System and method for cascade utilization of cold and heat in air conditioning water system

Abstract

The present invention relates to a system and method for cascade utilization of cold and heat in an air-conditioning water system. It solves the technical problems of unreasonable utilization of existing air-conditioning water systems. It comprises a heat pump unit, one end of which is respectively connected in parallel with a circulating water pump I and a circulating water pump II, the circulating water pump I and the circulating water pump II are both connected to a water distributor, the other end of the heat pump unit is connected to a water collector, a south area room end and a north area room end are respectively provided between the water distributor and the water collector, and a series-parallel switching structure is provided between the water distributor and the water collector. The advantage is that this operation mode realizes the cascade utilization of cold and heat, thereby avoiding the waste of cold and heat. The sensor is used to monitor the return water temperature and then control the opening and closing of the valve, so as to realize the switching of high and low load conditions of the system, the series-parallel switching of the water system pipelines, and the control of the flow direction of cold and hot water.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy supply equipment, and in particular relates to a system and method for cascading cold and heat utilization of an air-conditioning water system. Background Art

[0002] The HVAC system eliminates the excess heat and cold loads in the room, thereby providing a suitable environment for the indoor personnel. According to statistics, the energy consumption of the HVAC system accounts for about 60% of the building's energy consumption, and its energy-saving potential is huge. Due to the orientation of the building, there is a difference in the load between the south-facing room and the north-facing room. In summer, the direct sunlight increases the heat gain of the south-facing room, making the cold load of the south-facing room greater than that of the north-facing room; while in winter, the radiation received by the north-facing room is relatively less than that of the south-facing room, making the heat load of the south-facing room less than that of the north-facing room. The traditional working mode of the air conditioning water system is that the unit prepares 7 / 12℃ supply and return water to eliminate the terminal load of the room. Relevant literature points out that according to actual engineering measurements, the return water temperature of the air conditioning in some building rooms after terminal heat exchange is only about 10℃, and the water system presents a "large flow, small temperature difference" phenomenon, which undoubtedly causes a waste of cooling capacity. Therefore, how to use the load more reasonably to adjust the working state of the air conditioner is a topic that needs to be studied urgently. Summary of the invention

[0003] The object of the present invention is to provide a cascaded cold and heat utilization system for an air-conditioning water system with a reasonable design and capable of realizing cascaded cold and heat utilization in view of the above problems.

[0004] Another object of the present invention is to provide a method for cascading cold and heat utilization of an air-conditioning water system that is easy to implement and can avoid waste of cold and heat in order to solve the above-mentioned problem.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: the air-conditioning water system cold and heat cascade utilization system includes a heat pump unit, characterized in that one end of the heat pump unit is respectively connected to the circulating water pump I and the circulating water pump II in parallel, the circulating water pump I and the circulating water pump II are both connected to the water distributor, the other end of the heat pump unit is connected to the water collector, the south area room end and the north area room end are respectively provided between the water distributor and the water collector, and the south area room end and the north area room end are arranged opposite to each other, and a series-parallel switching structure is provided between the water distributor and the water collector, which can connect the heat pump unit in parallel with the south area room end and the north area room end respectively, or can connect the heat pump unit, the south area room end and the north area room end in series in sequence.

[0006] In the above-mentioned air-conditioning water system cold and heat cascade utilization system, the series-parallel switching structure includes a stop valve I connected to one end of the north zone room, the stop valve I is connected to a water distributor, the other end of the north zone room is connected to a water collector through a stop valve V, and the end of the north zone room connected to the stop valve I is connected to the water collector through a stop valve III, one end of the south zone room is connected to the water distributor through a stop valve II, the other end of the south zone room is respectively connected in parallel with the stop valve V and the north zone room, and the end of the south zone room connected to the stop valve II is connected to the water collector through a stop valve IV.

[0007] In the above-mentioned air-conditioning water system cold and heat cascade utilization system, a temperature sensor I is provided at the end of the north zone room connected to the water collector.

[0008] In the above-mentioned air-conditioning water system cold and heat cascade utilization system, a temperature sensor II is provided at the end of the south zone room connected to the water collector.

[0009] Preferably, the stop valve I, stop valve II, stop valve III, stop valve IV and stop valve V are sequentially connected and respectively connected to the MCU module, and the circulating water pump I and circulating water pump II are both connected to the MCU module. The temperature sensor I and the temperature sensor II are respectively connected to the MCU module.

