CN-121994519-A - Shallow coaxial well heat absorption and heat exchange test device

Abstract

The invention provides a shallow coaxial well heat absorption and extraction heat exchange test device, which relates to the technical field of geothermal energy resource investigation equipment, and comprises a heat preservation water tank, wherein a water outlet of the heat preservation water tank is connected with a water inlet of a coaxial well through a circulating pump, a heat meter and a water inlet temperature sensor of the coaxial well, the water outlet of the coaxial well is connected with an electric heater, the water outlet of the electric heater is connected with a second quick connector, an electric heater water outlet temperature sensor is arranged between the water outlet of the electric heater and the second quick connector, and the water inlet of the heat preservation water tank is provided with a first quick connector; the system comprises a control cabinet, an air source heat pump water outlet temperature sensor, a corrugated pipe, an electric heater water outlet temperature sensor, an air source heat pump water outlet temperature sensor and a heat meter, wherein the air source heat pump water outlet temperature sensor is connected between a first quick connector and a second quick connector under a heat absorption working condition in winter, the first quick connector and the second quick connector are connected with the corrugated pipe under a heat extraction working condition in summer, and the electric heater water outlet temperature sensor, the air source heat pump water outlet temperature sensor and the heat meter are all connected with the control cabinet. The invention accurately simulates two working conditions of heat absorption in winter and heat extraction in summer through one set of devices.

Inventors

• ZHANG JING
• ZHANG ZHENRUI
• ZHAO WENYU
• LIU YIXUAN

Assignees

• 中国煤炭地质总局水文地质局

Dates

Publication Date

20260508

Application Date

20251230

Claims (8)

1. 1. The heat absorption and extraction heat exchange test device for the shallow coaxial well is characterized by comprising a heat preservation water tank, an electric heater, an air source heat pump, a circulating pump, a coaxial well, a control monitoring cabinet, a heat meter and a corrugated pipe; the water outlet of the heat preservation water tank is connected with the water inlet of the coaxial well through the circulating pump, the heat meter and the water inlet temperature sensor of the coaxial well, the water outlet of the coaxial well is connected with the electric heater, the water outlet of the electric heater is connected with the second quick connector, the water outlet temperature sensor of the electric heater is arranged between the water outlet of the electric heater and the second quick connector, and the water inlet of the heat preservation water tank is provided with the first quick connector; An air source heat pump and an air source heat pump water outlet temperature sensor of an air source heat pump water outlet are connected between the first quick connector and the second quick connector under the heat absorption working condition in winter; the first quick connector and the second quick connector are connected with the corrugated pipe under the working condition of heat removal in summer; and the electric heater water outlet temperature sensor, the air source heat pump water outlet temperature sensor and the calorimeter are all connected with the control detection cabinet.
2. 2. The shallow coaxial well heat absorption and exchange test device according to claim 1 is characterized in that the electric heater is connected with an electric heating controller, the electric heating controller is respectively connected with a coaxial well water inlet temperature sensor and a control monitoring cabinet, and the electric heating controller controls two operation modes of the electric heater through feedback signals of the coaxial well water inlet temperature sensor, wherein the two operation modes comprise a set temperature mode, the power of the electric heater is adjusted to enable the water inlet temperature of the coaxial well to be kept constant, and a constant heat flow mode, the electric heater is operated according to the set power, and stable heat flow is output.
3. 3. The heat absorption and heat exchange test device for the shallow coaxial well is characterized in that the circulating pump is connected with the control monitoring cabinet through a frequency converter, the rotating speed of the circulating pump is adjusted according to the set flow of the frequency converter, and the heat meter collects the parameters of the water inlet temperature, the water outlet temperature, the water flow and the heat exchange amount of the coaxial well in real time.
4. 4. The shallow coaxial well heat absorption and heat exchange test device according to claim 1, wherein the coaxial well comprises a wellhead device, a heat exchange sleeve, a heat insulation central tube and a ground temperature monitoring line; the ground temperature monitoring lines are provided with temperature measuring points at intervals along the axial direction and are used for monitoring the temperature changes of stratum with different depths.
5. 5. The shallow coaxial well heat absorption and heat exchange test device according to claim 1, wherein the control monitoring cabinet integrates a data acquisition module, a data processing module and a remote communication module, and supports real-time display, storage and remote transmission of test parameters.
6. 6. The shallow coaxial well heat absorption and heat exchange test device according to claim 1, wherein the corrugated pipe replaces the air source heat pump and the air source heat pump water outlet temperature sensor in summer working conditions, and is connected with the electric heater water outlet and the heat preservation water tank water inlet, so that equipment idle interference is avoided in winter working conditions.
7. 7. The heat absorption and heat exchange test device for the shallow coaxial well is characterized in that the first quick connector and the second quick connector are detachable sealing connectors, so that quick switching of heat sources under winter working conditions and summer working conditions is supported, and leakage of pipelines is prevented.
8. 8. The heat absorption and heat exchange test device for the shallow coaxial well is characterized in that the control monitoring cabinet monitors water inlet and outlet temperature, flow, pressure and stratum temperature of the coaxial well in real time, automatically adjusts rotation speed of a circulating pump and heat source power, maintains set working conditions, stores test data and supports remote access.

