A steam heat exchange constant pressure make-up water system

Abstract

The present invention discloses a steam heat exchange constant pressure make-up water system, which is characterized in that the steam heat exchange constant pressure make-up water system includes a water heat exchanger, a condensate heat exchanger, a main hot water pump, a standby hot water pump, and an expansion water tank. Municipal steam is divided into two paths, the branch path is connected to the expansion water tank, the main path is heated through the hot water heat exchanger to form condensate, and after being reheated through the condensate heat exchanger, it is divided into two paths. The branch path is connected to the inlet of the standby hot water pump, and the main path is discharged outdoors. After the hot water return water is preheated through the condensate heat exchanger, it is finally heated through the hot water heat exchanger to form hot water supply, and is sent to users through the main hot water pump and the standby hot water pump. An expansion water tank is provided on the hot water supply pipe after the pump. It can not only meet the normal and stable operation of the steam hot water heat exchange system, but also utilize the waste heat, residual pressure, residual water of the steam and its condensate, and the idle standby water pump, reducing the investment cost and operation cost.

Description

Technical Field

[0001] The present invention relates to a steam heat exchange constant pressure make-up water system, which is applied to various industrial plants and civil buildings that use municipal steam as a heat source for heat exchange and use a hot water system. It can use steam and its condensate for constant pressure make-up water and belongs to the technical field of hot water supply. Background Art

[0002] Various industrial plants and civil buildings generally have requirements for heating, air conditioning, living or process production, and need to use hot water at a certain temperature. When the heat source comes from municipal steam, the conventional method is to set up a steam-water heat exchanger. The municipal steam on the primary side forms condensate and is discharged after heat exchange, and the secondary side is the hot water return water that forms hot water supply output after heat exchange. As Figure 1 shown, in a closed-loop hot water system on the secondary side of the heat exchanger, a constant pressure make-up water device is provided on the hot water supply pipe, and the constant pressure is achieved through a gas expansion tank, and the make-up water is achieved through a make-up water pump.

[0003] However, this method usually sets a constant pressure make-up water device on the hot water return pipe, and it is necessary to regularly supplement gas into the expansion water tank for constant pressure, supplement water sources such as tap water for make-up water, and equip a make-up water pump to send the make-up water into the hot water system. This not only requires the configuration of relevant equipment, but also consumes a certain amount of water, electricity and gas. On the other hand, the condensate after heat exchange of municipal steam is directly discharged, and the waste heat and waste water are not fully utilized, resulting in low energy utilization efficiency. Summary of the Invention

[0004] In order to solve the above technical problems, the technical solution of the present invention is to provide a steam heat exchange constant pressure make-up water system. It can not only meet the normal and stable operation of the steam hot water heat exchange system, but also utilize the waste heat, residual pressure, waste water of steam and its condensate and idle standby water pumps to reduce the investment cost and operation cost.

[0005] To achieve the above object, the present invention provides a steam heat exchange constant pressure make-up water system, which includes a hot water heat exchanger, a condensate heat exchanger, a hot water main pump, a hot water standby pump, and an expansion water tank. The municipal steam is divided into two paths, one branch is connected to the expansion water tank, and the main path forms condensate after heat exchange through the hot water heat exchanger, and is divided into two paths after further heat exchange through the condensate heat exchanger. One branch is connected to the inlet of the hot water standby pump, and the main path is discharged outdoors. The hot water return water is preheated through the condensate heat exchanger, and then finally forms hot water supply through the hot water heat exchanger, and is sent to users through the hot water main pump and the hot water standby pump. An expansion water tank is provided on the hot water supply pipe after the pump.

[0006] Preferably, before the municipal steam enters the hot water heat exchanger, a branch is connected to the expansion water tank after being decompressed to the constant pressure required by the expansion water tank through a pressure reducing valve.

[0007] Preferably, the expansion water tank is provided on the hot water supply pipe behind the main hot water pump and the standby hot water pump, with a safety valve at the top. The tank wall is connected to the municipal steam, and the bottom is connected to the hot water supply.

[0008] Preferably, the hot water heat exchanger is a steam-water heat exchanger. The condensate outlet formed after heat exchange of the municipal steam on the primary side is connected to the inlet of the primary side of the condensate heat exchanger, the hot water return inlet on the secondary side is connected to the outlet of the secondary side of the condensate heat exchanger, and the hot water supply outlet is connected to the main hot water pump and the standby hot water pump.

