Mechanical constant temperature water mixing device with pressure tapping throttling control

Abstract

This invention discloses a mechanical thermostatic mixing device employing pressure tapping and throttling control. The device comprises a housing with a water supply inlet, a water supply outlet, a return water inlet, and a return water outlet; a rotor rotatably disposed within the housing and rotating under the influence of an external fluid pressure difference; a throttling device disposed on a pressure tapping pipe between the water supply outlet and the rotor; and a pressure tapping pipe sequentially connecting the water supply outlet, the throttling device, the rotor cavity, and the return water outlet. This invention relates to the field of thermostatic control technology in HVAC engineering. The beneficial effects of this invention are that it is mainly applied to the mixing operation between heating supply and return water pipes, overcoming many drawbacks of existing mixing devices, achieving thermostatic control of the water supply temperature in floor radiant heating systems, improving thermal comfort, improving the sanitary environment of heating sites, simplifying the heating system structure, increasing energy efficiency, and making the system more green, economical, and safe.

Description

Technical Field

[0001] This invention relates to the field of constant temperature control in HVAC engineering, and in particular to a mechanical constant temperature mixing device that employs pressure tapping and throttling control. Background Technology

[0002] A persistent contradiction exists in the design of heating systems for industrial projects such as gas stations. Industrial buildings like power distribution rooms, control rooms, and fire pump rooms require radiator heating, while civil buildings such as office buildings and dormitories require radiant floor heating. According to the "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" (GB 50736-2012), the supply and return water temperatures for radiators are 75℃ / 50℃, and for radiant floor heating systems, they are 60℃ / 50℃. These stations often use their own on-site hot water boiler systems as the heat source. Setting up two boiler systems would increase investment and be uneconomical, and the boiler outlet water temperature must be set according to the higher one. Therefore, a mixing device needs to be installed before the manifold in the radiant floor heating building to mix a portion of the low-temperature water from the return pipe into the supply pipe, ensuring that the supply water temperature of the radiant floor heating system meets the code requirements.

[0003] The current mixing device works by installing a small pipeline pump between the return pipe and the supply pipe to mix the water from the return pipe to the supply pipe. The mixing device is installed at the inlet and outlet of each manifold, so a power supply is required at each manifold.

[0004] Technical defects:

[0005] 1. Under the current technology, the mixing device needs to be powered. Taking a single-story office building with a floor area of ​​600㎡ as an example, 8-10 manifolds need to be installed, and each one needs to be equipped with a wall socket, which is not aesthetically pleasing and inconvenient to use.

[0006] 2. In addition to the main equipment such as valves, pipeline pumps, etc., the existing mixing device also needs to be used with a thermostatic valve to achieve constant temperature control. The temperature detector senses the indoor temperature and feeds back to the thermostatic valve actuator, thereby adjusting the water supply flow and temperature, making the system relatively complex.

[0007] 3. If there is gas accumulation or excessive pressure in the manifold, a small amount of water needs to be sprayed out through the vent. If there are wall sockets nearby, this may pose a certain danger.

[0008] 4. In addition, manifolds are often installed in relatively quiet areas such as offices or dormitories. Especially at night, the pump in the mixing device can generate some noise, which can affect rest.

[0009] 5. Due to the limited power of pipeline pumps, mixing devices are generally used in small-diameter pipes, and mixing devices with a diameter of DN32 or larger are difficult to purchase on the market;

[0010] In view of this, this device was designed to address the aforementioned problems. Summary of the Invention

[0011] The purpose of this invention is to solve the above-mentioned problems by designing a mechanical constant temperature mixing device that employs pressure tapping and throttling control.

[0012] The technical solution of the present invention to achieve the above objectives is a mechanical constant temperature mixing device with pressure tapping and throttling control, comprising a housing, on which a water supply inlet, a water supply outlet, a return water inlet, and a return water outlet are provided;

[0013] The rotor is rotatably disposed within the housing and rotates under the action of an external fluid pressure differential;

[0014] A throttling device is installed on the pressure tapping pipeline between the water supply outlet and the rotor;

[0015] A pressure tapping pipe is used to sequentially connect the water supply outlet, the throttling device, the rotor cavity, and the return water outlet;

[0016] The rotor has a closed cavity formed by a rigid body and at least one elastic diaphragm. The cavity has a cavity inlet and a cavity outlet. The cavity inlet is connected to the water supply outlet via the pressure tapping pipe, and the cavity outlet is connected to the return water outlet via the pressure tapping pipe.

[0017] The throttling device is equipped with a thermistor, which can change its shape according to the temperature change of the medium it contacts, thereby adjusting the throttling effect of the throttling device.

[0018] The elastic diaphragm undergoes elastic deformation under the combined action of the water supply pressure, the water return pressure, and the pressure inside the cavity, thereby changing the volume of the mixing unit between the rotor and the housing.

[0019] Preferably, the rotor includes four elastic diaphragms, which together with the rigid body portion and the inner wall of the housing form four variable-volume mixing units.

[0020] Preferably, the elastic diaphragm is made of an elastic rubber material.

