Control system for optimizing heat supply of low-temperature heat source through bypass differential pressure method

Abstract

The utility model relates to the field of heat supply, in particular to a control system for optimizing heat supply of a low-temperature heat source through a bypass differential pressure method, which comprises the low-temperature heat source mainly including an air source heat pump, a sewage source heat pump and the like. The low-temperature heat source inlet is communicated with a low-temperature heat source outlet valve, is sequentially connected with a flow meter, a bypass pipe, a three-way electric control valve, a pump front valve, a flexible connector, a circulating water pump, a flexible connector, a low-temperature heat source inlet valve and a low-temperature heat source inlet filter valve, and is connected back to the low-temperature heat source inlet. The utility model provides a control system for optimizing heat supply of a low-temperature heat source by a bypass differential pressure method, which is used for solving the problem that energy is not saved due to large flow and small temperature difference in the existing heat supply of the low-temperature heat source.

Description

Technical Field

[0001] The utility model relates to the technical field of heating, in particular to a control system for optimizing heating of a low-temperature heat source by a bypass pressure difference method. Background Art

[0002] In the existing low-temperature heat source heating system, the low-temperature heat source heating equipment and the heating users are connected in series. Due to the large flow and small temperature difference characteristics of the low-temperature heat source, the heating users also have large flow and small temperature difference, and ultimately the heating system does not operate energy-efficiently. Utility Model Content

[0003] In order to solve the above technical problems, this solution provides a control system for optimizing low-temperature heat source heating by a bypass pressure difference method, which is used to solve the problem of large flow and small temperature difference in existing low-temperature heat source heating, resulting in low energy conservation.

[0004] The technical solution of this utility model is as follows:

[0005] This solution discloses a control system for optimizing low-temperature heat source heating by bypass pressure difference method, including low-temperature heat source and heating users, mainly air source heat pump, sewage source heat pump, etc.;

[0006] The low-temperature heat source inlet is connected to the low-temperature heat source outlet valve, which is sequentially connected with a flow meter, a bypass pipe, a three-way electric regulating valve, a pump front valve, a soft connection, a circulating water pump, a soft connection, a low-temperature heat source inlet valve, a low-temperature heat source inlet filter valve, and is connected back to the low-temperature heat source inlet.

[0007] Preferably, the heating user is connected in series between the flow meter and the three-way electric regulating valve.

[0008] Technical effects and advantages of the utility model:

[0009] By adding a bypass pipe and a converging three-way electric regulating valve between the low-temperature heat source heating equipment and the heating users, it is suitable for situations where the low-temperature heat source provides heating to public building users, the heating users need heating in different areas and at different times, and the heating load keeps changing. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the composition of a control system for optimizing heating from a low-temperature heat source using a bypass pressure difference method provided in an embodiment of the present application;

[0011] In the figure:

[0012] 1: Heating user 1, 2: Heating user 2, 3: Low-temperature heat source, 4: Flow meter, 5: Calorimeter, 6: Three-way electric regulating valve, 7: Circulating water pump, 8: Soft connection, 9: Valve, 10: Filter valve, 11: Bypass pipe, 12: Differential pressure before and after the low-temperature heat source, 13: Differential pressure before and after the heating user, 14: Controller. DETAILED DESCRIPTION

[0013] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific purposes.

[0014] Example 1

[0015] See also Figure 1 In this embodiment, a control system for optimizing low-temperature heat source heating by a bypass pressure difference method is provided, including: a low-temperature heat source and a heating user, wherein valves are provided at the inlet and outlet of the low-temperature heat source and the inlet and outlet of the heating user.

[0016] The outlet of the low-temperature heat source is connected in sequence with a flow meter and a calorimeter and is connected to the inlet of the heating user. The outlet of the heating user is connected with a circulating water pump and is connected back to the inlet of the low-temperature heat source. Flexible connections are provided on both sides of the circulating water pump. A filter valve is provided at the inlet of the low-temperature heat source.

[0017] The system also includes a bypass pipe, a three-way valve and a controller.

[0018] Among them, one end of the bypass pipe is connected between the flow meter and the calorimeter, the two ends of the three-way valve are connected between the outlet valve of the heating user and the circulating water pump, and the other end of the bypass pipe is connected to the other end of the three-way valve; the controller controls the frequency of the circulating water pump according to the pressure difference before and after the low-temperature heat source, so as to meet the operation of the low-temperature heat source heating equipment at the rated flow rate, and the controller controls the opening of the three-way valve according to the pressure difference before and after the heating user, so as to meet the flow rate required by the heating user.

[0019] In a preferred embodiment, the three-way valve is a three-way electric regulating valve. The heating users are connected in series between the flow meter and the three-way valve, and the heating users are connected in parallel.

[0020] As an example to further illustrate:

[0021] The pressure difference before and after the low-temperature heat source is the pressure difference △P1 between the inlet and outlet of the low-temperature heat source. A frequency converter is connected to the circulating water pump. The controller controls the frequency of the circulating water pump through the frequency converter. The controller controls the frequency of the circulating water pump according to the set value pressure difference △P1 to ensure that the pressure difference △P1 is within the required range.