[0010] The air conditioning water system cold and heat cascade utilization method of the air conditioning water system cold and heat cascade utilization system is as follows: The air conditioning water system cold and heat cascade utilization method comprises the following steps:

[0011] A. Summer working condition: When the building is under low load, the heat pump unit, the south room terminal and the north room terminal are connected in series in sequence through the series-parallel switching structure. When the building is under high load, the heat pump unit is connected in parallel with the south room terminal and the north room terminal respectively through the series-parallel switching structure.

[0012] B. Winter working conditions: When the building is under low load, the heat pump unit, the north room terminal and the south room terminal are connected in series in sequence through a series-parallel switching structure. When the building is under high load, the heat pump unit is connected in parallel with the south room terminal and the north room terminal respectively through a series-parallel switching structure.

[0013] In the above-mentioned method for cascade utilization of cold and heat of the air-conditioning water system, in step A, when the building is under low load, under this working condition, stop valve I is closed, stop valve II is opened, stop valve III is opened, stop valve IV is closed, and stop valve V is closed, and the end of the room in the south area and the end of the room in the north area are in a series state; the chilled water generated by the heat pump unit is first transported to the end of the room in the south area through the circulating water pump II through the water distributor, and the chilled water after eliminating the load of the room in the south area flows to the end of the room in the north area, and finally returns to the heat pump unit through the water collector.

[0014] In the above-mentioned method for cascade utilization of cold and heat of the air-conditioning water system, in step A, when the building load increases, the stop valve I, stop valve V, and circulating water pump I are controlled to be opened, and the stop valve III is controlled to be closed. The end of the room in the south area and the end of the room in the north area, which were originally in a series state, are changed to a parallel state. The chilled water generated by the heat pump unit passes through the parallel water pump through the water distributor to form two north and south branches. After eliminating the room load of each branch, the water is returned to the heat pump unit after merging into the water collector by opening the stop valve V. Under this working condition, the valve status is that the stop valve I is open, the stop valve II is open, the stop valve III is closed, the stop valve IV is closed, and the stop valve V is open.

[0015] In the above-mentioned method for cascade utilization of cold and heat of the air-conditioning water system, in step B, when the building is under low load, under this working condition, stop valve I is open, stop valve II is closed, stop valve III is closed, stop valve IV is open, and stop valve V is closed, the end of the room in the south area and the end of the room in the north area are in series connection, and the hot water generated by the heat pump unit is first transported to the end of the room in the north area through the circulating water pump I through the water distributor, and the hot water after eliminating the load of the room in the north area flows to the end of the room in the south area, and finally returns to the heat pump unit through the water collector.

[0016] In the above-mentioned method for cascade utilization of cold and heat of the air-conditioning water system, in step B, when the building load increases, the stop valve II, stop valve V, and circulating water pump II are controlled to be opened, and the stop valve IV is controlled to be closed. The end of the room in the south area and the end of the room in the north area, which were originally in a series state, are changed to a parallel state. The hot water generated by the heat pump unit is formed into two north-south branches through the parallel water pump through the water divider. After eliminating the room load of each branch, the hot water is returned to the heat pump unit after merging into the water collector by opening the stop valve V. Under this working condition, the valve status is that the stop valve I is open, the stop valve II is open, the stop valve III is closed, the stop valve IV is closed, and the stop valve V is open.

[0017] In the above-mentioned method for cascade utilization of cold and heat of the air-conditioning water system, in step A, when the building load increases, the temperature sensor II behind the room end of the south zone senses that the return water temperature increases, and then controls the stop valve I, stop valve V, and circulating water pump I to open, and controls the stop valve III to close; in step B, when the building load increases, the temperature sensor I behind the room end of the north zone senses that the return water temperature decreases, and then controls the stop valve II, stop valve V, and circulating water pump II to open, and controls the stop valve IV to close.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] 1. This operation mode realizes the cascade utilization of cold and heat: in summer or winter working conditions, the low-temperature chilled water or high-temperature hot water prepared by the unit will first pass through the end of the south room or the end of the north room with a higher load, and then pass through the end of the north room or the end of the south room with a lower load after heat exchange, thereby avoiding the waste of cold and heat.

