local monitor computer 16, remote monitoring computer 18 by converter 15 respectively by secondary cold switching station controller 13; Secondary cold switching station controller 13 by the analog quantity input module with cold building cooling pipe network water supply temperature sensor 7, with cold building cooling pipe network return water temperature sensor 8, with cold building cooling pipe network frequency conversion water circulating pump 9, supply backwater differential pressure pickup 10 with cold building cooling pipe network, outdoor environment Temperature Humidity Sensor 14 connects, pass through digital quantity input module respectively, analog output module, the digital quantity output module be connected with cold building cooling pipe network frequency conversion water circulating pump 9, secondary cold switching station controller 13 is also respectively by the analog quantity input module, analog output module is connected with secondary cold switching station plate exchanger secondary side circling water flow rate control valve 11, secondary cold switching station plate exchanger secondary side circling water flow rate bypass regulator valve 12.
Adopt the adjustment process of one's respective area central cooling secondary cold switching station cold regulating system to be:
(1) chooses with the most representative refrigerated area of cold building and terminal air-conditioning equipment, the constant parameter of the terminal air-conditioning equipment of representative refrigerated area is deposited in the data field of secondary cold switching station controller 13 by remote monitoring computer 18 or local monitor computer 16;
(2) in secondary cold switching station system running, representative refrigerated area humiture setting value is input to the data field of secondary cold switching station controller 13 by remote monitoring computer 18 or local monitor computer 16, secondary cold switching station controller 13 is constantly gathered with cold building outdoor environment humiture value by the analog quantity input module, and in conjunction with indoor temperature and humidity setting value, carry out corresponding calculation process, obtain the required freezing supply water temperature value of the terminal air-conditioning equipment of the cold building of current usefulness with the variation of personnel amount in the cold building;
With the required freezing supply water temperature computational methods of the terminal air-conditioning equipment of cold building be:
Mainly comprise with cold architecture indoor refrigeration duty: room conduction heat, house interior produce heat, absorption chamber outer air heat, other refrigeration dutys.Wherein:
1) room conduction heat: heat is transmitted to indoor by metope, window face, it is influenced by the indoor and outdoor climate parameter jointly, and computing formula is as follows:
Wall load: Q
Wall=K
WallF
Wall(t
w-t
n),
Forms temperature difference load: Q
Window t=K
WindowF
Window(t
w-t
n),
Forms radiation load: Q
Window f=C
aF
WindowC
sD
JmaxC
LQ
2) heat that produces in the room: comprise human-body radiating, light heat radiation, electromechanical equipment heat radiation.Human-body radiating Q wherein
The people=heat gain from occupant * room number, this sub-load changes with occupancy.
3) suction chamber outer air heat: this part heat is divided into sensible heat and latent heat, is formulated as:
Sensible heat: Q
Show=1.2 (t
w-t
n) V
Newly,
Latent heat: Q
Dive=3000 (d
w-d
n) V
Newly,
This sub-load also depends on the state parameter of indoor-outdoor air.