[0009] Preferably, the condensate heat exchanger is a water-water heat exchanger. The outlet of the primary side is connected to the condensate drainage, the inlet of the secondary side is connected to the hot water return, and the valves on both sides are fully open without adjustment.

[0010] Preferably, the inlet of the standby hot water pump is divided into two paths. One path is connected to the hot water supply outlet of the hot water heat exchanger through a standby control valve, and the other path is connected to the condensate outlet of the condensate heat exchanger through a bypass control valve and a check valve.

[0011] Preferably, both the main hot water pump and the standby hot water pump are variable frequency pumps. The main hot water pump and the standby hot water pump adjust the flow rate according to the pressure difference between the hot water supply and the hot water return. The standby hot water pump can also adjust the flow rate according to the pressure of the expansion water tank.

[0012] The beneficial effects of the present invention are as follows: On the premise of ensuring the normal and stable operation of the steam-hot water heat exchange system, the municipal steam is used to supplement steam and pressure to the expansion water tank, the municipal steam condensate is used to preheat the hot water return, and it also serves as the makeup water for the hot water system, reducing the influence of the low temperature of the conventional tap water makeup water on the temperature of the hot water system. At the same time, the standby circulation pump of the hot water system also serves as a makeup water pump, improving the utilization rate of idle equipment. The invention effectively utilizes the waste heat, waste pressure, and waste water of the steam and its condensate, improves the energy utilization efficiency, and saves the investment cost and operation cost of the equipment. Description of the Drawings

[0013] Figure 1 Schematic diagram of the steam heat exchange constant pressure makeup water system in the prior art.

[0014] Figure 2 Schematic diagram of a steam heat exchange constant pressure makeup water system provided in this embodiment.

[0015] Explanation of the reference numerals:

[0016] 1 is the municipal steam, 2 is the condensate, 3 is the hot water heat exchanger, 4 is the standby control valve, 5 is the bypass control valve, 6 is the check valve, 7 is the main hot water pump, 8 is the standby hot water pump, 9 is the pressure reducing valve, 10 is the safety valve, 11 is the expansion water tank, 12 is the hot water supply, 13 is the hot water return, 14 is the condensate heat exchanger. Detailed Description of the Invention

[0017] To make the present invention more obvious and understandable, the following is a detailed description with preferred embodiments and in conjunction with the accompanying drawings.

[0018] Embodiment

[0019] Figure 2 The figure shows a schematic diagram of a steam heat exchange constant pressure make-up water system provided in this embodiment. The steam heat exchange constant pressure make-up water system includes a hot water heat exchanger 3, a condensate heat exchanger 14, a hot water main pump 7, a hot water standby pump 8, and an expansion water tank 11. Municipal steam 1 is divided into two paths. The branch path is connected to the expansion water tank 11, and the main path forms condensate 2 after heat exchange in the hot water heat exchanger 3. After further heat exchange in the condensate heat exchanger 14, it is divided into two paths. The branch path is connected to the inlet of the hot water standby pump 8, and the main path is discharged outdoors. The hot water return 13 is preheated in the condensate heat exchanger 14 and then finally forms hot water supply 12 through heat exchange in the hot water heat exchanger 3, and is sent to users through the hot water main pump 7 and the hot water standby pump 8. An expansion water tank 11 is provided on the hot water supply 12 pipe after the pump.

[0020] Before the above-mentioned municipal steam 1 enters the hot water heat exchanger 3, a branch path is depressurized by a pressure reducing valve 9 to the constant pressure required for the expansion water tank 11 and then connected to the expansion water tank 11.

[0021] The above-mentioned expansion water tank 11 is provided on the hot water supply 12 pipe after the hot water main pump 7 and the hot water standby pump 8. A safety valve 10 is provided at the top. The tank wall is connected to the municipal steam 1, and the bottom is connected to the hot water supply 12.

[0022] The above-mentioned hot water heat exchanger 3 is a steam-water heat exchanger. The condensate 2 outlet formed after heat exchange of the municipal steam 1 on the primary side is connected to the primary side inlet of the condensate heat exchanger 14. The hot water return 13 inlet on the secondary side is connected to the secondary side outlet of the condensate heat exchanger 14. The hot water supply 12 outlet is connected to the hot water main pump 7 and the hot water standby pump 8.