Description

Shallow coaxial well heat absorption and heat exchange test device Technical Field The invention relates to the technical field of geothermal energy resource investigation equipment, in particular to a shallow coaxial well heat absorption and heat exchange test device. Background Shallow geothermal energy is used as a clean, stable and renewable energy source, and development and utilization of the shallow geothermal energy are important ways for achieving the aim of double carbon. The coaxial well type geothermal heat exchange system has wide application prospect in heating and refrigerating of town buildings due to the advantages of no water taking during heat extraction, small occupied area, high system efficiency and the like. However, whether a shallow geothermal energy project is feasible or not is a key premise that the thermophysical parameters of the rock-soil body of the project are accurately obtained, and the heat exchange performance of the coaxial well in two seasons (heat absorption/heat extraction) in winter and summer under long-term operation is accurately estimated. This requires a test device that can simulate real conditions and is reliable in data. Most existing devices or methods, such as conventional thermal response tests, are designed to simulate the summer heat removal conditions (heat injection into the subsurface) to obtain the thermal conductivity of the rock and soil. For the simulation of conditions where heat is absorbed from the subsurface in winter, either it is missing or another completely different set of equipment is required. The existing single-working-condition test cannot comprehensively reflect the annual operation characteristics of the coaxial well. There are significant differences in the temperature field changes, heat recovery capacity, and possibly heat accumulation effects of the rock mass during the heat absorption and removal processes. The winter heating performance can not be accurately predicted only by summer data, so that deviation exists in system design, and investment waste or the heating effect is possibly caused to be not up to standard. In view of the above problems, it is desirable to provide a shallow coaxial well heat absorption and extraction heat exchange test device, which realizes seamless switching in a set of device and accurately simulates two working conditions of heat absorption in winter and heat extraction in summer. Disclosure of Invention Aiming at the problems in the background technology, the invention provides a shallow coaxial well heat absorption and extraction heat exchange test device, which realizes seamless switching in a set of device and accurately simulates two working conditions of heat absorption in winter and heat extraction in summer. The invention provides a shallow coaxial well heat absorption and heat exchange test device which comprises a heat preservation water tank, an electric heater, an air source heat pump, a circulating pump, a coaxial well, a control monitoring cabinet, a heat meter and a corrugated pipe; the water outlet of the heat preservation water tank is connected with the water inlet of the coaxial well through the circulating pump, the heat meter and the water inlet temperature sensor of the coaxial well, the water outlet of the coaxial well is connected with the electric heater, the water outlet of the electric heater is connected with the second quick connector, the water outlet temperature sensor of the electric heater is arranged between the water outlet of the electric heater and the second quick connector, and the water inlet of the heat preservation water tank is provided with the first quick connector; An air source heat pump and an air source heat pump water outlet temperature sensor of an air source heat pump water outlet are connected between the first quick connector and the second quick connector under the heat absorption working condition in winter; the first quick connector and the second quick connector are connected with the corrugated pipe under the working condition of heat removal in summer; and the electric heater water outlet temperature sensor, the air source heat pump water outlet temperature sensor and the calorimeter are all connected with the control detection cabinet. The electric heater is connected with an electric heating controller, the electric heating controller is respectively connected with the water inlet temperature sensor of the coaxial well and the control monitoring cabinet, and the electric heating controller controls two operation modes of the electric heater through feedback signals of the water inlet temperature sensor of the coaxial well, wherein the two operation modes comprise a set temperature mode, the power of the electric heater is regulated to keep the water inlet temperature of the coaxial well constant, and a constant heat flow mode, the electric heater operates according to the set power and outputs stable heat flow. As a further improveme