Each alphabetical meaning in the above formula:
K
Wall, K
Window----is respectively body of wall and window heat transfer coefficient,
F
Wall, F
Window----is respectively body of wall and window areas,
t
w, t
n----is respectively outdoor, indoor temperature,
d
w, d
n----is respectively outdoor, indoor water capacity,
V
Newly----resh air requirement,
C
a----effective area coefficient,
C
s----windowpane comprehensively block coefficient,
C
Jmax----insolation gets the maximum of thermal factor,
C
LQThe refrigeration duty coefficient of----exterior window,
Calculate and can draw by above formula:
1), can similarly calculate with the current actual refrigeration duty Q of the terminal air-conditioning equipment of cold building by inspection side room external environment humiture when one timing of indoor temperature and humidity controlling value
1
2) certain when outdoor temperature humidity side value, when adjusting the indoor temperature and humidity setting value, also can similarly calculate with the current actual refrigeration duty Q of the terminal air-conditioning equipment of cold building
1
With Q
1The freezing inflow temperature computing formula of the terminal air-conditioning equipment of substitution can obtain under above-mentioned two kinds of conditions with the required freezing supply water temperature value of the terminal air-conditioning equipment of cold building:
t
S1, t
S0Air conditioner end equipment air intlet wet-bulb temperature under----expression actual condition and the standard condition,
t
W1, t
W10Freezing supply water temperature under----expression actual condition and the standard condition,
Q
1, Q
0The refrigeration duty of----expression actual condition and standard condition lower end equipment,
T wherein
S1Determine jointly that by indoor return air and outdoor new wind its actual work condition state parameter draws by following two formula and correlation computations:
i
w, i
n----is respectively outdoor, indoor enthalpy
V----air conditioner end equipment air quantity
i
1, d
1----air conditioner end equipment air intlet enthalpy and water capacity
Result of calculation substitution psychrometric chart is calculated t
S1, and then draw under the current state with the required freezing supply water temperature value t of the terminal air-conditioning equipment of cold building
W1
(3) serve as the control target with this required freezing supply water temperature value, keep with the freezing water supply total flow of the terminal air-conditioning equipment of cold building constant, and under the prerequisite of secondary cold switching station plate exchanger secondary side effluent temperature constancy, the cold switching station controller 13 of secondary is regulated secondary cold switching station plate exchanger secondary side circling water flow rate and bypass flow ratio by analog output module, use the freezing supply water temperature of the terminal air-conditioning equipment of cold building to equate, realize adjusting with the freezing supply water temperature of the terminal air-conditioning equipment of cold building with required freezing supply water temperature value;
(4) when causing with the terminal air-conditioning equipment number change of cold building when changing with the freezing water supply total flow of the terminal air-conditioning equipment of cold building, secondary cold switching station controller 13 is by digital quantity output and analog output module adjustment operation platform number and the frequency with cold building cooling pipe network frequency conversion water circulating pump 9, keep freezing constant, realize adjusting with the freezing water supply total flow of the terminal air-conditioning equipment of cold building for backwater pressure reduction with cold building cooling pipe network.
The adjustment process of above-mentioned secondary cold switching station plate exchanger secondary side circling water flow rate and bypass flow ratio is meant:
(1) improves when the indoor temperature and humidity setting value is whole, the outdoor environment humiture reduces or reduces with personnel amount in the cold building, cause the whole reduction of terminal air-conditioning equipment refrigeration duty, when need improving the freezing supply water temperature of the terminal air-conditioning equipment of the cold building of current usefulness, with current required freezing supply water temperature value is the control target, secondary cold switching station controller 13 reduces secondary cold switching station heat-exchangers of the plate type secondary side circling water flow rate control valve 11 apertures by analog output module, secondary cold switching station heat-exchangers of the plate type secondary side circling water flow rate is reduced, plate type heat exchanger heat exchange amount reduces, secondary cold switching station controller 13 increases secondary cold switching station heat-exchangers of the plate type secondary side backwater bypass regulator valve 12 apertures by analog output module simultaneously, use the freezing water supply total flow of the terminal air-conditioning equipment of cold building to remain unchanged, equate with required freezing supply water temperature value with the freezing supply water temperature of the terminal air-conditioning equipment of cold building;
(2) reduce when the indoor temperature and humidity setting value is whole, the outdoor environment humiture raises or increases with personnel amount in the cold building, cause the whole increase of terminal air-conditioning equipment refrigeration duty, when needing to reduce with the freezing supply water temperature of the terminal air-conditioning equipment of cold building, with current required freezing supply water temperature value is the control target, secondary cold switching station controller 13 strengthens secondary cold switching station heat-exchangers of the plate type secondary side circling water flow rate control valve 11 apertures by analog output module, secondary cold switching station heat-exchangers of the plate type 1 secondary side circling water flow rate is increased, plate type heat exchanger heat exchange amount increases, secondary cold switching station controller 13 reduces secondary cold switching station heat-exchangers of the plate type secondary side backwater bypass regulator valve 12 apertures by analog output module simultaneously, use the freezing water supply total flow of the terminal air-conditioning equipment of cold building to remain unchanged, equate with required freezing supply water temperature value with the freezing supply water temperature of the terminal air-conditioning equipment of cold building.
As mentioned above, just can realize the present invention preferably.