[0021] Preferably, the thermal element is a thermal spring made of temperature memory material, which can change its curvature according to temperature changes, thereby changing the flow cross section of the flow channel in the throttling device.

[0022] Preferably, the throttling device has a hot water inlet and a hot water outlet, and the thermal spring is disposed in the flow channel between the hot water inlet and the hot water outlet.

[0023] Preferably, the throttling device is installed on the pressure tapping pipe connecting the water supply outlet and the cavity inlet.

[0024] Preferably, the rotor rotates around the central axis inside the housing under the action of the difference between the supply water pressure and the return water pressure.

[0025] Preferably, the water supply inlet and return outlet on the shell are respectively used to connect to the boiler's water supply pipe and return pipe, and the water supply outlet and return inlet are respectively used to connect to the heat user's water supply pipe and return pipe.

[0026] The mechanical constant temperature mixing device with pressure tapping and throttling control, manufactured using the technical solution of this invention, is mainly used for mixing operations between heating supply and return water pipes. It overcomes many drawbacks of existing mixing devices, maintains constant temperature control of the water supply temperature of the ground radiant heating system, improves thermal comfort, enhances the sanitary environment of the heating site, simplifies the structure of the heating system, increases energy-saving effect, and is more green, economical, and safe. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the water mixing device of the present invention and the flow direction of the hot water medium.

[0028] Figure 2 for Figure 1 A schematic diagram of the device from another perspective.

[0029] Figure 3 This is a schematic diagram of the cross-sectional structure of the rotor.

[0030] Figure 4 This is a schematic diagram of the rotor's three-dimensional structure, showing the rigid body, elastic diaphragm, and cavity inlet and outlet.

[0031] Figure 5 This is a schematic diagram of the internal structure of the throttling device, showing the shape of the thermal spring under low and high temperature conditions.

[0032] Figure 6 This is a schematic diagram showing the deformation of the rotor's elastic diaphragm under the combined action of supply and return water pressure and cavity pressure.

[0033] Figure 7 This is a schematic diagram showing the changes in volume and position of a single mixing unit as the rotor rotates one revolution.

[0034] Explanation of markings in the diagram:

[0035] 1-Water supply inlet pipe; 2-Water supply outlet pipe; 3-Return water inlet pipe; 4-Return water outlet pipe; 5-Throttling device; 5a-Hot water inlet; 5b-Hot water outlet; 5c-Thermosensitive spring; 6-Pressure tapping pipe; 7-Rotor; 7a-Rigid body part; 7b-Elastic diaphragm; 7c-Cavity; 7d-Cavity inlet; 7e-Cavity outlet; 8-Shell. Detailed Implementation

[0036] The invention will now be described in detail with reference to the accompanying drawings. A mechanical constant-temperature mixing device employing pressure tapping and throttling control is described below. Figure 1 and Figure 2 As shown, the mechanical constant-temperature mixing device of the present invention includes a housing 8 and a rotor 7 installed inside the housing 8. A water supply inlet pipe 1, a water supply outlet pipe 2, a return water inlet pipe 3, and a return water outlet pipe 4 are connected to the housing 8. The flow direction of the hot water medium is shown by the arrows in the figure. High-temperature water from the boiler enters the housing 8 through the water supply inlet pipe 1, mixes with some return water inside and is cooled, then is sent to the heat user through the water supply outlet pipe 2. Low-temperature return water from the heat user enters through the return water inlet pipe 3, a portion of which is mixed with the supply water, and the majority of the remainder flows back to the boiler through the return water outlet pipe 4. Driven by the combined pressure difference between the supply and return water, the rotor 7 can rotate continuously around its central axis inside the housing 8.

[0037] like Figure 3 and Figure 4 As shown, the rotor 7 consists of four rigid body parts (i.e., rigid metal skeleton parts) 7a at the four corners and four concave elastic diaphragms 7b. The rigid body parts 7a, together with the upper and lower end faces, form the rotor skeleton, and the four elastic diaphragms 7b enclose a closed cavity 7c. The cavity 7c has a cavity inlet 7d and a cavity outlet 7e at its upper and lower ends, respectively. The cavity inlet 7d is connected to the water supply outlet pipe 2 through a pressure tapping pipe 6, and a throttling device 5 is installed on the connecting pipe; the cavity outlet 7e is connected to the return water outlet pipe 4 through the pressure tapping pipe 6.

[0038] like Figure 5 As shown, the throttling device 5 has a hot water inlet 5a, a hot water outlet 5b, and an internal thermal spring 5c. The thermal spring 5c ​​is made of a temperature memory material, and its shape can change with the temperature of the contact medium. When the temperature is low, the thermal spring bends more, the gap between adjacent spring wires is wider, and the obstruction to fluid flow is smaller (weak throttling effect); when the temperature rises, the curvature of the thermal spring decreases, the spring tends to stretch and the gap between the spring wires narrows, the throttling effect is enhanced, and the pressure at the hot water outlet 5b is significantly reduced.