[0020] 2. The sensor is used to monitor the return water temperature and then control the opening and closing of the valve, realizing the switching of high and low system load conditions, the series and parallel switching of the water system pipelines, and controlling the flow direction of hot and cold water. The operation is convenient, simple and fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the series connection state in the summer operation mode of the present invention;

[0022] Figure 2 It is a schematic diagram of the structure of the parallel state in the winter and summer operation modes of the present invention;

[0023] Figure 3 It is a schematic diagram of the structure of the series connection state in the winter operation mode of the present invention;

[0024] In the figure, heat pump unit 1, water distributor 2, water collector 3, south area room terminal 4, north area room terminal 5, circulating water pump Ⅰ6, circulating water pump Ⅱ7, temperature sensor Ⅱ8, temperature sensor Ⅰ9, stop valve Ⅰ10, stop valve Ⅱ11, stop valve Ⅲ12, stop valve Ⅳ13, stop valve Ⅴ14. DETAILED DESCRIPTION

[0025] like Figure 1-3 As shown, the cold and heat cascade utilization system of the air-conditioning water system comprises a heat pump unit 1, one end of the heat pump unit 1 is respectively connected to the circulating water pump I6 and the circulating water pump II7 in parallel, the circulating water pump I6 and the circulating water pump II7 are both connected to the water distributor 2, the other end of the heat pump unit 1 is connected to the water collector 3, a south area room terminal 4 and a north area room terminal 5 are respectively provided between the water distributor 2 and the water collector 3, and the south area room terminal 4 and the north area room terminal 5 are arranged oppositely, and a series-parallel switching structure is provided between the water distributor 2 and the water collector 3, which can connect the heat pump unit 1 in parallel with the south area room terminal 4 and the north area room terminal 5 respectively, or can connect the heat pump unit 1, the south area room terminal 4 and the north area room terminal 5 in series in sequence.

[0026] Specifically, the series-parallel switching structure here includes a stop valve I10 connected to one end of the north zone room terminal 5, the stop valve I10 is connected to the water distributor 2, the other end of the north zone room terminal 5 is connected to the water collector 3 through the stop valve V14, and the end of the north zone room terminal 5 connected to the stop valve I10 is connected to the water collector 3 through the stop valve III12, one end of the south zone room terminal 4 is connected to the water distributor 2 through the stop valve II11, the other end of the south zone room terminal 4 is respectively connected to the stop valve V14 and the north zone room terminal 5 in parallel, and the end of the south zone room terminal 4 connected to the stop valve II11 is connected to the water collector 3 through the stop valve IV13. Further, the end of the north zone room terminal 5 connected to the water collector 3 is provided with a temperature sensor I9. Among them, the end of the south zone room terminal 4 connected to the water collector 3 is provided with a temperature sensor II8.

[0027] Preferably, the stop valve I10, stop valve II11, stop valve III12, stop valve IV13 and stop valve V14 are connected in sequence and are respectively connected to the MCU module, and the circulating water pump I6 and circulating water pump II7 are both connected to the MCU module, wherein the temperature sensor I9 and the temperature sensor II8 are respectively connected to the MCU module. The sensor is used to monitor the return water temperature and then control the opening and closing of the valve, realizing the switching of high and low load conditions of the system, the series and parallel switching of the water system pipeline, and controlling the flow direction of hot and cold water.

[0028] The operation mode of this system realizes the cascade utilization of cold and heat: in summer (winter) working conditions, the low-temperature chilled water (high-temperature hot water) prepared by the unit is first passed through the end of the south room (the end of the north room) with higher load, and then passed through the end of the north room (the end of the south room) with lower load after heat exchange, thereby avoiding the waste of cold and heat. At the same time, by sensing the return water temperature, the switching of high and low load working conditions is realized. This mode has strong adaptability, flexible and convenient adjustment, and has broad application prospects in the field of building energy conservation.

[0029] The cold and heat cascade utilization method of the air-conditioning water system is divided into two operating modes, summer and winter. Each seasonal operating mode is further divided into two operating modes, series (low load condition) and parallel (high load condition).

[0030] In summer, when the building is under low load, the south room terminal 4 and the north room terminal 5 are in series connection. The chilled water generated by the heat pump unit 1 is first transported to the south room terminal 4 through the circulating water pump II 7 and the water distributor 2. After eliminating the load of the south room, the chilled water flows to the north room terminal 5, and finally returns to the heat pump unit 1 through the water collector 3. In this working condition, the valve status is that the stop valve I 10 is closed, the stop valve II 11 is open, the stop valve III 12 is open, the stop valve IV 13 is closed, and the stop valve V 14 is closed.