[0022] Preferably, the pressure difference △P1 is negatively correlated with the frequency of the circulating water pump. When the △P1 measurement value is higher than the △P1 set value, the controller controls the frequency converter to reduce the frequency of the circulating water pump. When the △P1 measurement value is lower than the △P1 set value, the controller controls the frequency converter to increase the frequency of the circulating water pump, so that the measurement value gradually approaches the set value.

[0023] As an example to further illustrate:

[0024] The pressure difference before and after the heating user is the pressure difference △P2 between the inlet and outlet of the heating user. The measuring point on one side of the pressure difference △P2 is located between the bypass pipe and the calorimeter, and the measuring point on the other side of the pressure difference △P2 is located between the outlet valve of the heating user and the three-way valve.

[0025] The relationship between the pressure difference △P2 and the opening of the three-way valve is negatively correlated. When the △P2 measurement value is higher than the △P2 set value, the controller controls the three-way valve to reduce the valve opening. When the △P2 measurement value is lower than the △P2 set value, the controller controls the three-way valve to increase the valve opening, so that the measurement value gradually approaches the set value.

[0026] The main technical points in the above embodiments are:

[0027] (1) Determination of the set value of the pressure difference △P1 before and after the low-temperature heat source

[0028] The set value of the pressure difference △P1 before and after the low-temperature heat source is mainly the sum of the resistance of the low-temperature heat source at the rated flow, the resistance of the filter valve, the resistance of the supply and return water main pipe, etc. This set value can ensure that no matter how many low-temperature heat sources are operated in parallel, the flow required by the low-temperature heat source can be met, avoiding shutdown due to low flow.

[0029] (2) Determination of the set value of the pressure difference △P2 before and after the heating user

[0030] The setting value of the pressure difference △P2 before and after the heating users is mainly the sum of the resistance of the heating users at the rated flow, the resistance of the filter valve, the resistance of the supply and return pipes, etc. This setting value can ensure that no matter how many heating users are started, the flow required by the users can be met, avoiding the situation where the flow is too small and the heating is poor, and the flow is too large and the energy is wasted.

[0031] (3) Calculation of bypass pipe diameter

[0032] The flow rate of the bypass pipe is determined based on the difference between the flow rate required by the low-temperature heat source and the flow rate required by the heating user, and the diameter of the bypass pipe is determined while meeting the requirements of the specified flow velocity and specific friction resistance.

[0033] (4) Calculation of the diameter of the three-way regulating valve

[0034] According to the required flow rate of heating users and the pressure difference before and after the three-way regulating valve, the caliber and KVS value of the three-way regulating valve are determined through the selection calculation of the regulating valve and the manufacturer's samples to ensure that the valve opening is within the range of 30-80% at the rated design flow rate.

[0035] As an example to further illustrate:

[0036] The water flow is as follows:

[0037] Low-temperature heat source water flow direction 1: low-temperature heat source 3 inlet → low-temperature heat source 3 → low-temperature heat source 3 outlet → low-temperature heat source 3 outlet valve 9 → flow meter 4 → bypass pipe 11 → three-way electric regulating valve 6 → pump front valve 9 → flexible connection 8 → circulating water pump 7 → flexible connection 8 → low-temperature heat source inlet valve 9 → low-temperature heat source 3 inlet filter valve → low-temperature heat source 3 inlet;

[0038] Water flow direction of heating user 1(2) 1: heating user 1(2) inlet → heating user 1(2) → heating user 1(2) outlet → heating user 1(2) outlet valve 9 → three-way electric regulating valve 6 → valve before pump 9 → flexible connection 8 → circulating water pump 7 → flexible connection 8 → low-temperature heat source inlet valve 9 → low-temperature heat source 3 inlet filter valve → low-temperature heat source 3 inlet low-temperature heat source 3 inlet → low-temperature heat source 3 outlet → low-temperature heat source 3 → low-temperature heat source 3 outlet → low-temperature heat source 3 outlet valve 9 → flow meter 4 → calorimeter 5 → heating user 1(2) inlet valve 9 → heating user 1(2) inlet

[0039] When using the utility model, the controller 14 controls the frequency of the circulating pump according to the set value of the pressure difference △P1 before and after the low-temperature heat source, ensuring that the pressure difference △P1 before and after the low-temperature heat source is within the required range, thereby satisfying the operation of the low-temperature heat source heating equipment at the rated flow rate. The relationship between the pressure difference △P1 before and after the low-temperature heat source and the frequency of the circulating pump is negatively correlated, that is, when the △P1 measurement value is higher than the △P1 set value, the controller 14 controls the circulating pump inverter to reduce the frequency of the circulating pump. When the △P1 measurement value is lower than the △P1 set value, the controller 14 controls the circulating pump inverter to increase the frequency of the circulating pump, so that the measured value gradually approaches the set value.