[0039] When the device is running, the supply water pressure is Pg, the return water pressure is Ph, and Pg > Ph. The hot water in cavity 7c is a fluid drawn from the supply water outlet pipe 2 and depressurized by the throttling device 5, with its pressure Pq falling between the two, i.e., Pg > Pq > Ph. Under these three pressures, the elastic diaphragm 7b will undergo asymmetric deformation: as... Figure 6 As shown by the dashed line, the diaphragm on the water supply side is further recessed into the cavity 7c, while on the water return side it slightly rebounds outward. Four mixing units are precisely formed between the elastic diaphragm 7b and the inner wall of the housing 8.

[0040] Figure 7 The diagram shows that when the mixing unit is in position I, it is filled with low-temperature return water. As it rotates to position II, the volume and internal temperature of the mixing unit remain unchanged. When it rotates to position III, the volume of the mixing unit increases because Pg > Ph, and the supply and return water are fully mixed. Then, when it reaches position IV, the mixed hot water is supplied to the downstream heat users.

[0041] The constant temperature control mechanism of this device is as follows: it is achieved by a pressure control loop consisting of the throttling device 5, the pressure tapping pipe 6, and the rotor cavity 7c. When the water temperature in the water supply outlet pipe 2 rises, hot water enters the throttling device 5 through the pressure tapping pipe 6. The thermal spring 5c ​​inside the throttling device deforms due to heat, and its curvature decreases. Figure 5 As shown in the high-temperature state, the flow channel between the springs becomes smaller and the throttling effect is enhanced. The pressure at the hot water outlet 5b decreases, which in turn reduces the pressure Pq inside the rotor cavity 7c. This causes the volume of the aforementioned mixing unit at position I to increase, increasing the amount of water mixed from the return water to the supply water. The supply water temperature decreases, thus achieving temperature feedback regulation.

[0042] The above technical solutions only embody the preferred technical solutions of the present invention. Any modifications that may be made by those skilled in the art to certain parts thereof embody the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. A mechanical constant temperature mixing device employing pressure tapping and throttling control, comprising: The shell (8) is provided with a water supply inlet (1), a water supply outlet (2), a return water inlet (3) and a return water outlet (4); The rotor (7) is rotatably disposed within the housing (8) and rotates under the action of external fluid pressure differential; A throttling device (5) is installed on the pressure tapping pipeline between the water supply outlet (2) and the rotor (7); Pressure tapping pipe (6) is used to connect the water supply outlet (2), the throttling device (5), the cavity of the rotor (7) and the return water outlet (4) in sequence; Its features are, The rotor (7) has a closed cavity (7c) formed by a rigid body part (7a) and at least one elastic diaphragm (7b). The cavity (7c) is provided with a cavity inlet (7d) and a cavity outlet (7e). The cavity inlet (7d) is connected to the water supply outlet (2) via the pressure tapping pipe (6), and the cavity outlet (7e) is connected to the return water outlet (4) via the pressure tapping pipe (6).

2. The mechanical constant temperature mixing device according to claim 1, characterized in that, The throttling device (5) is equipped with a thermosensitive element (5c). The thermosensitive element can change its shape according to the temperature change of the medium it contacts, thereby adjusting the throttling effect of the throttling device. The elastic diaphragm (7b) undergoes elastic deformation under the combined action of the water supply side pressure, the water return side pressure and the pressure in the cavity (7c) of the housing (8), thereby changing the volume of the mixing unit between the rotor (7) and the housing (8).

3. The mechanical constant temperature mixing device according to claim 1, characterized in that, The rotor (7) includes four elastic diaphragms (7b), which together with the rigid body portion (7a) and the inner wall of the housing (8) form four variable volume mixing units.

4. The mechanical constant temperature mixing device according to claim 3, characterized in that, The elastic diaphragm (7b) is made of elastic rubber material.

5. The mechanical constant temperature mixing device according to claim 1, characterized in that, The thermal element is a thermal spring (5c) made of temperature memory material. The thermal spring can change its curvature according to temperature changes, thereby changing the flow cross section of the flow channel in the throttling device.

6. The mechanical constant temperature mixing device according to claim 5, characterized in that, The throttling device (5) has a hot water inlet (5a) and a hot water outlet (5b), and the thermal spring (5c) is disposed in the flow channel between the hot water inlet (5a) and the hot water outlet (5b).

7. The mechanical constant temperature mixing device according to claim 1, characterized in that, The throttling device (5) is installed on the pressure tapping pipe (6) that connects the water supply outlet (2) and the cavity inlet (7d).

8. The mechanical constant temperature mixing device according to any one of claims 1 to 7, characterized in that, The rotor (7) rotates around the central axis inside the housing under the action of the difference between the supply water pressure and the return water pressure.

9. The mechanical constant temperature mixing device according to any one of claims 1 to 7, characterized in that, The water supply inlet (1) and return outlet (4) on the shell (8) are respectively used to connect to the water supply pipe and return pipe of the boiler, and the water supply outlet (2) and return inlet (3) are respectively used to connect to the water supply pipe and return pipe of the heat user.

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