[0031] In summer conditions, when the building load increases, the temperature sensor Ⅱ8 behind the south room terminal 4 senses the return water temperature rise, and then controls the stop valve Ⅰ10, stop valve Ⅴ14, and circulating water pump Ⅰ6 to open, and controls the stop valve Ⅲ12 to close. At this time, the south room terminal 4 and the north room terminal 5, which were originally in series, are changed to parallel state. The chilled water generated by the heat pump unit 1 passes through the parallel water pump through the water distributor 2 to form two north and south branches. After eliminating the room load of each branch, it is returned to the heat pump unit 1 after merging to the water collector 3 by opening the stop valve Ⅴ14. The valve status under this condition is that the stop valve Ⅰ10 is open, the stop valve Ⅱ11 is open, the stop valve Ⅲ12 is closed, the stop valve Ⅳ13 is closed, and the stop valve Ⅴ14 is open.

[0032] In winter, when the building is under low load, the south room terminal 4 and the north room terminal 5 are in series connection. The hot water generated by the heat pump unit 1 is first transported to the north room terminal 5 through the circulating water pump Ⅰ6 through the water distributor 2. After eliminating the load of the north room, the hot water flows to the south room terminal 4, and finally returns to the heat pump unit 1 through the water collector 3. Under this condition, the valve status is that the stop valve Ⅰ10 is open, the stop valve Ⅱ11 is closed, the stop valve Ⅲ12 is closed, the stop valve Ⅳ13 is open, and the stop valve Ⅴ14 is closed.

[0033] In winter conditions, when the building load increases, the temperature sensor I9 behind the north room terminal 5 senses that the return water temperature decreases, and then controls the stop valve II11, stop valve V14, and circulating water pump II7 to open, and controls the stop valve IV13 to close. At this time, the south room terminal 4 and the north room terminal 5, which were originally in series, are changed to parallel state. The hot water generated by the heat pump unit 1 passes through the parallel water pump through the water distributor 2 to form two north and south branches. After eliminating the room load of each branch, the hot water is returned to the heat pump unit 1 after merging to the water collector 3 by opening the stop valve V14. The valve status under this condition is that the stop valve I10 is open, the stop valve II11 is open, the stop valve III12 is closed, the stop valve IV13 is closed, and the stop valve V14 is open.

[0034] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0035] Although the terminology such as heat pump unit 1, water distributor 2, water collector 3, south zone room terminal 4, north zone room terminal 5, circulating water pump I 6, circulating water pump II 7, temperature sensor II 8, temperature sensor I 9, stop valve I 10, stop valve II 11, stop valve III 12, stop valve IV 13, stop valve V 14 is used more frequently in this article, the possibility of using other terms is not excluded. The use of these terms is only for more convenient description and explanation of the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A method for cascading cold and heat utilization of an air conditioning water system, comprising a heat pump unit (1), characterized in that: One end of the heat pump unit (1) is connected in parallel with a circulating water pump I (6) and a circulating water pump II (7), and the circulating water pump I (6) and the circulating water pump II (7) are both connected to a water distributor (2). The other end of the heat pump unit (1) is connected to a water collector (3), and a south area room terminal (4) and a north area room terminal (5) are respectively provided between the water distributor (2) and the water collector (3), and the south area room terminal (4) and the north area room terminal (5) are arranged opposite to each other. A series-parallel switching structure is provided between the water distributor (2) and the water collector (3), which can connect the heat pump unit (1) in parallel with the south area room terminal (4) and the north area room terminal (5), or can connect the heat pump unit (1), the south area room terminal (4) and the north area room terminal (5) in series in sequence; The series-parallel switching structure comprises a stop valve I (10) connected to one end of the north zone room terminal (5), the stop valve I (10) is connected to the water distributor (2), the other end of the north zone room terminal (5) is connected to the water collector (3) via a stop valve V (14), and the end of the north zone room terminal (5) connected to the stop valve I (10) is connected to the water collector (3) via a stop valve III (12), one end of the south zone room terminal (4) is connected to the water distributor (2) via a stop valve II (11), the other end of the south zone room terminal (4) is respectively connected to the stop valve V (14) and the north zone room terminal (5), and the end of the south zone room terminal (4) connected to the stop valve II (11) is connected to the water collector (3) via a stop valve IV (13); The method for cascade utilization of cold and heat in an air conditioning water system comprises the following steps: A. Summer working condition: when the building is under low load, the heat pump unit (1), the south zone room terminal (4) and the north zone room terminal (5) are sequentially connected in series through a series-parallel switching structure; when the building is under high load, the heat pump unit (1) is respectively connected in parallel with the south zone room terminal (4) and the north zone room terminal (5) through a series-parallel switching structure; B. Winter working condition: When the building is under low load, the heat pump unit (1), the north zone room terminal (5) and the south zone room terminal (4) are connected in series in sequence through a series-parallel switching structure. When the building is under high load, the heat pump unit (1) is connected in parallel with the south zone room terminal (4) and the north zone room terminal (5) through a series-parallel switching structure.