[0040] The controller 14 controls the opening of the three-way electric regulating valve 6 according to the set value of the pressure difference △P2 before and after the heating user, ensuring that the pressure difference before and after the heating user is within the required range, thereby meeting the flow required by the heating user. The relationship between the pressure difference △P2 before and after the heating user and the opening of the three-way electric regulating valve 6 is negatively correlated, that is, when the △P2 measurement value is higher than the △P2 set value, the controller 14 controls the three-way electric regulating valve to reduce the valve opening, and when the △P2 measurement value is lower than the △P2 set value, the controller 14 controls the three-way electric regulating valve to increase the valve opening, so that the measurement value gradually approaches the set value.

[0041] Ultimately, the low-temperature heat source heating equipment can operate with large flow and small temperature difference, and the heating users can operate with small flow and large temperature difference, thus achieving the goal of efficient and energy-saving operation of the low-temperature heat source system.

[0042] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. Structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to conventional means in the field unless otherwise specified and limited.

Claims

1. A control system for optimizing low-temperature heat source heating by bypass pressure difference method, comprising a low-temperature heat source and a heating user, wherein valves are provided at the inlet and outlet of the low-temperature heat source and the inlet and outlet of the heating user, and characterized in that: The outlet of the low-temperature heat source is connected in sequence to an inlet provided with a flow meter and a calorimeter and connected to a heating user, and the outlet of the heating user is connected to an inlet provided with a circulating water pump and connected back to the low-temperature heat source; It also includes a bypass pipe, a three-way valve and a controller; One end of the bypass pipe is connected between the flow meter and the calorimeter, the two ends of the three-way valve are connected between the heating user outlet valve and the circulating water pump, and the other end of the bypass pipe is connected to the other end of the three-way valve; The controller controls the frequency of the circulating water pump according to the pressure difference before and after the low-temperature heat source, thereby satisfying the operation of the low-temperature heat source heating equipment at the rated flow rate. The controller controls the opening of the three-way valve according to the pressure difference before and after the heating user, thereby satisfying the flow rate required by the heating user.

2. A control system for optimizing low-temperature heat source heating by bypass pressure difference method according to claim 1, characterized in that: The heating users are connected in series between the flow meter and the three-way valve, and the heating users are arranged in parallel; the three-way valve is a three-way electric regulating valve.

3. A control system for optimizing low-temperature heat source heating by bypass pressure difference method according to claim 1, characterized in that: Soft connections are provided on both sides of the circulating water pump, and a filter valve is provided at the inlet of the low-temperature heat source.

4. A control system for optimizing low-temperature heat source heating by bypass pressure difference method according to claim 2, characterized in that: The pressure difference before and after the low-temperature heat source is the pressure difference △P1 between the inlet and outlet of the low-temperature heat source. A frequency converter is connected to the circulating water pump. The controller controls the frequency of the circulating water pump through the frequency converter. The controller controls the frequency of the circulating water pump according to the set value pressure difference △P1 to ensure that the pressure difference △P1 is within the required range.

5. A control system for optimizing low-temperature heat source heating by bypass pressure difference method according to claim 4, characterized in that: The pressure difference before and after the heating user is the pressure difference △P2 between the inlet and outlet of the heating user. The measuring point on one side of the pressure difference △P2 is located between the bypass pipe and the calorimeter, and the measuring point on the other side of the pressure difference △P2 is located between the outlet valve of the heating user and the three-way valve.

6. A control system for optimizing low-temperature heat source heating by bypass pressure difference method according to claim 4, characterized in that: The pressure difference △P1 is negatively correlated with the frequency of the circulating water pump. When the △P1 measurement value is higher than the △P1 set value, the controller controls the frequency converter to reduce the frequency of the circulating water pump. When the △P1 measurement value is lower than the △P1 set value, the controller controls the frequency converter to increase the frequency of the circulating water pump, so that the measurement value gradually approaches the set value.

7. A control system for optimizing low-temperature heat source heating by bypass pressure difference method according to claim 5, characterized in that: The relationship between the pressure difference △P2 and the opening of the three-way valve is negatively correlated. When the △P2 measurement value is higher than the △P2 set value, the controller controls the three-way valve to reduce the valve opening. When the △P2 measurement value is lower than the △P2 set value, the controller controls the three-way valve to increase the valve opening, so that the measurement value gradually approaches the set value.

8. A control system for optimizing low-temperature heat source heating by bypass pressure difference method according to claim 1, characterized in that: Air source heat pump or sewage source heat pump heating is used as the low-temperature heat source.

9. A control system for optimizing low-temperature heat source heating by bypass pressure difference method according to claim 6, characterized in that: The diameter and KVS value of the three-way valve are determined according to the flow rate required by the heating user and the pressure difference before and after the three-way valve.

10. A control system for optimizing low-temperature heat source heating by bypass pressure difference method according to claim 7, characterized in that: The flow rate and diameter of the bypass pipe are determined based on the difference between the flow rate required by the low-temperature heat source and the flow rate required by the heating user.

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