[0023] The above-mentioned condensate heat exchanger 14 is a water-water heat exchanger. The primary side outlet is connected to the drainage of the condensate 2, and the secondary side inlet is connected to the hot water return 13. The valves on both sides are fully open without adjustment.

[0024] The inlet of the above-mentioned hot water standby pump 8 is divided into two paths. One path is connected to the hot water supply 12 outlet of the hot water heat exchanger 3 through a standby control valve 4, and the other path is connected to the condensate 2 outlet of the condensate heat exchanger 14 through a bypass control valve 5 and a check valve 6.

[0025] The above-mentioned hot water main pump 7 and hot water standby pump 8 are both variable frequency pumps. The hot water main pump 7 and hot water standby pump 8 adjust the flow rate according to the pressure difference between the hot water supply 12 and the hot water return 13. The hot water standby pump 8 can also adjust the flow rate according to the pressure of the expansion water tank 11.

[0026] When the main hot water pump 7 fails, close the bypass control valve 5, open the standby control valve 4, start the standby hot water pump 8, and conduct the circulation of the hot water system. When the pressure of the expansion water tank 11 decreases and the hot water system needs to be replenished with water, close the standby control valve 4, open the bypass control valve 5, start the standby hot water pump 8, and replenish water to the hot water system.

Claims

1. A steam heat exchange constant pressure water replenishment system, characterized in that, The described steam heat exchange constant pressure make-up water system includes a hot water heat exchanger (3), a condensate heat exchanger (14), a hot water main pump (7), a hot water standby pump (8), and an expansion water tank (11); The municipal steam (1) is divided into two paths. The branch path is connected to the expansion water tank (11), and the main path forms condensate (2) after heat exchange in the hot water heat exchanger (3). After further heat exchange in the condensate heat exchanger (14), it is divided into two paths. The branch path is connected to the inlet of the hot water standby pump (8), and the main path is discharged outdoors; The hot water return water (13) is preheated in the condensate heat exchanger (14) and then finally forms hot water supply (12) through heat exchange in the hot water heat exchanger (3), and is sent to users through the hot water main pump (7) and the hot water standby pump (8). An expansion water tank (11) is provided on the hot water supply (12) pipe after the pumps. The described expansion water tank (11) is provided on the hot water supply (12) pipe after the hot water main pump (7) and the hot water standby pump (8), with a safety valve (10) provided at the top. The tank wall is connected to the municipal steam (1), and the bottom is connected to the hot water supply (12). The described hot water heat exchanger (3) is a steam-water heat exchanger. The outlet of the condensate (2) formed after heat exchange of the municipal steam (1) on the primary side is connected to the inlet of the primary side of the condensate heat exchanger (14). The inlet of the hot water return water (13) on the secondary side is connected to the outlet of the secondary side of the condensate heat exchanger (14). The outlet of the hot water supply (12) is connected to the hot water main pump (7) and the hot water standby pump (8). The described condensate heat exchanger (14) is a water-water heat exchanger. The outlet of the primary side is connected to the drainage of the condensate (2), and the inlet of the secondary side is connected to the hot water return water (13). The valves on both sides are fully open without adjustment. Both the described hot water main pump (7) and the hot water standby pump (8) are variable frequency pumps. The hot water main pump (7) and the hot water standby pump (8) adjust the flow rate according to the pressure difference between the hot water supply (12) and the hot water return water (13). The hot water standby pump (8) can also adjust the flow rate according to the pressure of the expansion water tank (11).

2. The steam heat exchange constant pressure water replenishment system according to claim 1, characterized in that Before the municipal steam (1) enters the hot water heat exchanger (3), a branch path passes through a pressure reducing valve (9) to reduce the pressure to the constant pressure required by the expansion water tank (11) and then is connected to the expansion water tank (11).

3. The steam heat exchange constant pressure make-up water system according to claim 1, characterized in that The inlet of the described hot water standby pump (8) is divided into two paths. One path is connected to the outlet of the hot water supply (12) of the hot water heat exchanger (3) through a standby control valve (4), and the other path is connected to the outlet of the condensate (2) of the condensate heat exchanger (14) through a bypass control valve (5) and a check valve (6).

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