2. The method for cascading cold and heat utilization of an air conditioning water system according to claim 1, characterized in that: A temperature sensor I (9) is provided at one end of the north zone room end (5) connected to the water collector (3).

3. The method for cascading cold and heat utilization of an air conditioning water system according to claim 2, characterized in that: A temperature sensor II (8) is provided at one end of the southern room end (4) connected to the water collector (3).

4. The method for cascade utilization of cold and heat in an air-conditioning water system according to claim 1, characterized in that: In step A, when the building is under low load, under this working condition, the stop valve I (10) is closed, the stop valve II (11) is opened, the stop valve III (12) is opened, the stop valve IV (13) is closed, and the stop valve V (14) is closed. The south zone room terminal (4) and the north zone room terminal (5) are in a series state. The chilled water generated by the heat pump unit (1) is first transported to the south zone room terminal (4) through the circulating water pump II (7) and the water distributor (2). After the load of the south zone room is eliminated, the chilled water flows to the north zone room terminal (5), and finally returns to the heat pump unit (1) through the water collector (3).

5. The method for cascading cold and heat utilization of an air conditioning water system according to claim 1, characterized in that: In step A, when the building load increases, the stop valve I (10), the stop valve V (14), and the circulating water pump I (6) are controlled to open, and the stop valve III (12) is controlled to close. The southern room terminal (4) and the northern room terminal (5) which were originally in a series state are changed to a parallel state. The chilled water generated by the heat pump unit (1) passes through the parallel water pump through the water distributor (2) to form two north and south branches. After the load of each branch room is eliminated, the stop valve V (14) is opened to converge to the water collector (3) and then return to the heat pump unit (1). Under this working condition, the valve states are as follows: the stop valve I (10) is open, the stop valve II (11) is open, the stop valve III (12) is closed, the stop valve IV (13) is closed, and the stop valve V (14) is open.

6. The method for cascade utilization of cold and heat in an air-conditioning water system according to claim 4, characterized in that: In step B, when the building is under low load, under this working condition, the stop valve I (10) is open, the stop valve II (11) is closed, the stop valve III (12) is closed, the stop valve IV (13) is open, and the stop valve V (14) is closed. The south zone room terminal (4) and the north zone room terminal (5) are in a series state. The hot water generated by the heat pump unit (1) is first transported to the north zone room terminal (5) through the circulating water pump I (6) and the water distributor (2). After the north zone room load is eliminated, the hot water flows to the south zone room terminal (4), and finally returns to the heat pump unit (1) through the water collector (3).

7. The method for cascading cold and heat utilization of an air conditioning water system according to claim 6, characterized in that: In step B, when the building load increases, the stop valve II (11), the stop valve V (14), and the circulating water pump II (7) are controlled to open, and the stop valve IV (13) is controlled to close. The southern room terminal (4) and the northern room terminal (5) which were originally in a series state are changed to a parallel state. The hot water generated by the heat pump unit (1) passes through the parallel water pump through the water distributor (2) to form two north and south branches. After the load of each branch room is eliminated, the stop valve V (14) is opened to converge to the water collector (3) and then return to the heat pump unit (1). Under this working condition, the valve states are as follows: the stop valve I (10) is open, the stop valve II (11) is open, the stop valve III (12) is closed, the stop valve IV (13) is closed, and the stop valve V (14) is open.

8. The method for cascading cold and heat utilization of an air conditioning water system according to claim 7, characterized in that: In step A, when the building load increases, the temperature sensor II (8) behind the room end (4) in the south zone senses that the return water temperature increases, thereby controlling the stop valve I (10), the stop valve V (14), and the circulating water pump I (6) to open, and controlling the stop valve III (12) to close. In step B, when the building load increases, the temperature sensor I (9) behind the room end (5) in the north zone senses that the return water temperature decreases, thereby controlling the stop valve II (11), the stop valve V (14), and the circulating water pump II (7) to open, and controlling the stop valve IV (13) to close.

Images